swh:1:snp:49cd9498d6cccc5e78252c27dcb645bcf7bf0c91
Tip revision: c79f46a282390e0f5b306007bf7b11a46d529538 authored by Linus Torvalds on 05 January 2020, 22:23:27 UTC
Linux 5.5-rc5
Linux 5.5-rc5
Tip revision: c79f46a
rpmh.c
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2016-2018, The Linux Foundation. All rights reserved.
*/
#include <linux/atomic.h>
#include <linux/bug.h>
#include <linux/interrupt.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/wait.h>
#include <soc/qcom/rpmh.h>
#include "rpmh-internal.h"
#define RPMH_TIMEOUT_MS msecs_to_jiffies(10000)
#define DEFINE_RPMH_MSG_ONSTACK(dev, s, q, name) \
struct rpmh_request name = { \
.msg = { \
.state = s, \
.cmds = name.cmd, \
.num_cmds = 0, \
.wait_for_compl = true, \
}, \
.cmd = { { 0 } }, \
.completion = q, \
.dev = dev, \
.needs_free = false, \
}
#define ctrlr_to_drv(ctrlr) container_of(ctrlr, struct rsc_drv, client)
/**
* struct cache_req: the request object for caching
*
* @addr: the address of the resource
* @sleep_val: the sleep vote
* @wake_val: the wake vote
* @list: linked list obj
*/
struct cache_req {
u32 addr;
u32 sleep_val;
u32 wake_val;
struct list_head list;
};
/**
* struct batch_cache_req - An entry in our batch catch
*
* @list: linked list obj
* @count: number of messages
* @rpm_msgs: the messages
*/
struct batch_cache_req {
struct list_head list;
int count;
struct rpmh_request rpm_msgs[];
};
static struct rpmh_ctrlr *get_rpmh_ctrlr(const struct device *dev)
{
struct rsc_drv *drv = dev_get_drvdata(dev->parent);
return &drv->client;
}
void rpmh_tx_done(const struct tcs_request *msg, int r)
{
struct rpmh_request *rpm_msg = container_of(msg, struct rpmh_request,
msg);
struct completion *compl = rpm_msg->completion;
bool free = rpm_msg->needs_free;
rpm_msg->err = r;
if (r)
dev_err(rpm_msg->dev, "RPMH TX fail in msg addr=%#x, err=%d\n",
rpm_msg->msg.cmds[0].addr, r);
if (!compl)
goto exit;
/* Signal the blocking thread we are done */
complete(compl);
exit:
if (free)
kfree(rpm_msg);
}
static struct cache_req *__find_req(struct rpmh_ctrlr *ctrlr, u32 addr)
{
struct cache_req *p, *req = NULL;
list_for_each_entry(p, &ctrlr->cache, list) {
if (p->addr == addr) {
req = p;
break;
}
}
return req;
}
static struct cache_req *cache_rpm_request(struct rpmh_ctrlr *ctrlr,
enum rpmh_state state,
struct tcs_cmd *cmd)
{
struct cache_req *req;
unsigned long flags;
spin_lock_irqsave(&ctrlr->cache_lock, flags);
req = __find_req(ctrlr, cmd->addr);
if (req)
goto existing;
req = kzalloc(sizeof(*req), GFP_ATOMIC);
if (!req) {
req = ERR_PTR(-ENOMEM);
goto unlock;
}
req->addr = cmd->addr;
req->sleep_val = req->wake_val = UINT_MAX;
INIT_LIST_HEAD(&req->list);
list_add_tail(&req->list, &ctrlr->cache);
existing:
switch (state) {
case RPMH_ACTIVE_ONLY_STATE:
if (req->sleep_val != UINT_MAX)
req->wake_val = cmd->data;
break;
case RPMH_WAKE_ONLY_STATE:
req->wake_val = cmd->data;
break;
case RPMH_SLEEP_STATE:
req->sleep_val = cmd->data;
break;
default:
break;
}
ctrlr->dirty = true;
unlock:
spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
return req;
}
/**
* __rpmh_write: Cache and send the RPMH request
*
* @dev: The device making the request
* @state: Active/Sleep request type
* @rpm_msg: The data that needs to be sent (cmds).
*
* Cache the RPMH request and send if the state is ACTIVE_ONLY.
* SLEEP/WAKE_ONLY requests are not sent to the controller at
* this time. Use rpmh_flush() to send them to the controller.
*/
static int __rpmh_write(const struct device *dev, enum rpmh_state state,
struct rpmh_request *rpm_msg)
{
struct rpmh_ctrlr *ctrlr = get_rpmh_ctrlr(dev);
int ret = -EINVAL;
struct cache_req *req;
int i;
rpm_msg->msg.state = state;
/* Cache the request in our store and link the payload */
for (i = 0; i < rpm_msg->msg.num_cmds; i++) {
req = cache_rpm_request(ctrlr, state, &rpm_msg->msg.cmds[i]);
if (IS_ERR(req))
return PTR_ERR(req);
}
rpm_msg->msg.state = state;
if (state == RPMH_ACTIVE_ONLY_STATE) {
WARN_ON(irqs_disabled());
ret = rpmh_rsc_send_data(ctrlr_to_drv(ctrlr), &rpm_msg->msg);
} else {
/* Clean up our call by spoofing tx_done */
ret = 0;
rpmh_tx_done(&rpm_msg->msg, ret);
}
return ret;
}
static int __fill_rpmh_msg(struct rpmh_request *req, enum rpmh_state state,
const struct tcs_cmd *cmd, u32 n)
{
if (!cmd || !n || n > MAX_RPMH_PAYLOAD)
return -EINVAL;
memcpy(req->cmd, cmd, n * sizeof(*cmd));
req->msg.state = state;
req->msg.cmds = req->cmd;
req->msg.num_cmds = n;
return 0;
}
/**
* rpmh_write_async: Write a set of RPMH commands
*
* @dev: The device making the request
* @state: Active/sleep set
* @cmd: The payload data
* @n: The number of elements in payload
*
* Write a set of RPMH commands, the order of commands is maintained
* and will be sent as a single shot.
*/
int rpmh_write_async(const struct device *dev, enum rpmh_state state,
const struct tcs_cmd *cmd, u32 n)
{
struct rpmh_request *rpm_msg;
int ret;
rpm_msg = kzalloc(sizeof(*rpm_msg), GFP_ATOMIC);
if (!rpm_msg)
return -ENOMEM;
rpm_msg->needs_free = true;
ret = __fill_rpmh_msg(rpm_msg, state, cmd, n);
if (ret) {
kfree(rpm_msg);
return ret;
}
return __rpmh_write(dev, state, rpm_msg);
}
EXPORT_SYMBOL(rpmh_write_async);
/**
* rpmh_write: Write a set of RPMH commands and block until response
*
* @rc: The RPMH handle got from rpmh_get_client
* @state: Active/sleep set
* @cmd: The payload data
* @n: The number of elements in @cmd
*
* May sleep. Do not call from atomic contexts.
*/
int rpmh_write(const struct device *dev, enum rpmh_state state,
const struct tcs_cmd *cmd, u32 n)
{
DECLARE_COMPLETION_ONSTACK(compl);
DEFINE_RPMH_MSG_ONSTACK(dev, state, &compl, rpm_msg);
int ret;
if (!cmd || !n || n > MAX_RPMH_PAYLOAD)
return -EINVAL;
memcpy(rpm_msg.cmd, cmd, n * sizeof(*cmd));
rpm_msg.msg.num_cmds = n;
ret = __rpmh_write(dev, state, &rpm_msg);
if (ret)
return ret;
ret = wait_for_completion_timeout(&compl, RPMH_TIMEOUT_MS);
WARN_ON(!ret);
return (ret > 0) ? 0 : -ETIMEDOUT;
}
EXPORT_SYMBOL(rpmh_write);
static void cache_batch(struct rpmh_ctrlr *ctrlr, struct batch_cache_req *req)
{
unsigned long flags;
spin_lock_irqsave(&ctrlr->cache_lock, flags);
list_add_tail(&req->list, &ctrlr->batch_cache);
spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
}
static int flush_batch(struct rpmh_ctrlr *ctrlr)
{
struct batch_cache_req *req;
const struct rpmh_request *rpm_msg;
unsigned long flags;
int ret = 0;
int i;
/* Send Sleep/Wake requests to the controller, expect no response */
spin_lock_irqsave(&ctrlr->cache_lock, flags);
list_for_each_entry(req, &ctrlr->batch_cache, list) {
for (i = 0; i < req->count; i++) {
rpm_msg = req->rpm_msgs + i;
ret = rpmh_rsc_write_ctrl_data(ctrlr_to_drv(ctrlr),
&rpm_msg->msg);
if (ret)
break;
}
}
spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
return ret;
}
static void invalidate_batch(struct rpmh_ctrlr *ctrlr)
{
struct batch_cache_req *req, *tmp;
unsigned long flags;
spin_lock_irqsave(&ctrlr->cache_lock, flags);
list_for_each_entry_safe(req, tmp, &ctrlr->batch_cache, list)
kfree(req);
INIT_LIST_HEAD(&ctrlr->batch_cache);
spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
}
/**
* rpmh_write_batch: Write multiple sets of RPMH commands and wait for the
* batch to finish.
*
* @dev: the device making the request
* @state: Active/sleep set
* @cmd: The payload data
* @n: The array of count of elements in each batch, 0 terminated.
*
* Write a request to the RSC controller without caching. If the request
* state is ACTIVE, then the requests are treated as completion request
* and sent to the controller immediately. The function waits until all the
* commands are complete. If the request was to SLEEP or WAKE_ONLY, then the
* request is sent as fire-n-forget and no ack is expected.
*
* May sleep. Do not call from atomic contexts for ACTIVE_ONLY requests.
*/
int rpmh_write_batch(const struct device *dev, enum rpmh_state state,
const struct tcs_cmd *cmd, u32 *n)
{
struct batch_cache_req *req;
struct rpmh_request *rpm_msgs;
struct completion *compls;
struct rpmh_ctrlr *ctrlr = get_rpmh_ctrlr(dev);
unsigned long time_left;
int count = 0;
int ret, i;
void *ptr;
if (!cmd || !n)
return -EINVAL;
while (n[count] > 0)
count++;
if (!count)
return -EINVAL;
ptr = kzalloc(sizeof(*req) +
count * (sizeof(req->rpm_msgs[0]) + sizeof(*compls)),
GFP_ATOMIC);
if (!ptr)
return -ENOMEM;
req = ptr;
compls = ptr + sizeof(*req) + count * sizeof(*rpm_msgs);
req->count = count;
rpm_msgs = req->rpm_msgs;
for (i = 0; i < count; i++) {
__fill_rpmh_msg(rpm_msgs + i, state, cmd, n[i]);
cmd += n[i];
}
if (state != RPMH_ACTIVE_ONLY_STATE) {
cache_batch(ctrlr, req);
return 0;
}
for (i = 0; i < count; i++) {
struct completion *compl = &compls[i];
init_completion(compl);
rpm_msgs[i].completion = compl;
ret = rpmh_rsc_send_data(ctrlr_to_drv(ctrlr), &rpm_msgs[i].msg);
if (ret) {
pr_err("Error(%d) sending RPMH message addr=%#x\n",
ret, rpm_msgs[i].msg.cmds[0].addr);
break;
}
}
time_left = RPMH_TIMEOUT_MS;
while (i--) {
time_left = wait_for_completion_timeout(&compls[i], time_left);
if (!time_left) {
/*
* Better hope they never finish because they'll signal
* the completion that we're going to free once
* we've returned from this function.
*/
WARN_ON(1);
ret = -ETIMEDOUT;
goto exit;
}
}
exit:
kfree(ptr);
return ret;
}
EXPORT_SYMBOL(rpmh_write_batch);
static int is_req_valid(struct cache_req *req)
{
return (req->sleep_val != UINT_MAX &&
req->wake_val != UINT_MAX &&
req->sleep_val != req->wake_val);
}
static int send_single(const struct device *dev, enum rpmh_state state,
u32 addr, u32 data)
{
DEFINE_RPMH_MSG_ONSTACK(dev, state, NULL, rpm_msg);
struct rpmh_ctrlr *ctrlr = get_rpmh_ctrlr(dev);
/* Wake sets are always complete and sleep sets are not */
rpm_msg.msg.wait_for_compl = (state == RPMH_WAKE_ONLY_STATE);
rpm_msg.cmd[0].addr = addr;
rpm_msg.cmd[0].data = data;
rpm_msg.msg.num_cmds = 1;
return rpmh_rsc_write_ctrl_data(ctrlr_to_drv(ctrlr), &rpm_msg.msg);
}
/**
* rpmh_flush: Flushes the buffered active and sleep sets to TCS
*
* @dev: The device making the request
*
* Return: -EBUSY if the controller is busy, probably waiting on a response
* to a RPMH request sent earlier.
*
* This function is always called from the sleep code from the last CPU
* that is powering down the entire system. Since no other RPMH API would be
* executing at this time, it is safe to run lockless.
*/
int rpmh_flush(const struct device *dev)
{
struct cache_req *p;
struct rpmh_ctrlr *ctrlr = get_rpmh_ctrlr(dev);
int ret;
if (!ctrlr->dirty) {
pr_debug("Skipping flush, TCS has latest data.\n");
return 0;
}
/* First flush the cached batch requests */
ret = flush_batch(ctrlr);
if (ret)
return ret;
/*
* Nobody else should be calling this function other than system PM,
* hence we can run without locks.
*/
list_for_each_entry(p, &ctrlr->cache, list) {
if (!is_req_valid(p)) {
pr_debug("%s: skipping RPMH req: a:%#x s:%#x w:%#x",
__func__, p->addr, p->sleep_val, p->wake_val);
continue;
}
ret = send_single(dev, RPMH_SLEEP_STATE, p->addr, p->sleep_val);
if (ret)
return ret;
ret = send_single(dev, RPMH_WAKE_ONLY_STATE,
p->addr, p->wake_val);
if (ret)
return ret;
}
ctrlr->dirty = false;
return 0;
}
EXPORT_SYMBOL(rpmh_flush);
/**
* rpmh_invalidate: Invalidate all sleep and active sets
* sets.
*
* @dev: The device making the request
*
* Invalidate the sleep and active values in the TCS blocks.
*/
int rpmh_invalidate(const struct device *dev)
{
struct rpmh_ctrlr *ctrlr = get_rpmh_ctrlr(dev);
int ret;
invalidate_batch(ctrlr);
ctrlr->dirty = true;
do {
ret = rpmh_rsc_invalidate(ctrlr_to_drv(ctrlr));
} while (ret == -EAGAIN);
return ret;
}
EXPORT_SYMBOL(rpmh_invalidate);