[PATCH 0/4] irqchip/riscv-imsic: IRQ handling optimizations

[PATCH 0/4] irqchip/riscv-imsic: IRQ handling optimizations

[Samuel Holland]

This series includes a small cleanup to imsic_irq_set_affinity() and a
series of optimizations to the IMSIC IRQ handling hot path.

Benchmarks on a SiFive P470-based board (95% confidence interval):
  perf bench sched messaging: 5.20% to  7.08% improvement
  perf bench sched pipe     : 8.47% to 13.85% improvement


Samuel Holland (4):
  irqchip/riscv-imsic: Remove redundant irq_data lookups
  irqchip/riscv-imsic: Embed the vector array in lpriv
  irqchip/riscv-imsic: Inline imsic_vector_from_local_id()
  irqchip/riscv-imsic: Remove irq_desc lookup from hot path

 drivers/irqchip/irq-riscv-imsic-early.c    | 11 +++-----
 drivers/irqchip/irq-riscv-imsic-platform.c | 11 ++++----
 drivers/irqchip/irq-riscv-imsic-state.c    | 30 +++++-----------------
 drivers/irqchip/irq-riscv-imsic-state.h    |  8 +++---
 4 files changed, 19 insertions(+), 41 deletions(-)

-- 
2.47.2

base-commit: 9b332cece987ee1790b2ed4c989e28162fa47860
branch: up/imsic-opt

[PATCH 1/4] irqchip/riscv-imsic: Remove redundant irq_data lookups

[Samuel Holland]

imsic_irq_set_affinity() already takes the irq_data pointer as a
parameter, so it is pointless to look it up again from the IRQ number.

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

 drivers/irqchip/irq-riscv-imsic-platform.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-riscv-imsic-platform.c b/drivers/irqchip/irq-riscv-imsic-platform.c
index 643c8e459611..7228a33f6c37 100644
--- a/drivers/irqchip/irq-riscv-imsic-platform.c
+++ b/drivers/irqchip/irq-riscv-imsic-platform.c
@@ -158,11 +158,11 @@ static int imsic_irq_set_affinity(struct irq_data *d, const struct cpumask *mask
 		tmp_vec.local_id = new_vec->local_id;
 
 		/* Point device to the temporary vector */
-		imsic_msi_update_msg(irq_get_irq_data(d->irq), &tmp_vec);
+		imsic_msi_update_msg(d, &tmp_vec);
 	}
 
 	/* Point device to the new vector */
-	imsic_msi_update_msg(irq_get_irq_data(d->irq), new_vec);
+	imsic_msi_update_msg(d, new_vec);
 
 	/* Update irq descriptors with the new vector */
 	d->chip_data = new_vec;
-- 
2.47.2

[tip: irq/drivers] irqchip/riscv-imsic: Remove redundant irq_data lookups

[tip-bot2 for Samuel Holland]

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

Commit-ID:     bbec970f417aa9796d6b36b60b5fc5df09ce5904
Gitweb:        https://git.kernel.org/tip/bbec970f417aa9796d6b36b60b5fc5df09ce5904
Author:        Samuel Holland <samuel.holland@sifive.com>
AuthorDate:    Wed, 15 Oct 2025 12:55:12 -07:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Thu, 16 Oct 2025 13:12:50 +02:00

irqchip/riscv-imsic: Remove redundant irq_data lookups

imsic_irq_set_affinity() already takes the irq_data pointer as a
parameter, so it is pointless to look it up again from the IRQ number.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 drivers/irqchip/irq-riscv-imsic-platform.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-riscv-imsic-platform.c b/drivers/irqchip/irq-riscv-imsic-platform.c
index 643c8e4..7228a33 100644
--- a/drivers/irqchip/irq-riscv-imsic-platform.c
+++ b/drivers/irqchip/irq-riscv-imsic-platform.c
@@ -158,11 +158,11 @@ static int imsic_irq_set_affinity(struct irq_data *d, const struct cpumask *mask
 		tmp_vec.local_id = new_vec->local_id;
 
 		/* Point device to the temporary vector */
-		imsic_msi_update_msg(irq_get_irq_data(d->irq), &tmp_vec);
+		imsic_msi_update_msg(d, &tmp_vec);
 	}
 
 	/* Point device to the new vector */
-	imsic_msi_update_msg(irq_get_irq_data(d->irq), new_vec);
+	imsic_msi_update_msg(d, new_vec);
 
 	/* Update irq descriptors with the new vector */
 	d->chip_data = new_vec;

[tip: irq/drivers] irqchip/riscv-imsic: Remove redundant irq_data lookups

[tip-bot2 for Samuel Holland]

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

Commit-ID:     69f81d15ae737f3e22451aa00fdaed95bfa2d65d
Gitweb:        https://git.kernel.org/tip/69f81d15ae737f3e22451aa00fdaed95bfa2d65d
Author:        Samuel Holland <samuel.holland@sifive.com>
AuthorDate:    Wed, 15 Oct 2025 12:55:12 -07:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Thu, 16 Oct 2025 17:26:35 +02:00

irqchip/riscv-imsic: Remove redundant irq_data lookups

imsic_irq_set_affinity() already takes the irq_data pointer as a
parameter, so it is pointless to look it up again from the IRQ number.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 drivers/irqchip/irq-riscv-imsic-platform.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-riscv-imsic-platform.c b/drivers/irqchip/irq-riscv-imsic-platform.c
index 643c8e4..7228a33 100644
--- a/drivers/irqchip/irq-riscv-imsic-platform.c
+++ b/drivers/irqchip/irq-riscv-imsic-platform.c
@@ -158,11 +158,11 @@ static int imsic_irq_set_affinity(struct irq_data *d, const struct cpumask *mask
 		tmp_vec.local_id = new_vec->local_id;
 
 		/* Point device to the temporary vector */
-		imsic_msi_update_msg(irq_get_irq_data(d->irq), &tmp_vec);
+		imsic_msi_update_msg(d, &tmp_vec);
 	}
 
 	/* Point device to the new vector */
-	imsic_msi_update_msg(irq_get_irq_data(d->irq), new_vec);
+	imsic_msi_update_msg(d, new_vec);
 
 	/* Update irq descriptors with the new vector */
 	d->chip_data = new_vec;

[tip: irq/drivers] irqchip/riscv-imsic: Remove redundant irq_data lookups

[tip-bot2 for Samuel Holland]

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

Commit-ID:     c475c0b71314b222af576f93e2d32df077f14ad2
Gitweb:        https://git.kernel.org/tip/c475c0b71314b222af576f93e2d32df077f14ad2
Author:        Samuel Holland <samuel.holland@sifive.com>
AuthorDate:    Wed, 15 Oct 2025 12:55:12 -07:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Thu, 16 Oct 2025 18:17:28 +02:00

irqchip/riscv-imsic: Remove redundant irq_data lookups

imsic_irq_set_affinity() already takes the irq_data pointer as a
parameter, so it is pointless to look it up again from the IRQ number.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 drivers/irqchip/irq-riscv-imsic-platform.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-riscv-imsic-platform.c b/drivers/irqchip/irq-riscv-imsic-platform.c
index 643c8e4..7228a33 100644
--- a/drivers/irqchip/irq-riscv-imsic-platform.c
+++ b/drivers/irqchip/irq-riscv-imsic-platform.c
@@ -158,11 +158,11 @@ static int imsic_irq_set_affinity(struct irq_data *d, const struct cpumask *mask
 		tmp_vec.local_id = new_vec->local_id;
 
 		/* Point device to the temporary vector */
-		imsic_msi_update_msg(irq_get_irq_data(d->irq), &tmp_vec);
+		imsic_msi_update_msg(d, &tmp_vec);
 	}
 
 	/* Point device to the new vector */
-	imsic_msi_update_msg(irq_get_irq_data(d->irq), new_vec);
+	imsic_msi_update_msg(d, new_vec);
 
 	/* Update irq descriptors with the new vector */
 	d->chip_data = new_vec;

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

[Samuel Holland]

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

[tip-bot2 for Samuel Holland]

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 {

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

[tip-bot2 for Samuel Holland]

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

[tip-bot2 for Samuel Holland]

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 {

[PATCH 3/4] irqchip/riscv-imsic: Inline imsic_vector_from_local_id()

[Samuel Holland]

This function is only called from one place, which is in the IRQ
handling hot path. Inline it to improve code generation and to take
advantage of this_cpu operations. lpriv and imsic->base_domain can
never be NULL because irq_set_chained_handler() is called after they
are allocated.

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

 drivers/irqchip/irq-riscv-imsic-early.c | 11 +++--------
 drivers/irqchip/irq-riscv-imsic-state.c | 10 ----------
 drivers/irqchip/irq-riscv-imsic-state.h |  2 --
 3 files changed, 3 insertions(+), 20 deletions(-)

diff --git a/drivers/irqchip/irq-riscv-imsic-early.c b/drivers/irqchip/irq-riscv-imsic-early.c
index 2c4c682627b8..6bac67cc0b6d 100644
--- a/drivers/irqchip/irq-riscv-imsic-early.c
+++ b/drivers/irqchip/irq-riscv-imsic-early.c
@@ -91,9 +91,8 @@ static int __init imsic_ipi_domain_init(void) { return 0; }
  */
 static void imsic_handle_irq(struct irq_desc *desc)
 {
+	struct imsic_local_priv *lpriv = this_cpu_ptr(imsic->lpriv);
 	struct irq_chip *chip = irq_desc_get_chip(desc);
-	int cpu = smp_processor_id();
-	struct imsic_vector *vec;
 	unsigned long local_id;
 
 	/*
@@ -113,16 +112,12 @@ static void imsic_handle_irq(struct irq_desc *desc)
 			continue;
 		}
 
-		if (unlikely(!imsic->base_domain))
-			continue;
-
-		vec = imsic_vector_from_local_id(cpu, local_id);
-		if (!vec) {
+		if (unlikely(local_id > imsic->global.nr_ids)) {
 			pr_warn_ratelimited("vector not found for local ID 0x%lx\n", local_id);
 			continue;
 		}
 
-		generic_handle_irq(vec->irq);
+		generic_handle_irq(lpriv->vectors[local_id].irq);
 	}
 
 	chained_irq_exit(chip, desc);
diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c
index 9a499efdebe3..385368052d5c 100644
--- a/drivers/irqchip/irq-riscv-imsic-state.c
+++ b/drivers/irqchip/irq-riscv-imsic-state.c
@@ -434,16 +434,6 @@ void imsic_vector_debug_show_summary(struct seq_file *m, int ind)
 }
 #endif
 
-struct imsic_vector *imsic_vector_from_local_id(unsigned int cpu, unsigned int local_id)
-{
-	struct imsic_local_priv *lpriv = per_cpu_ptr(imsic->lpriv, cpu);
-
-	if (!lpriv || imsic->global.nr_ids < local_id)
-		return NULL;
-
-	return &lpriv->vectors[local_id];
-}
-
 struct imsic_vector *imsic_vector_alloc(unsigned int irq, const struct cpumask *mask)
 {
 	struct imsic_vector *vec = NULL;
diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h
index 196457f1bbca..6332501dcbd8 100644
--- a/drivers/irqchip/irq-riscv-imsic-state.h
+++ b/drivers/irqchip/irq-riscv-imsic-state.h
@@ -95,8 +95,6 @@ static inline struct imsic_vector *imsic_vector_get_move(struct imsic_vector *ve
 void imsic_vector_force_move_cleanup(struct imsic_vector *vec);
 void imsic_vector_move(struct imsic_vector *old_vec, struct imsic_vector *new_vec);
 
-struct imsic_vector *imsic_vector_from_local_id(unsigned int cpu, unsigned int local_id);
-
 struct imsic_vector *imsic_vector_alloc(unsigned int irq, const struct cpumask *mask);
 void imsic_vector_free(struct imsic_vector *vector);
 
-- 
2.47.2

[tip: irq/drivers] irqchip/riscv-imsic: Inline imsic_vector_from_local_id()

[tip-bot2 for Samuel Holland]

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

Commit-ID:     45f8fdcfbf4e49075172cf1a3fd812b90160e903
Gitweb:        https://git.kernel.org/tip/45f8fdcfbf4e49075172cf1a3fd812b90160e903
Author:        Samuel Holland <samuel.holland@sifive.com>
AuthorDate:    Wed, 15 Oct 2025 12:55:14 -07:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Thu, 16 Oct 2025 13:12:50 +02:00

irqchip/riscv-imsic: Inline imsic_vector_from_local_id()

This function is only called from one place, which is in the interrupt
handling hot path. Inline it to improve code generation and to take
advantage of this_cpu operations. lpriv and imsic->base_domain can never be
NULL because irq_set_chained_handler() is called after they are allocated.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 drivers/irqchip/irq-riscv-imsic-early.c | 11 +++--------
 drivers/irqchip/irq-riscv-imsic-state.c | 10 ----------
 drivers/irqchip/irq-riscv-imsic-state.h |  2 --
 3 files changed, 3 insertions(+), 20 deletions(-)

diff --git a/drivers/irqchip/irq-riscv-imsic-early.c b/drivers/irqchip/irq-riscv-imsic-early.c
index 2c4c682..6bac67c 100644
--- a/drivers/irqchip/irq-riscv-imsic-early.c
+++ b/drivers/irqchip/irq-riscv-imsic-early.c
@@ -91,9 +91,8 @@ static int __init imsic_ipi_domain_init(void) { return 0; }
  */
 static void imsic_handle_irq(struct irq_desc *desc)
 {
+	struct imsic_local_priv *lpriv = this_cpu_ptr(imsic->lpriv);
 	struct irq_chip *chip = irq_desc_get_chip(desc);
-	int cpu = smp_processor_id();
-	struct imsic_vector *vec;
 	unsigned long local_id;
 
 	/*
@@ -113,16 +112,12 @@ static void imsic_handle_irq(struct irq_desc *desc)
 			continue;
 		}
 
-		if (unlikely(!imsic->base_domain))
-			continue;
-
-		vec = imsic_vector_from_local_id(cpu, local_id);
-		if (!vec) {
+		if (unlikely(local_id > imsic->global.nr_ids)) {
 			pr_warn_ratelimited("vector not found for local ID 0x%lx\n", local_id);
 			continue;
 		}
 
-		generic_handle_irq(vec->irq);
+		generic_handle_irq(lpriv->vectors[local_id].irq);
 	}
 
 	chained_irq_exit(chip, desc);
diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c
index 9a499ef..3853680 100644
--- a/drivers/irqchip/irq-riscv-imsic-state.c
+++ b/drivers/irqchip/irq-riscv-imsic-state.c
@@ -434,16 +434,6 @@ void imsic_vector_debug_show_summary(struct seq_file *m, int ind)
 }
 #endif
 
-struct imsic_vector *imsic_vector_from_local_id(unsigned int cpu, unsigned int local_id)
-{
-	struct imsic_local_priv *lpriv = per_cpu_ptr(imsic->lpriv, cpu);
-
-	if (!lpriv || imsic->global.nr_ids < local_id)
-		return NULL;
-
-	return &lpriv->vectors[local_id];
-}
-
 struct imsic_vector *imsic_vector_alloc(unsigned int irq, const struct cpumask *mask)
 {
 	struct imsic_vector *vec = NULL;
diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h
index 196457f..6332501 100644
--- a/drivers/irqchip/irq-riscv-imsic-state.h
+++ b/drivers/irqchip/irq-riscv-imsic-state.h
@@ -95,8 +95,6 @@ static inline struct imsic_vector *imsic_vector_get_move(struct imsic_vector *ve
 void imsic_vector_force_move_cleanup(struct imsic_vector *vec);
 void imsic_vector_move(struct imsic_vector *old_vec, struct imsic_vector *new_vec);
 
-struct imsic_vector *imsic_vector_from_local_id(unsigned int cpu, unsigned int local_id);
-
 struct imsic_vector *imsic_vector_alloc(unsigned int irq, const struct cpumask *mask);
 void imsic_vector_free(struct imsic_vector *vector);
 

[tip: irq/drivers] irqchip/riscv-imsic: Inline imsic_vector_from_local_id()

[tip-bot2 for Samuel Holland]

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

Commit-ID:     a8b91cb35847a316d5609b6819b6fa65dd7fbf5b
Gitweb:        https://git.kernel.org/tip/a8b91cb35847a316d5609b6819b6fa65dd7fbf5b
Author:        Samuel Holland <samuel.holland@sifive.com>
AuthorDate:    Wed, 15 Oct 2025 12:55:14 -07:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Thu, 16 Oct 2025 17:26:35 +02:00

irqchip/riscv-imsic: Inline imsic_vector_from_local_id()

This function is only called from one place, which is in the interrupt
handling hot path. Inline it to improve code generation and to take
advantage of this_cpu operations. lpriv and imsic->base_domain can never be
NULL because irq_set_chained_handler() is called after they are allocated.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 drivers/irqchip/irq-riscv-imsic-early.c | 11 +++--------
 drivers/irqchip/irq-riscv-imsic-state.c | 10 ----------
 drivers/irqchip/irq-riscv-imsic-state.h |  2 --
 3 files changed, 3 insertions(+), 20 deletions(-)

diff --git a/drivers/irqchip/irq-riscv-imsic-early.c b/drivers/irqchip/irq-riscv-imsic-early.c
index 2c4c682..6bac67c 100644
--- a/drivers/irqchip/irq-riscv-imsic-early.c
+++ b/drivers/irqchip/irq-riscv-imsic-early.c
@@ -91,9 +91,8 @@ static int __init imsic_ipi_domain_init(void) { return 0; }
  */
 static void imsic_handle_irq(struct irq_desc *desc)
 {
+	struct imsic_local_priv *lpriv = this_cpu_ptr(imsic->lpriv);
 	struct irq_chip *chip = irq_desc_get_chip(desc);
-	int cpu = smp_processor_id();
-	struct imsic_vector *vec;
 	unsigned long local_id;
 
 	/*
@@ -113,16 +112,12 @@ static void imsic_handle_irq(struct irq_desc *desc)
 			continue;
 		}
 
-		if (unlikely(!imsic->base_domain))
-			continue;
-
-		vec = imsic_vector_from_local_id(cpu, local_id);
-		if (!vec) {
+		if (unlikely(local_id > imsic->global.nr_ids)) {
 			pr_warn_ratelimited("vector not found for local ID 0x%lx\n", local_id);
 			continue;
 		}
 
-		generic_handle_irq(vec->irq);
+		generic_handle_irq(lpriv->vectors[local_id].irq);
 	}
 
 	chained_irq_exit(chip, desc);
diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c
index 9a499ef..3853680 100644
--- a/drivers/irqchip/irq-riscv-imsic-state.c
+++ b/drivers/irqchip/irq-riscv-imsic-state.c
@@ -434,16 +434,6 @@ void imsic_vector_debug_show_summary(struct seq_file *m, int ind)
 }
 #endif
 
-struct imsic_vector *imsic_vector_from_local_id(unsigned int cpu, unsigned int local_id)
-{
-	struct imsic_local_priv *lpriv = per_cpu_ptr(imsic->lpriv, cpu);
-
-	if (!lpriv || imsic->global.nr_ids < local_id)
-		return NULL;
-
-	return &lpriv->vectors[local_id];
-}
-
 struct imsic_vector *imsic_vector_alloc(unsigned int irq, const struct cpumask *mask)
 {
 	struct imsic_vector *vec = NULL;
diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h
index 196457f..6332501 100644
--- a/drivers/irqchip/irq-riscv-imsic-state.h
+++ b/drivers/irqchip/irq-riscv-imsic-state.h
@@ -95,8 +95,6 @@ static inline struct imsic_vector *imsic_vector_get_move(struct imsic_vector *ve
 void imsic_vector_force_move_cleanup(struct imsic_vector *vec);
 void imsic_vector_move(struct imsic_vector *old_vec, struct imsic_vector *new_vec);
 
-struct imsic_vector *imsic_vector_from_local_id(unsigned int cpu, unsigned int local_id);
-
 struct imsic_vector *imsic_vector_alloc(unsigned int irq, const struct cpumask *mask);
 void imsic_vector_free(struct imsic_vector *vector);
 

[tip: irq/drivers] irqchip/riscv-imsic: Inline imsic_vector_from_local_id()

[tip-bot2 for Samuel Holland]

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

Commit-ID:     3a16b053840e04c45325dc313a23986ec7f37a50
Gitweb:        https://git.kernel.org/tip/3a16b053840e04c45325dc313a23986ec7f37a50
Author:        Samuel Holland <samuel.holland@sifive.com>
AuthorDate:    Wed, 15 Oct 2025 12:55:14 -07:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Thu, 16 Oct 2025 18:17:28 +02:00

irqchip/riscv-imsic: Inline imsic_vector_from_local_id()

This function is only called from one place, which is in the interrupt
handling hot path. Inline it to improve code generation and to take
advantage of this_cpu operations. lpriv and imsic->base_domain can never be
NULL because irq_set_chained_handler() is called after they are allocated.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 drivers/irqchip/irq-riscv-imsic-early.c | 11 +++--------
 drivers/irqchip/irq-riscv-imsic-state.c | 10 ----------
 drivers/irqchip/irq-riscv-imsic-state.h |  2 --
 3 files changed, 3 insertions(+), 20 deletions(-)

diff --git a/drivers/irqchip/irq-riscv-imsic-early.c b/drivers/irqchip/irq-riscv-imsic-early.c
index 2c4c682..6bac67c 100644
--- a/drivers/irqchip/irq-riscv-imsic-early.c
+++ b/drivers/irqchip/irq-riscv-imsic-early.c
@@ -91,9 +91,8 @@ static int __init imsic_ipi_domain_init(void) { return 0; }
  */
 static void imsic_handle_irq(struct irq_desc *desc)
 {
+	struct imsic_local_priv *lpriv = this_cpu_ptr(imsic->lpriv);
 	struct irq_chip *chip = irq_desc_get_chip(desc);
-	int cpu = smp_processor_id();
-	struct imsic_vector *vec;
 	unsigned long local_id;
 
 	/*
@@ -113,16 +112,12 @@ static void imsic_handle_irq(struct irq_desc *desc)
 			continue;
 		}
 
-		if (unlikely(!imsic->base_domain))
-			continue;
-
-		vec = imsic_vector_from_local_id(cpu, local_id);
-		if (!vec) {
+		if (unlikely(local_id > imsic->global.nr_ids)) {
 			pr_warn_ratelimited("vector not found for local ID 0x%lx\n", local_id);
 			continue;
 		}
 
-		generic_handle_irq(vec->irq);
+		generic_handle_irq(lpriv->vectors[local_id].irq);
 	}
 
 	chained_irq_exit(chip, desc);
diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c
index 9a499ef..3853680 100644
--- a/drivers/irqchip/irq-riscv-imsic-state.c
+++ b/drivers/irqchip/irq-riscv-imsic-state.c
@@ -434,16 +434,6 @@ void imsic_vector_debug_show_summary(struct seq_file *m, int ind)
 }
 #endif
 
-struct imsic_vector *imsic_vector_from_local_id(unsigned int cpu, unsigned int local_id)
-{
-	struct imsic_local_priv *lpriv = per_cpu_ptr(imsic->lpriv, cpu);
-
-	if (!lpriv || imsic->global.nr_ids < local_id)
-		return NULL;
-
-	return &lpriv->vectors[local_id];
-}
-
 struct imsic_vector *imsic_vector_alloc(unsigned int irq, const struct cpumask *mask)
 {
 	struct imsic_vector *vec = NULL;
diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h
index 196457f..6332501 100644
--- a/drivers/irqchip/irq-riscv-imsic-state.h
+++ b/drivers/irqchip/irq-riscv-imsic-state.h
@@ -95,8 +95,6 @@ static inline struct imsic_vector *imsic_vector_get_move(struct imsic_vector *ve
 void imsic_vector_force_move_cleanup(struct imsic_vector *vec);
 void imsic_vector_move(struct imsic_vector *old_vec, struct imsic_vector *new_vec);
 
-struct imsic_vector *imsic_vector_from_local_id(unsigned int cpu, unsigned int local_id);
-
 struct imsic_vector *imsic_vector_alloc(unsigned int irq, const struct cpumask *mask);
 void imsic_vector_free(struct imsic_vector *vector);
 

[PATCH 4/4] irqchip/riscv-imsic: Remove irq_desc lookup from hot path

[Samuel Holland]

The IMSIC driver uses the IRQ matrix allocator, so there is an arbitrary
mapping from the per-CPU interrupt identity to the global irq number. As
a result, the driver maintains a table of vectors so it can look up the
virq number during interrupt handling. The driver uses the virq for one
main purpose: it gets passed to generic_handle_irq(), which then uses it
to look up the irq_desc in the sparse_irqs tree.

Taking inspiration from the loongarch AVEC irqchip driver, skip the tree
lookup by storing a pointer to the irq_desc in the vector table and
calling generic_handle_irq_desc() directly.

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

 drivers/irqchip/irq-riscv-imsic-early.c    |  2 +-
 drivers/irqchip/irq-riscv-imsic-platform.c |  7 ++++---
 drivers/irqchip/irq-riscv-imsic-state.c    | 10 +++++-----
 drivers/irqchip/irq-riscv-imsic-state.h    |  4 ++--
 4 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/drivers/irqchip/irq-riscv-imsic-early.c b/drivers/irqchip/irq-riscv-imsic-early.c
index 6bac67cc0b6d..f3afcfa3242d 100644
--- a/drivers/irqchip/irq-riscv-imsic-early.c
+++ b/drivers/irqchip/irq-riscv-imsic-early.c
@@ -117,7 +117,7 @@ static void imsic_handle_irq(struct irq_desc *desc)
 			continue;
 		}
 
-		generic_handle_irq(lpriv->vectors[local_id].irq);
+		generic_handle_irq_desc(lpriv->vectors[local_id].desc);
 	}
 
 	chained_irq_exit(chip, desc);
diff --git a/drivers/irqchip/irq-riscv-imsic-platform.c b/drivers/irqchip/irq-riscv-imsic-platform.c
index 7228a33f6c37..89618d2791c2 100644
--- a/drivers/irqchip/irq-riscv-imsic-platform.c
+++ b/drivers/irqchip/irq-riscv-imsic-platform.c
@@ -131,7 +131,7 @@ static int imsic_irq_set_affinity(struct irq_data *d, const struct cpumask *mask
 		return -EBUSY;
 
 	/* Get a new vector on the desired set of CPUs */
-	new_vec = imsic_vector_alloc(old_vec->irq, mask_val);
+	new_vec = imsic_vector_alloc(old_vec->desc, mask_val);
 	if (!new_vec)
 		return -ENOSPC;
 
@@ -225,13 +225,14 @@ static struct irq_chip imsic_irq_base_chip = {
 static int imsic_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
 				  unsigned int nr_irqs, void *args)
 {
+	struct irq_data *data = irq_get_irq_data(virq);
 	struct imsic_vector *vec;
 
 	/* Multi-MSI is not supported yet. */
 	if (nr_irqs > 1)
 		return -EOPNOTSUPP;
 
-	vec = imsic_vector_alloc(virq, cpu_online_mask);
+	vec = imsic_vector_alloc(irq_data_to_desc(data), cpu_online_mask);
 	if (!vec)
 		return -ENOSPC;
 
@@ -239,7 +240,7 @@ static int imsic_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
 			    handle_edge_irq, NULL, NULL);
 	irq_set_noprobe(virq);
 	irq_set_affinity(virq, cpu_online_mask);
-	irq_data_update_effective_affinity(irq_get_irq_data(virq), cpumask_of(vec->cpu));
+	irq_data_update_effective_affinity(data, cpumask_of(vec->cpu));
 
 	return 0;
 }
diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c
index 385368052d5c..f37800da3746 100644
--- a/drivers/irqchip/irq-riscv-imsic-state.c
+++ b/drivers/irqchip/irq-riscv-imsic-state.c
@@ -179,7 +179,8 @@ static bool __imsic_local_sync(struct imsic_local_priv *lpriv)
 			tvec = vec->local_id == mvec->local_id ?
 				NULL : &lpriv->vectors[mvec->local_id];
 
-			if (tvec && !irq_can_move_in_process_context(irq_get_irq_data(vec->irq)) &&
+			if (tvec &&
+			    !irq_can_move_in_process_context(irq_desc_get_irq_data(vec->desc)) &&
 			    __imsic_id_read_clear_pending(tvec->local_id)) {
 				/* Retrigger temporary vector if it was already in-use */
 				if (READ_ONCE(tvec->enable)) {
@@ -434,7 +435,7 @@ void imsic_vector_debug_show_summary(struct seq_file *m, int ind)
 }
 #endif
 
-struct imsic_vector *imsic_vector_alloc(unsigned int irq, const struct cpumask *mask)
+struct imsic_vector *imsic_vector_alloc(struct irq_desc *desc, const struct cpumask *mask)
 {
 	struct imsic_vector *vec = NULL;
 	struct imsic_local_priv *lpriv;
@@ -450,7 +451,7 @@ struct imsic_vector *imsic_vector_alloc(unsigned int irq, const struct cpumask *
 
 	lpriv = per_cpu_ptr(imsic->lpriv, cpu);
 	vec = &lpriv->vectors[local_id];
-	vec->irq = irq;
+	vec->desc = desc;
 	vec->enable = false;
 	vec->move_next = NULL;
 	vec->move_prev = NULL;
@@ -463,7 +464,7 @@ void imsic_vector_free(struct imsic_vector *vec)
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&imsic->matrix_lock, flags);
-	vec->irq = 0;
+	vec->desc = NULL;
 	irq_matrix_free(imsic->matrix, vec->cpu, vec->local_id, false);
 	raw_spin_unlock_irqrestore(&imsic->matrix_lock, flags);
 }
@@ -516,7 +517,6 @@ static int __init imsic_local_init(void)
 			vec = &lpriv->vectors[i];
 			vec->cpu = cpu;
 			vec->local_id = i;
-			vec->irq = 0;
 		}
 	}
 
diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h
index 6332501dcbd8..a09dd140461b 100644
--- a/drivers/irqchip/irq-riscv-imsic-state.h
+++ b/drivers/irqchip/irq-riscv-imsic-state.h
@@ -20,7 +20,7 @@ struct imsic_vector {
 	unsigned int				cpu;
 	unsigned int				local_id;
 	/* Details saved by driver in the vector */
-	unsigned int				irq;
+	struct irq_desc				*desc;
 	/* Details accessed using local lock held */
 	bool					enable;
 	struct imsic_vector			*move_next;
@@ -95,7 +95,7 @@ static inline struct imsic_vector *imsic_vector_get_move(struct imsic_vector *ve
 void imsic_vector_force_move_cleanup(struct imsic_vector *vec);
 void imsic_vector_move(struct imsic_vector *old_vec, struct imsic_vector *new_vec);
 
-struct imsic_vector *imsic_vector_alloc(unsigned int irq, const struct cpumask *mask);
+struct imsic_vector *imsic_vector_alloc(struct irq_desc *desc, const struct cpumask *mask);
 void imsic_vector_free(struct imsic_vector *vector);
 
 void imsic_vector_debug_show(struct seq_file *m, struct imsic_vector *vec, int ind);
-- 
2.47.2

Re: [PATCH 4/4] irqchip/riscv-imsic: Remove irq_desc lookup from hot path

[Thomas Gleixner]

On Wed, Oct 15 2025 at 12:55, Samuel Holland wrote:
> The IMSIC driver uses the IRQ matrix allocator, so there is an arbitrary
> mapping from the per-CPU interrupt identity to the global irq number. As
> a result, the driver maintains a table of vectors so it can look up the
> virq number during interrupt handling. The driver uses the virq for one
> main purpose: it gets passed to generic_handle_irq(), which then uses it
> to look up the irq_desc in the sparse_irqs tree.
>
> Taking inspiration from the loongarch AVEC irqchip driver, skip the tree

which got the idea from x86 :)

> -struct imsic_vector *imsic_vector_alloc(unsigned int irq, const struct cpumask *mask)
> +struct imsic_vector *imsic_vector_alloc(struct irq_desc *desc, const struct cpumask *mask)
>  {
>  	struct imsic_vector *vec = NULL;
>  	struct imsic_local_priv *lpriv;
> @@ -450,7 +451,7 @@ struct imsic_vector *imsic_vector_alloc(unsigned int irq, const struct cpumask *
>  
>  	lpriv = per_cpu_ptr(imsic->lpriv, cpu);
>  	vec = &lpriv->vectors[local_id];
> -	vec->irq = irq;
> +	vec->desc = desc;
>  	vec->enable = false;
>  	vec->move_next = NULL;
>  	vec->move_prev = NULL;
> @@ -463,7 +464,7 @@ void imsic_vector_free(struct imsic_vector *vec)
>  	unsigned long flags;
>  
>  	raw_spin_lock_irqsave(&imsic->matrix_lock, flags);
> -	vec->irq = 0;
> +	vec->desc = NULL;
>  	irq_matrix_free(imsic->matrix, vec->cpu, vec->local_id, false);
>  	raw_spin_unlock_irqrestore(&imsic->matrix_lock, flags);

This is only correct when it is guaranteed that the interrupt can't be
raised in the CPU _before_ a interrupt allocation completed throughout
the hierarchy and _after_ the freeing hierarchy walk started. Otherwise
this might end up accessing a half initialized or half torn down
descriptor.

If it is, then please add a comment describing it. If not then you need
to implement the activate/deactivate callbacks for your interrupt domain
and do the store/clear of vec->desc there.

Thanks,

        tglx