Messages in this thread | | | From | Bartosz Golaszewski <> | Date | Tue, 11 Dec 2018 15:02:48 +0100 | Subject | Re: [PATCH] irq/irq_sim: store multiple interrupt offsets in a bitmap |
| |
pt., 9 lis 2018 o 18:21 Bartosz Golaszewski <brgl@bgdev.pl> napisał(a): > > 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> > --- > include/linux/irq_sim.h | 2 +- > 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); > } > } > -- > 2.19.1 >
Ping and Cc'ing Marc Zyngier. Any chance of getting this in for 4.21?
Bart
| |