irqchip/riscv-imsic: IRQ handling optimizations

[PATCH 2/4] irqchip/riscv-imsic: Embed the vector array in lpriv

Posted by Samuel Holland 2 months ago

Reduce pointer chasing and the number of allocations by using a flexible
array member for the vector array instead of a separate allocation.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
---

 drivers/irqchip/irq-riscv-imsic-state.c | 10 ++--------
 drivers/irqchip/irq-riscv-imsic-state.h |  2 +-
 2 files changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c
index dc95ad856d80..9a499efdebe3 100644
--- a/drivers/irqchip/irq-riscv-imsic-state.c
+++ b/drivers/irqchip/irq-riscv-imsic-state.c
@@ -487,7 +487,6 @@ static void __init imsic_local_cleanup(void)
 		lpriv = per_cpu_ptr(imsic->lpriv, cpu);
 
 		bitmap_free(lpriv->dirty_bitmap);
-		kfree(lpriv->vectors);
 	}
 
 	free_percpu(imsic->lpriv);
@@ -501,7 +500,8 @@ static int __init imsic_local_init(void)
 	int cpu, i;
 
 	/* Allocate per-CPU private state */
-	imsic->lpriv = alloc_percpu(typeof(*imsic->lpriv));
+	imsic->lpriv = __alloc_percpu(struct_size(imsic->lpriv, vectors, global->nr_ids + 1),
+				      __alignof__(*imsic->lpriv));
 	if (!imsic->lpriv)
 		return -ENOMEM;
 
@@ -521,12 +521,6 @@ static int __init imsic_local_init(void)
 		timer_setup(&lpriv->timer, imsic_local_timer_callback, TIMER_PINNED);
 #endif
 
-		/* Allocate vector array */
-		lpriv->vectors = kcalloc(global->nr_ids + 1, sizeof(*lpriv->vectors),
-					 GFP_KERNEL);
-		if (!lpriv->vectors)
-			goto fail_local_cleanup;
-
 		/* Setup vector array */
 		for (i = 0; i <= global->nr_ids; i++) {
 			vec = &lpriv->vectors[i];
diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h
index 57f951952b0c..196457f1bbca 100644
--- a/drivers/irqchip/irq-riscv-imsic-state.h
+++ b/drivers/irqchip/irq-riscv-imsic-state.h
@@ -40,7 +40,7 @@ struct imsic_local_priv {
 #endif
 
 	/* Local vector table */
-	struct imsic_vector			*vectors;
+	struct imsic_vector			vectors[];
 };
 
 struct imsic_priv {
-- 
2.47.2

[tip: irq/drivers] irqchip/riscv-imsic: Embed the vector array in lpriv

Posted by tip-bot2 for Samuel Holland 2 months ago

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

Commit-ID:     79eaabc61dfbf5a4b680f42d3a113d05333c3960
Gitweb:        https://git.kernel.org/tip/79eaabc61dfbf5a4b680f42d3a113d05333c3960
Author:        Samuel Holland <samuel.holland@sifive.com>
AuthorDate:    Wed, 15 Oct 2025 12:55:13 -07:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Thu, 16 Oct 2025 18:17:28 +02:00

irqchip/riscv-imsic: Embed the vector array in lpriv

Reduce pointer chasing and the number of allocations by using a flexible
array member for the vector array instead of a separate allocation.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 drivers/irqchip/irq-riscv-imsic-state.c | 10 ++--------
 drivers/irqchip/irq-riscv-imsic-state.h |  2 +-
 2 files changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c
index dc95ad8..9a499ef 100644
--- a/drivers/irqchip/irq-riscv-imsic-state.c
+++ b/drivers/irqchip/irq-riscv-imsic-state.c
@@ -487,7 +487,6 @@ static void __init imsic_local_cleanup(void)
 		lpriv = per_cpu_ptr(imsic->lpriv, cpu);
 
 		bitmap_free(lpriv->dirty_bitmap);
-		kfree(lpriv->vectors);
 	}
 
 	free_percpu(imsic->lpriv);
@@ -501,7 +500,8 @@ static int __init imsic_local_init(void)
 	int cpu, i;
 
 	/* Allocate per-CPU private state */
-	imsic->lpriv = alloc_percpu(typeof(*imsic->lpriv));
+	imsic->lpriv = __alloc_percpu(struct_size(imsic->lpriv, vectors, global->nr_ids + 1),
+				      __alignof__(*imsic->lpriv));
 	if (!imsic->lpriv)
 		return -ENOMEM;
 
@@ -521,12 +521,6 @@ static int __init imsic_local_init(void)
 		timer_setup(&lpriv->timer, imsic_local_timer_callback, TIMER_PINNED);
 #endif
 
-		/* Allocate vector array */
-		lpriv->vectors = kcalloc(global->nr_ids + 1, sizeof(*lpriv->vectors),
-					 GFP_KERNEL);
-		if (!lpriv->vectors)
-			goto fail_local_cleanup;
-
 		/* Setup vector array */
 		for (i = 0; i <= global->nr_ids; i++) {
 			vec = &lpriv->vectors[i];
diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h
index 57f9519..196457f 100644
--- a/drivers/irqchip/irq-riscv-imsic-state.h
+++ b/drivers/irqchip/irq-riscv-imsic-state.h
@@ -40,7 +40,7 @@ struct imsic_local_priv {
 #endif
 
 	/* Local vector table */
-	struct imsic_vector			*vectors;
+	struct imsic_vector			vectors[];
 };
 
 struct imsic_priv {

[tip: irq/drivers] irqchip/riscv-imsic: Embed the vector array in lpriv

Posted by tip-bot2 for Samuel Holland 2 months ago

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

Commit-ID:     6efefb71195ae1c93913615bcf0e7c5a63083e35
Gitweb:        https://git.kernel.org/tip/6efefb71195ae1c93913615bcf0e7c5a63083e35
Author:        Samuel Holland <samuel.holland@sifive.com>
AuthorDate:    Wed, 15 Oct 2025 12:55:13 -07:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Thu, 16 Oct 2025 17:26:35 +02:00

irqchip/riscv-imsic: Embed the vector array in lpriv

Reduce pointer chasing and the number of allocations by using a flexible
array member for the vector array instead of a separate allocation.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 drivers/irqchip/irq-riscv-imsic-state.c | 10 ++--------
 drivers/irqchip/irq-riscv-imsic-state.h |  2 +-
 2 files changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c
index dc95ad8..9a499ef 100644
--- a/drivers/irqchip/irq-riscv-imsic-state.c
+++ b/drivers/irqchip/irq-riscv-imsic-state.c
@@ -487,7 +487,6 @@ static void __init imsic_local_cleanup(void)
 		lpriv = per_cpu_ptr(imsic->lpriv, cpu);
 
 		bitmap_free(lpriv->dirty_bitmap);
-		kfree(lpriv->vectors);
 	}
 
 	free_percpu(imsic->lpriv);
@@ -501,7 +500,8 @@ static int __init imsic_local_init(void)
 	int cpu, i;
 
 	/* Allocate per-CPU private state */
-	imsic->lpriv = alloc_percpu(typeof(*imsic->lpriv));
+	imsic->lpriv = __alloc_percpu(struct_size(imsic->lpriv, vectors, global->nr_ids + 1),
+				      __alignof__(*imsic->lpriv));
 	if (!imsic->lpriv)
 		return -ENOMEM;
 
@@ -521,12 +521,6 @@ static int __init imsic_local_init(void)
 		timer_setup(&lpriv->timer, imsic_local_timer_callback, TIMER_PINNED);
 #endif
 
-		/* Allocate vector array */
-		lpriv->vectors = kcalloc(global->nr_ids + 1, sizeof(*lpriv->vectors),
-					 GFP_KERNEL);
-		if (!lpriv->vectors)
-			goto fail_local_cleanup;
-
 		/* Setup vector array */
 		for (i = 0; i <= global->nr_ids; i++) {
 			vec = &lpriv->vectors[i];
diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h
index 57f9519..196457f 100644
--- a/drivers/irqchip/irq-riscv-imsic-state.h
+++ b/drivers/irqchip/irq-riscv-imsic-state.h
@@ -40,7 +40,7 @@ struct imsic_local_priv {
 #endif
 
 	/* Local vector table */
-	struct imsic_vector			*vectors;
+	struct imsic_vector			vectors[];
 };
 
 struct imsic_priv {

[tip: irq/drivers] irqchip/riscv-imsic: Embed the vector array in lpriv

Posted by tip-bot2 for Samuel Holland 2 months ago

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

Commit-ID:     424eafac024552b352d765afc392b090e55bfbf6
Gitweb:        https://git.kernel.org/tip/424eafac024552b352d765afc392b090e55bfbf6
Author:        Samuel Holland <samuel.holland@sifive.com>
AuthorDate:    Wed, 15 Oct 2025 12:55:13 -07:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Thu, 16 Oct 2025 13:12:50 +02:00

irqchip/riscv-imsic: Embed the vector array in lpriv

Reduce pointer chasing and the number of allocations by using a flexible
array member for the vector array instead of a separate allocation.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 drivers/irqchip/irq-riscv-imsic-state.c | 10 ++--------
 drivers/irqchip/irq-riscv-imsic-state.h |  2 +-
 2 files changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c
index dc95ad8..9a499ef 100644
--- a/drivers/irqchip/irq-riscv-imsic-state.c
+++ b/drivers/irqchip/irq-riscv-imsic-state.c
@@ -487,7 +487,6 @@ static void __init imsic_local_cleanup(void)
 		lpriv = per_cpu_ptr(imsic->lpriv, cpu);
 
 		bitmap_free(lpriv->dirty_bitmap);
-		kfree(lpriv->vectors);
 	}
 
 	free_percpu(imsic->lpriv);
@@ -501,7 +500,8 @@ static int __init imsic_local_init(void)
 	int cpu, i;
 
 	/* Allocate per-CPU private state */
-	imsic->lpriv = alloc_percpu(typeof(*imsic->lpriv));
+	imsic->lpriv = __alloc_percpu(struct_size(imsic->lpriv, vectors, global->nr_ids + 1),
+				      __alignof__(*imsic->lpriv));
 	if (!imsic->lpriv)
 		return -ENOMEM;
 
@@ -521,12 +521,6 @@ static int __init imsic_local_init(void)
 		timer_setup(&lpriv->timer, imsic_local_timer_callback, TIMER_PINNED);
 #endif
 
-		/* Allocate vector array */
-		lpriv->vectors = kcalloc(global->nr_ids + 1, sizeof(*lpriv->vectors),
-					 GFP_KERNEL);
-		if (!lpriv->vectors)
-			goto fail_local_cleanup;
-
 		/* Setup vector array */
 		for (i = 0; i <= global->nr_ids; i++) {
 			vec = &lpriv->vectors[i];
diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h
index 57f9519..196457f 100644
--- a/drivers/irqchip/irq-riscv-imsic-state.h
+++ b/drivers/irqchip/irq-riscv-imsic-state.h
@@ -40,7 +40,7 @@ struct imsic_local_priv {
 #endif
 
 	/* Local vector table */
-	struct imsic_vector			*vectors;
+	struct imsic_vector			vectors[];
 };
 
 struct imsic_priv {