From aac00c7fa1149fd5b5a5110096ffa78dcb120b79 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:06 +0200 Subject: [PATCH 01/28] clk: test: Switch to clk_hw_get_clk Following the clk_hw->clk pointer is equivalent to calling clk_hw_get_clk(), but will make the job harder if we need to rework that part in the future. Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-2-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- drivers/clk/clk_test.c | 74 +++++++++++++++++++++++++++++++----------- 1 file changed, 55 insertions(+), 19 deletions(-) diff --git a/drivers/clk/clk_test.c b/drivers/clk/clk_test.c index 6731a822f4e3..7646356f30cb 100644 --- a/drivers/clk/clk_test.c +++ b/drivers/clk/clk_test.c @@ -160,12 +160,14 @@ static void clk_test_get_rate(struct kunit *test) { struct clk_dummy_context *ctx = test->priv; struct clk_hw *hw = &ctx->hw; - struct clk *clk = hw->clk; + struct clk *clk = clk_hw_get_clk(hw, NULL); unsigned long rate; rate = clk_get_rate(clk); KUNIT_ASSERT_GT(test, rate, 0); KUNIT_EXPECT_EQ(test, rate, ctx->rate); + + clk_put(clk); } /* @@ -179,7 +181,7 @@ static void clk_test_set_get_rate(struct kunit *test) { struct clk_dummy_context *ctx = test->priv; struct clk_hw *hw = &ctx->hw; - struct clk *clk = hw->clk; + struct clk *clk = clk_hw_get_clk(hw, NULL); unsigned long rate; KUNIT_ASSERT_EQ(test, @@ -189,6 +191,8 @@ static void clk_test_set_get_rate(struct kunit *test) rate = clk_get_rate(clk); KUNIT_ASSERT_GT(test, rate, 0); KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_RATE_1); + + clk_put(clk); } /* @@ -202,7 +206,7 @@ static void clk_test_set_set_get_rate(struct kunit *test) { struct clk_dummy_context *ctx = test->priv; struct clk_hw *hw = &ctx->hw; - struct clk *clk = hw->clk; + struct clk *clk = clk_hw_get_clk(hw, NULL); unsigned long rate; KUNIT_ASSERT_EQ(test, @@ -216,6 +220,8 @@ static void clk_test_set_set_get_rate(struct kunit *test) rate = clk_get_rate(clk); KUNIT_ASSERT_GT(test, rate, 0); KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_RATE_2); + + clk_put(clk); } /* @@ -226,7 +232,7 @@ static void clk_test_round_set_get_rate(struct kunit *test) { struct clk_dummy_context *ctx = test->priv; struct clk_hw *hw = &ctx->hw; - struct clk *clk = hw->clk; + struct clk *clk = clk_hw_get_clk(hw, NULL); unsigned long rounded_rate, set_rate; rounded_rate = clk_round_rate(clk, DUMMY_CLOCK_RATE_1); @@ -240,6 +246,8 @@ static void clk_test_round_set_get_rate(struct kunit *test) set_rate = clk_get_rate(clk); KUNIT_ASSERT_GT(test, set_rate, 0); KUNIT_EXPECT_EQ(test, rounded_rate, set_rate); + + clk_put(clk); } static struct kunit_case clk_test_cases[] = { @@ -314,7 +322,7 @@ static void clk_test_orphan_transparent_parent_mux_set_range(struct kunit *test) { struct clk_single_parent_ctx *ctx = test->priv; struct clk_hw *hw = &ctx->hw; - struct clk *clk = hw->clk; + struct clk *clk = clk_hw_get_clk(hw, NULL); unsigned long rate, new_rate; rate = clk_get_rate(clk); @@ -329,6 +337,8 @@ static void clk_test_orphan_transparent_parent_mux_set_range(struct kunit *test) new_rate = clk_get_rate(clk); KUNIT_ASSERT_GT(test, new_rate, 0); KUNIT_EXPECT_EQ(test, rate, new_rate); + + clk_put(clk); } static struct kunit_case clk_orphan_transparent_single_parent_mux_test_cases[] = { @@ -352,7 +362,7 @@ static void clk_range_test_set_range(struct kunit *test) { struct clk_dummy_context *ctx = test->priv; struct clk_hw *hw = &ctx->hw; - struct clk *clk = hw->clk; + struct clk *clk = clk_hw_get_clk(hw, NULL); unsigned long rate; KUNIT_ASSERT_EQ(test, @@ -365,6 +375,8 @@ static void clk_range_test_set_range(struct kunit *test) KUNIT_ASSERT_GT(test, rate, 0); KUNIT_EXPECT_GE(test, rate, DUMMY_CLOCK_RATE_1); KUNIT_EXPECT_LE(test, rate, DUMMY_CLOCK_RATE_2); + + clk_put(clk); } /* @@ -375,13 +387,15 @@ static void clk_range_test_set_range_invalid(struct kunit *test) { struct clk_dummy_context *ctx = test->priv; struct clk_hw *hw = &ctx->hw; - struct clk *clk = hw->clk; + struct clk *clk = clk_hw_get_clk(hw, NULL); KUNIT_EXPECT_LT(test, clk_set_rate_range(clk, DUMMY_CLOCK_RATE_1 + 1000, DUMMY_CLOCK_RATE_1), 0); + + clk_put(clk); } /* @@ -420,7 +434,7 @@ static void clk_range_test_set_range_round_rate_lower(struct kunit *test) { struct clk_dummy_context *ctx = test->priv; struct clk_hw *hw = &ctx->hw; - struct clk *clk = hw->clk; + struct clk *clk = clk_hw_get_clk(hw, NULL); long rate; KUNIT_ASSERT_EQ(test, @@ -433,6 +447,8 @@ static void clk_range_test_set_range_round_rate_lower(struct kunit *test) KUNIT_ASSERT_GT(test, rate, 0); KUNIT_EXPECT_GE(test, rate, DUMMY_CLOCK_RATE_1); KUNIT_EXPECT_LE(test, rate, DUMMY_CLOCK_RATE_2); + + clk_put(clk); } /* @@ -443,7 +459,7 @@ static void clk_range_test_set_range_set_rate_lower(struct kunit *test) { struct clk_dummy_context *ctx = test->priv; struct clk_hw *hw = &ctx->hw; - struct clk *clk = hw->clk; + struct clk *clk = clk_hw_get_clk(hw, NULL); unsigned long rate; KUNIT_ASSERT_EQ(test, @@ -460,6 +476,8 @@ static void clk_range_test_set_range_set_rate_lower(struct kunit *test) KUNIT_ASSERT_GT(test, rate, 0); KUNIT_EXPECT_GE(test, rate, DUMMY_CLOCK_RATE_1); KUNIT_EXPECT_LE(test, rate, DUMMY_CLOCK_RATE_2); + + clk_put(clk); } /* @@ -472,7 +490,7 @@ static void clk_range_test_set_range_set_round_rate_consistent_lower(struct kuni { struct clk_dummy_context *ctx = test->priv; struct clk_hw *hw = &ctx->hw; - struct clk *clk = hw->clk; + struct clk *clk = clk_hw_get_clk(hw, NULL); long rounded; KUNIT_ASSERT_EQ(test, @@ -489,6 +507,8 @@ static void clk_range_test_set_range_set_round_rate_consistent_lower(struct kuni 0); KUNIT_EXPECT_EQ(test, rounded, clk_get_rate(clk)); + + clk_put(clk); } /* @@ -499,7 +519,7 @@ static void clk_range_test_set_range_round_rate_higher(struct kunit *test) { struct clk_dummy_context *ctx = test->priv; struct clk_hw *hw = &ctx->hw; - struct clk *clk = hw->clk; + struct clk *clk = clk_hw_get_clk(hw, NULL); long rate; KUNIT_ASSERT_EQ(test, @@ -512,6 +532,8 @@ static void clk_range_test_set_range_round_rate_higher(struct kunit *test) KUNIT_ASSERT_GT(test, rate, 0); KUNIT_EXPECT_GE(test, rate, DUMMY_CLOCK_RATE_1); KUNIT_EXPECT_LE(test, rate, DUMMY_CLOCK_RATE_2); + + clk_put(clk); } /* @@ -522,7 +544,7 @@ static void clk_range_test_set_range_set_rate_higher(struct kunit *test) { struct clk_dummy_context *ctx = test->priv; struct clk_hw *hw = &ctx->hw; - struct clk *clk = hw->clk; + struct clk *clk = clk_hw_get_clk(hw, NULL); unsigned long rate; KUNIT_ASSERT_EQ(test, @@ -539,6 +561,8 @@ static void clk_range_test_set_range_set_rate_higher(struct kunit *test) KUNIT_ASSERT_GT(test, rate, 0); KUNIT_EXPECT_GE(test, rate, DUMMY_CLOCK_RATE_1); KUNIT_EXPECT_LE(test, rate, DUMMY_CLOCK_RATE_2); + + clk_put(clk); } /* @@ -551,7 +575,7 @@ static void clk_range_test_set_range_set_round_rate_consistent_higher(struct kun { struct clk_dummy_context *ctx = test->priv; struct clk_hw *hw = &ctx->hw; - struct clk *clk = hw->clk; + struct clk *clk = clk_hw_get_clk(hw, NULL); long rounded; KUNIT_ASSERT_EQ(test, @@ -568,6 +592,8 @@ static void clk_range_test_set_range_set_round_rate_consistent_higher(struct kun 0); KUNIT_EXPECT_EQ(test, rounded, clk_get_rate(clk)); + + clk_put(clk); } /* @@ -582,7 +608,7 @@ static void clk_range_test_set_range_get_rate_raised(struct kunit *test) { struct clk_dummy_context *ctx = test->priv; struct clk_hw *hw = &ctx->hw; - struct clk *clk = hw->clk; + struct clk *clk = clk_hw_get_clk(hw, NULL); unsigned long rate; KUNIT_ASSERT_EQ(test, @@ -598,6 +624,8 @@ static void clk_range_test_set_range_get_rate_raised(struct kunit *test) rate = clk_get_rate(clk); KUNIT_ASSERT_GT(test, rate, 0); KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_RATE_1); + + clk_put(clk); } /* @@ -612,7 +640,7 @@ static void clk_range_test_set_range_get_rate_lowered(struct kunit *test) { struct clk_dummy_context *ctx = test->priv; struct clk_hw *hw = &ctx->hw; - struct clk *clk = hw->clk; + struct clk *clk = clk_hw_get_clk(hw, NULL); unsigned long rate; KUNIT_ASSERT_EQ(test, @@ -628,6 +656,8 @@ static void clk_range_test_set_range_get_rate_lowered(struct kunit *test) rate = clk_get_rate(clk); KUNIT_ASSERT_GT(test, rate, 0); KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_RATE_2); + + clk_put(clk); } static struct kunit_case clk_range_test_cases[] = { @@ -664,7 +694,7 @@ static void clk_range_test_set_range_rate_maximized(struct kunit *test) { struct clk_dummy_context *ctx = test->priv; struct clk_hw *hw = &ctx->hw; - struct clk *clk = hw->clk; + struct clk *clk = clk_hw_get_clk(hw, NULL); unsigned long rate; KUNIT_ASSERT_EQ(test, @@ -700,6 +730,8 @@ static void clk_range_test_set_range_rate_maximized(struct kunit *test) rate = clk_get_rate(clk); KUNIT_ASSERT_GT(test, rate, 0); KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_RATE_2); + + clk_put(clk); } /* @@ -714,7 +746,7 @@ static void clk_range_test_multiple_set_range_rate_maximized(struct kunit *test) { struct clk_dummy_context *ctx = test->priv; struct clk_hw *hw = &ctx->hw; - struct clk *clk = hw->clk; + struct clk *clk = clk_hw_get_clk(hw, NULL); struct clk *user1, *user2; unsigned long rate; @@ -758,6 +790,7 @@ static void clk_range_test_multiple_set_range_rate_maximized(struct kunit *test) clk_put(user2); clk_put(user1); + clk_put(clk); } static struct kunit_case clk_range_maximize_test_cases[] = { @@ -785,7 +818,7 @@ static void clk_range_test_set_range_rate_minimized(struct kunit *test) { struct clk_dummy_context *ctx = test->priv; struct clk_hw *hw = &ctx->hw; - struct clk *clk = hw->clk; + struct clk *clk = clk_hw_get_clk(hw, NULL); unsigned long rate; KUNIT_ASSERT_EQ(test, @@ -821,6 +854,8 @@ static void clk_range_test_set_range_rate_minimized(struct kunit *test) rate = clk_get_rate(clk); KUNIT_ASSERT_GT(test, rate, 0); KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_RATE_1); + + clk_put(clk); } /* @@ -835,7 +870,7 @@ static void clk_range_test_multiple_set_range_rate_minimized(struct kunit *test) { struct clk_dummy_context *ctx = test->priv; struct clk_hw *hw = &ctx->hw; - struct clk *clk = hw->clk; + struct clk *clk = clk_hw_get_clk(hw, NULL); struct clk *user1, *user2; unsigned long rate; @@ -875,6 +910,7 @@ static void clk_range_test_multiple_set_range_rate_minimized(struct kunit *test) clk_put(user2); clk_put(user1); + clk_put(clk); } static struct kunit_case clk_range_minimize_test_cases[] = { From d77388223240884b918b8d85f88f132916afbf06 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:07 +0200 Subject: [PATCH 02/28] clk: Drop the rate range on clk_put() When clk_put() is called we don't make another clk_set_rate() call to re-evaluate the rate boundaries. This is unlike clk_set_rate_range() that evaluates the rate again each time it is called. However, clk_put() is essentially equivalent to clk_set_rate_range() since after clk_put() completes the consumer's boundaries shouldn't be enforced anymore. Let's add a call to clk_set_rate_range() in clk_put() to make sure those rate boundaries are dropped and the clock provider drivers can react. In order to be as non-intrusive as possible, we'll just make that call if the clock had non-default boundaries. Also add a few tests to make sure this case is covered. Fixes: c80ac50cbb37 ("clk: Always set the rate on clk_set_range_rate") Tested-by: Alexander Stein # imx8mp Tested-by: Marek Szyprowski # exynos4210, meson g12b Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-3-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- drivers/clk/clk.c | 45 +++++++++++------ drivers/clk/clk_test.c | 110 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 141 insertions(+), 14 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 7fc191c15507..a5e0ab8bd6be 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -2325,19 +2325,15 @@ int clk_set_rate_exclusive(struct clk *clk, unsigned long rate) } EXPORT_SYMBOL_GPL(clk_set_rate_exclusive); -/** - * clk_set_rate_range - set a rate range for a clock source - * @clk: clock source - * @min: desired minimum clock rate in Hz, inclusive - * @max: desired maximum clock rate in Hz, inclusive - * - * Returns success (0) or negative errno. - */ -int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max) +static int clk_set_rate_range_nolock(struct clk *clk, + unsigned long min, + unsigned long max) { int ret = 0; unsigned long old_min, old_max, rate; + lockdep_assert_held(&prepare_lock); + if (!clk) return 0; @@ -2350,8 +2346,6 @@ int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max) return -EINVAL; } - clk_prepare_lock(); - if (clk->exclusive_count) clk_core_rate_unprotect(clk->core); @@ -2395,6 +2389,28 @@ out: if (clk->exclusive_count) clk_core_rate_protect(clk->core); + return ret; +} + +/** + * clk_set_rate_range - set a rate range for a clock source + * @clk: clock source + * @min: desired minimum clock rate in Hz, inclusive + * @max: desired maximum clock rate in Hz, inclusive + * + * Return: 0 for success or negative errno on failure. + */ +int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max) +{ + int ret; + + if (!clk) + return 0; + + clk_prepare_lock(); + + ret = clk_set_rate_range_nolock(clk, min, max); + clk_prepare_unlock(); return ret; @@ -4348,9 +4364,10 @@ void __clk_put(struct clk *clk) } hlist_del(&clk->clks_node); - if (clk->min_rate > clk->core->req_rate || - clk->max_rate < clk->core->req_rate) - clk_core_set_rate_nolock(clk->core, clk->core->req_rate); + + /* If we had any boundaries on that clock, let's drop them. */ + if (clk->min_rate > 0 || clk->max_rate < ULONG_MAX) + clk_set_rate_range_nolock(clk, 0, ULONG_MAX); owner = clk->core->owner; kref_put(&clk->core->ref, __clk_release); diff --git a/drivers/clk/clk_test.c b/drivers/clk/clk_test.c index 7646356f30cb..7d9da88c39ee 100644 --- a/drivers/clk/clk_test.c +++ b/drivers/clk/clk_test.c @@ -793,9 +793,66 @@ static void clk_range_test_multiple_set_range_rate_maximized(struct kunit *test) clk_put(clk); } +/* + * Test that if we have several subsequent calls to + * clk_set_rate_range(), across multiple users, the core will reevaluate + * whether a new rate is needed, including when a user drop its clock. + * + * With clk_dummy_maximize_rate_ops, this means that the rate will + * trail along the maximum as it evolves. + */ +static void clk_range_test_multiple_set_range_rate_put_maximized(struct kunit *test) +{ + struct clk_dummy_context *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + struct clk *user1, *user2; + unsigned long rate; + + user1 = clk_hw_get_clk(hw, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, user1); + + user2 = clk_hw_get_clk(hw, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, user2); + + KUNIT_ASSERT_EQ(test, + clk_set_rate(clk, DUMMY_CLOCK_RATE_2 + 1000), + 0); + + KUNIT_ASSERT_EQ(test, + clk_set_rate_range(user1, + 0, + DUMMY_CLOCK_RATE_2), + 0); + + rate = clk_get_rate(clk); + KUNIT_ASSERT_GT(test, rate, 0); + KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_RATE_2); + + KUNIT_ASSERT_EQ(test, + clk_set_rate_range(user2, + 0, + DUMMY_CLOCK_RATE_1), + 0); + + rate = clk_get_rate(clk); + KUNIT_ASSERT_GT(test, rate, 0); + KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_RATE_1); + + clk_put(user2); + + rate = clk_get_rate(clk); + KUNIT_ASSERT_GT(test, rate, 0); + KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_RATE_2); + + clk_put(user1); + clk_put(clk); +} + static struct kunit_case clk_range_maximize_test_cases[] = { KUNIT_CASE(clk_range_test_set_range_rate_maximized), KUNIT_CASE(clk_range_test_multiple_set_range_rate_maximized), + KUNIT_CASE(clk_range_test_multiple_set_range_rate_put_maximized), {} }; @@ -913,9 +970,62 @@ static void clk_range_test_multiple_set_range_rate_minimized(struct kunit *test) clk_put(clk); } +/* + * Test that if we have several subsequent calls to + * clk_set_rate_range(), across multiple users, the core will reevaluate + * whether a new rate is needed, including when a user drop its clock. + * + * With clk_dummy_minimize_rate_ops, this means that the rate will + * trail along the minimum as it evolves. + */ +static void clk_range_test_multiple_set_range_rate_put_minimized(struct kunit *test) +{ + struct clk_dummy_context *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + struct clk *user1, *user2; + unsigned long rate; + + user1 = clk_hw_get_clk(hw, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, user1); + + user2 = clk_hw_get_clk(hw, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, user2); + + KUNIT_ASSERT_EQ(test, + clk_set_rate_range(user1, + DUMMY_CLOCK_RATE_1, + ULONG_MAX), + 0); + + rate = clk_get_rate(clk); + KUNIT_ASSERT_GT(test, rate, 0); + KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_RATE_1); + + KUNIT_ASSERT_EQ(test, + clk_set_rate_range(user2, + DUMMY_CLOCK_RATE_2, + ULONG_MAX), + 0); + + rate = clk_get_rate(clk); + KUNIT_ASSERT_GT(test, rate, 0); + KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_RATE_2); + + clk_put(user2); + + rate = clk_get_rate(clk); + KUNIT_ASSERT_GT(test, rate, 0); + KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_RATE_1); + + clk_put(user1); + clk_put(clk); +} + static struct kunit_case clk_range_minimize_test_cases[] = { KUNIT_CASE(clk_range_test_set_range_rate_minimized), KUNIT_CASE(clk_range_test_multiple_set_range_rate_minimized), + KUNIT_CASE(clk_range_test_multiple_set_range_rate_put_minimized), {} }; From facf949b2e6934d381050417bf4e34b20c93be09 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:08 +0200 Subject: [PATCH 03/28] clk: Skip clamping when rounding if there's no boundaries Commit 948fb0969eae ("clk: Always clamp the rounded rate") recently started to clamp the request rate in the clk_rate_request passed as an argument of clk_core_determine_round_nolock() with the min_rate and max_rate fields of that same request. While the clk_rate_requests created by the framework itself always have those fields set, some drivers will create it themselves and don't always fill min_rate and max_rate. In such a case, we end up clamping the rate with a minimum and maximum of 0, thus always rounding the rate to 0. Let's skip the clamping if both min_rate and max_rate are set to 0 and complain so that it gets fixed. Fixes: 948fb0969eae ("clk: Always clamp the rounded rate") Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-4-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- drivers/clk/clk.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index a5e0ab8bd6be..9d63163244d4 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1341,7 +1341,19 @@ static int clk_core_determine_round_nolock(struct clk_core *core, if (!core) return 0; - req->rate = clamp(req->rate, req->min_rate, req->max_rate); + /* + * Some clock providers hand-craft their clk_rate_requests and + * might not fill min_rate and max_rate. + * + * If it's the case, clamping the rate is equivalent to setting + * the rate to 0 which is bad. Skip the clamping but complain so + * that it gets fixed, hopefully. + */ + if (!req->min_rate && !req->max_rate) + pr_warn("%s: %s: clk_rate_request has initialized min or max rate.\n", + __func__, core->name); + else + req->rate = clamp(req->rate, req->min_rate, req->max_rate); /* * At this point, core protection will be disabled From f24a0b1c22c2e90abb4ee1f7a3b0f0d8fc2ede5f Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:09 +0200 Subject: [PATCH 04/28] clk: Mention that .recalc_rate can return 0 on error Multiple platforms (amlogic, imx8) return 0 when the clock rate cannot be determined properly by the recalc_rate hook. Mention in the documentation that the framework is ok with that. Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-5-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- include/linux/clk-provider.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 1615010aa0ec..9a14cfa0d201 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -118,8 +118,9 @@ struct clk_duty { * * @recalc_rate Recalculate the rate of this clock, by querying hardware. The * parent rate is an input parameter. It is up to the caller to - * ensure that the prepare_mutex is held across this call. - * Returns the calculated rate. Optional, but recommended - if + * ensure that the prepare_mutex is held across this call. If the + * driver cannot figure out a rate for this clock, it must return + * 0. Returns the calculated rate. Optional, but recommended - if * this op is not set then clock rate will be initialized to 0. * * @round_rate: Given a target rate as input, returns the closest rate actually From bde8870cd8c3a3913ddbc19f8422a21828e14d99 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:10 +0200 Subject: [PATCH 05/28] clk: Clarify clk_get_rate() expectations As shown by a number of clock users already, clk_get_rate() can be called whether or not the clock is enabled. Similarly, a number of clock drivers will return a rate of 0 whenever the rate cannot be figured out. Since it was a bit ambiguous before, let's make it clear in the clk_get_rate() documentation. Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-6-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- drivers/clk/clk.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 9d63163244d4..caa2eb640441 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1672,8 +1672,9 @@ static unsigned long clk_core_get_rate_recalc(struct clk_core *core) * @clk: the clk whose rate is being returned * * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag - * is set, which means a recalc_rate will be issued. - * If clk is NULL then returns 0. + * is set, which means a recalc_rate will be issued. Can be called regardless of + * the clock enabledness. If clk is NULL, or if an error occurred, then returns + * 0. */ unsigned long clk_get_rate(struct clk *clk) { From 090962b6a90a2bf81142f6d5da9492380d5fba08 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:11 +0200 Subject: [PATCH 06/28] clk: tests: Add test suites description We start to have a few test suites, and we'll add more, so it will get pretty confusing to figure out what is supposed to be tested in what suite. Let's add some comments to explain what setup they create, and what we should be testing in every suite. Tested-by: Alexander Stein # imx8mp Tested-by: Marek Szyprowski # exynos4210, meson g12b Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-7-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- drivers/clk/clk_test.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/drivers/clk/clk_test.c b/drivers/clk/clk_test.c index 7d9da88c39ee..1a7cb482ec58 100644 --- a/drivers/clk/clk_test.c +++ b/drivers/clk/clk_test.c @@ -258,6 +258,11 @@ static struct kunit_case clk_test_cases[] = { {} }; +/* + * Test suite for a basic rate clock, without any parent. + * + * These tests exercise the rate API with simple scenarios + */ static struct kunit_suite clk_test_suite = { .name = "clk-test", .init = clk_test_init, @@ -346,6 +351,14 @@ static struct kunit_case clk_orphan_transparent_single_parent_mux_test_cases[] = {} }; +/* + * Test suite for a basic mux clock with one parent. The parent is + * registered after its child. The clock will thus be an orphan when + * registered, but will no longer be when the tests run. + * + * These tests make sure a clock that used to be orphan has a sane, + * consistent, behaviour. + */ static struct kunit_suite clk_orphan_transparent_single_parent_test_suite = { .name = "clk-orphan-transparent-single-parent-test", .init = clk_orphan_transparent_single_parent_mux_test_init, @@ -675,6 +688,12 @@ static struct kunit_case clk_range_test_cases[] = { {} }; +/* + * Test suite for a basic rate clock, without any parent. + * + * These tests exercise the rate range API: clk_set_rate_range(), + * clk_set_min_rate(), clk_set_max_rate(), clk_drop_range(). + */ static struct kunit_suite clk_range_test_suite = { .name = "clk-range-test", .init = clk_test_init, @@ -856,6 +875,13 @@ static struct kunit_case clk_range_maximize_test_cases[] = { {} }; +/* + * Test suite for a basic rate clock, without any parent. + * + * These tests exercise the rate range API: clk_set_rate_range(), + * clk_set_min_rate(), clk_set_max_rate(), clk_drop_range(), with a + * driver that will always try to run at the highest possible rate. + */ static struct kunit_suite clk_range_maximize_test_suite = { .name = "clk-range-maximize-test", .init = clk_maximize_test_init, @@ -1029,6 +1055,13 @@ static struct kunit_case clk_range_minimize_test_cases[] = { {} }; +/* + * Test suite for a basic rate clock, without any parent. + * + * These tests exercise the rate range API: clk_set_rate_range(), + * clk_set_min_rate(), clk_set_max_rate(), clk_drop_range(), with a + * driver that will always try to run at the lowest possible rate. + */ static struct kunit_suite clk_range_minimize_test_suite = { .name = "clk-range-minimize-test", .init = clk_minimize_test_init, From 7d79c26b60e623a9a089d771f81c5997bda577cd Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:12 +0200 Subject: [PATCH 07/28] clk: tests: Add reference to the orphan mux bug report Some more context might be useful for unit-tests covering a previously reported bug, so let's add a link to the discussion for that bug. Tested-by: Alexander Stein # imx8mp Tested-by: Marek Szyprowski # exynos4210, meson g12b Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-8-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- drivers/clk/clk_test.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/clk/clk_test.c b/drivers/clk/clk_test.c index 1a7cb482ec58..b8e32406a6e4 100644 --- a/drivers/clk/clk_test.c +++ b/drivers/clk/clk_test.c @@ -322,6 +322,9 @@ static void clk_orphan_transparent_single_parent_mux_test_exit(struct kunit *tes /* * Test that a mux-only clock, with an initial rate within a range, * will still have the same rate after the range has been enforced. + * + * See: + * https://lore.kernel.org/linux-clk/7720158d-10a7-a17b-73a4-a8615c9c6d5c@collabora.com/ */ static void clk_test_orphan_transparent_parent_mux_set_range(struct kunit *test) { From 350575abec48ef5363abd832386cb5a33861cb10 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:13 +0200 Subject: [PATCH 08/28] clk: tests: Add tests for uncached clock The clock framework supports clocks that can have their rate changed without the kernel knowing about it using the CLK_GET_RATE_NOCACHE flag. As its name suggests, this flag turns off the rate caching in the clock framework, reading out the rate from the hardware any time we need to read it. Let's add a couple of tests to make sure it works as intended. Tested-by: Alexander Stein # imx8mp Tested-by: Marek Szyprowski # exynos4210, meson g12b Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-9-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- drivers/clk/clk_test.c | 93 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 92 insertions(+), 1 deletion(-) diff --git a/drivers/clk/clk_test.c b/drivers/clk/clk_test.c index b8e32406a6e4..b269420dafcc 100644 --- a/drivers/clk/clk_test.c +++ b/drivers/clk/clk_test.c @@ -270,6 +270,96 @@ static struct kunit_suite clk_test_suite = { .test_cases = clk_test_cases, }; +static int clk_uncached_test_init(struct kunit *test) +{ + struct clk_dummy_context *ctx; + int ret; + + ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + test->priv = ctx; + + ctx->rate = DUMMY_CLOCK_INIT_RATE; + ctx->hw.init = CLK_HW_INIT_NO_PARENT("test-clk", + &clk_dummy_rate_ops, + CLK_GET_RATE_NOCACHE); + + ret = clk_hw_register(NULL, &ctx->hw); + if (ret) + return ret; + + return 0; +} + +/* + * Test that for an uncached clock, the clock framework doesn't cache + * the rate and clk_get_rate() will return the underlying clock rate + * even if it changed. + */ +static void clk_test_uncached_get_rate(struct kunit *test) +{ + struct clk_dummy_context *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + unsigned long rate; + + rate = clk_get_rate(clk); + KUNIT_ASSERT_GT(test, rate, 0); + KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_INIT_RATE); + + /* We change the rate behind the clock framework's back */ + ctx->rate = DUMMY_CLOCK_RATE_1; + rate = clk_get_rate(clk); + KUNIT_ASSERT_GT(test, rate, 0); + KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_RATE_1); + + clk_put(clk); +} + +/* + * Test that for an uncached clock, clk_set_rate_range() will work + * properly if the rate hasn't changed. + */ +static void clk_test_uncached_set_range(struct kunit *test) +{ + struct clk_dummy_context *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + unsigned long rate; + + KUNIT_ASSERT_EQ(test, + clk_set_rate_range(clk, + DUMMY_CLOCK_RATE_1, + DUMMY_CLOCK_RATE_2), + 0); + + rate = clk_get_rate(clk); + KUNIT_ASSERT_GT(test, rate, 0); + KUNIT_EXPECT_GE(test, rate, DUMMY_CLOCK_RATE_1); + KUNIT_EXPECT_LE(test, rate, DUMMY_CLOCK_RATE_2); + + clk_put(clk); +} + +static struct kunit_case clk_uncached_test_cases[] = { + KUNIT_CASE(clk_test_uncached_get_rate), + KUNIT_CASE(clk_test_uncached_set_range), + {} +}; + +/* + * Test suite for a basic, uncached, rate clock, without any parent. + * + * These tests exercise the rate API with simple scenarios + */ +static struct kunit_suite clk_uncached_test_suite = { + .name = "clk-uncached-test", + .init = clk_uncached_test_init, + .exit = clk_test_exit, + .test_cases = clk_uncached_test_cases, +}; + struct clk_single_parent_ctx { struct clk_dummy_context parent_ctx; struct clk_hw hw; @@ -1077,6 +1167,7 @@ kunit_test_suites( &clk_orphan_transparent_single_parent_test_suite, &clk_range_test_suite, &clk_range_maximize_test_suite, - &clk_range_minimize_test_suite + &clk_range_minimize_test_suite, + &clk_uncached_test_suite ); MODULE_LICENSE("GPL v2"); From 02cdeace1e1ed210eb9fc2ce562d93580b1dcfe5 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:14 +0200 Subject: [PATCH 09/28] clk: tests: Add tests for single parent mux We have a few tests for a mux with a single parent, testing the case where it used to be orphan. Let's leverage most of the code but register the clock properly to test a few trivial things. Tested-by: Alexander Stein # imx8mp Tested-by: Marek Szyprowski # exynos4210, meson g12b Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-10-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- drivers/clk/clk_test.c | 194 +++++++++++++++++++++++++++++++++++++++-- 1 file changed, 185 insertions(+), 9 deletions(-) diff --git a/drivers/clk/clk_test.c b/drivers/clk/clk_test.c index b269420dafcc..06c9220873bb 100644 --- a/drivers/clk/clk_test.c +++ b/drivers/clk/clk_test.c @@ -365,6 +365,189 @@ struct clk_single_parent_ctx { struct clk_hw hw; }; +static int clk_single_parent_mux_test_init(struct kunit *test) +{ + struct clk_single_parent_ctx *ctx; + int ret; + + ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + test->priv = ctx; + + ctx->parent_ctx.rate = DUMMY_CLOCK_INIT_RATE; + ctx->parent_ctx.hw.init = + CLK_HW_INIT_NO_PARENT("parent-clk", + &clk_dummy_rate_ops, + 0); + + ret = clk_hw_register(NULL, &ctx->parent_ctx.hw); + if (ret) + return ret; + + ctx->hw.init = CLK_HW_INIT("test-clk", "parent-clk", + &clk_dummy_single_parent_ops, + CLK_SET_RATE_PARENT); + + ret = clk_hw_register(NULL, &ctx->hw); + if (ret) + return ret; + + return 0; +} + +static void +clk_single_parent_mux_test_exit(struct kunit *test) +{ + struct clk_single_parent_ctx *ctx = test->priv; + + clk_hw_unregister(&ctx->hw); + clk_hw_unregister(&ctx->parent_ctx.hw); +} + +/* + * Test that for a clock with a single parent, clk_get_parent() actually + * returns the parent. + */ +static void +clk_test_single_parent_mux_get_parent(struct kunit *test) +{ + struct clk_single_parent_ctx *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + struct clk *parent = clk_hw_get_clk(&ctx->parent_ctx.hw, NULL); + + KUNIT_EXPECT_TRUE(test, clk_is_match(clk_get_parent(clk), parent)); + + clk_put(parent); + clk_put(clk); +} + +/* + * Test that for a clock that can't modify its rate and with a single + * parent, if we set disjoints range on the parent and then the child, + * the second will return an error. + * + * FIXME: clk_set_rate_range() only considers the current clock when + * evaluating whether ranges are disjoints and not the upstream clocks + * ranges. + */ +static void +clk_test_single_parent_mux_set_range_disjoint_child_last(struct kunit *test) +{ + struct clk_single_parent_ctx *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + struct clk *parent; + int ret; + + kunit_skip(test, "This needs to be fixed in the core."); + + parent = clk_get_parent(clk); + KUNIT_ASSERT_PTR_NE(test, parent, NULL); + + ret = clk_set_rate_range(parent, 1000, 2000); + KUNIT_ASSERT_EQ(test, ret, 0); + + ret = clk_set_rate_range(clk, 3000, 4000); + KUNIT_EXPECT_LT(test, ret, 0); + + clk_put(clk); +} + +/* + * Test that for a clock that can't modify its rate and with a single + * parent, if we set disjoints range on the child and then the parent, + * the second will return an error. + * + * FIXME: clk_set_rate_range() only considers the current clock when + * evaluating whether ranges are disjoints and not the downstream clocks + * ranges. + */ +static void +clk_test_single_parent_mux_set_range_disjoint_parent_last(struct kunit *test) +{ + struct clk_single_parent_ctx *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + struct clk *parent; + int ret; + + kunit_skip(test, "This needs to be fixed in the core."); + + parent = clk_get_parent(clk); + KUNIT_ASSERT_PTR_NE(test, parent, NULL); + + ret = clk_set_rate_range(clk, 1000, 2000); + KUNIT_ASSERT_EQ(test, ret, 0); + + ret = clk_set_rate_range(parent, 3000, 4000); + KUNIT_EXPECT_LT(test, ret, 0); + + clk_put(clk); +} + +/* + * Test that for a clock that can't modify its rate and with a single + * parent, if we set a range on the parent and a more restrictive one on + * the child, and then call clk_round_rate(), the boundaries of the + * two clocks are taken into account. + */ +static void +clk_test_single_parent_mux_set_range_round_rate_child_smaller(struct kunit *test) +{ + struct clk_single_parent_ctx *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + struct clk *parent; + unsigned long rate; + int ret; + + parent = clk_get_parent(clk); + KUNIT_ASSERT_PTR_NE(test, parent, NULL); + + ret = clk_set_rate_range(parent, DUMMY_CLOCK_RATE_1, DUMMY_CLOCK_RATE_2); + KUNIT_ASSERT_EQ(test, ret, 0); + + ret = clk_set_rate_range(clk, DUMMY_CLOCK_RATE_1 + 1000, DUMMY_CLOCK_RATE_2 - 1000); + KUNIT_ASSERT_EQ(test, ret, 0); + + rate = clk_round_rate(clk, DUMMY_CLOCK_RATE_1 - 1000); + KUNIT_ASSERT_GT(test, rate, 0); + KUNIT_EXPECT_GE(test, rate, DUMMY_CLOCK_RATE_1 + 1000); + KUNIT_EXPECT_LE(test, rate, DUMMY_CLOCK_RATE_2 - 1000); + + rate = clk_round_rate(clk, DUMMY_CLOCK_RATE_2 + 1000); + KUNIT_ASSERT_GT(test, rate, 0); + KUNIT_EXPECT_GE(test, rate, DUMMY_CLOCK_RATE_1 + 1000); + KUNIT_EXPECT_LE(test, rate, DUMMY_CLOCK_RATE_2 - 1000); + + clk_put(clk); +} + +static struct kunit_case clk_single_parent_mux_test_cases[] = { + KUNIT_CASE(clk_test_single_parent_mux_get_parent), + KUNIT_CASE(clk_test_single_parent_mux_set_range_disjoint_child_last), + KUNIT_CASE(clk_test_single_parent_mux_set_range_disjoint_parent_last), + KUNIT_CASE(clk_test_single_parent_mux_set_range_round_rate_child_smaller), + {} +}; + +/* + * Test suite for a basic mux clock with one parent, with + * CLK_SET_RATE_PARENT on the child. + * + * These tests exercise the consumer API and check that the state of the + * child and parent are sane and consistent. + */ +static struct kunit_suite +clk_single_parent_mux_test_suite = { + .name = "clk-single-parent-mux-test", + .init = clk_single_parent_mux_test_init, + .exit = clk_single_parent_mux_test_exit, + .test_cases = clk_single_parent_mux_test_cases, +}; + static int clk_orphan_transparent_single_parent_mux_test_init(struct kunit *test) { struct clk_single_parent_ctx *ctx; @@ -401,14 +584,6 @@ static int clk_orphan_transparent_single_parent_mux_test_init(struct kunit *test return 0; } -static void clk_orphan_transparent_single_parent_mux_test_exit(struct kunit *test) -{ - struct clk_single_parent_ctx *ctx = test->priv; - - clk_hw_unregister(&ctx->hw); - clk_hw_unregister(&ctx->parent_ctx.hw); -} - /* * Test that a mux-only clock, with an initial rate within a range, * will still have the same rate after the range has been enforced. @@ -455,7 +630,7 @@ static struct kunit_case clk_orphan_transparent_single_parent_mux_test_cases[] = static struct kunit_suite clk_orphan_transparent_single_parent_test_suite = { .name = "clk-orphan-transparent-single-parent-test", .init = clk_orphan_transparent_single_parent_mux_test_init, - .exit = clk_orphan_transparent_single_parent_mux_test_exit, + .exit = clk_single_parent_mux_test_exit, .test_cases = clk_orphan_transparent_single_parent_mux_test_cases, }; @@ -1168,6 +1343,7 @@ kunit_test_suites( &clk_range_test_suite, &clk_range_maximize_test_suite, &clk_range_minimize_test_suite, + &clk_single_parent_mux_test_suite, &clk_uncached_test_suite ); MODULE_LICENSE("GPL v2"); From 74933ef22c1c3d3d1456c2f949f1910ce2aab1f1 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:15 +0200 Subject: [PATCH 10/28] clk: tests: Add tests for mux with multiple parents We'll need to test a few corner cases that occur when we have a mux clock whose default parent is missing. For now, let's create the context structure and the trivial ops, along with a test suite that just tests trivial things for now, without considering the orphan case. Tested-by: Alexander Stein # imx8mp Tested-by: Marek Szyprowski # exynos4210, meson g12b Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-11-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- drivers/clk/clk_test.c | 121 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 121 insertions(+) diff --git a/drivers/clk/clk_test.c b/drivers/clk/clk_test.c index 06c9220873bb..1ccafd4fabff 100644 --- a/drivers/clk/clk_test.c +++ b/drivers/clk/clk_test.c @@ -108,6 +108,39 @@ static const struct clk_ops clk_dummy_single_parent_ops = { .get_parent = clk_dummy_single_get_parent, }; +struct clk_multiple_parent_ctx { + struct clk_dummy_context parents_ctx[2]; + struct clk_hw hw; + u8 current_parent; +}; + +static int clk_multiple_parents_mux_set_parent(struct clk_hw *hw, u8 index) +{ + struct clk_multiple_parent_ctx *ctx = + container_of(hw, struct clk_multiple_parent_ctx, hw); + + if (index >= clk_hw_get_num_parents(hw)) + return -EINVAL; + + ctx->current_parent = index; + + return 0; +} + +static u8 clk_multiple_parents_mux_get_parent(struct clk_hw *hw) +{ + struct clk_multiple_parent_ctx *ctx = + container_of(hw, struct clk_multiple_parent_ctx, hw); + + return ctx->current_parent; +} + +static const struct clk_ops clk_multiple_parents_mux_ops = { + .get_parent = clk_multiple_parents_mux_get_parent, + .set_parent = clk_multiple_parents_mux_set_parent, + .determine_rate = __clk_mux_determine_rate_closest, +}; + static int clk_test_init_with_ops(struct kunit *test, const struct clk_ops *ops) { struct clk_dummy_context *ctx; @@ -360,6 +393,93 @@ static struct kunit_suite clk_uncached_test_suite = { .test_cases = clk_uncached_test_cases, }; +static int +clk_multiple_parents_mux_test_init(struct kunit *test) +{ + struct clk_multiple_parent_ctx *ctx; + const char *parents[2] = { "parent-0", "parent-1"}; + int ret; + + ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + test->priv = ctx; + + ctx->parents_ctx[0].hw.init = CLK_HW_INIT_NO_PARENT("parent-0", + &clk_dummy_rate_ops, + 0); + ctx->parents_ctx[0].rate = DUMMY_CLOCK_RATE_1; + ret = clk_hw_register(NULL, &ctx->parents_ctx[0].hw); + if (ret) + return ret; + + ctx->parents_ctx[1].hw.init = CLK_HW_INIT_NO_PARENT("parent-1", + &clk_dummy_rate_ops, + 0); + ctx->parents_ctx[1].rate = DUMMY_CLOCK_RATE_2; + ret = clk_hw_register(NULL, &ctx->parents_ctx[1].hw); + if (ret) + return ret; + + ctx->current_parent = 0; + ctx->hw.init = CLK_HW_INIT_PARENTS("test-mux", parents, + &clk_multiple_parents_mux_ops, + CLK_SET_RATE_PARENT); + ret = clk_hw_register(NULL, &ctx->hw); + if (ret) + return ret; + + return 0; +} + +static void +clk_multiple_parents_mux_test_exit(struct kunit *test) +{ + struct clk_multiple_parent_ctx *ctx = test->priv; + + clk_hw_unregister(&ctx->hw); + clk_hw_unregister(&ctx->parents_ctx[0].hw); + clk_hw_unregister(&ctx->parents_ctx[1].hw); +} + +/* + * Test that for a clock with multiple parents, clk_get_parent() + * actually returns the current one. + */ +static void +clk_test_multiple_parents_mux_get_parent(struct kunit *test) +{ + struct clk_multiple_parent_ctx *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + struct clk *parent = clk_hw_get_clk(&ctx->parents_ctx[0].hw, NULL); + + KUNIT_EXPECT_TRUE(test, clk_is_match(clk_get_parent(clk), parent)); + + clk_put(parent); + clk_put(clk); +} + +static struct kunit_case clk_multiple_parents_mux_test_cases[] = { + KUNIT_CASE(clk_test_multiple_parents_mux_get_parent), + {} +}; + +/* + * Test suite for a basic mux clock with two parents, with + * CLK_SET_RATE_PARENT on the child. + * + * These tests exercise the consumer API and check that the state of the + * child and parents are sane and consistent. + */ +static struct kunit_suite +clk_multiple_parents_mux_test_suite = { + .name = "clk-multiple-parents-mux-test", + .init = clk_multiple_parents_mux_test_init, + .exit = clk_multiple_parents_mux_test_exit, + .test_cases = clk_multiple_parents_mux_test_cases, +}; + struct clk_single_parent_ctx { struct clk_dummy_context parent_ctx; struct clk_hw hw; @@ -1339,6 +1459,7 @@ static struct kunit_suite clk_range_minimize_test_suite = { kunit_test_suites( &clk_test_suite, + &clk_multiple_parents_mux_test_suite, &clk_orphan_transparent_single_parent_test_suite, &clk_range_test_suite, &clk_range_maximize_test_suite, From 2e9cad1abc7149c5e6aeee7e76a6c363d392da8b Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:16 +0200 Subject: [PATCH 11/28] clk: tests: Add some tests for orphan with multiple parents Let's leverage the dummy mux with multiple parents we have to create a mux whose default parent will never be registered, and thus will always be orphan by default. We can then create some tests to make sure that the clock API behaves properly in such a case, and that the transition to a non-orphan clock when we change the parent is done properly. Tested-by: Alexander Stein # imx8mp Tested-by: Marek Szyprowski # exynos4210, meson g12b Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-12-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- drivers/clk/clk_test.c | 237 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 237 insertions(+) diff --git a/drivers/clk/clk_test.c b/drivers/clk/clk_test.c index 1ccafd4fabff..ceed49c5a88b 100644 --- a/drivers/clk/clk_test.c +++ b/drivers/clk/clk_test.c @@ -480,6 +480,242 @@ clk_multiple_parents_mux_test_suite = { .test_cases = clk_multiple_parents_mux_test_cases, }; +static int +clk_orphan_transparent_multiple_parent_mux_test_init(struct kunit *test) +{ + struct clk_multiple_parent_ctx *ctx; + const char *parents[2] = { "missing-parent", "proper-parent"}; + int ret; + + ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + test->priv = ctx; + + ctx->parents_ctx[1].hw.init = CLK_HW_INIT_NO_PARENT("proper-parent", + &clk_dummy_rate_ops, + 0); + ctx->parents_ctx[1].rate = DUMMY_CLOCK_INIT_RATE; + ret = clk_hw_register(NULL, &ctx->parents_ctx[1].hw); + if (ret) + return ret; + + ctx->hw.init = CLK_HW_INIT_PARENTS("test-orphan-mux", parents, + &clk_multiple_parents_mux_ops, + CLK_SET_RATE_PARENT); + ret = clk_hw_register(NULL, &ctx->hw); + if (ret) + return ret; + + return 0; +} + +static void +clk_orphan_transparent_multiple_parent_mux_test_exit(struct kunit *test) +{ + struct clk_multiple_parent_ctx *ctx = test->priv; + + clk_hw_unregister(&ctx->hw); + clk_hw_unregister(&ctx->parents_ctx[1].hw); +} + +/* + * Test that, for a mux whose current parent hasn't been registered yet and is + * thus orphan, clk_get_parent() will return NULL. + */ +static void +clk_test_orphan_transparent_multiple_parent_mux_get_parent(struct kunit *test) +{ + struct clk_multiple_parent_ctx *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + + KUNIT_EXPECT_PTR_EQ(test, clk_get_parent(clk), NULL); + + clk_put(clk); +} + +/* + * Test that, for a mux whose current parent hasn't been registered yet, + * calling clk_set_parent() to a valid parent will properly update the + * mux parent and its orphan status. + */ +static void +clk_test_orphan_transparent_multiple_parent_mux_set_parent(struct kunit *test) +{ + struct clk_multiple_parent_ctx *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + struct clk *parent, *new_parent; + int ret; + + parent = clk_hw_get_clk(&ctx->parents_ctx[1].hw, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, parent); + + ret = clk_set_parent(clk, parent); + KUNIT_ASSERT_EQ(test, ret, 0); + + new_parent = clk_get_parent(clk); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, parent); + KUNIT_EXPECT_TRUE(test, clk_is_match(parent, new_parent)); + + clk_put(parent); + clk_put(clk); +} + +/* + * Test that, for a mux that started orphan but got switched to a valid + * parent, the rate of the mux and its new parent are consistent. + */ +static void +clk_test_orphan_transparent_multiple_parent_mux_set_parent_get_rate(struct kunit *test) +{ + struct clk_multiple_parent_ctx *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + struct clk *parent; + unsigned long parent_rate, rate; + int ret; + + parent = clk_hw_get_clk(&ctx->parents_ctx[1].hw, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, parent); + + parent_rate = clk_get_rate(parent); + KUNIT_ASSERT_GT(test, parent_rate, 0); + + ret = clk_set_parent(clk, parent); + KUNIT_ASSERT_EQ(test, ret, 0); + + rate = clk_get_rate(clk); + KUNIT_ASSERT_GT(test, rate, 0); + KUNIT_EXPECT_EQ(test, parent_rate, rate); + + clk_put(parent); + clk_put(clk); +} + +/* + * Test that, for a mux that started orphan but got switched to a valid + * parent, calling clk_set_rate_range() will affect the parent state if + * its rate is out of range. + */ +static void +clk_test_orphan_transparent_multiple_parent_mux_set_parent_set_range_modified(struct kunit *test) +{ + struct clk_multiple_parent_ctx *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + struct clk *parent; + unsigned long rate; + int ret; + + parent = clk_hw_get_clk(&ctx->parents_ctx[1].hw, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, parent); + + ret = clk_set_parent(clk, parent); + KUNIT_ASSERT_EQ(test, ret, 0); + + ret = clk_set_rate_range(clk, DUMMY_CLOCK_RATE_1, DUMMY_CLOCK_RATE_2); + KUNIT_ASSERT_EQ(test, ret, 0); + + rate = clk_get_rate(clk); + KUNIT_ASSERT_GT(test, rate, 0); + KUNIT_EXPECT_GE(test, rate, DUMMY_CLOCK_RATE_1); + KUNIT_EXPECT_LE(test, rate, DUMMY_CLOCK_RATE_2); + + clk_put(parent); + clk_put(clk); +} + +/* + * Test that, for a mux whose current parent hasn't been registered yet, + * calling clk_set_rate_range() will succeed, and will be taken into + * account when rounding a rate. + */ +static void +clk_test_orphan_transparent_multiple_parent_mux_set_range_round_rate(struct kunit *test) +{ + struct clk_multiple_parent_ctx *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + unsigned long rate; + int ret; + + ret = clk_set_rate_range(clk, DUMMY_CLOCK_RATE_1, DUMMY_CLOCK_RATE_2); + KUNIT_ASSERT_EQ(test, ret, 0); + + rate = clk_round_rate(clk, DUMMY_CLOCK_RATE_1 - 1000); + KUNIT_ASSERT_GT(test, rate, 0); + KUNIT_EXPECT_GE(test, rate, DUMMY_CLOCK_RATE_1); + KUNIT_EXPECT_LE(test, rate, DUMMY_CLOCK_RATE_2); + + clk_put(clk); +} + +/* + * Test that, for a mux that started orphan, was assigned and rate and + * then got switched to a valid parent, its rate is eventually within + * range. + * + * FIXME: Even though we update the rate as part of clk_set_parent(), we + * don't evaluate whether that new rate is within range and needs to be + * adjusted. + */ +static void +clk_test_orphan_transparent_multiple_parent_mux_set_range_set_parent_get_rate(struct kunit *test) +{ + struct clk_multiple_parent_ctx *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + struct clk *parent; + unsigned long rate; + int ret; + + kunit_skip(test, "This needs to be fixed in the core."); + + clk_hw_set_rate_range(hw, DUMMY_CLOCK_RATE_1, DUMMY_CLOCK_RATE_2); + + parent = clk_hw_get_clk(&ctx->parents_ctx[1].hw, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, parent); + + ret = clk_set_parent(clk, parent); + KUNIT_ASSERT_EQ(test, ret, 0); + + rate = clk_get_rate(clk); + KUNIT_ASSERT_GT(test, rate, 0); + KUNIT_EXPECT_GE(test, rate, DUMMY_CLOCK_RATE_1); + KUNIT_EXPECT_LE(test, rate, DUMMY_CLOCK_RATE_2); + + clk_put(parent); + clk_put(clk); +} + +static struct kunit_case clk_orphan_transparent_multiple_parent_mux_test_cases[] = { + KUNIT_CASE(clk_test_orphan_transparent_multiple_parent_mux_get_parent), + KUNIT_CASE(clk_test_orphan_transparent_multiple_parent_mux_set_parent), + KUNIT_CASE(clk_test_orphan_transparent_multiple_parent_mux_set_parent_get_rate), + KUNIT_CASE(clk_test_orphan_transparent_multiple_parent_mux_set_parent_set_range_modified), + KUNIT_CASE(clk_test_orphan_transparent_multiple_parent_mux_set_range_round_rate), + KUNIT_CASE(clk_test_orphan_transparent_multiple_parent_mux_set_range_set_parent_get_rate), + {} +}; + +/* + * Test suite for a basic mux clock with two parents. The default parent + * isn't registered, only the second parent is. By default, the clock + * will thus be orphan. + * + * These tests exercise the behaviour of the consumer API when dealing + * with an orphan clock, and how we deal with the transition to a valid + * parent. + */ +static struct kunit_suite clk_orphan_transparent_multiple_parent_mux_test_suite = { + .name = "clk-orphan-transparent-multiple-parent-mux-test", + .init = clk_orphan_transparent_multiple_parent_mux_test_init, + .exit = clk_orphan_transparent_multiple_parent_mux_test_exit, + .test_cases = clk_orphan_transparent_multiple_parent_mux_test_cases, +}; + struct clk_single_parent_ctx { struct clk_dummy_context parent_ctx; struct clk_hw hw; @@ -1460,6 +1696,7 @@ static struct kunit_suite clk_range_minimize_test_suite = { kunit_test_suites( &clk_test_suite, &clk_multiple_parents_mux_test_suite, + &clk_orphan_transparent_multiple_parent_mux_test_suite, &clk_orphan_transparent_single_parent_test_suite, &clk_range_test_suite, &clk_range_maximize_test_suite, From 3afb07231d603d51dca6a5d5e16d9d8f422f9b5f Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:17 +0200 Subject: [PATCH 12/28] clk: Take into account uncached clocks in clk_set_rate_range() clk_set_rate_range() will use the last requested rate for the clock when it calls into the driver set_rate hook. However, if CLK_GET_RATE_NOCACHE is set on that clock, the last requested rate might not be matching the current rate of the clock. In such a case, let's read out the rate from the hardware and use that in our set_rate instead. Tested-by: Alexander Stein # imx8mp Tested-by: Marek Szyprowski # exynos4210, meson g12b Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-13-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- drivers/clk/clk.c | 6 +++++- drivers/clk/clk_test.c | 31 +++++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+), 1 deletion(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index caa2eb640441..53b28e63deae 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -2373,6 +2373,10 @@ static int clk_set_rate_range_nolock(struct clk *clk, goto out; } + rate = clk->core->req_rate; + if (clk->core->flags & CLK_GET_RATE_NOCACHE) + rate = clk_core_get_rate_recalc(clk->core); + /* * Since the boundaries have been changed, let's give the * opportunity to the provider to adjust the clock rate based on @@ -2390,7 +2394,7 @@ static int clk_set_rate_range_nolock(struct clk *clk, * - the determine_rate() callback does not really check for * this corner case when determining the rate */ - rate = clamp(clk->core->req_rate, min, max); + rate = clamp(rate, min, max); ret = clk_core_set_rate_nolock(clk->core, rate); if (ret) { /* rollback the changes */ diff --git a/drivers/clk/clk_test.c b/drivers/clk/clk_test.c index ceed49c5a88b..d3e121f21ae2 100644 --- a/drivers/clk/clk_test.c +++ b/drivers/clk/clk_test.c @@ -375,9 +375,40 @@ static void clk_test_uncached_set_range(struct kunit *test) clk_put(clk); } +/* + * Test that for an uncached clock, clk_set_rate_range() will work + * properly if the rate has changed in hardware. + * + * In this case, it means that if the rate wasn't initially in the range + * we're trying to set, but got changed at some point into the range + * without the kernel knowing about it, its rate shouldn't be affected. + */ +static void clk_test_uncached_updated_rate_set_range(struct kunit *test) +{ + struct clk_dummy_context *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + unsigned long rate; + + /* We change the rate behind the clock framework's back */ + ctx->rate = DUMMY_CLOCK_RATE_1 + 1000; + KUNIT_ASSERT_EQ(test, + clk_set_rate_range(clk, + DUMMY_CLOCK_RATE_1, + DUMMY_CLOCK_RATE_2), + 0); + + rate = clk_get_rate(clk); + KUNIT_ASSERT_GT(test, rate, 0); + KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_RATE_1 + 1000); + + clk_put(clk); +} + static struct kunit_case clk_uncached_test_cases[] = { KUNIT_CASE(clk_test_uncached_get_rate), KUNIT_CASE(clk_test_uncached_set_range), + KUNIT_CASE(clk_test_uncached_updated_rate_set_range), {} }; From cb1b1dd96241f37ea41d241946d5153c48141cd5 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:18 +0200 Subject: [PATCH 13/28] clk: Set req_rate on reparenting If a non-rate clock started by default with a parent that never registered, core->req_rate will be 0. The expectation is that whenever the parent will be registered, req_rate will be updated with the new value that has just been computed. However, if that clock is a mux, clk_set_parent() can also make that clock no longer orphan. In this case however, we never update req_rate. The natural solution to this would be to update core->rate and core->req_rate in clk_reparent() by calling clk_recalc(). However, this doesn't work in all cases. Indeed, clk_recalc() is called by __clk_set_parent_before(), __clk_set_parent() and clk_core_reparent(). Both __clk_set_parent_before() and __clk_set_parent will call clk_recalc() with the enable_lock taken through a call to clk_enable_lock(), the underlying locking primitive being a spinlock. clk_recalc() calls the backing driver .recalc_rate hook, and that implementation might sleep if the underlying device uses a bus with accesses that might sleep, such as i2c. In such a situation, we would end up sleeping while holding a spinlock, and thus in an atomic section. In order to work around this, we can move the core->rate and core->req_rate update to the clk_recalc() calling sites, after the enable_lock has been released if it was taken. The only situation that could still be problematic is the clk_core_reparent() -> clk_reparent() case that doesn't have any locking. clk_core_reparent() is itself called by clk_hw_reparent(), which is then called by 4 drivers: * clk-stm32mp1.c, stm32/clk-stm32-core.c and tegra/clk-tegra210-emc.c use it in their set_parent implementation. The set_parent hook is only called by __clk_set_parent() and clk_change_rate(), both of them calling it without the enable_lock taken. * clk/tegra/clk-tegra124-emc.c calls it as part of its set_rate implementation. set_rate is only called by clk_change_rate(), again without the enable_lock taken. In both cases we can't end up in a situation where the clk_hw_reparent() caller would hold a spinlock, so it seems like this is a good workaround. Let's also add some unit tests to make sure we cover the original bug. Tested-by: Alexander Stein # imx8mp Tested-by: Marek Szyprowski # exynos4210, meson g12b Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-14-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- drivers/clk/clk.c | 22 ++++ drivers/clk/clk_test.c | 239 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 261 insertions(+) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 53b28e63deae..91bb1ea0e147 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1765,6 +1765,23 @@ static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan) clk_core_update_orphan_status(child, is_orphan); } +/* + * Update the orphan rate and req_rate of @core and all its children. + */ +static void clk_core_update_orphan_child_rates(struct clk_core *core) +{ + struct clk_core *child; + unsigned long parent_rate = 0; + + if (core->parent) + parent_rate = core->parent->rate; + + core->rate = core->req_rate = clk_recalc(core, parent_rate); + + hlist_for_each_entry(child, &core->children, child_node) + clk_core_update_orphan_child_rates(child); +} + static void clk_reparent(struct clk_core *core, struct clk_core *new_parent) { bool was_orphan = core->orphan; @@ -1834,6 +1851,8 @@ static struct clk_core *__clk_set_parent_before(struct clk_core *core, clk_reparent(core, parent); clk_enable_unlock(flags); + clk_core_update_orphan_child_rates(core); + return old_parent; } @@ -1878,6 +1897,8 @@ static int __clk_set_parent(struct clk_core *core, struct clk_core *parent, flags = clk_enable_lock(); clk_reparent(core, old_parent); clk_enable_unlock(flags); + + clk_core_update_orphan_child_rates(core); __clk_set_parent_after(core, old_parent, parent); return ret; @@ -2506,6 +2527,7 @@ static void clk_core_reparent(struct clk_core *core, struct clk_core *new_parent) { clk_reparent(core, new_parent); + clk_core_update_orphan_child_rates(core); __clk_recalc_accuracies(core); __clk_recalc_rates(core, POST_RATE_CHANGE); } diff --git a/drivers/clk/clk_test.c b/drivers/clk/clk_test.c index d3e121f21ae2..d1b1372f7aaa 100644 --- a/drivers/clk/clk_test.c +++ b/drivers/clk/clk_test.c @@ -594,6 +594,41 @@ clk_test_orphan_transparent_multiple_parent_mux_set_parent(struct kunit *test) clk_put(clk); } +/* + * Test that, for a mux that started orphan but got switched to a valid + * parent, calling clk_drop_range() on the mux won't affect the parent + * rate. + */ +static void +clk_test_orphan_transparent_multiple_parent_mux_set_parent_drop_range(struct kunit *test) +{ + struct clk_multiple_parent_ctx *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + struct clk *parent; + unsigned long parent_rate, new_parent_rate; + int ret; + + parent = clk_hw_get_clk(&ctx->parents_ctx[1].hw, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, parent); + + parent_rate = clk_get_rate(parent); + KUNIT_ASSERT_GT(test, parent_rate, 0); + + ret = clk_set_parent(clk, parent); + KUNIT_ASSERT_EQ(test, ret, 0); + + ret = clk_drop_range(clk); + KUNIT_ASSERT_EQ(test, ret, 0); + + new_parent_rate = clk_get_rate(clk); + KUNIT_ASSERT_GT(test, new_parent_rate, 0); + KUNIT_EXPECT_EQ(test, parent_rate, new_parent_rate); + + clk_put(parent); + clk_put(clk); +} + /* * Test that, for a mux that started orphan but got switched to a valid * parent, the rate of the mux and its new parent are consistent. @@ -625,6 +660,39 @@ clk_test_orphan_transparent_multiple_parent_mux_set_parent_get_rate(struct kunit clk_put(clk); } +/* + * Test that, for a mux that started orphan but got switched to a valid + * parent, calling clk_put() on the mux won't affect the parent rate. + */ +static void +clk_test_orphan_transparent_multiple_parent_mux_set_parent_put(struct kunit *test) +{ + struct clk_multiple_parent_ctx *ctx = test->priv; + struct clk *clk, *parent; + unsigned long parent_rate, new_parent_rate; + int ret; + + parent = clk_hw_get_clk(&ctx->parents_ctx[1].hw, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, parent); + + clk = clk_hw_get_clk(&ctx->hw, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, clk); + + parent_rate = clk_get_rate(parent); + KUNIT_ASSERT_GT(test, parent_rate, 0); + + ret = clk_set_parent(clk, parent); + KUNIT_ASSERT_EQ(test, ret, 0); + + clk_put(clk); + + new_parent_rate = clk_get_rate(parent); + KUNIT_ASSERT_GT(test, new_parent_rate, 0); + KUNIT_EXPECT_EQ(test, parent_rate, new_parent_rate); + + clk_put(parent); +} + /* * Test that, for a mux that started orphan but got switched to a valid * parent, calling clk_set_rate_range() will affect the parent state if @@ -658,6 +726,43 @@ clk_test_orphan_transparent_multiple_parent_mux_set_parent_set_range_modified(st clk_put(clk); } +/* + * Test that, for a mux that started orphan but got switched to a valid + * parent, calling clk_set_rate_range() won't affect the parent state if + * its rate is within range. + */ +static void +clk_test_orphan_transparent_multiple_parent_mux_set_parent_set_range_untouched(struct kunit *test) +{ + struct clk_multiple_parent_ctx *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + struct clk *parent; + unsigned long parent_rate, new_parent_rate; + int ret; + + parent = clk_hw_get_clk(&ctx->parents_ctx[1].hw, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, parent); + + parent_rate = clk_get_rate(parent); + KUNIT_ASSERT_GT(test, parent_rate, 0); + + ret = clk_set_parent(clk, parent); + KUNIT_ASSERT_EQ(test, ret, 0); + + ret = clk_set_rate_range(clk, + DUMMY_CLOCK_INIT_RATE - 1000, + DUMMY_CLOCK_INIT_RATE + 1000); + KUNIT_ASSERT_EQ(test, ret, 0); + + new_parent_rate = clk_get_rate(parent); + KUNIT_ASSERT_GT(test, new_parent_rate, 0); + KUNIT_EXPECT_EQ(test, parent_rate, new_parent_rate); + + clk_put(parent); + clk_put(clk); +} + /* * Test that, for a mux whose current parent hasn't been registered yet, * calling clk_set_rate_range() will succeed, and will be taken into @@ -724,8 +829,11 @@ clk_test_orphan_transparent_multiple_parent_mux_set_range_set_parent_get_rate(st static struct kunit_case clk_orphan_transparent_multiple_parent_mux_test_cases[] = { KUNIT_CASE(clk_test_orphan_transparent_multiple_parent_mux_get_parent), KUNIT_CASE(clk_test_orphan_transparent_multiple_parent_mux_set_parent), + KUNIT_CASE(clk_test_orphan_transparent_multiple_parent_mux_set_parent_drop_range), KUNIT_CASE(clk_test_orphan_transparent_multiple_parent_mux_set_parent_get_rate), + KUNIT_CASE(clk_test_orphan_transparent_multiple_parent_mux_set_parent_put), KUNIT_CASE(clk_test_orphan_transparent_multiple_parent_mux_set_parent_set_range_modified), + KUNIT_CASE(clk_test_orphan_transparent_multiple_parent_mux_set_parent_set_range_untouched), KUNIT_CASE(clk_test_orphan_transparent_multiple_parent_mux_set_range_round_rate), KUNIT_CASE(clk_test_orphan_transparent_multiple_parent_mux_set_range_set_parent_get_rate), {} @@ -1021,6 +1129,136 @@ static struct kunit_suite clk_orphan_transparent_single_parent_test_suite = { .test_cases = clk_orphan_transparent_single_parent_mux_test_cases, }; +struct clk_single_parent_two_lvl_ctx { + struct clk_dummy_context parent_parent_ctx; + struct clk_dummy_context parent_ctx; + struct clk_hw hw; +}; + +static int +clk_orphan_two_level_root_last_test_init(struct kunit *test) +{ + struct clk_single_parent_two_lvl_ctx *ctx; + int ret; + + ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + test->priv = ctx; + + ctx->parent_ctx.hw.init = + CLK_HW_INIT("intermediate-parent", + "root-parent", + &clk_dummy_single_parent_ops, + CLK_SET_RATE_PARENT); + ret = clk_hw_register(NULL, &ctx->parent_ctx.hw); + if (ret) + return ret; + + ctx->hw.init = + CLK_HW_INIT("test-clk", "intermediate-parent", + &clk_dummy_single_parent_ops, + CLK_SET_RATE_PARENT); + ret = clk_hw_register(NULL, &ctx->hw); + if (ret) + return ret; + + ctx->parent_parent_ctx.rate = DUMMY_CLOCK_INIT_RATE; + ctx->parent_parent_ctx.hw.init = + CLK_HW_INIT_NO_PARENT("root-parent", + &clk_dummy_rate_ops, + 0); + ret = clk_hw_register(NULL, &ctx->parent_parent_ctx.hw); + if (ret) + return ret; + + return 0; +} + +static void +clk_orphan_two_level_root_last_test_exit(struct kunit *test) +{ + struct clk_single_parent_two_lvl_ctx *ctx = test->priv; + + clk_hw_unregister(&ctx->hw); + clk_hw_unregister(&ctx->parent_ctx.hw); + clk_hw_unregister(&ctx->parent_parent_ctx.hw); +} + +/* + * Test that, for a clock whose parent used to be orphan, clk_get_rate() + * will return the proper rate. + */ +static void +clk_orphan_two_level_root_last_test_get_rate(struct kunit *test) +{ + struct clk_single_parent_two_lvl_ctx *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + unsigned long rate; + + rate = clk_get_rate(clk); + KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_INIT_RATE); + + clk_put(clk); +} + +/* + * Test that, for a clock whose parent used to be orphan, + * clk_set_rate_range() won't affect its rate if it is already within + * range. + * + * See (for Exynos 4210): + * https://lore.kernel.org/linux-clk/366a0232-bb4a-c357-6aa8-636e398e05eb@samsung.com/ + */ +static void +clk_orphan_two_level_root_last_test_set_range(struct kunit *test) +{ + struct clk_single_parent_two_lvl_ctx *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + unsigned long rate; + int ret; + + ret = clk_set_rate_range(clk, + DUMMY_CLOCK_INIT_RATE - 1000, + DUMMY_CLOCK_INIT_RATE + 1000); + KUNIT_ASSERT_EQ(test, ret, 0); + + rate = clk_get_rate(clk); + KUNIT_ASSERT_GT(test, rate, 0); + KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_INIT_RATE); + + clk_put(clk); +} + +static struct kunit_case +clk_orphan_two_level_root_last_test_cases[] = { + KUNIT_CASE(clk_orphan_two_level_root_last_test_get_rate), + KUNIT_CASE(clk_orphan_two_level_root_last_test_set_range), + {} +}; + +/* + * Test suite for a basic, transparent, clock with a parent that is also + * such a clock. The parent's parent is registered last, while the + * parent and its child are registered in that order. The intermediate + * and leaf clocks will thus be orphan when registered, but the leaf + * clock itself will always have its parent and will never be + * reparented. Indeed, it's only orphan because its parent is. + * + * These tests exercise the behaviour of the consumer API when dealing + * with an orphan clock, and how we deal with the transition to a valid + * parent. + */ +static struct kunit_suite +clk_orphan_two_level_root_last_test_suite = { + .name = "clk-orphan-two-level-root-last-test", + .init = clk_orphan_two_level_root_last_test_init, + .exit = clk_orphan_two_level_root_last_test_exit, + .test_cases = clk_orphan_two_level_root_last_test_cases, +}; + /* * Test that clk_set_rate_range won't return an error for a valid range * and that it will make sure the rate of the clock is within the @@ -1729,6 +1967,7 @@ kunit_test_suites( &clk_multiple_parents_mux_test_suite, &clk_orphan_transparent_multiple_parent_mux_test_suite, &clk_orphan_transparent_single_parent_test_suite, + &clk_orphan_two_level_root_last_test_suite, &clk_range_test_suite, &clk_range_maximize_test_suite, &clk_range_minimize_test_suite, From 718af795d3fd786928506cd5251597fbe29c7fda Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:19 +0200 Subject: [PATCH 14/28] clk: Change clk_core_init_rate_req prototype The expectation is that a clk_rate_request structure is supposed to be initialized using clk_core_init_rate_req(), yet the rate we want to request still needs to be set by hand. Let's just pass the rate as a function argument so that callers don't have any extra work to do. Tested-by: Alexander Stein # imx8mp Tested-by: Marek Szyprowski # exynos4210, meson g12b Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-15-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- drivers/clk/clk.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 91bb1ea0e147..75cfde9f917f 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1380,13 +1380,16 @@ static int clk_core_determine_round_nolock(struct clk_core *core, } static void clk_core_init_rate_req(struct clk_core * const core, - struct clk_rate_request *req) + struct clk_rate_request *req, + unsigned long rate) { struct clk_core *parent; if (WARN_ON(!core || !req)) return; + req->rate = rate; + parent = core->parent; if (parent) { req->best_parent_hw = parent->hw; @@ -1412,7 +1415,7 @@ static int clk_core_round_rate_nolock(struct clk_core *core, return 0; } - clk_core_init_rate_req(core, req); + clk_core_init_rate_req(core, req, req->rate); if (clk_core_can_round(core)) return clk_core_determine_round_nolock(core, req); @@ -2004,11 +2007,10 @@ static struct clk_core *clk_calc_new_rates(struct clk_core *core, if (clk_core_can_round(core)) { struct clk_rate_request req; - req.rate = rate; req.min_rate = min_rate; req.max_rate = max_rate; - clk_core_init_rate_req(core, &req); + clk_core_init_rate_req(core, &req, rate); ret = clk_core_determine_round_nolock(core, &req); if (ret < 0) From 8cd9c39dce5b54494f967235f7eeac7c30c08b97 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:20 +0200 Subject: [PATCH 15/28] clk: Move clk_core_init_rate_req() from clk_core_round_rate_nolock() to its caller The clk_rate_request structure is used internally as an argument for the clk_core_determine_round_nolock() and clk_core_round_rate_nolock(). In both cases, the clk_core_init_rate_req() function is used to initialize the clk_rate_request structure. However, the expectation on who gets to call that function is inconsistent between those two functions. Indeed, clk_core_determine_round_nolock() will assume the structure is properly initialized and will just use it. On the other hand, clk_core_round_rate_nolock() will call clk_core_init_rate_req() itself, expecting the caller to have filled only a minimal set of parameters (rate, min_rate and max_rate). If we ignore the calling convention inconsistency, this leads to a second inconsistency for drivers: * If they get called by the framework through clk_core_round_rate_nolock(), the rate, min_rate and max_rate fields will be filled by the caller, and the best_parent_rate and best_parent_hw fields will get filled by clk_core_init_rate_req(). * If they get called by a driver through __clk_determine_rate (and thus clk_core_round_rate_nolock), only best_parent_rate and best_parent_hw are being explicitly set by the framework. Even though we can reasonably expect rate to be set, only one of the 6 in-tree users explicitly set min_rate and max_rate. * If they get called by the framework through clk_core_determine_round_nolock(), then we have two callpaths. Either it will be called by clk_core_round_rate_nolock() itself, or it will be called by clk_calc_new_rates(), which will properly initialize rate, min_rate, max_rate itself, and best_parent_rate and best_parent_hw through clk_core_init_rate_req(). Even though the first and third case seems equivalent, they aren't when the clock has CLK_SET_RATE_PARENT. Indeed, in such a case clk_core_round_rate_nolock() will call itself on the current parent clock with the same clk_rate_request structure. The clk_core_init_rate_req() function will then be called on the parent clock, with the child clk_rate_request pointer and will fill the best_parent_rate and best_parent_hw fields with the parent context. When the whole recursion stops and the call returns, the initial caller will end up with a clk_rate_request structure with some information of the child clock (rate, min_rate, max_rate) and some others of the last clock up the tree whose child had CLK_SET_RATE_PARENT (best_parent_hw, best_parent_rate). In the most common case, best_parent_rate is going to be equal on all the parent clocks so it's not a big deal. However, best_parent_hw is going to point to a clock that never has been a valid parent for that clock which is definitely confusing. In order to fix the calling inconsistency, let's move the clk_core_init_rate_req() calls to the callers, which will also help a bit with the clk_core_round_rate_nolock() recursion. Tested-by: Alexander Stein # imx8mp Tested-by: Marek Szyprowski # exynos4210, meson g12b Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-16-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- drivers/clk/clk.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 75cfde9f917f..553e1e9eb300 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1415,8 +1415,6 @@ static int clk_core_round_rate_nolock(struct clk_core *core, return 0; } - clk_core_init_rate_req(core, req, req->rate); - if (clk_core_can_round(core)) return clk_core_determine_round_nolock(core, req); else if (core->flags & CLK_SET_RATE_PARENT) @@ -1464,8 +1462,8 @@ unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate) int ret; struct clk_rate_request req; + clk_core_init_rate_req(hw->core, &req, rate); clk_core_get_boundaries(hw->core, &req.min_rate, &req.max_rate); - req.rate = rate; ret = clk_core_round_rate_nolock(hw->core, &req); if (ret) @@ -1497,8 +1495,8 @@ long clk_round_rate(struct clk *clk, unsigned long rate) if (clk->exclusive_count) clk_core_rate_unprotect(clk->core); + clk_core_init_rate_req(clk->core, &req, rate); clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate); - req.rate = rate; ret = clk_core_round_rate_nolock(clk->core, &req); @@ -2209,8 +2207,8 @@ static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core, if (cnt < 0) return cnt; + clk_core_init_rate_req(core, &req, req_rate); clk_core_get_boundaries(core, &req.min_rate, &req.max_rate); - req.rate = req_rate; ret = clk_core_round_rate_nolock(core, &req); From c35e84b0977617f96fb1dbef3fb8d71a861325c0 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:21 +0200 Subject: [PATCH 16/28] clk: Introduce clk_hw_init_rate_request() clk-divider instantiates clk_rate_request internally for its round_rate implementations to share the code with its determine_rate implementations. However, it's missing a few fields (min_rate, max_rate) that would be initialized properly if it was using clk_core_init_rate_req(). Let's create the clk_hw_init_rate_request() function for clock providers to be able to share the code to instation clk_rate_requests with the framework. This will also be useful for some tests introduced in later patches. Tested-by: Alexander Stein # imx8mp Tested-by: Marek Szyprowski # exynos4210, meson g12b Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-17-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- drivers/clk/clk-divider.c | 20 ++++++++++---------- drivers/clk/clk.c | 20 ++++++++++++++++++++ include/linux/clk-provider.h | 6 ++++++ 3 files changed, 36 insertions(+), 10 deletions(-) diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c index f6b2bf558486..a2c2b5203b0a 100644 --- a/drivers/clk/clk-divider.c +++ b/drivers/clk/clk-divider.c @@ -386,13 +386,13 @@ long divider_round_rate_parent(struct clk_hw *hw, struct clk_hw *parent, const struct clk_div_table *table, u8 width, unsigned long flags) { - struct clk_rate_request req = { - .rate = rate, - .best_parent_rate = *prate, - .best_parent_hw = parent, - }; + struct clk_rate_request req; int ret; + clk_hw_init_rate_request(hw, &req, rate); + req.best_parent_rate = *prate; + req.best_parent_hw = parent; + ret = divider_determine_rate(hw, &req, table, width, flags); if (ret) return ret; @@ -408,13 +408,13 @@ long divider_ro_round_rate_parent(struct clk_hw *hw, struct clk_hw *parent, const struct clk_div_table *table, u8 width, unsigned long flags, unsigned int val) { - struct clk_rate_request req = { - .rate = rate, - .best_parent_rate = *prate, - .best_parent_hw = parent, - }; + struct clk_rate_request req; int ret; + clk_hw_init_rate_request(hw, &req, rate); + req.best_parent_rate = *prate; + req.best_parent_hw = parent; + ret = divider_ro_determine_rate(hw, &req, table, width, flags, val); if (ret) return ret; diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 553e1e9eb300..96b372ff23c2 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1400,6 +1400,26 @@ static void clk_core_init_rate_req(struct clk_core * const core, } } +/** + * clk_hw_init_rate_request - Initializes a clk_rate_request + * @hw: the clk for which we want to submit a rate request + * @req: the clk_rate_request structure we want to initialise + * @rate: the rate which is to be requested + * + * Initializes a clk_rate_request structure to submit to + * __clk_determine_rate() or similar functions. + */ +void clk_hw_init_rate_request(const struct clk_hw *hw, + struct clk_rate_request *req, + unsigned long rate) +{ + if (WARN_ON(!hw || !req)) + return; + + clk_core_init_rate_req(hw->core, req, rate); +} +EXPORT_SYMBOL_GPL(clk_hw_init_rate_request); + static bool clk_core_can_round(struct clk_core * const core) { return core->ops->determine_rate || core->ops->round_rate; diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 9a14cfa0d201..d857717aa386 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -42,6 +42,8 @@ struct dentry; * struct clk_rate_request - Structure encoding the clk constraints that * a clock user might require. * + * Should be initialized by calling clk_hw_init_rate_request(). + * * @rate: Requested clock rate. This field will be adjusted by * clock drivers according to hardware capabilities. * @min_rate: Minimum rate imposed by clk users. @@ -60,6 +62,10 @@ struct clk_rate_request { struct clk_hw *best_parent_hw; }; +void clk_hw_init_rate_request(const struct clk_hw *hw, + struct clk_rate_request *req, + unsigned long rate); + /** * struct clk_duty - Struture encoding the duty cycle ratio of a clock * From 11c84a38fcff30197f6e8af29e65531a5734ee05 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:22 +0200 Subject: [PATCH 17/28] clk: Add our request boundaries in clk_core_init_rate_req The expectation is that a new clk_rate_request is initialized through a call to clk_core_init_rate_req(). However, at the moment it only fills the parent rate and clk_hw pointer, but omits the other fields such as the clock rate boundaries. Some users of that function will update them after calling it, but most don't. As we are passed the clk_core pointer, we have access to those boundaries in clk_core_init_rate_req() however, so let's just fill it there and remove it from the few callers that do it right. Tested-by: Alexander Stein # imx8mp Tested-by: Marek Szyprowski # exynos4210, meson g12b Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-18-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- drivers/clk/clk.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 96b372ff23c2..2794bd3bef4b 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1389,6 +1389,7 @@ static void clk_core_init_rate_req(struct clk_core * const core, return; req->rate = rate; + clk_core_get_boundaries(core, &req->min_rate, &req->max_rate); parent = core->parent; if (parent) { @@ -1483,7 +1484,6 @@ unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate) struct clk_rate_request req; clk_core_init_rate_req(hw->core, &req, rate); - clk_core_get_boundaries(hw->core, &req.min_rate, &req.max_rate); ret = clk_core_round_rate_nolock(hw->core, &req); if (ret) @@ -1516,7 +1516,6 @@ long clk_round_rate(struct clk *clk, unsigned long rate) clk_core_rate_unprotect(clk->core); clk_core_init_rate_req(clk->core, &req, rate); - clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate); ret = clk_core_round_rate_nolock(clk->core, &req); @@ -2025,9 +2024,6 @@ static struct clk_core *clk_calc_new_rates(struct clk_core *core, if (clk_core_can_round(core)) { struct clk_rate_request req; - req.min_rate = min_rate; - req.max_rate = max_rate; - clk_core_init_rate_req(core, &req, rate); ret = clk_core_determine_round_nolock(core, &req); @@ -2228,7 +2224,6 @@ static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core, return cnt; clk_core_init_rate_req(core, &req, req_rate); - clk_core_get_boundaries(core, &req.min_rate, &req.max_rate); ret = clk_core_round_rate_nolock(core, &req); From 666650b25ac43700a1cce96e51a32fc89c973d28 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:23 +0200 Subject: [PATCH 18/28] clk: Switch from __clk_determine_rate to clk_core_round_rate_nolock clk_mux_determine_rate_flags() will call into __clk_determine_rate() with a clk_hw pointer, while it has access to the clk_core pointer already. This leads to back and forth between clk_hw and clk_core, while __clk_determine_rate will only call clk_core_round_rate_nolock() with the clk_core pointer it retrieved from the clk_hw. Let's simplify things a bit by calling into clk_core_round_rate_nolock directly. Tested-by: Alexander Stein # imx8mp Tested-by: Marek Szyprowski # exynos4210, meson g12b Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-19-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- drivers/clk/clk.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 2794bd3bef4b..f8a8bdd552d6 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -536,6 +536,9 @@ static bool mux_is_better_rate(unsigned long rate, unsigned long now, return now <= rate && now > best; } +static int clk_core_round_rate_nolock(struct clk_core *core, + struct clk_rate_request *req); + int clk_mux_determine_rate_flags(struct clk_hw *hw, struct clk_rate_request *req, unsigned long flags) @@ -549,8 +552,12 @@ int clk_mux_determine_rate_flags(struct clk_hw *hw, if (core->flags & CLK_SET_RATE_NO_REPARENT) { parent = core->parent; if (core->flags & CLK_SET_RATE_PARENT) { - ret = __clk_determine_rate(parent ? parent->hw : NULL, - &parent_req); + if (!parent) { + req->rate = 0; + return 0; + } + + ret = clk_core_round_rate_nolock(parent, &parent_req); if (ret) return ret; @@ -573,7 +580,7 @@ int clk_mux_determine_rate_flags(struct clk_hw *hw, if (core->flags & CLK_SET_RATE_PARENT) { parent_req = *req; - ret = __clk_determine_rate(parent->hw, &parent_req); + ret = clk_core_round_rate_nolock(parent, &parent_req); if (ret) continue; } else { From 1234a2c40b8cf16041fb9acd730160e6c5b4ba13 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:24 +0200 Subject: [PATCH 19/28] clk: Introduce clk_core_has_parent() We will need to know if a clk_core pointer has a given parent in other functions, so let's create a clk_core_has_parent() function that clk_has_parent() will call into. For good measure, let's add some unit tests as well to make sure it works properly. Tested-by: Alexander Stein # imx8mp Tested-by: Marek Szyprowski # exynos4210, meson g12b Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-20-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju [sboyd@kernel.org: Move tmp declaration, fix conditional to check for current parent] Signed-off-by: Stephen Boyd --- drivers/clk/clk.c | 37 +++++++++++++++++++++--------------- drivers/clk/clk_test.c | 43 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 65 insertions(+), 15 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index f8a8bdd552d6..8e4a8b9aa320 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -539,6 +539,27 @@ static bool mux_is_better_rate(unsigned long rate, unsigned long now, static int clk_core_round_rate_nolock(struct clk_core *core, struct clk_rate_request *req); +static bool clk_core_has_parent(struct clk_core *core, const struct clk_core *parent) +{ + struct clk_core *tmp; + unsigned int i; + + /* Optimize for the case where the parent is already the parent. */ + if (core->parent == parent) + return true; + + for (i = 0; i < core->num_parents; i++) { + tmp = clk_core_get_parent_by_index(core, i); + if (!tmp) + continue; + + if (tmp == parent) + return true; + } + + return false; +} + int clk_mux_determine_rate_flags(struct clk_hw *hw, struct clk_rate_request *req, unsigned long flags) @@ -2574,25 +2595,11 @@ void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent) */ bool clk_has_parent(struct clk *clk, struct clk *parent) { - struct clk_core *core, *parent_core; - int i; - /* NULL clocks should be nops, so return success if either is NULL. */ if (!clk || !parent) return true; - core = clk->core; - parent_core = parent->core; - - /* Optimize for the case where the parent is already the parent. */ - if (core->parent == parent_core) - return true; - - for (i = 0; i < core->num_parents; i++) - if (!strcmp(core->parents[i].name, parent_core->name)) - return true; - - return false; + return clk_core_has_parent(clk->core, parent->core); } EXPORT_SYMBOL_GPL(clk_has_parent); diff --git a/drivers/clk/clk_test.c b/drivers/clk/clk_test.c index d1b1372f7aaa..7068517428e2 100644 --- a/drivers/clk/clk_test.c +++ b/drivers/clk/clk_test.c @@ -491,8 +491,32 @@ clk_test_multiple_parents_mux_get_parent(struct kunit *test) clk_put(clk); } +/* + * Test that for a clock with a multiple parents, clk_has_parent() + * actually reports all of them as parents. + */ +static void +clk_test_multiple_parents_mux_has_parent(struct kunit *test) +{ + struct clk_multiple_parent_ctx *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + struct clk *parent; + + parent = clk_hw_get_clk(&ctx->parents_ctx[0].hw, NULL); + KUNIT_EXPECT_TRUE(test, clk_has_parent(clk, parent)); + clk_put(parent); + + parent = clk_hw_get_clk(&ctx->parents_ctx[1].hw, NULL); + KUNIT_EXPECT_TRUE(test, clk_has_parent(clk, parent)); + clk_put(parent); + + clk_put(clk); +} + static struct kunit_case clk_multiple_parents_mux_test_cases[] = { KUNIT_CASE(clk_test_multiple_parents_mux_get_parent), + KUNIT_CASE(clk_test_multiple_parents_mux_has_parent), {} }; @@ -918,6 +942,24 @@ clk_test_single_parent_mux_get_parent(struct kunit *test) clk_put(clk); } +/* + * Test that for a clock with a single parent, clk_has_parent() actually + * reports it as a parent. + */ +static void +clk_test_single_parent_mux_has_parent(struct kunit *test) +{ + struct clk_single_parent_ctx *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + struct clk *parent = clk_hw_get_clk(&ctx->parent_ctx.hw, NULL); + + KUNIT_EXPECT_TRUE(test, clk_has_parent(clk, parent)); + + clk_put(parent); + clk_put(clk); +} + /* * Test that for a clock that can't modify its rate and with a single * parent, if we set disjoints range on the parent and then the child, @@ -1022,6 +1064,7 @@ clk_test_single_parent_mux_set_range_round_rate_child_smaller(struct kunit *test static struct kunit_case clk_single_parent_mux_test_cases[] = { KUNIT_CASE(clk_test_single_parent_mux_get_parent), + KUNIT_CASE(clk_test_single_parent_mux_has_parent), KUNIT_CASE(clk_test_single_parent_mux_set_range_disjoint_child_last), KUNIT_CASE(clk_test_single_parent_mux_set_range_disjoint_parent_last), KUNIT_CASE(clk_test_single_parent_mux_set_range_round_rate_child_smaller), From 22fb0e284fbc3c1b85d24c5a1df8ea3ac82ab1d1 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:25 +0200 Subject: [PATCH 20/28] clk: Constify clk_has_parent() clk_has_parent() doesn't modify the clocks being passed, so let's make it const. Suggested-by: Stephen Boyd Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-21-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- drivers/clk/clk.c | 2 +- include/linux/clk.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 8e4a8b9aa320..3b68a9b8234a 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -2593,7 +2593,7 @@ void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent) * * Returns true if @parent is a possible parent for @clk, false otherwise. */ -bool clk_has_parent(struct clk *clk, struct clk *parent) +bool clk_has_parent(const struct clk *clk, const struct clk *parent) { /* NULL clocks should be nops, so return success if either is NULL. */ if (!clk || !parent) diff --git a/include/linux/clk.h b/include/linux/clk.h index c13061cabdfc..1ef013324237 100644 --- a/include/linux/clk.h +++ b/include/linux/clk.h @@ -799,7 +799,7 @@ int clk_set_rate_exclusive(struct clk *clk, unsigned long rate); * * Returns true if @parent is a possible parent for @clk, false otherwise. */ -bool clk_has_parent(struct clk *clk, struct clk *parent); +bool clk_has_parent(const struct clk *clk, const struct clk *parent); /** * clk_set_rate_range - set a rate range for a clock source From 262ca38f4b6eb418b20b8e1d6d8495c6a98727c1 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:26 +0200 Subject: [PATCH 21/28] clk: Stop forwarding clk_rate_requests to the parent If the clock cannot modify its rate and has CLK_SET_RATE_PARENT, clk_mux_determine_rate_flags(), clk_core_round_rate_nolock() and a number of drivers will forward the clk_rate_request to the parent clock. clk_core_round_rate_nolock() will pass the pointer directly, which means that we pass a clk_rate_request to the parent that has the rate, min_rate and max_rate of the child, and the best_parent_rate and best_parent_hw fields will be relative to the child as well, so will point to our current clock and its rate. The most common case for CLK_SET_RATE_PARENT is that the child and parent clock rates will be equal, so the rate field isn't a worry, but the other fields are. Similarly, if the parent clock driver ever modifies the best_parent_rate or best_parent_hw, this will be applied to the child once the call to clk_core_round_rate_nolock() is done. best_parent_hw is probably not going to be a valid parent, and best_parent_rate might lead to a parent rate change different to the one that was initially computed. clk_mux_determine_rate_flags() and the affected drivers will copy the request before forwarding it to the parents, so they won't be affected by the latter issue, but the former is still going to be there and will lead to erroneous data and context being passed to the various clock drivers in the same sub-tree. Let's create two new functions, clk_core_forward_rate_req() and clk_hw_forward_rate_request() for the framework and the clock providers that will copy a request from a child clock and update the context to match the parent's. We also update the relevant call sites in the framework and drivers to use that new function. Let's also add a test to make sure we avoid regressions there. Tested-by: Alexander Stein # imx8mp Tested-by: Marek Szyprowski # exynos4210, meson g12b Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-22-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- drivers/clk/at91/clk-generated.c | 5 +- drivers/clk/at91/clk-master.c | 13 ++- drivers/clk/at91/clk-peripheral.c | 4 +- drivers/clk/clk-composite.c | 6 +- drivers/clk/clk.c | 84 ++++++++++++-- drivers/clk/clk_test.c | 182 ++++++++++++++++++++++++++++++ include/linux/clk-provider.h | 5 + 7 files changed, 281 insertions(+), 18 deletions(-) diff --git a/drivers/clk/at91/clk-generated.c b/drivers/clk/at91/clk-generated.c index d429ba52a719..943ea67bf135 100644 --- a/drivers/clk/at91/clk-generated.c +++ b/drivers/clk/at91/clk-generated.c @@ -136,7 +136,6 @@ static int clk_generated_determine_rate(struct clk_hw *hw, { struct clk_generated *gck = to_clk_generated(hw); struct clk_hw *parent = NULL; - struct clk_rate_request req_parent = *req; long best_rate = -EINVAL; unsigned long min_rate, parent_rate; int best_diff = -1; @@ -192,7 +191,9 @@ static int clk_generated_determine_rate(struct clk_hw *hw, goto end; for (div = 1; div < GENERATED_MAX_DIV + 2; div++) { - req_parent.rate = req->rate * div; + struct clk_rate_request req_parent; + + clk_hw_forward_rate_request(hw, req, parent, &req_parent, req->rate * div); if (__clk_determine_rate(parent, &req_parent)) continue; clk_generated_best_diff(req, parent, req_parent.rate, div, diff --git a/drivers/clk/at91/clk-master.c b/drivers/clk/at91/clk-master.c index 164e2959c7cf..b7cd1924de52 100644 --- a/drivers/clk/at91/clk-master.c +++ b/drivers/clk/at91/clk-master.c @@ -581,7 +581,6 @@ static int clk_sama7g5_master_determine_rate(struct clk_hw *hw, struct clk_rate_request *req) { struct clk_master *master = to_clk_master(hw); - struct clk_rate_request req_parent = *req; struct clk_hw *parent; long best_rate = LONG_MIN, best_diff = LONG_MIN; unsigned long parent_rate; @@ -618,11 +617,15 @@ static int clk_sama7g5_master_determine_rate(struct clk_hw *hw, goto end; for (div = 0; div < MASTER_PRES_MAX + 1; div++) { - if (div == MASTER_PRES_MAX) - req_parent.rate = req->rate * 3; - else - req_parent.rate = req->rate << div; + struct clk_rate_request req_parent; + unsigned long req_rate; + if (div == MASTER_PRES_MAX) + req_rate = req->rate * 3; + else + req_rate = req->rate << div; + + clk_hw_forward_rate_request(hw, req, parent, &req_parent, req_rate); if (__clk_determine_rate(parent, &req_parent)) continue; diff --git a/drivers/clk/at91/clk-peripheral.c b/drivers/clk/at91/clk-peripheral.c index e14fa5ac734c..5104d4025484 100644 --- a/drivers/clk/at91/clk-peripheral.c +++ b/drivers/clk/at91/clk-peripheral.c @@ -269,7 +269,6 @@ static int clk_sam9x5_peripheral_determine_rate(struct clk_hw *hw, { struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw); struct clk_hw *parent = clk_hw_get_parent(hw); - struct clk_rate_request req_parent = *req; unsigned long parent_rate = clk_hw_get_rate(parent); unsigned long tmp_rate; long best_rate = LONG_MIN; @@ -302,8 +301,9 @@ static int clk_sam9x5_peripheral_determine_rate(struct clk_hw *hw, goto end; for (shift = 0; shift <= PERIPHERAL_MAX_SHIFT; shift++) { - req_parent.rate = req->rate << shift; + struct clk_rate_request req_parent; + clk_hw_forward_rate_request(hw, req, parent, &req_parent, req->rate << shift); if (__clk_determine_rate(parent, &req_parent)) continue; diff --git a/drivers/clk/clk-composite.c b/drivers/clk/clk-composite.c index b9c5f904f535..edfa94641bbf 100644 --- a/drivers/clk/clk-composite.c +++ b/drivers/clk/clk-composite.c @@ -85,10 +85,11 @@ static int clk_composite_determine_rate(struct clk_hw *hw, req->best_parent_hw = NULL; if (clk_hw_get_flags(hw) & CLK_SET_RATE_NO_REPARENT) { - struct clk_rate_request tmp_req = *req; + struct clk_rate_request tmp_req; parent = clk_hw_get_parent(mux_hw); + clk_hw_forward_rate_request(hw, req, parent, &tmp_req, req->rate); ret = clk_composite_determine_rate_for_parent(rate_hw, &tmp_req, parent, @@ -104,12 +105,13 @@ static int clk_composite_determine_rate(struct clk_hw *hw, } for (i = 0; i < clk_hw_get_num_parents(mux_hw); i++) { - struct clk_rate_request tmp_req = *req; + struct clk_rate_request tmp_req; parent = clk_hw_get_parent_by_index(mux_hw, i); if (!parent) continue; + clk_hw_forward_rate_request(hw, req, parent, &tmp_req, req->rate); ret = clk_composite_determine_rate_for_parent(rate_hw, &tmp_req, parent, diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 3b68a9b8234a..3f60eb836980 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -536,6 +536,10 @@ static bool mux_is_better_rate(unsigned long rate, unsigned long now, return now <= rate && now > best; } +static void clk_core_init_rate_req(struct clk_core * const core, + struct clk_rate_request *req, + unsigned long rate); + static int clk_core_round_rate_nolock(struct clk_core *core, struct clk_rate_request *req); @@ -560,6 +564,25 @@ static bool clk_core_has_parent(struct clk_core *core, const struct clk_core *pa return false; } +static void +clk_core_forward_rate_req(struct clk_core *core, + const struct clk_rate_request *old_req, + struct clk_core *parent, + struct clk_rate_request *req, + unsigned long parent_rate) +{ + if (WARN_ON(!clk_core_has_parent(core, parent))) + return; + + clk_core_init_rate_req(parent, req, parent_rate); + + if (req->min_rate < old_req->min_rate) + req->min_rate = old_req->min_rate; + + if (req->max_rate > old_req->max_rate) + req->max_rate = old_req->max_rate; +} + int clk_mux_determine_rate_flags(struct clk_hw *hw, struct clk_rate_request *req, unsigned long flags) @@ -567,17 +590,19 @@ int clk_mux_determine_rate_flags(struct clk_hw *hw, struct clk_core *core = hw->core, *parent, *best_parent = NULL; int i, num_parents, ret; unsigned long best = 0; - struct clk_rate_request parent_req = *req; /* if NO_REPARENT flag set, pass through to current parent */ if (core->flags & CLK_SET_RATE_NO_REPARENT) { parent = core->parent; if (core->flags & CLK_SET_RATE_PARENT) { + struct clk_rate_request parent_req; + if (!parent) { req->rate = 0; return 0; } + clk_core_forward_rate_req(core, req, parent, &parent_req, req->rate); ret = clk_core_round_rate_nolock(parent, &parent_req); if (ret) return ret; @@ -595,23 +620,29 @@ int clk_mux_determine_rate_flags(struct clk_hw *hw, /* find the parent that can provide the fastest rate <= rate */ num_parents = core->num_parents; for (i = 0; i < num_parents; i++) { + unsigned long parent_rate; + parent = clk_core_get_parent_by_index(core, i); if (!parent) continue; if (core->flags & CLK_SET_RATE_PARENT) { - parent_req = *req; + struct clk_rate_request parent_req; + + clk_core_forward_rate_req(core, req, parent, &parent_req, req->rate); ret = clk_core_round_rate_nolock(parent, &parent_req); if (ret) continue; + + parent_rate = parent_req.rate; } else { - parent_req.rate = clk_core_get_rate_nolock(parent); + parent_rate = clk_core_get_rate_nolock(parent); } - if (mux_is_better_rate(req->rate, parent_req.rate, + if (mux_is_better_rate(req->rate, parent_rate, best, flags)) { best_parent = parent; - best = parent_req.rate; + best = parent_rate; } } @@ -1449,6 +1480,31 @@ void clk_hw_init_rate_request(const struct clk_hw *hw, } EXPORT_SYMBOL_GPL(clk_hw_init_rate_request); +/** + * clk_hw_forward_rate_request - Forwards a clk_rate_request to a clock's parent + * @hw: the original clock that got the rate request + * @old_req: the original clk_rate_request structure we want to forward + * @parent: the clk we want to forward @old_req to + * @req: the clk_rate_request structure we want to initialise + * @parent_rate: The rate which is to be requested to @parent + * + * Initializes a clk_rate_request structure to submit to a clock parent + * in __clk_determine_rate() or similar functions. + */ +void clk_hw_forward_rate_request(const struct clk_hw *hw, + const struct clk_rate_request *old_req, + const struct clk_hw *parent, + struct clk_rate_request *req, + unsigned long parent_rate) +{ + if (WARN_ON(!hw || !old_req || !parent || !req)) + return; + + clk_core_forward_rate_req(hw->core, old_req, + parent->core, req, + parent_rate); +} + static bool clk_core_can_round(struct clk_core * const core) { return core->ops->determine_rate || core->ops->round_rate; @@ -1457,6 +1513,8 @@ static bool clk_core_can_round(struct clk_core * const core) static int clk_core_round_rate_nolock(struct clk_core *core, struct clk_rate_request *req) { + int ret; + lockdep_assert_held(&prepare_lock); if (!core) { @@ -1466,8 +1524,20 @@ static int clk_core_round_rate_nolock(struct clk_core *core, if (clk_core_can_round(core)) return clk_core_determine_round_nolock(core, req); - else if (core->flags & CLK_SET_RATE_PARENT) - return clk_core_round_rate_nolock(core->parent, req); + + if (core->flags & CLK_SET_RATE_PARENT) { + struct clk_rate_request parent_req; + + clk_core_forward_rate_req(core, req, core->parent, &parent_req, req->rate); + ret = clk_core_round_rate_nolock(core->parent, &parent_req); + if (ret) + return ret; + + req->best_parent_rate = parent_req.rate; + req->rate = parent_req.rate; + + return 0; + } req->rate = core->rate; return 0; diff --git a/drivers/clk/clk_test.c b/drivers/clk/clk_test.c index 7068517428e2..3004ef368bd7 100644 --- a/drivers/clk/clk_test.c +++ b/drivers/clk/clk_test.c @@ -1024,6 +1024,36 @@ clk_test_single_parent_mux_set_range_disjoint_parent_last(struct kunit *test) clk_put(clk); } +/* + * Test that for a clock that can't modify its rate and with a single + * parent, if we set a range on the parent and then call + * clk_round_rate(), the boundaries of the parent are taken into + * account. + */ +static void +clk_test_single_parent_mux_set_range_round_rate_parent_only(struct kunit *test) +{ + struct clk_single_parent_ctx *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + struct clk *parent; + unsigned long rate; + int ret; + + parent = clk_get_parent(clk); + KUNIT_ASSERT_PTR_NE(test, parent, NULL); + + ret = clk_set_rate_range(parent, DUMMY_CLOCK_RATE_1, DUMMY_CLOCK_RATE_2); + KUNIT_ASSERT_EQ(test, ret, 0); + + rate = clk_round_rate(clk, DUMMY_CLOCK_RATE_1 - 1000); + KUNIT_ASSERT_GT(test, rate, 0); + KUNIT_EXPECT_GE(test, rate, DUMMY_CLOCK_RATE_1); + KUNIT_EXPECT_LE(test, rate, DUMMY_CLOCK_RATE_2); + + clk_put(clk); +} + /* * Test that for a clock that can't modify its rate and with a single * parent, if we set a range on the parent and a more restrictive one on @@ -1062,12 +1092,52 @@ clk_test_single_parent_mux_set_range_round_rate_child_smaller(struct kunit *test clk_put(clk); } +/* + * Test that for a clock that can't modify its rate and with a single + * parent, if we set a range on the child and a more restrictive one on + * the parent, and then call clk_round_rate(), the boundaries of the + * two clocks are taken into account. + */ +static void +clk_test_single_parent_mux_set_range_round_rate_parent_smaller(struct kunit *test) +{ + struct clk_single_parent_ctx *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + struct clk *parent; + unsigned long rate; + int ret; + + parent = clk_get_parent(clk); + KUNIT_ASSERT_PTR_NE(test, parent, NULL); + + ret = clk_set_rate_range(parent, DUMMY_CLOCK_RATE_1 + 1000, DUMMY_CLOCK_RATE_2 - 1000); + KUNIT_ASSERT_EQ(test, ret, 0); + + ret = clk_set_rate_range(clk, DUMMY_CLOCK_RATE_1, DUMMY_CLOCK_RATE_2); + KUNIT_ASSERT_EQ(test, ret, 0); + + rate = clk_round_rate(clk, DUMMY_CLOCK_RATE_1 - 1000); + KUNIT_ASSERT_GT(test, rate, 0); + KUNIT_EXPECT_GE(test, rate, DUMMY_CLOCK_RATE_1 + 1000); + KUNIT_EXPECT_LE(test, rate, DUMMY_CLOCK_RATE_2 - 1000); + + rate = clk_round_rate(clk, DUMMY_CLOCK_RATE_2 + 1000); + KUNIT_ASSERT_GT(test, rate, 0); + KUNIT_EXPECT_GE(test, rate, DUMMY_CLOCK_RATE_1 + 1000); + KUNIT_EXPECT_LE(test, rate, DUMMY_CLOCK_RATE_2 - 1000); + + clk_put(clk); +} + static struct kunit_case clk_single_parent_mux_test_cases[] = { KUNIT_CASE(clk_test_single_parent_mux_get_parent), KUNIT_CASE(clk_test_single_parent_mux_has_parent), KUNIT_CASE(clk_test_single_parent_mux_set_range_disjoint_child_last), KUNIT_CASE(clk_test_single_parent_mux_set_range_disjoint_parent_last), KUNIT_CASE(clk_test_single_parent_mux_set_range_round_rate_child_smaller), + KUNIT_CASE(clk_test_single_parent_mux_set_range_round_rate_parent_only), + KUNIT_CASE(clk_test_single_parent_mux_set_range_round_rate_parent_smaller), {} }; @@ -2005,7 +2075,119 @@ static struct kunit_suite clk_range_minimize_test_suite = { .test_cases = clk_range_minimize_test_cases, }; +struct clk_leaf_mux_ctx { + struct clk_multiple_parent_ctx mux_ctx; + struct clk_hw hw; +}; + +static int +clk_leaf_mux_set_rate_parent_test_init(struct kunit *test) +{ + struct clk_leaf_mux_ctx *ctx; + const char *top_parents[2] = { "parent-0", "parent-1" }; + int ret; + + ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + test->priv = ctx; + + ctx->mux_ctx.parents_ctx[0].hw.init = CLK_HW_INIT_NO_PARENT("parent-0", + &clk_dummy_rate_ops, + 0); + ctx->mux_ctx.parents_ctx[0].rate = DUMMY_CLOCK_RATE_1; + ret = clk_hw_register(NULL, &ctx->mux_ctx.parents_ctx[0].hw); + if (ret) + return ret; + + ctx->mux_ctx.parents_ctx[1].hw.init = CLK_HW_INIT_NO_PARENT("parent-1", + &clk_dummy_rate_ops, + 0); + ctx->mux_ctx.parents_ctx[1].rate = DUMMY_CLOCK_RATE_2; + ret = clk_hw_register(NULL, &ctx->mux_ctx.parents_ctx[1].hw); + if (ret) + return ret; + + ctx->mux_ctx.current_parent = 0; + ctx->mux_ctx.hw.init = CLK_HW_INIT_PARENTS("test-mux", top_parents, + &clk_multiple_parents_mux_ops, + 0); + ret = clk_hw_register(NULL, &ctx->mux_ctx.hw); + if (ret) + return ret; + + ctx->hw.init = CLK_HW_INIT_HW("test-clock", &ctx->mux_ctx.hw, + &clk_dummy_single_parent_ops, + CLK_SET_RATE_PARENT); + ret = clk_hw_register(NULL, &ctx->hw); + if (ret) + return ret; + + return 0; +} + +static void clk_leaf_mux_set_rate_parent_test_exit(struct kunit *test) +{ + struct clk_leaf_mux_ctx *ctx = test->priv; + + clk_hw_unregister(&ctx->hw); + clk_hw_unregister(&ctx->mux_ctx.hw); + clk_hw_unregister(&ctx->mux_ctx.parents_ctx[0].hw); + clk_hw_unregister(&ctx->mux_ctx.parents_ctx[1].hw); +} + +/* + * Test that, for a clock that will forward any rate request to its + * parent, the rate request structure returned by __clk_determine_rate + * is sane and will be what we expect. + */ +static void clk_leaf_mux_set_rate_parent_determine_rate(struct kunit *test) +{ + struct clk_leaf_mux_ctx *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + struct clk_rate_request req; + unsigned long rate; + int ret; + + rate = clk_get_rate(clk); + KUNIT_ASSERT_EQ(test, rate, DUMMY_CLOCK_RATE_1); + + clk_hw_init_rate_request(hw, &req, DUMMY_CLOCK_RATE_2); + + ret = __clk_determine_rate(hw, &req); + KUNIT_ASSERT_EQ(test, ret, 0); + + KUNIT_EXPECT_EQ(test, req.rate, DUMMY_CLOCK_RATE_2); + KUNIT_EXPECT_EQ(test, req.best_parent_rate, DUMMY_CLOCK_RATE_2); + KUNIT_EXPECT_PTR_EQ(test, req.best_parent_hw, &ctx->mux_ctx.hw); + + clk_put(clk); +} + +static struct kunit_case clk_leaf_mux_set_rate_parent_test_cases[] = { + KUNIT_CASE(clk_leaf_mux_set_rate_parent_determine_rate), + {} +}; + +/* + * Test suite for a clock whose parent is a mux with multiple parents. + * The leaf clock has CLK_SET_RATE_PARENT, and will forward rate + * requests to the mux, which will then select which parent is the best + * fit for a given rate. + * + * These tests exercise the behaviour of muxes, and the proper selection + * of parents. + */ +static struct kunit_suite clk_leaf_mux_set_rate_parent_test_suite = { + .name = "clk-leaf-mux-set-rate-parent", + .init = clk_leaf_mux_set_rate_parent_test_init, + .exit = clk_leaf_mux_set_rate_parent_test_exit, + .test_cases = clk_leaf_mux_set_rate_parent_test_cases, +}; + kunit_test_suites( + &clk_leaf_mux_set_rate_parent_test_suite, &clk_test_suite, &clk_multiple_parents_mux_test_suite, &clk_orphan_transparent_multiple_parent_mux_test_suite, diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index d857717aa386..8bce6c524f29 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -65,6 +65,11 @@ struct clk_rate_request { void clk_hw_init_rate_request(const struct clk_hw *hw, struct clk_rate_request *req, unsigned long rate); +void clk_hw_forward_rate_request(const struct clk_hw *core, + const struct clk_rate_request *old_req, + const struct clk_hw *parent, + struct clk_rate_request *req, + unsigned long parent_rate); /** * struct clk_duty - Struture encoding the duty cycle ratio of a clock From b46fd8dbe8ad3fe6dcd44dcdf01a736c50d90a68 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:27 +0200 Subject: [PATCH 22/28] clk: Zero the clk_rate_request structure In order to make sure we don't carry anything over from an already existing clk_rate_request pointer we would pass to clk_core_init_rate_req(), let's zero the entire structure before initializing it. Tested-by: Alexander Stein # imx8mp Tested-by: Marek Szyprowski # exynos4210, meson g12b Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-23-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- drivers/clk/clk.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 3f60eb836980..6b358448885b 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1447,6 +1447,8 @@ static void clk_core_init_rate_req(struct clk_core * const core, if (WARN_ON(!core || !req)) return; + memset(req, 0, sizeof(*req)); + req->rate = rate; clk_core_get_boundaries(core, &req->min_rate, &req->max_rate); From 253993253466ba7187730b196174146d5247e97b Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:28 +0200 Subject: [PATCH 23/28] clk: Introduce the clk_hw_get_rate_range function Some clock providers are hand-crafting their clk_rate_request, and need to figure out the current boundaries of their clk_hw to fill it properly. Let's create such a function for clock providers. Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-24-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- drivers/clk/clk.c | 16 ++++++++++++++++ include/linux/clk-provider.h | 2 ++ 2 files changed, 18 insertions(+) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 6b358448885b..ec518dc5d462 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -684,6 +684,22 @@ static void clk_core_get_boundaries(struct clk_core *core, *max_rate = min(*max_rate, clk_user->max_rate); } +/* + * clk_hw_get_rate_range() - returns the clock rate range for a hw clk + * @hw: the hw clk we want to get the range from + * @min_rate: pointer to the variable that will hold the minimum + * @max_rate: pointer to the variable that will hold the maximum + * + * Fills the @min_rate and @max_rate variables with the minimum and + * maximum that clock can reach. + */ +void clk_hw_get_rate_range(struct clk_hw *hw, unsigned long *min_rate, + unsigned long *max_rate) +{ + clk_core_get_boundaries(hw->core, min_rate, max_rate); +} +EXPORT_SYMBOL_GPL(clk_hw_get_rate_range); + static bool clk_core_check_boundaries(struct clk_core *core, unsigned long min_rate, unsigned long max_rate) diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 8bce6c524f29..8724a3547a79 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -1267,6 +1267,8 @@ int clk_mux_determine_rate_flags(struct clk_hw *hw, struct clk_rate_request *req, unsigned long flags); void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent); +void clk_hw_get_rate_range(struct clk_hw *hw, unsigned long *min_rate, + unsigned long *max_rate); void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate, unsigned long max_rate); From af1e62f2ffe2b7fa90653f273efced0e0eabf7cc Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:29 +0200 Subject: [PATCH 24/28] clk: qcom: clk-rcg2: Take clock boundaries into consideration for gfx3d The gfx3d clock is hand-crafting its own clk_rate_request in clk_gfx3d_determine_rate to pass to the parent of that clock. However, since the clk_rate_request is zero'd at creation, it will have a max_rate of 0 which will break any code depending on the clock boundaries. That includes the recent commit 948fb0969eae ("clk: Always clamp the rounded rate") which will clamp the rate given to clk_round_rate() to the current clock boundaries. For the gfx3d clock, it means that since both the min_rate and max_rate fields are set at zero, clk_round_rate() now always return 0. Let's initialize the min_rate and max_rate fields properly for that clock. Fixes: 948fb0969eae ("clk: Always clamp the rounded rate") Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-25-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- drivers/clk/qcom/clk-rcg2.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c index 28019edd2a50..ee536b457952 100644 --- a/drivers/clk/qcom/clk-rcg2.c +++ b/drivers/clk/qcom/clk-rcg2.c @@ -908,6 +908,15 @@ static int clk_gfx3d_determine_rate(struct clk_hw *hw, req->best_parent_hw = p2; } + clk_hw_get_rate_range(req->best_parent_hw, + &parent_req.min_rate, &parent_req.max_rate); + + if (req->min_rate > parent_req.min_rate) + parent_req.min_rate = req->min_rate; + + if (req->max_rate < parent_req.max_rate) + parent_req.max_rate = req->max_rate; + ret = __clk_determine_rate(req->best_parent_hw, &parent_req); if (ret) return ret; From 433fb8a611ca2a32112668225beabda2302c9634 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:30 +0200 Subject: [PATCH 25/28] clk: tests: Add missing test case for ranges Let's add a test on the rate range after a reparenting. This fails for now, but it's worth having it to document the corner cases we don't support yet. Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-26-maxime@cerno.tech Tested-by: Naresh Kamboju Tested-by: Linux Kernel Functional Testing Signed-off-by: Stephen Boyd --- drivers/clk/clk_test.c | 53 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) diff --git a/drivers/clk/clk_test.c b/drivers/clk/clk_test.c index 3004ef368bd7..509256c5567a 100644 --- a/drivers/clk/clk_test.c +++ b/drivers/clk/clk_test.c @@ -514,9 +514,62 @@ clk_test_multiple_parents_mux_has_parent(struct kunit *test) clk_put(clk); } +/* + * Test that for a clock with a multiple parents, if we set a range on + * that clock and the parent is changed, its rate after the reparenting + * is still within the range we asked for. + * + * FIXME: clk_set_parent() only does the reparenting but doesn't + * reevaluate whether the new clock rate is within its boundaries or + * not. + */ +static void +clk_test_multiple_parents_mux_set_range_set_parent_get_rate(struct kunit *test) +{ + struct clk_multiple_parent_ctx *ctx = test->priv; + struct clk_hw *hw = &ctx->hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + struct clk *parent1, *parent2; + unsigned long rate; + int ret; + + kunit_skip(test, "This needs to be fixed in the core."); + + parent1 = clk_hw_get_clk(&ctx->parents_ctx[0].hw, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, parent1); + KUNIT_ASSERT_TRUE(test, clk_is_match(clk_get_parent(clk), parent1)); + + parent2 = clk_hw_get_clk(&ctx->parents_ctx[1].hw, NULL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, parent2); + + ret = clk_set_rate(parent1, DUMMY_CLOCK_RATE_1); + KUNIT_ASSERT_EQ(test, ret, 0); + + ret = clk_set_rate(parent2, DUMMY_CLOCK_RATE_2); + KUNIT_ASSERT_EQ(test, ret, 0); + + ret = clk_set_rate_range(clk, + DUMMY_CLOCK_RATE_1 - 1000, + DUMMY_CLOCK_RATE_1 + 1000); + KUNIT_ASSERT_EQ(test, ret, 0); + + ret = clk_set_parent(clk, parent2); + KUNIT_ASSERT_EQ(test, ret, 0); + + rate = clk_get_rate(clk); + KUNIT_ASSERT_GT(test, rate, 0); + KUNIT_EXPECT_GE(test, rate, DUMMY_CLOCK_RATE_1 - 1000); + KUNIT_EXPECT_LE(test, rate, DUMMY_CLOCK_RATE_1 + 1000); + + clk_put(parent2); + clk_put(parent1); + clk_put(clk); +} + static struct kunit_case clk_multiple_parents_mux_test_cases[] = { KUNIT_CASE(clk_test_multiple_parents_mux_get_parent), KUNIT_CASE(clk_test_multiple_parents_mux_has_parent), + KUNIT_CASE(clk_test_multiple_parents_mux_set_range_set_parent_get_rate), {} }; From 096f2a0c6469c8a8e70cfbb83345b7ada2929f13 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Mon, 10 Oct 2022 16:47:38 +0200 Subject: [PATCH 26/28] clk: Update req_rate on __clk_recalc_rates() Commit cb1b1dd96241 ("clk: Set req_rate on reparenting") introduced a new function, clk_core_update_orphan_child_rates(), that updates the req_rate field on reparenting. It turns out that that function will interfere with the clock notifying done by __clk_recalc_rates(). This ends up reporting the new rate in both the old_rate and new_rate fields of struct clk_notifier_data. Since clk_core_update_orphan_child_rates() is basically __clk_recalc_rates() without the notifiers, and with the req_rate field update, we can drop clk_core_update_orphan_child_rates() entirely, and make __clk_recalc_rates() update req_rate. However, __clk_recalc_rates() is being called in several code paths: when retrieving a rate (most likely through clk_get_rate()), when changing parents (through clk_set_rate() or clk_hw_reparent()), or when updating the orphan status (through clk_core_reparent_orphans_nolock(), called at registration). Updating req_rate on reparenting or initialisation makes sense, but we shouldn't do it on clk_get_rate(). Thus an extra flag has been added to update or not req_rate depending on the context. Fixes: cb1b1dd96241 ("clk: Set req_rate on reparenting") Link: https://lore.kernel.org/linux-clk/0acc7217-762c-7c0d-45a0-55c384824ce4@samsung.com/ Link: https://lore.kernel.org/linux-clk/Y0QNSx+ZgqKSvPOC@sirena.org.uk/ Reported-by: Marek Szyprowski Reported-by: Mark Brown Suggested-by: Stephen Boyd Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20221010-rpi-clk-fixes-again-v1-1-d87ba82ac404@cerno.tech Tested-by: Marek Szyprowski Signed-off-by: Stephen Boyd --- drivers/clk/clk.c | 39 +++++++++++---------------------------- 1 file changed, 11 insertions(+), 28 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index ec518dc5d462..47b33c5b28e1 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1760,6 +1760,7 @@ static unsigned long clk_recalc(struct clk_core *core, /** * __clk_recalc_rates * @core: first clk in the subtree + * @update_req: Whether req_rate should be updated with the new rate * @msg: notification type (see include/linux/clk.h) * * Walks the subtree of clks starting with clk and recalculates rates as it @@ -1769,7 +1770,8 @@ static unsigned long clk_recalc(struct clk_core *core, * clk_recalc_rates also propagates the POST_RATE_CHANGE notification, * if necessary. */ -static void __clk_recalc_rates(struct clk_core *core, unsigned long msg) +static void __clk_recalc_rates(struct clk_core *core, bool update_req, + unsigned long msg) { unsigned long old_rate; unsigned long parent_rate = 0; @@ -1783,6 +1785,8 @@ static void __clk_recalc_rates(struct clk_core *core, unsigned long msg) parent_rate = core->parent->rate; core->rate = clk_recalc(core, parent_rate); + if (update_req) + core->req_rate = core->rate; /* * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE @@ -1792,13 +1796,13 @@ static void __clk_recalc_rates(struct clk_core *core, unsigned long msg) __clk_notify(core, msg, old_rate, core->rate); hlist_for_each_entry(child, &core->children, child_node) - __clk_recalc_rates(child, msg); + __clk_recalc_rates(child, update_req, msg); } static unsigned long clk_core_get_rate_recalc(struct clk_core *core) { if (core && (core->flags & CLK_GET_RATE_NOCACHE)) - __clk_recalc_rates(core, 0); + __clk_recalc_rates(core, false, 0); return clk_core_get_rate_nolock(core); } @@ -1901,23 +1905,6 @@ static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan) clk_core_update_orphan_status(child, is_orphan); } -/* - * Update the orphan rate and req_rate of @core and all its children. - */ -static void clk_core_update_orphan_child_rates(struct clk_core *core) -{ - struct clk_core *child; - unsigned long parent_rate = 0; - - if (core->parent) - parent_rate = core->parent->rate; - - core->rate = core->req_rate = clk_recalc(core, parent_rate); - - hlist_for_each_entry(child, &core->children, child_node) - clk_core_update_orphan_child_rates(child); -} - static void clk_reparent(struct clk_core *core, struct clk_core *new_parent) { bool was_orphan = core->orphan; @@ -1987,8 +1974,6 @@ static struct clk_core *__clk_set_parent_before(struct clk_core *core, clk_reparent(core, parent); clk_enable_unlock(flags); - clk_core_update_orphan_child_rates(core); - return old_parent; } @@ -2034,7 +2019,6 @@ static int __clk_set_parent(struct clk_core *core, struct clk_core *parent, clk_reparent(core, old_parent); clk_enable_unlock(flags); - clk_core_update_orphan_child_rates(core); __clk_set_parent_after(core, old_parent, parent); return ret; @@ -2658,9 +2642,8 @@ static void clk_core_reparent(struct clk_core *core, struct clk_core *new_parent) { clk_reparent(core, new_parent); - clk_core_update_orphan_child_rates(core); __clk_recalc_accuracies(core); - __clk_recalc_rates(core, POST_RATE_CHANGE); + __clk_recalc_rates(core, true, POST_RATE_CHANGE); } void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent) @@ -2744,9 +2727,9 @@ static int clk_core_set_parent_nolock(struct clk_core *core, /* propagate rate an accuracy recalculation accordingly */ if (ret) { - __clk_recalc_rates(core, ABORT_RATE_CHANGE); + __clk_recalc_rates(core, true, ABORT_RATE_CHANGE); } else { - __clk_recalc_rates(core, POST_RATE_CHANGE); + __clk_recalc_rates(core, true, POST_RATE_CHANGE); __clk_recalc_accuracies(core); } @@ -3643,7 +3626,7 @@ static void clk_core_reparent_orphans_nolock(void) __clk_set_parent_before(orphan, parent); __clk_set_parent_after(orphan, parent, NULL); __clk_recalc_accuracies(orphan); - __clk_recalc_rates(orphan, 0); + __clk_recalc_rates(orphan, true, 0); /* * __clk_init_parent() will set the initial req_rate to From 589a2004881f0941ca46146a5de68b3666d1d54a Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Mon, 10 Oct 2022 16:47:39 +0200 Subject: [PATCH 27/28] clk: tests: Add tests for notifiers We're recently encountered a regression due to the rates reported through the clk_notifier_data being off when changing parents. Let's add a test suite and a test to make sure that we do get notified and with the proper rates. Suggested-by: Stephen Boyd Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20221010-rpi-clk-fixes-again-v1-2-d87ba82ac404@cerno.tech Tested-by: Marek Szyprowski Signed-off-by: Stephen Boyd --- drivers/clk/clk_test.c | 156 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 156 insertions(+) diff --git a/drivers/clk/clk_test.c b/drivers/clk/clk_test.c index 509256c5567a..f9a5c2964c65 100644 --- a/drivers/clk/clk_test.c +++ b/drivers/clk/clk_test.c @@ -2239,10 +2239,166 @@ static struct kunit_suite clk_leaf_mux_set_rate_parent_test_suite = { .test_cases = clk_leaf_mux_set_rate_parent_test_cases, }; +struct clk_mux_notifier_rate_change { + bool done; + unsigned long old_rate; + unsigned long new_rate; + wait_queue_head_t wq; +}; + +struct clk_mux_notifier_ctx { + struct clk_multiple_parent_ctx mux_ctx; + struct clk *clk; + struct notifier_block clk_nb; + struct clk_mux_notifier_rate_change pre_rate_change; + struct clk_mux_notifier_rate_change post_rate_change; +}; + +#define NOTIFIER_TIMEOUT_MS 100 + +static int clk_mux_notifier_callback(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct clk_notifier_data *clk_data = data; + struct clk_mux_notifier_ctx *ctx = container_of(nb, + struct clk_mux_notifier_ctx, + clk_nb); + + if (action & PRE_RATE_CHANGE) { + ctx->pre_rate_change.old_rate = clk_data->old_rate; + ctx->pre_rate_change.new_rate = clk_data->new_rate; + ctx->pre_rate_change.done = true; + wake_up_interruptible(&ctx->pre_rate_change.wq); + } + + if (action & POST_RATE_CHANGE) { + ctx->post_rate_change.old_rate = clk_data->old_rate; + ctx->post_rate_change.new_rate = clk_data->new_rate; + ctx->post_rate_change.done = true; + wake_up_interruptible(&ctx->post_rate_change.wq); + } + + return 0; +} + +static int clk_mux_notifier_test_init(struct kunit *test) +{ + struct clk_mux_notifier_ctx *ctx; + const char *top_parents[2] = { "parent-0", "parent-1" }; + int ret; + + ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + test->priv = ctx; + ctx->clk_nb.notifier_call = clk_mux_notifier_callback; + init_waitqueue_head(&ctx->pre_rate_change.wq); + init_waitqueue_head(&ctx->post_rate_change.wq); + + ctx->mux_ctx.parents_ctx[0].hw.init = CLK_HW_INIT_NO_PARENT("parent-0", + &clk_dummy_rate_ops, + 0); + ctx->mux_ctx.parents_ctx[0].rate = DUMMY_CLOCK_RATE_1; + ret = clk_hw_register(NULL, &ctx->mux_ctx.parents_ctx[0].hw); + if (ret) + return ret; + + ctx->mux_ctx.parents_ctx[1].hw.init = CLK_HW_INIT_NO_PARENT("parent-1", + &clk_dummy_rate_ops, + 0); + ctx->mux_ctx.parents_ctx[1].rate = DUMMY_CLOCK_RATE_2; + ret = clk_hw_register(NULL, &ctx->mux_ctx.parents_ctx[1].hw); + if (ret) + return ret; + + ctx->mux_ctx.current_parent = 0; + ctx->mux_ctx.hw.init = CLK_HW_INIT_PARENTS("test-mux", top_parents, + &clk_multiple_parents_mux_ops, + 0); + ret = clk_hw_register(NULL, &ctx->mux_ctx.hw); + if (ret) + return ret; + + ctx->clk = clk_hw_get_clk(&ctx->mux_ctx.hw, NULL); + ret = clk_notifier_register(ctx->clk, &ctx->clk_nb); + if (ret) + return ret; + + return 0; +} + +static void clk_mux_notifier_test_exit(struct kunit *test) +{ + struct clk_mux_notifier_ctx *ctx = test->priv; + struct clk *clk = ctx->clk; + + clk_notifier_unregister(clk, &ctx->clk_nb); + clk_put(clk); + + clk_hw_unregister(&ctx->mux_ctx.hw); + clk_hw_unregister(&ctx->mux_ctx.parents_ctx[0].hw); + clk_hw_unregister(&ctx->mux_ctx.parents_ctx[1].hw); +} + +/* + * Test that if the we have a notifier registered on a mux, the core + * will notify us when we switch to another parent, and with the proper + * old and new rates. + */ +static void clk_mux_notifier_set_parent_test(struct kunit *test) +{ + struct clk_mux_notifier_ctx *ctx = test->priv; + struct clk_hw *hw = &ctx->mux_ctx.hw; + struct clk *clk = clk_hw_get_clk(hw, NULL); + struct clk *new_parent = clk_hw_get_clk(&ctx->mux_ctx.parents_ctx[1].hw, NULL); + int ret; + + ret = clk_set_parent(clk, new_parent); + KUNIT_ASSERT_EQ(test, ret, 0); + + ret = wait_event_interruptible_timeout(ctx->pre_rate_change.wq, + ctx->pre_rate_change.done, + msecs_to_jiffies(NOTIFIER_TIMEOUT_MS)); + KUNIT_ASSERT_GT(test, ret, 0); + + KUNIT_EXPECT_EQ(test, ctx->pre_rate_change.old_rate, DUMMY_CLOCK_RATE_1); + KUNIT_EXPECT_EQ(test, ctx->pre_rate_change.new_rate, DUMMY_CLOCK_RATE_2); + + ret = wait_event_interruptible_timeout(ctx->post_rate_change.wq, + ctx->post_rate_change.done, + msecs_to_jiffies(NOTIFIER_TIMEOUT_MS)); + KUNIT_ASSERT_GT(test, ret, 0); + + KUNIT_EXPECT_EQ(test, ctx->post_rate_change.old_rate, DUMMY_CLOCK_RATE_1); + KUNIT_EXPECT_EQ(test, ctx->post_rate_change.new_rate, DUMMY_CLOCK_RATE_2); + + clk_put(new_parent); + clk_put(clk); +} + +static struct kunit_case clk_mux_notifier_test_cases[] = { + KUNIT_CASE(clk_mux_notifier_set_parent_test), + {} +}; + +/* + * Test suite for a mux with multiple parents, and a notifier registered + * on the mux. + * + * These tests exercise the behaviour of notifiers. + */ +static struct kunit_suite clk_mux_notifier_test_suite = { + .name = "clk-mux-notifier", + .init = clk_mux_notifier_test_init, + .exit = clk_mux_notifier_test_exit, + .test_cases = clk_mux_notifier_test_cases, +}; + kunit_test_suites( &clk_leaf_mux_set_rate_parent_test_suite, &clk_test_suite, &clk_multiple_parents_mux_test_suite, + &clk_mux_notifier_test_suite, &clk_orphan_transparent_multiple_parent_mux_test_suite, &clk_orphan_transparent_single_parent_test_suite, &clk_orphan_two_level_root_last_test_suite, From b05ea3314390e9cb3c27cf2928d48e38fef97050 Mon Sep 17 00:00:00 2001 From: AngeloGioacchino Del Regno Date: Tue, 11 Oct 2022 15:55:48 +0200 Subject: [PATCH 28/28] clk: mediatek: clk-mux: Add .determine_rate() callback Since commit 262ca38f4b6e ("clk: Stop forwarding clk_rate_requests to the parent"), the clk_rate_request is .. as the title says, not forwarded anymore to the parent: this produces an issue with the MediaTek clock MUX driver during GPU DVFS on MT8195, but not on MT8192 or others. This is because, differently from others, like MT8192 where all of the clocks in the MFG parents tree are of mtk_mux type, but in the parent tree of MT8195's MFG clock, we have one mtk_mux clock and one (clk framework generic) mux clock, like so: names: mfg_bg3d -> mfg_ck_fast_ref -> top_mfg_core_tmp (or) mfgpll types: mtk_gate -> mux -> mtk_mux (or) mtk_pll To solve this issue and also keep the GPU DVFS clocks code working as expected, wire up a .determine_rate() callback for the mtk_mux ops; for that, the standard clk_mux_determine_rate_flags() was used as it was possible to. This commit was successfully tested on MT6795 Xperia M5, MT8173 Elm, MT8192 Spherion and MT8195 Tomato; no regressions were seen. For the sake of some more documentation about this issue here's the trace of it: [ 12.211587] ------------[ cut here ]------------ [ 12.211589] WARNING: CPU: 6 PID: 78 at drivers/clk/clk.c:1462 clk_core_init_rate_req+0x84/0x90 [ 12.211593] Modules linked in: stp crct10dif_ce mtk_adsp_common llc rfkill snd_sof_xtensa_dsp panfrost(+) sbs_battery cros_ec_lid_angle cros_ec_sensors snd_sof_of cros_ec_sensors_core hid_multitouch cros_usbpd_logger snd_sof gpu_sched snd_sof_utils fuse ipv6 [ 12.211614] CPU: 6 PID: 78 Comm: kworker/u16:2 Tainted: G W 6.0.0-next-20221011+ #58 [ 12.211616] Hardware name: Acer Tomato (rev2) board (DT) [ 12.211617] Workqueue: devfreq_wq devfreq_monitor [ 12.211620] pstate: 40400009 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 12.211622] pc : clk_core_init_rate_req+0x84/0x90 [ 12.211625] lr : clk_core_forward_rate_req+0xa4/0xe4 [ 12.211627] sp : ffff80000893b8e0 [ 12.211628] x29: ffff80000893b8e0 x28: ffffdddf92f9b000 x27: ffff46a2c0e8bc05 [ 12.211632] x26: ffff46a2c1041200 x25: 0000000000000000 x24: 00000000173eed80 [ 12.211636] x23: ffff80000893b9c0 x22: ffff80000893b940 x21: 0000000000000000 [ 12.211641] x20: ffff46a2c1039f00 x19: ffff46a2c1039f00 x18: 0000000000000000 [ 12.211645] x17: 0000000000000038 x16: 000000000000d904 x15: 0000000000000003 [ 12.211649] x14: ffffdddf9357ce48 x13: ffffdddf935e71c8 x12: 000000000004803c [ 12.211653] x11: 00000000a867d7ad x10: 00000000a867d7ad x9 : ffffdddf90c28df4 [ 12.211657] x8 : ffffdddf9357a980 x7 : 0000000000000000 x6 : 0000000000000004 [ 12.211661] x5 : ffffffffffffffc8 x4 : 00000000173eed80 x3 : ffff80000893b940 [ 12.211665] x2 : 00000000173eed80 x1 : ffff80000893b940 x0 : 0000000000000000 [ 12.211669] Call trace: [ 12.211670] clk_core_init_rate_req+0x84/0x90 [ 12.211673] clk_core_round_rate_nolock+0xe8/0x10c [ 12.211675] clk_mux_determine_rate_flags+0x174/0x1f0 [ 12.211677] clk_mux_determine_rate+0x1c/0x30 [ 12.211680] clk_core_determine_round_nolock+0x74/0x130 [ 12.211682] clk_core_round_rate_nolock+0x58/0x10c [ 12.211684] clk_core_round_rate_nolock+0xf4/0x10c [ 12.211686] clk_core_set_rate_nolock+0x194/0x2ac [ 12.211688] clk_set_rate+0x40/0x94 [ 12.211691] _opp_config_clk_single+0x38/0xa0 [ 12.211693] _set_opp+0x1b0/0x500 [ 12.211695] dev_pm_opp_set_rate+0x120/0x290 [ 12.211697] panfrost_devfreq_target+0x3c/0x50 [panfrost] [ 12.211705] devfreq_set_target+0x8c/0x2d0 [ 12.211707] devfreq_update_target+0xcc/0xf4 [ 12.211708] devfreq_monitor+0x40/0x1d0 [ 12.211710] process_one_work+0x294/0x664 [ 12.211712] worker_thread+0x7c/0x45c [ 12.211713] kthread+0x104/0x110 [ 12.211716] ret_from_fork+0x10/0x20 [ 12.211718] irq event stamp: 7102 [ 12.211719] hardirqs last enabled at (7101): [] finish_task_switch.isra.0+0xec/0x2f0 [ 12.211723] hardirqs last disabled at (7102): [] el1_dbg+0x24/0x90 [ 12.211726] softirqs last enabled at (6716): [] __do_softirq+0x414/0x588 [ 12.211728] softirqs last disabled at (6507): [] ____do_softirq+0x18/0x24 [ 12.211730] ---[ end trace 0000000000000000 ]--- Fixes: 262ca38f4b6e ("clk: Stop forwarding clk_rate_requests to the parent") Signed-off-by: AngeloGioacchino Del Regno Link: https://lore.kernel.org/r/20221011135548.318323-1-angelogioacchino.delregno@collabora.com Signed-off-by: Stephen Boyd --- drivers/clk/mediatek/clk-mux.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/clk/mediatek/clk-mux.c b/drivers/clk/mediatek/clk-mux.c index cd5f9fd8cb98..5d217f7377ee 100644 --- a/drivers/clk/mediatek/clk-mux.c +++ b/drivers/clk/mediatek/clk-mux.c @@ -128,9 +128,18 @@ static int mtk_clk_mux_set_parent_setclr_lock(struct clk_hw *hw, u8 index) return 0; } +static int mtk_clk_mux_determine_rate(struct clk_hw *hw, + struct clk_rate_request *req) +{ + struct mtk_clk_mux *mux = to_mtk_clk_mux(hw); + + return clk_mux_determine_rate_flags(hw, req, mux->data->flags); +} + const struct clk_ops mtk_mux_clr_set_upd_ops = { .get_parent = mtk_clk_mux_get_parent, .set_parent = mtk_clk_mux_set_parent_setclr_lock, + .determine_rate = mtk_clk_mux_determine_rate, }; EXPORT_SYMBOL_GPL(mtk_mux_clr_set_upd_ops); @@ -140,6 +149,7 @@ const struct clk_ops mtk_mux_gate_clr_set_upd_ops = { .is_enabled = mtk_clk_mux_is_enabled, .get_parent = mtk_clk_mux_get_parent, .set_parent = mtk_clk_mux_set_parent_setclr_lock, + .determine_rate = mtk_clk_mux_determine_rate, }; EXPORT_SYMBOL_GPL(mtk_mux_gate_clr_set_upd_ops);