2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-29 23:53:55 +08:00
linux-next/drivers/soc/qcom/rpmh-internal.h
Douglas Anderson d2a8cfc6f3 soc: qcom: rpmh-rsc: Remove the pm_lock
It has been postulated that the pm_lock is bad for performance because
a CPU currently running rpmh_flush() could block other CPUs from
coming out of idle.  Similarly CPUs coming out of / going into idle
all need to contend with each other for the spinlock just to update
the variable tracking who's in PM.

Let's optimize this a bit.  Specifically:

- Use a count rather than a bitmask.  This is faster to access and
  also means we can use the atomic_inc_return() function to really
  detect who the last one to enter PM was.
- Accept that it's OK if we race and are doing the flush (because we
  think we're last) while another CPU is coming out of idle.  As long
  as we block that CPU if/when it tries to do an active-only transfer
  we're OK.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20200504104917.v6.5.I295cb72bc5334a2af80313cbe97cb5c9dcb1442c@changeid
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
2020-05-15 11:45:21 -07:00

133 lines
4.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (c) 2016-2018, The Linux Foundation. All rights reserved.
*/
#ifndef __RPM_INTERNAL_H__
#define __RPM_INTERNAL_H__
#include <linux/bitmap.h>
#include <soc/qcom/tcs.h>
#define TCS_TYPE_NR 4
#define MAX_CMDS_PER_TCS 16
#define MAX_TCS_PER_TYPE 3
#define MAX_TCS_NR (MAX_TCS_PER_TYPE * TCS_TYPE_NR)
#define MAX_TCS_SLOTS (MAX_CMDS_PER_TCS * MAX_TCS_PER_TYPE)
struct rsc_drv;
/**
* struct tcs_group: group of Trigger Command Sets (TCS) to send state requests
* to the controller
*
* @drv: The controller.
* @type: Type of the TCS in this group - active, sleep, wake.
* @mask: Mask of the TCSes relative to all the TCSes in the RSC.
* @offset: Start of the TCS group relative to the TCSes in the RSC.
* @num_tcs: Number of TCSes in this type.
* @ncpt: Number of commands in each TCS.
* @req: Requests that are sent from the TCS; only used for ACTIVE_ONLY
* transfers (could be on a wake/sleep TCS if we are borrowing for
* an ACTIVE_ONLY transfer).
* Start: grab drv->lock, set req, set tcs_in_use, drop drv->lock,
* trigger
* End: get irq, access req,
* grab drv->lock, clear tcs_in_use, drop drv->lock
* @slots: Indicates which of @cmd_addr are occupied; only used for
* SLEEP / WAKE TCSs. Things are tightly packed in the
* case that (ncpt < MAX_CMDS_PER_TCS). That is if ncpt = 2 and
* MAX_CMDS_PER_TCS = 16 then bit[2] = the first bit in 2nd TCS.
*/
struct tcs_group {
struct rsc_drv *drv;
int type;
u32 mask;
u32 offset;
int num_tcs;
int ncpt;
const struct tcs_request *req[MAX_TCS_PER_TYPE];
DECLARE_BITMAP(slots, MAX_TCS_SLOTS);
};
/**
* struct rpmh_request: the message to be sent to rpmh-rsc
*
* @msg: the request
* @cmd: the payload that will be part of the @msg
* @completion: triggered when request is done
* @dev: the device making the request
* @err: err return from the controller
* @needs_free: check to free dynamically allocated request object
*/
struct rpmh_request {
struct tcs_request msg;
struct tcs_cmd cmd[MAX_RPMH_PAYLOAD];
struct completion *completion;
const struct device *dev;
int err;
bool needs_free;
};
/**
* struct rpmh_ctrlr: our representation of the controller
*
* @cache: the list of cached requests
* @cache_lock: synchronize access to the cache data
* @dirty: was the cache updated since flush
* @batch_cache: Cache sleep and wake requests sent as batch
*/
struct rpmh_ctrlr {
struct list_head cache;
spinlock_t cache_lock;
bool dirty;
struct list_head batch_cache;
};
/**
* struct rsc_drv: the Direct Resource Voter (DRV) of the
* Resource State Coordinator controller (RSC)
*
* @name: Controller identifier.
* @tcs_base: Start address of the TCS registers in this controller.
* @id: Instance id in the controller (Direct Resource Voter).
* @num_tcs: Number of TCSes in this DRV.
* @rsc_pm: CPU PM notifier for controller.
* Used when solver mode is not present.
* @cpus_in_pm: Number of CPUs not in idle power collapse.
* Used when solver mode is not present.
* @tcs: TCS groups.
* @tcs_in_use: S/W state of the TCS; only set for ACTIVE_ONLY
* transfers, but might show a sleep/wake TCS in use if
* it was borrowed for an active_only transfer. You
* must hold the lock in this struct (AKA drv->lock) in
* order to update this.
* @lock: Synchronize state of the controller. If RPMH's cache
* lock will also be held, the order is: drv->lock then
* cache_lock.
* @client: Handle to the DRV's client.
*/
struct rsc_drv {
const char *name;
void __iomem *tcs_base;
int id;
int num_tcs;
struct notifier_block rsc_pm;
atomic_t cpus_in_pm;
struct tcs_group tcs[TCS_TYPE_NR];
DECLARE_BITMAP(tcs_in_use, MAX_TCS_NR);
spinlock_t lock;
struct rpmh_ctrlr client;
};
int rpmh_rsc_send_data(struct rsc_drv *drv, const struct tcs_request *msg);
int rpmh_rsc_write_ctrl_data(struct rsc_drv *drv,
const struct tcs_request *msg);
void rpmh_rsc_invalidate(struct rsc_drv *drv);
void rpmh_tx_done(const struct tcs_request *msg, int r);
int rpmh_flush(struct rpmh_ctrlr *ctrlr);
#endif /* __RPM_INTERNAL_H__ */