diff options
| author | Bartosz Golaszewski <brgl@bgdev.pl> | 2018-11-09 18:21:32 +0100 |
|---|---|---|
| committer | Marc Zyngier <marc.zyngier@arm.com> | 2018-12-13 10:35:31 +0100 |
| commit | 06459901d55ee2f690b8e1fe084fb03061d617cf (patch) | |
| tree | 80ca6e836924930684dfaa8ee308267ad71e5e5e | |
| parent | platform-msi: Free descriptors in platform_msi_domain_free() (diff) | |
| download | linux-06459901d55ee2f690b8e1fe084fb03061d617cf.tar.xz linux-06459901d55ee2f690b8e1fe084fb03061d617cf.zip | |
irq/irq_sim: Store multiple interrupt offsets in a bitmap
Two threads can try to fire the irq_sim with different offsets and will
end up fighting for the irq_work asignment. Thomas Gleixner suggested a
solution based on a bitfield where we set a bit for every offset
associated with an interrupt that should be fired and then iterate over
all set bits in the interrupt handler.
This is a slightly modified solution using a bitmap so that we don't
impose a limit on the number of interrupts one can allocate with
irq_sim.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| -rw-r--r-- | include/linux/irq_sim.h | 2 | ||||
| -rw-r--r-- | kernel/irq/irq_sim.c | 23 |
2 files changed, 22 insertions, 3 deletions
diff --git a/include/linux/irq_sim.h b/include/linux/irq_sim.h index 630a57e55db6..4500d453a63e 100644 --- a/include/linux/irq_sim.h +++ b/include/linux/irq_sim.h @@ -16,7 +16,7 @@ struct irq_sim_work_ctx { struct irq_work work; - int irq; + unsigned long *pending; }; struct irq_sim_irq_ctx { diff --git a/kernel/irq/irq_sim.c b/kernel/irq/irq_sim.c index dd20d0d528d4..98a20e1594ce 100644 --- a/kernel/irq/irq_sim.c +++ b/kernel/irq/irq_sim.c @@ -34,9 +34,20 @@ static struct irq_chip irq_sim_irqchip = { static void irq_sim_handle_irq(struct irq_work *work) { struct irq_sim_work_ctx *work_ctx; + unsigned int offset = 0; + struct irq_sim *sim; + int irqnum; work_ctx = container_of(work, struct irq_sim_work_ctx, work); - handle_simple_irq(irq_to_desc(work_ctx->irq)); + sim = container_of(work_ctx, struct irq_sim, work_ctx); + + while (!bitmap_empty(work_ctx->pending, sim->irq_count)) { + offset = find_next_bit(work_ctx->pending, + sim->irq_count, offset); + clear_bit(offset, work_ctx->pending); + irqnum = irq_sim_irqnum(sim, offset); + handle_simple_irq(irq_to_desc(irqnum)); + } } /** @@ -63,6 +74,13 @@ int irq_sim_init(struct irq_sim *sim, unsigned int num_irqs) return sim->irq_base; } + sim->work_ctx.pending = bitmap_zalloc(num_irqs, GFP_KERNEL); + if (!sim->work_ctx.pending) { + kfree(sim->irqs); + irq_free_descs(sim->irq_base, num_irqs); + return -ENOMEM; + } + for (i = 0; i < num_irqs; i++) { sim->irqs[i].irqnum = sim->irq_base + i; sim->irqs[i].enabled = false; @@ -89,6 +107,7 @@ EXPORT_SYMBOL_GPL(irq_sim_init); void irq_sim_fini(struct irq_sim *sim) { irq_work_sync(&sim->work_ctx.work); + bitmap_free(sim->work_ctx.pending); irq_free_descs(sim->irq_base, sim->irq_count); kfree(sim->irqs); } @@ -143,7 +162,7 @@ EXPORT_SYMBOL_GPL(devm_irq_sim_init); void irq_sim_fire(struct irq_sim *sim, unsigned int offset) { if (sim->irqs[offset].enabled) { - sim->work_ctx.irq = irq_sim_irqnum(sim, offset); + set_bit(offset, sim->work_ctx.pending); irq_work_queue(&sim->work_ctx.work); } } |