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Message-Id: <20241029102938.685835-2-avri.altman@wdc.com>
Date: Tue, 29 Oct 2024 12:29:37 +0200
From: Avri Altman <avri.altman@....com>
To: "Martin K . Petersen" <martin.petersen@...cle.com>
Cc: linux-scsi@...r.kernel.org,
linux-kernel@...r.kernel.org,
Bart Van Assche <bvanassche@....org>,
Avri Altman <avri.altman@....com>
Subject: [PATCH v2 1/2] scsi: ufs: core: Introduce a new clock_gating lock
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.
Signed-off-by: Avri Altman <avri.altman@....com>
---
drivers/ufs/core/ufshcd.c | 97 ++++++++++++++++-----------------------
include/ufs/ufshcd.h | 8 +++-
2 files changed, 46 insertions(+), 59 deletions(-)
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 099373a25017..3373debe7b94 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -1811,19 +1811,16 @@ 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);
@@ -1858,7 +1855,7 @@ 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:
@@ -1874,11 +1871,11 @@ void ufshcd_hold(struct ufs_hba *hba)
*/
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;
@@ -1907,17 +1904,17 @@ void ufshcd_hold(struct ufs_hba *hba)
*/
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);
@@ -1925,29 +1922,24 @@ 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 (ufshcd_is_ufs_dev_busy(hba) || hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL)
+ return;
}
- if (ufshcd_is_ufs_dev_busy(hba) || hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL)
- goto rel_lock;
-
- spin_unlock_irqrestore(hba->host->host_lock, flags);
-
/* put the link into hibern8 mode before turning off clocks */
if (ufshcd_can_hibern8_during_gating(hba)) {
ret = ufshcd_uic_hibern8_enter(hba);
@@ -1957,7 +1949,7 @@ 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);
}
@@ -1977,16 +1969,12 @@ 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 */
@@ -2013,11 +2001,9 @@ 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);
@@ -2032,11 +2018,9 @@ 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);
@@ -2064,7 +2048,6 @@ 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))
@@ -2072,18 +2055,18 @@ static ssize_t ufshcd_clkgate_enable_store(struct device *dev,
value = !!value;
- spin_lock_irqsave(hba->host->host_lock, flags);
- if (value == hba->clk_gating.is_enabled)
- goto out;
+ scoped_guard(spinlock_irqsave, &hba->clk_gating.lock) {
+ if (value == hba->clk_gating.is_enabled)
+ goto out;
- if (value)
- __ufshcd_release(hba);
- else
- hba->clk_gating.active_reqs++;
+ if (value)
+ __ufshcd_release(hba);
+ else
+ hba->clk_gating.active_reqs++;
- hba->clk_gating.is_enabled = value;
+ hba->clk_gating.is_enabled = value;
+ }
out:
- spin_unlock_irqrestore(hba->host->host_lock, flags);
return count;
}
@@ -2125,6 +2108,8 @@ 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);
@@ -9122,7 +9107,6 @@ 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;
@@ -9173,11 +9157,10 @@ static int ufshcd_setup_clocks(struct ufs_hba *hba, bool on)
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)
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index 9ea2a7411bb5..3d42532efbd1 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -402,6 +402,8 @@ 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
* @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
@@ -412,11 +414,14 @@ 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;
@@ -425,7 +430,6 @@ struct ufs_clk_gating {
bool is_enabled;
bool is_initialized;
int active_reqs;
- struct workqueue_struct *clk_gating_workq;
};
/**
--
2.25.1
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