mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2025-04-12 16:47:42 +00:00
Code Issues Packages Projects Releases Wiki Activity

scsi: ufs: core: Introduce a new clock_gating lock

Browse Source 
Introduce a new clock gating lock to serialize access to some of the clock
gating members instead of the host_lock.

While at it, simplify the code with the guard() macro and co for automatic
cleanup of the new lock. There are some explicit
spin_lock_irqsave()/spin_unlock_irqrestore() snaking instances I left
behind because I couldn't make heads or tails of it.

Additionally, move the trace_ufshcd_clk_gating() call from inside the
region protected by the lock as it doesn't needs protection.

Signed-off-by: Avri Altman <avri.altman@wdc.com>
Link: https://lore.kernel.org/r/20241124070808.194860-4-avri.altman@wdc.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Avri Altman 2024-11-24 09:08:07 +02:00 committed by Martin K. Petersen
parent 7869c6521f
commit 209f4e43b8
2 changed files with 59 additions and 59 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

109
drivers/ufs/core/ufshcd.c
View File

@ -1816,19 +1816,16 @@ static void ufshcd_exit_clk_scaling(struct ufs_hba *hba)
static void ufshcd_ungate_work(struct work_struct *work)
{
int ret;
unsigned long flags;
struct ufs_hba *hba = container_of(work, struct ufs_hba,
clk_gating.ungate_work);
cancel_delayed_work_sync(&hba->clk_gating.gate_work);
spin_lock_irqsave(hba->host->host_lock, flags);
if (hba->clk_gating.state == CLKS_ON) {
spin_unlock_irqrestore(hba->host->host_lock, flags);
return;
scoped_guard(spinlock_irqsave, &hba->clk_gating.lock) {
if (hba->clk_gating.state == CLKS_ON)
return;
}
spin_unlock_irqrestore(hba->host->host_lock, flags);
ufshcd_hba_vreg_set_hpm(hba);
ufshcd_setup_clocks(hba, true);
@ -1863,7 +1860,7 @@ void ufshcd_hold(struct ufs_hba *hba)
if (!ufshcd_is_clkgating_allowed(hba) ||
!hba->clk_gating.is_initialized)
return;
spin_lock_irqsave(hba->host->host_lock, flags);
spin_lock_irqsave(&hba->clk_gating.lock, flags);
hba->clk_gating.active_reqs++;
start:
@ -1879,11 +1876,11 @@ start:
*/
if (ufshcd_can_hibern8_during_gating(hba) &&
ufshcd_is_link_hibern8(hba)) {
spin_unlock_irqrestore(hba->host->host_lock, flags);
spin_unlock_irqrestore(&hba->clk_gating.lock, flags);
flush_result = flush_work(&hba->clk_gating.ungate_work);
if (hba->clk_gating.is_suspended && !flush_result)
return;
spin_lock_irqsave(hba->host->host_lock, flags);
spin_lock_irqsave(&hba->clk_gating.lock, flags);
goto start;
}
break;
@ -1912,17 +1909,17 @@ start:
*/
fallthrough;
case REQ_CLKS_ON:
spin_unlock_irqrestore(hba->host->host_lock, flags);
spin_unlock_irqrestore(&hba->clk_gating.lock, flags);
flush_work(&hba->clk_gating.ungate_work);
/* Make sure state is CLKS_ON before returning */
spin_lock_irqsave(hba->host->host_lock, flags);
spin_lock_irqsave(&hba->clk_gating.lock, flags);
goto start;
default:
dev_err(hba->dev, "%s: clk gating is in invalid state %d\n",
__func__, hba->clk_gating.state);
break;
}
spin_unlock_irqrestore(hba->host->host_lock, flags);
spin_unlock_irqrestore(&hba->clk_gating.lock, flags);
}
EXPORT_SYMBOL_GPL(ufshcd_hold);
@ -1930,30 +1927,32 @@ static void ufshcd_gate_work(struct work_struct *work)
{
struct ufs_hba *hba = container_of(work, struct ufs_hba,
clk_gating.gate_work.work);
unsigned long flags;
int ret;
spin_lock_irqsave(hba->host->host_lock, flags);
/*
* In case you are here to cancel this work the gating state
* would be marked as REQ_CLKS_ON. In this case save time by
* skipping the gating work and exit after changing the clock
* state to CLKS_ON.
*/
if (hba->clk_gating.is_suspended ||
(hba->clk_gating.state != REQ_CLKS_OFF)) {
hba->clk_gating.state = CLKS_ON;
trace_ufshcd_clk_gating(dev_name(hba->dev),
hba->clk_gating.state);
goto rel_lock;
scoped_guard(spinlock_irqsave, &hba->clk_gating.lock) {
/*
* In case you are here to cancel this work the gating state
* would be marked as REQ_CLKS_ON. In this case save time by
* skipping the gating work and exit after changing the clock
* state to CLKS_ON.
*/
if (hba->clk_gating.is_suspended ||
hba->clk_gating.state != REQ_CLKS_OFF) {
hba->clk_gating.state = CLKS_ON;
trace_ufshcd_clk_gating(dev_name(hba->dev),
hba->clk_gating.state);
return;
}
if (hba->clk_gating.active_reqs)
return;
}
if (ufshcd_is_ufs_dev_busy(hba) ||
hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL ||
hba->clk_gating.active_reqs)
goto rel_lock;
spin_unlock_irqrestore(hba->host->host_lock, flags);
scoped_guard(spinlock_irqsave, hba->host->host_lock) {
if (ufshcd_is_ufs_dev_busy(hba) ||
hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL)
return;
}
/* put the link into hibern8 mode before turning off clocks */
if (ufshcd_can_hibern8_during_gating(hba)) {
@ -1964,7 +1963,7 @@ static void ufshcd_gate_work(struct work_struct *work)
__func__, ret);
trace_ufshcd_clk_gating(dev_name(hba->dev),
hba->clk_gating.state);
goto out;
return;
}
ufshcd_set_link_hibern8(hba);
}
@ -1984,32 +1983,34 @@ static void ufshcd_gate_work(struct work_struct *work)
* prevent from doing cancel work multiple times when there are
* new requests arriving before the current cancel work is done.
*/
spin_lock_irqsave(hba->host->host_lock, flags);
guard(spinlock_irqsave)(&hba->clk_gating.lock);
if (hba->clk_gating.state == REQ_CLKS_OFF) {
hba->clk_gating.state = CLKS_OFF;
trace_ufshcd_clk_gating(dev_name(hba->dev),
hba->clk_gating.state);
}
rel_lock:
spin_unlock_irqrestore(hba->host->host_lock, flags);
out:
return;
}
/* host lock must be held before calling this variant */
static void __ufshcd_release(struct ufs_hba *hba)
{
lockdep_assert_held(&hba->clk_gating.lock);
if (!ufshcd_is_clkgating_allowed(hba))
return;
hba->clk_gating.active_reqs--;
if (hba->clk_gating.active_reqs || hba->clk_gating.is_suspended ||
hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL ||
ufshcd_has_pending_tasks(hba) || !hba->clk_gating.is_initialized ||
!hba->clk_gating.is_initialized ||
hba->clk_gating.state == CLKS_OFF)
return;
scoped_guard(spinlock_irqsave, hba->host->host_lock) {
if (ufshcd_has_pending_tasks(hba) ||
hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL)
return;
}
hba->clk_gating.state = REQ_CLKS_OFF;
trace_ufshcd_clk_gating(dev_name(hba->dev), hba->clk_gating.state);
queue_delayed_work(hba->clk_gating.clk_gating_workq,
@ -2019,11 +2020,8 @@ static void __ufshcd_release(struct ufs_hba *hba)
void ufshcd_release(struct ufs_hba *hba)
{
unsigned long flags;
spin_lock_irqsave(hba->host->host_lock, flags);
guard(spinlock_irqsave)(&hba->clk_gating.lock);
__ufshcd_release(hba);
spin_unlock_irqrestore(hba->host->host_lock, flags);
}
EXPORT_SYMBOL_GPL(ufshcd_release);
@ -2038,11 +2036,9 @@ static ssize_t ufshcd_clkgate_delay_show(struct device *dev,
void ufshcd_clkgate_delay_set(struct device *dev, unsigned long value)
{
struct ufs_hba *hba = dev_get_drvdata(dev);
unsigned long flags;
spin_lock_irqsave(hba->host->host_lock, flags);
guard(spinlock_irqsave)(&hba->clk_gating.lock);
hba->clk_gating.delay_ms = value;
spin_unlock_irqrestore(hba->host->host_lock, flags);
}
EXPORT_SYMBOL_GPL(ufshcd_clkgate_delay_set);
@ -2070,7 +2066,6 @@ static ssize_t ufshcd_clkgate_enable_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
struct ufs_hba *hba = dev_get_drvdata(dev);
unsigned long flags;
u32 value;
if (kstrtou32(buf, 0, &value))
@ -2078,9 +2073,10 @@ static ssize_t ufshcd_clkgate_enable_store(struct device *dev,
value = !!value;
spin_lock_irqsave(hba->host->host_lock, flags);
guard(spinlock_irqsave)(&hba->clk_gating.lock);
if (value == hba->clk_gating.is_enabled)
goto out;
return count;
if (value)
__ufshcd_release(hba);
@ -2088,8 +2084,7 @@ static ssize_t ufshcd_clkgate_enable_store(struct device *dev,
hba->clk_gating.active_reqs++;
hba->clk_gating.is_enabled = value;
out:
spin_unlock_irqrestore(hba->host->host_lock, flags);
return count;
}
@ -2131,6 +2126,8 @@ static void ufshcd_init_clk_gating(struct ufs_hba *hba)
INIT_DELAYED_WORK(&hba->clk_gating.gate_work, ufshcd_gate_work);
INIT_WORK(&hba->clk_gating.ungate_work, ufshcd_ungate_work);
spin_lock_init(&hba->clk_gating.lock);
hba->clk_gating.clk_gating_workq = alloc_ordered_workqueue(
"ufs_clk_gating_%d", WQ_MEM_RECLAIM | WQ_HIGHPRI,
hba->host->host_no);
@ -9126,7 +9123,6 @@ static int ufshcd_setup_clocks(struct ufs_hba *hba, bool on)
int ret = 0;
struct ufs_clk_info *clki;
struct list_head *head = &hba->clk_list_head;
unsigned long flags;
ktime_t start = ktime_get();
bool clk_state_changed = false;
@ -9177,11 +9173,10 @@ out:
clk_disable_unprepare(clki->clk);
}
} else if (!ret && on) {
spin_lock_irqsave(hba->host->host_lock, flags);
hba->clk_gating.state = CLKS_ON;
scoped_guard(spinlock_irqsave, &hba->clk_gating.lock)
hba->clk_gating.state = CLKS_ON;
trace_ufshcd_clk_gating(dev_name(hba->dev),
hba->clk_gating.state);
spin_unlock_irqrestore(hba->host->host_lock, flags);
}
if (clk_state_changed)

9
include/ufs/ufshcd.h
View File

@ -403,6 +403,9 @@ enum clk_gating_state {
* delay_ms
* @ungate_work: worker to turn on clocks that will be used in case of
* interrupt context
* @clk_gating_workq: workqueue for clock gating work.
* @lock: serialize access to some struct ufs_clk_gating members. An outer lock
* relative to the host lock
* @state: the current clocks state
* @delay_ms: gating delay in ms
* @is_suspended: clk gating is suspended when set to 1 which can be used
@ -413,11 +416,14 @@ enum clk_gating_state {
* @is_initialized: Indicates whether clock gating is initialized or not
* @active_reqs: number of requests that are pending and should be waited for
* completion before gating clocks.
* @clk_gating_workq: workqueue for clock gating work.
*/
struct ufs_clk_gating {
struct delayed_work gate_work;
struct work_struct ungate_work;
struct workqueue_struct *clk_gating_workq;
spinlock_t lock;
enum clk_gating_state state;
unsigned long delay_ms;
bool is_suspended;
@ -426,7 +432,6 @@ struct ufs_clk_gating {
bool is_enabled;
bool is_initialized;
int active_reqs;
struct workqueue_struct *clk_gating_workq;
};
/**