forked from Minki/linux
e40b0c1628
I've been pouring through the rpmh-rsc code and trying to understand it. Document everything to the best of my ability. All documentation here is strictly from code analysis--no actual knowledge of the hardware was used. If something is wrong in here I either misunderstood the code, had a typo, or the code has a bug in it leading to my incorrect understanding. In a few places here I have documented things that don't make tons of sense. A future patch will try to address this. While this means I'm adding comments / todos and then later fixing them in the series, it seemed more urgent to get things documented first so that people could understand the later patches. Any comments I adjusted I also tried to make match kernel-doc better. Specifically: - kernel-doc says do not leave a blank line between the function description and the arguments - kernel-doc examples always have things starting w/ a capital and ending with a period. This should be a no-op. It's just comment changes. Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Maulik Shah <mkshah@codeaurora.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/20200413100321.v4.6.I52653eb85d7dc8981ee0dafcd0b6cc0f273e9425@changeid Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
141 lines
4.9 KiB
C
141 lines
4.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright (c) 2016-2018, The Linux Foundation. All rights reserved.
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*/
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#ifndef __RPM_INTERNAL_H__
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#define __RPM_INTERNAL_H__
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#include <linux/bitmap.h>
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#include <soc/qcom/tcs.h>
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#define TCS_TYPE_NR 4
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#define MAX_CMDS_PER_TCS 16
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#define MAX_TCS_PER_TYPE 3
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#define MAX_TCS_NR (MAX_TCS_PER_TYPE * TCS_TYPE_NR)
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#define MAX_TCS_SLOTS (MAX_CMDS_PER_TCS * MAX_TCS_PER_TYPE)
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struct rsc_drv;
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/**
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* struct tcs_group: group of Trigger Command Sets (TCS) to send state requests
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* to the controller
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*
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* @drv: The controller.
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* @type: Type of the TCS in this group - active, sleep, wake.
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* @mask: Mask of the TCSes relative to all the TCSes in the RSC.
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* @offset: Start of the TCS group relative to the TCSes in the RSC.
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* @num_tcs: Number of TCSes in this type.
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* @ncpt: Number of commands in each TCS.
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* @lock: Lock for synchronizing this TCS writes.
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* @req: Requests that are sent from the TCS; only used for ACTIVE_ONLY
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* transfers (could be on a wake/sleep TCS if we are borrowing for
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* an ACTIVE_ONLY transfer).
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* Start: grab drv->lock, set req, set tcs_in_use, drop drv->lock,
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* trigger
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* End: get irq, access req,
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* grab drv->lock, clear tcs_in_use, drop drv->lock
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* @slots: Indicates which of @cmd_addr are occupied; only used for
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* SLEEP / WAKE TCSs. Things are tightly packed in the
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* case that (ncpt < MAX_CMDS_PER_TCS). That is if ncpt = 2 and
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* MAX_CMDS_PER_TCS = 16 then bit[2] = the first bit in 2nd TCS.
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*/
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struct tcs_group {
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struct rsc_drv *drv;
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int type;
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u32 mask;
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u32 offset;
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int num_tcs;
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int ncpt;
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spinlock_t lock;
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const struct tcs_request *req[MAX_TCS_PER_TYPE];
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DECLARE_BITMAP(slots, MAX_TCS_SLOTS);
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};
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/**
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* struct rpmh_request: the message to be sent to rpmh-rsc
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*
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* @msg: the request
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* @cmd: the payload that will be part of the @msg
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* @completion: triggered when request is done
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* @dev: the device making the request
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* @err: err return from the controller
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* @needs_free: check to free dynamically allocated request object
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*/
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struct rpmh_request {
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struct tcs_request msg;
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struct tcs_cmd cmd[MAX_RPMH_PAYLOAD];
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struct completion *completion;
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const struct device *dev;
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int err;
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bool needs_free;
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};
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/**
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* struct rpmh_ctrlr: our representation of the controller
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*
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* @cache: the list of cached requests
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* @cache_lock: synchronize access to the cache data
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* @dirty: was the cache updated since flush
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* @batch_cache: Cache sleep and wake requests sent as batch
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*/
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struct rpmh_ctrlr {
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struct list_head cache;
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spinlock_t cache_lock;
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bool dirty;
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struct list_head batch_cache;
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};
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/**
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* struct rsc_drv: the Direct Resource Voter (DRV) of the
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* Resource State Coordinator controller (RSC)
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*
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* @name: Controller identifier.
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* @tcs_base: Start address of the TCS registers in this controller.
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* @id: Instance id in the controller (Direct Resource Voter).
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* @num_tcs: Number of TCSes in this DRV.
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* @rsc_pm: CPU PM notifier for controller.
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* Used when solver mode is not present.
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* @cpus_entered_pm: CPU mask for cpus in idle power collapse.
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* Used when solver mode is not present.
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* @tcs: TCS groups.
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* @tcs_in_use: S/W state of the TCS; only set for ACTIVE_ONLY
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* transfers, but might show a sleep/wake TCS in use if
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* it was borrowed for an active_only transfer. You
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* must hold both the lock in this struct and the
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* tcs_lock for the TCS in order to mark a TCS as
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* in-use, but you only need the lock in this structure
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* (aka the drv->lock) to mark one freed.
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* @lock: Synchronize state of the controller. If you will be
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* grabbing this lock and a tcs_lock at the same time,
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* grab the tcs_lock first so we always have a
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* consistent lock ordering.
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* @pm_lock: Synchronize during PM notifications.
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* Used when solver mode is not present.
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* @client: Handle to the DRV's client.
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*/
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struct rsc_drv {
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const char *name;
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void __iomem *tcs_base;
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int id;
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int num_tcs;
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struct notifier_block rsc_pm;
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struct cpumask cpus_entered_pm;
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struct tcs_group tcs[TCS_TYPE_NR];
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DECLARE_BITMAP(tcs_in_use, MAX_TCS_NR);
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spinlock_t lock;
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spinlock_t pm_lock;
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struct rpmh_ctrlr client;
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};
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int rpmh_rsc_send_data(struct rsc_drv *drv, const struct tcs_request *msg);
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int rpmh_rsc_write_ctrl_data(struct rsc_drv *drv,
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const struct tcs_request *msg);
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int rpmh_rsc_invalidate(struct rsc_drv *drv);
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void rpmh_tx_done(const struct tcs_request *msg, int r);
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int rpmh_flush(struct rpmh_ctrlr *ctrlr);
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#endif /* __RPM_INTERNAL_H__ */
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