From 6479450f72c1391c03f08affe0d0110f41ae7ca0 Mon Sep 17 00:00:00 2001
From: Heyi Guo <guoheyi@huawei.com>
Date: Thu, 24 Jan 2019 21:37:08 +0800
Subject: [PATCH 1/5] irqchip/gic-v4: Fix occasional VLPI drop
1. In current implementation, every VLPI will temporarily be mapped to
the first CPU in system (normally CPU0) and then moved to the real
scheduled CPU later.
2. So there is a time window and a VLPI may be sent to CPU0 instead of
the real scheduled vCPU, in a multi-CPU virtual machine.
3. However, CPU0 may have not been scheduled as a virtual CPU after
system boots up, so the value of its GICR_VPROPBASER is unknown at
that moment.
4. If the INTID of VLPI is larger than 2^(GICR_VPROPBASER.IDbits+1),
while IDbits is also in unknown state, GIC will behave as if the VLPI
is out of range and simply drop it, which results in interrupt missing
in Guest.
As no code will clear GICR_VPROPBASER at runtime, we can safely
initialize the IDbits field at boot time for each CPU to get rid of
this issue.
We also clear Valid bit of GICR_VPENDBASER in case any ancient
programming gets left in and causes memory corrupting. A new function
its_clear_vpend_valid() is added to reuse the code in
its_vpe_deschedule().
Fixes: e643d8034036 ("irqchip/gic-v3-its: Add VPE scheduling")
Signed-off-by: Heyi Guo <guoheyi@huawei.com>
Signed-off-by: Heyi Guo <heyi.guo@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
drivers/irqchip/irq-gic-v3-its.c | 66 ++++++++++++++++++++++++--------
1 file changed, 49 insertions(+), 17 deletions(-)
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 7f2a45445b00..36181197d5e0 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -2059,6 +2059,29 @@ static int __init allocate_lpi_tables(void)
return 0;
}
+static u64 its_clear_vpend_valid(void __iomem *vlpi_base)
+{
+ u32 count = 1000000; /* 1s! */
+ bool clean;
+ u64 val;
+
+ val = gits_read_vpendbaser(vlpi_base + GICR_VPENDBASER);
+ val &= ~GICR_VPENDBASER_Valid;
+ gits_write_vpendbaser(val, vlpi_base + GICR_VPENDBASER);
+
+ do {
+ val = gits_read_vpendbaser(vlpi_base + GICR_VPENDBASER);
+ clean = !(val & GICR_VPENDBASER_Dirty);
+ if (!clean) {
+ count--;
+ cpu_relax();
+ udelay(1);
+ }
+ } while (!clean && count);
+
+ return val;
+}
+
static void its_cpu_init_lpis(void)
{
void __iomem *rbase = gic_data_rdist_rd_base();
@@ -2144,6 +2167,30 @@ static void its_cpu_init_lpis(void)
val |= GICR_CTLR_ENABLE_LPIS;
writel_relaxed(val, rbase + GICR_CTLR);
+ if (gic_rdists->has_vlpis) {
+ void __iomem *vlpi_base = gic_data_rdist_vlpi_base();
+
+ /*
+ * It's possible for CPU to receive VLPIs before it is
+ * sheduled as a vPE, especially for the first CPU, and the
+ * VLPI with INTID larger than 2^(IDbits+1) will be considered
+ * as out of range and dropped by GIC.
+ * So we initialize IDbits to known value to avoid VLPI drop.
+ */
+ val = (LPI_NRBITS - 1) & GICR_VPROPBASER_IDBITS_MASK;
+ pr_debug("GICv4: CPU%d: Init IDbits to 0x%llx for GICR_VPROPBASER\n",
+ smp_processor_id(), val);
+ gits_write_vpropbaser(val, vlpi_base + GICR_VPROPBASER);
+
+ /*
+ * Also clear Valid bit of GICR_VPENDBASER, in case some
+ * ancient programming gets left in and has possibility of
+ * corrupting memory.
+ */
+ val = its_clear_vpend_valid(vlpi_base);
+ WARN_ON(val & GICR_VPENDBASER_Dirty);
+ }
+
/* Make sure the GIC has seen the above */
dsb(sy);
out:
@@ -2755,26 +2802,11 @@ static void its_vpe_schedule(struct its_vpe *vpe)
static void its_vpe_deschedule(struct its_vpe *vpe)
{
void __iomem *vlpi_base = gic_data_rdist_vlpi_base();
- u32 count = 1000000; /* 1s! */
- bool clean;
u64 val;
- /* We're being scheduled out */
- val = gits_read_vpendbaser(vlpi_base + GICR_VPENDBASER);
- val &= ~GICR_VPENDBASER_Valid;
- gits_write_vpendbaser(val, vlpi_base + GICR_VPENDBASER);
+ val = its_clear_vpend_valid(vlpi_base);
- do {
- val = gits_read_vpendbaser(vlpi_base + GICR_VPENDBASER);
- clean = !(val & GICR_VPENDBASER_Dirty);
- if (!clean) {
- count--;
- cpu_relax();
- udelay(1);
- }
- } while (!clean && count);
-
- if (unlikely(!clean && !count)) {
+ if (unlikely(val & GICR_VPENDBASER_Dirty)) {
pr_err_ratelimited("ITS virtual pending table not cleaning\n");
vpe->idai = false;
vpe->pending_last = true;
From 9791ec7df0e7b4d80706ccea8f24b6542f6059e9 Mon Sep 17 00:00:00 2001
From: Marc Zyngier <marc.zyngier@arm.com>
Date: Tue, 29 Jan 2019 10:02:33 +0000
Subject: [PATCH 2/5] irqchip/gic-v3-its: Plug allocation race for devices
sharing a DevID
On systems or VMs where multiple devices share a single DevID
(because they sit behind a PCI bridge, or because the HW is
broken in funky ways), we reuse the save its_device structure
in order to reflect this.
It turns out that there is a distinct lack of locking when looking
up the its_device, and two device being probed concurrently can result
in double allocations. That's obviously not nice.
A solution for this is to have a per-ITS mutex that serializes device
allocation.
A similar issue exists on the freeing side, which can run concurrently
with the allocation. On top of now taking the appropriate lock, we
also make sure that a shared device is never freed, as we have no way
to currently track the life cycle of such object.
Reported-by: Zheng Xiang <zhengxiang9@huawei.com>
Tested-by: Zheng Xiang <zhengxiang9@huawei.com>
Cc: stable@vger.kernel.org
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
drivers/irqchip/irq-gic-v3-its.c | 32 +++++++++++++++++++++++++++-----
1 file changed, 27 insertions(+), 5 deletions(-)
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 36181197d5e0..f25ec92f23ee 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -97,9 +97,14 @@ struct its_device;
* The ITS structure - contains most of the infrastructure, with the
* top-level MSI domain, the command queue, the collections, and the
* list of devices writing to it.
+ *
+ * dev_alloc_lock has to be taken for device allocations, while the
+ * spinlock must be taken to parse data structures such as the device
+ * list.
*/
struct its_node {
raw_spinlock_t lock;
+ struct mutex dev_alloc_lock;
struct list_head entry;
void __iomem *base;
phys_addr_t phys_base;
@@ -156,6 +161,7 @@ struct its_device {
void *itt;
u32 nr_ites;
u32 device_id;
+ bool shared;
};
static struct {
@@ -2469,6 +2475,7 @@ static int its_msi_prepare(struct irq_domain *domain, struct device *dev,
struct its_device *its_dev;
struct msi_domain_info *msi_info;
u32 dev_id;
+ int err = 0;
/*
* We ignore "dev" entierely, and rely on the dev_id that has
@@ -2491,6 +2498,7 @@ static int its_msi_prepare(struct irq_domain *domain, struct device *dev,
return -EINVAL;
}
+ mutex_lock(&its->dev_alloc_lock);
its_dev = its_find_device(its, dev_id);
if (its_dev) {
/*
@@ -2498,18 +2506,22 @@ static int its_msi_prepare(struct irq_domain *domain, struct device *dev,
* another alias (PCI bridge of some sort). No need to
* create the device.
*/
+ its_dev->shared = true;
pr_debug("Reusing ITT for devID %x\n", dev_id);
goto out;
}
its_dev = its_create_device(its, dev_id, nvec, true);
- if (!its_dev)
- return -ENOMEM;
+ if (!its_dev) {
+ err = -ENOMEM;
+ goto out;
+ }
pr_debug("ITT %d entries, %d bits\n", nvec, ilog2(nvec));
out:
+ mutex_unlock(&its->dev_alloc_lock);
info->scratchpad[0].ptr = its_dev;
- return 0;
+ return err;
}
static struct msi_domain_ops its_msi_domain_ops = {
@@ -2613,6 +2625,7 @@ static void its_irq_domain_free(struct irq_domain *domain, unsigned int virq,
{
struct irq_data *d = irq_domain_get_irq_data(domain, virq);
struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+ struct its_node *its = its_dev->its;
int i;
for (i = 0; i < nr_irqs; i++) {
@@ -2627,8 +2640,14 @@ static void its_irq_domain_free(struct irq_domain *domain, unsigned int virq,
irq_domain_reset_irq_data(data);
}
- /* If all interrupts have been freed, start mopping the floor */
- if (bitmap_empty(its_dev->event_map.lpi_map,
+ mutex_lock(&its->dev_alloc_lock);
+
+ /*
+ * If all interrupts have been freed, start mopping the
+ * floor. This is conditionned on the device not being shared.
+ */
+ if (!its_dev->shared &&
+ bitmap_empty(its_dev->event_map.lpi_map,
its_dev->event_map.nr_lpis)) {
its_lpi_free(its_dev->event_map.lpi_map,
its_dev->event_map.lpi_base,
@@ -2640,6 +2659,8 @@ static void its_irq_domain_free(struct irq_domain *domain, unsigned int virq,
its_free_device(its_dev);
}
+ mutex_unlock(&its->dev_alloc_lock);
+
irq_domain_free_irqs_parent(domain, virq, nr_irqs);
}
@@ -3549,6 +3570,7 @@ static int __init its_probe_one(struct resource *res,
}
raw_spin_lock_init(&its->lock);
+ mutex_init(&its->dev_alloc_lock);
INIT_LIST_HEAD(&its->entry);
INIT_LIST_HEAD(&its->its_device_list);
typer = gic_read_typer(its_base + GITS_TYPER);
From 45725e0fc3e7fe52fedb94f59806ec50e9618682 Mon Sep 17 00:00:00 2001
From: Marc Zyngier <marc.zyngier@arm.com>
Date: Tue, 29 Jan 2019 15:19:23 +0000
Subject: [PATCH 3/5] irqchip/gic-v3-its: Gracefully fail on LPI exhaustion
In the unlikely event that we cannot find any available LPI in the
system, we should gracefully return an error instead of carrying
on with no LPI allocated at all.
Fixes: 38dd7c494cf6 ("irqchip/gic-v3-its: Drop chunk allocation compatibility")
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
drivers/irqchip/irq-gic-v3-its.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index f25ec92f23ee..c3aba3fc818d 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -1586,6 +1586,9 @@ static unsigned long *its_lpi_alloc(int nr_irqs, u32 *base, int *nr_ids)
nr_irqs /= 2;
} while (nr_irqs > 0);
+ if (!nr_irqs)
+ err = -ENOSPC;
+
if (err)
goto out;
From 2380a22b60ce6f995eac806e69c66e397b59d045 Mon Sep 17 00:00:00 2001
From: Lubomir Rintel <lkundrak@v3.sk>
Date: Mon, 28 Jan 2019 16:59:35 +0100
Subject: [PATCH 4/5] irqchip/mmp: Only touch the PJ4 IRQ & FIQ bits on
enable/disable
Resetting bit 4 disables the interrupt delivery to the "secure
processor" core. This breaks the keyboard on a OLPC XO 1.75 laptop,
where the firmware running on the "secure processor" bit-bangs the
PS/2 protocol over the GPIO lines.
It is not clear what the rest of the bits are and Marvell was unhelpful
when asked for documentation. Aside from the SP bit, there are probably
priority bits.
Leaving the unknown bits as the firmware set them up seems to be a wiser
course of action compared to just turning them off.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Pavel Machek <pavel@ucw.cz>
[maz: fixed-up subject and commit message]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
drivers/irqchip/irq-mmp.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/irqchip/irq-mmp.c b/drivers/irqchip/irq-mmp.c
index 25f32e1d7764..3496b61a312a 100644
--- a/drivers/irqchip/irq-mmp.c
+++ b/drivers/irqchip/irq-mmp.c
@@ -34,6 +34,9 @@
#define SEL_INT_PENDING (1 << 6)
#define SEL_INT_NUM_MASK 0x3f
+#define MMP2_ICU_INT_ROUTE_PJ4_IRQ (1 << 5)
+#define MMP2_ICU_INT_ROUTE_PJ4_FIQ (1 << 6)
+
struct icu_chip_data {
int nr_irqs;
unsigned int virq_base;
@@ -190,7 +193,8 @@ static const struct mmp_intc_conf mmp_conf = {
static const struct mmp_intc_conf mmp2_conf = {
.conf_enable = 0x20,
.conf_disable = 0x0,
- .conf_mask = 0x7f,
+ .conf_mask = MMP2_ICU_INT_ROUTE_PJ4_IRQ |
+ MMP2_ICU_INT_ROUTE_PJ4_FIQ,
};
static void __exception_irq_entry mmp_handle_irq(struct pt_regs *regs)
From 56841070ccc87b463ac037d2d1f2beb8e5e35f0c Mon Sep 17 00:00:00 2001
From: Zenghui Yu <yuzenghui@huawei.com>
Date: Thu, 31 Jan 2019 11:19:43 +0000
Subject: [PATCH 5/5] irqchip/gic-v3-its: Fix ITT_entry_size accessor
According to ARM IHI 0069C (ID070116), we should use GITS_TYPER's
bits [7:4] as ITT_entry_size instead of [8:4]. Although this is
pretty annoying, it only results in a potential over-allocation
of memory, and nothing bad happens.
Fixes: 3dfa576bfb45 ("irqchip/gic-v3-its: Add probing for VLPI properties")
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
[maz: massaged subject and commit message]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
include/linux/irqchip/arm-gic-v3.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index 071b4cbdf010..c848a7cc502e 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -319,7 +319,7 @@
#define GITS_TYPER_PLPIS (1UL << 0)
#define GITS_TYPER_VLPIS (1UL << 1)
#define GITS_TYPER_ITT_ENTRY_SIZE_SHIFT 4
-#define GITS_TYPER_ITT_ENTRY_SIZE(r) ((((r) >> GITS_TYPER_ITT_ENTRY_SIZE_SHIFT) & 0x1f) + 1)
+#define GITS_TYPER_ITT_ENTRY_SIZE(r) ((((r) >> GITS_TYPER_ITT_ENTRY_SIZE_SHIFT) & 0xf) + 1)
#define GITS_TYPER_IDBITS_SHIFT 8
#define GITS_TYPER_DEVBITS_SHIFT 13
#define GITS_TYPER_DEVBITS(r) ((((r) >> GITS_TYPER_DEVBITS_SHIFT) & 0x1f) + 1)