[PATCH v1 0/2] genirq: refactor irq_forced_thread_fn()

[PATCH v1 0/2] genirq: refactor irq_forced_thread_fn()

[Andy Shevchenko]

The irq_forced_thread_fn() open codes the irq_forced_fn().
Refactor to reuse.

Andy Shevchenko (2):
  genirq: Move irq_forced_thread_fn() further in the code
  genirq: Reuse irq_thread_fn() for forced thread case

 kernel/irq/manage.c | 46 +++++++++++++++++++++------------------------
 1 file changed, 21 insertions(+), 25 deletions(-)

-- 
2.43.0.rc1.1336.g36b5255a03ac

[PATCH v1 1/2] genirq: Move irq_forced_thread_fn() further in the code

[Andy Shevchenko]

In a preparation of the refactoring, move irq_forced_thread_fn()
further in the code. No functional changes intented.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 kernel/irq/manage.c | 36 ++++++++++++++++++------------------
 1 file changed, 18 insertions(+), 18 deletions(-)

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index f0803d6bd296..310fbeed4d7a 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1181,6 +1181,24 @@ static void irq_finalize_oneshot(struct irq_desc *desc,
 	chip_bus_sync_unlock(desc);
 }
 
+/*
+ * Interrupts explicitly requested as threaded interrupts want to be
+ * preemptible - many of them need to sleep and wait for slow busses to
+ * complete.
+ */
+static irqreturn_t irq_thread_fn(struct irq_desc *desc,
+		struct irqaction *action)
+{
+	irqreturn_t ret;
+
+	ret = action->thread_fn(action->irq, action->dev_id);
+	if (ret == IRQ_HANDLED)
+		atomic_inc(&desc->threads_handled);
+
+	irq_finalize_oneshot(desc, action);
+	return ret;
+}
+
 /*
  * Interrupts which are not explicitly requested as threaded
  * interrupts rely on the implicit bh/preempt disable of the hard irq
@@ -1206,24 +1224,6 @@ irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
 	return ret;
 }
 
-/*
- * Interrupts explicitly requested as threaded interrupts want to be
- * preemptible - many of them need to sleep and wait for slow busses to
- * complete.
- */
-static irqreturn_t irq_thread_fn(struct irq_desc *desc,
-		struct irqaction *action)
-{
-	irqreturn_t ret;
-
-	ret = action->thread_fn(action->irq, action->dev_id);
-	if (ret == IRQ_HANDLED)
-		atomic_inc(&desc->threads_handled);
-
-	irq_finalize_oneshot(desc, action);
-	return ret;
-}
-
 void wake_threads_waitq(struct irq_desc *desc)
 {
 	if (atomic_dec_and_test(&desc->threads_active))
-- 
2.43.0.rc1.1336.g36b5255a03ac

[tip: irq/core] genirq: Move irq_thread_fn() further up in the code

[tip-bot2 for Andy Shevchenko]

The following commit has been merged into the irq/core branch of tip:

Commit-ID:     6f8b79683dfb37ee0661cf4c13a72f024c29f65c
Gitweb:        https://git.kernel.org/tip/6f8b79683dfb37ee0661cf4c13a72f024c29f65c
Author:        Andy Shevchenko <andriy.shevchenko@linux.intel.com>
AuthorDate:    Tue, 19 Nov 2024 12:42:34 +02:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Tue, 03 Dec 2024 11:59:10 +01:00

genirq: Move irq_thread_fn() further up in the code

In a preparation to reuse irq_thread_fn() move it further up in the
code. No functional change intended.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241119104339.2112455-2-andriy.shevchenko@linux.intel.com

---
 kernel/irq/manage.c | 35 ++++++++++++++++-------------------
 1 file changed, 16 insertions(+), 19 deletions(-)

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index f0803d6..230f470 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1182,45 +1182,42 @@ out_unlock:
 }
 
 /*
- * Interrupts which are not explicitly requested as threaded
- * interrupts rely on the implicit bh/preempt disable of the hard irq
- * context. So we need to disable bh here to avoid deadlocks and other
- * side effects.
+ * Interrupts explicitly requested as threaded interrupts want to be
+ * preemptible - many of them need to sleep and wait for slow busses to
+ * complete.
  */
-static irqreturn_t
-irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
+static irqreturn_t irq_thread_fn(struct irq_desc *desc,	struct irqaction *action)
 {
-	irqreturn_t ret;
+	irqreturn_t ret = action->thread_fn(action->irq, action->dev_id);
 
-	local_bh_disable();
-	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
-		local_irq_disable();
-	ret = action->thread_fn(action->irq, action->dev_id);
 	if (ret == IRQ_HANDLED)
 		atomic_inc(&desc->threads_handled);
 
 	irq_finalize_oneshot(desc, action);
-	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
-		local_irq_enable();
-	local_bh_enable();
 	return ret;
 }
 
 /*
- * Interrupts explicitly requested as threaded interrupts want to be
- * preemptible - many of them need to sleep and wait for slow busses to
- * complete.
+ * Interrupts which are not explicitly requested as threaded
+ * interrupts rely on the implicit bh/preempt disable of the hard irq
+ * context. So we need to disable bh here to avoid deadlocks and other
+ * side effects.
  */
-static irqreturn_t irq_thread_fn(struct irq_desc *desc,
-		struct irqaction *action)
+static irqreturn_t irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
 {
 	irqreturn_t ret;
 
+	local_bh_disable();
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+		local_irq_disable();
 	ret = action->thread_fn(action->irq, action->dev_id);
 	if (ret == IRQ_HANDLED)
 		atomic_inc(&desc->threads_handled);
 
 	irq_finalize_oneshot(desc, action);
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+		local_irq_enable();
+	local_bh_enable();
 	return ret;
 }
 

[PATCH v1 2/2] genirq: Reuse irq_thread_fn() for forced thread case

[Andy Shevchenko]

The irq_forced_thread_fn() uses the same action callback
as the non-forced variant but with different locking decorations.
Reuse irq_thread_fn() here to make that clear.

bloat-o-meter statistics on x86_64 (GCC-13, clang-18 shows no difference):

  Function                          old     new   delta
  irq_forced_thread_fn              118      55     -63
  Total: Before=13845, After=13782, chg -0.46%

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 kernel/irq/manage.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 310fbeed4d7a..2d9993f86fde 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1213,11 +1213,7 @@ irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
 	local_bh_disable();
 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 		local_irq_disable();
-	ret = action->thread_fn(action->irq, action->dev_id);
-	if (ret == IRQ_HANDLED)
-		atomic_inc(&desc->threads_handled);
-
-	irq_finalize_oneshot(desc, action);
+	ret = irq_thread_fn(desc, action);
 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 		local_irq_enable();
 	local_bh_enable();
-- 
2.43.0.rc1.1336.g36b5255a03ac

[tip: irq/core] genirq: Reuse irq_thread_fn() for forced thread case

[tip-bot2 for Andy Shevchenko]

The following commit has been merged into the irq/core branch of tip:

Commit-ID:     429f49ad361cd999ca221d8b562ae2552b7c3e2c
Gitweb:        https://git.kernel.org/tip/429f49ad361cd999ca221d8b562ae2552b7c3e2c
Author:        Andy Shevchenko <andriy.shevchenko@linux.intel.com>
AuthorDate:    Tue, 19 Nov 2024 12:42:35 +02:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Tue, 03 Dec 2024 11:59:10 +01:00

genirq: Reuse irq_thread_fn() for forced thread case

rq_forced_thread_fn() uses the same action callback as the non-forced
variant but with different locking decorations.  Reuse irq_thread_fn() here
to make that clear.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241119104339.2112455-3-andriy.shevchenko@linux.intel.com

---
 kernel/irq/manage.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 230f470..f300bb6 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1210,11 +1210,7 @@ static irqreturn_t irq_forced_thread_fn(struct irq_desc *desc, struct irqaction 
 	local_bh_disable();
 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 		local_irq_disable();
-	ret = action->thread_fn(action->irq, action->dev_id);
-	if (ret == IRQ_HANDLED)
-		atomic_inc(&desc->threads_handled);
-
-	irq_finalize_oneshot(desc, action);
+	ret = irq_thread_fn(desc, action);
 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 		local_irq_enable();
 	local_bh_enable();