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SubjectRe: [PATCH v2 2/9] irq/irq_sim: use irq domain
Bartosz,

On Tue, 12 Feb 2019 08:30:32 +0000,
Bartosz Golaszewski <bgolaszewski@baylibre.com> wrote:
>
> pon., 11 lut 2019 o 23:26 Marc Zyngier <marc.zyngier@arm.com> napisał(a):
> >
> > On Tue, 29 Jan 2019 09:44:04 +0100
> > Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> >
> > > From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> > >
> > > Delegate the offset to virq number mapping to the provided framework
> > > instead of handling it locally. Use the legacy domain as we want to
> > > preallocate the irq descriptors.
> >
> > Why?
> >
> > >
> > > Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> > > ---
> > > include/linux/irq_sim.h | 6 +--
> > > kernel/irq/irq_sim.c | 94 +++++++++++++++++++++++++++++------------
> > > 2 files changed, 71 insertions(+), 29 deletions(-)
> > >
> > > diff --git a/include/linux/irq_sim.h b/include/linux/irq_sim.h
> > > index eda132c22b57..b96c2f752320 100644
> > > --- a/include/linux/irq_sim.h
> > > +++ b/include/linux/irq_sim.h
> > > @@ -8,6 +8,7 @@
> > >
> > > #include <linux/irq.h>
> > > #include <linux/irq_work.h>
> > > +#include <linux/irqdomain.h>
> > > #include <linux/device.h>
> > >
> > > /*
> > > @@ -21,16 +22,15 @@ struct irq_sim_work_ctx {
> > > };
> > >
> > > struct irq_sim_irq_ctx {
> > > - int irqnum;
> > > bool enabled;
> > > };
> > >
> > > struct irq_sim {
> > > struct irq_chip chip;
> > > + struct irq_domain *domain;
> > > struct irq_sim_work_ctx work_ctx;
> > > - int irq_base;
> > > + int virq_base;
> > > unsigned int irq_count;
> > > - struct irq_sim_irq_ctx *irqs;
> > > };
> > >
> > > int irq_sim_init(struct irq_sim *sim, unsigned int num_irqs);
> > > diff --git a/kernel/irq/irq_sim.c b/kernel/irq/irq_sim.c
> > > index b732e4e2e45b..2bcdbab1bc5a 100644
> > > --- a/kernel/irq/irq_sim.c
> > > +++ b/kernel/irq/irq_sim.c
> > > @@ -44,6 +44,43 @@ static void irq_sim_handle_irq(struct irq_work *work)
> > > }
> > > }
> > >
> > > +static int irq_sim_domain_map(struct irq_domain *domain,
> > > + unsigned int virq, irq_hw_number_t hw)
> > > +{
> > > + struct irq_sim *sim = domain->host_data;
> > > + struct irq_sim_irq_ctx *ctx;
> > > +
> > > + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
> > > + if (!ctx)
> > > + return -ENOMEM;
> > > +
> > > + irq_set_chip(virq, &sim->chip);
> > > + irq_set_chip_data(virq, ctx);
> > > + irq_set_handler(virq, handle_simple_irq);
> >
> > Consider using modern APIs such as irq_domain_set_info().
> >
> > > + irq_modify_status(virq, IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE);
> >
> > Where is this requirement coming from?
> >
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static void irq_sim_domain_free(struct irq_domain *domain,
> > > + unsigned int virq, unsigned int num_irqs)
> > > +{
> > > + struct irq_sim_irq_ctx *ctx;
> > > + struct irq_data *irq;
> > > + int i;
> > > +
> > > + for (i = 0; i < num_irqs; i++) {
> > > + irq = irq_domain_get_irq_data(domain, virq + i);
> > > + ctx = irq_data_get_irq_chip_data(irq);
> > > + kfree(ctx);
> > > + }
> > > +}
> > > +
> > > +static const struct irq_domain_ops irq_sim_domain_ops = {
> > > + .map = irq_sim_domain_map,
> > > + .free = irq_sim_domain_free,
> >
> > The intended use of the v2 API is to have alloc and free as a pair, and
> > no map. So please choose which version of the API you're using here.
> > The safest bet would be to move what you do on map into alloc.
> >
> > > +};
> > > +
> > > /**
> > > * irq_sim_init - Initialize the interrupt simulator: allocate a range of
> > > * dummy interrupts.
> > > @@ -56,16 +93,15 @@ static void irq_sim_handle_irq(struct irq_work *work)
> > > */
> > > int irq_sim_init(struct irq_sim *sim, unsigned int num_irqs)
> > > {
> > > - int i;
> > > -
> > > - sim->irqs = kmalloc_array(num_irqs, sizeof(*sim->irqs), GFP_KERNEL);
> > > - if (!sim->irqs)
> > > + sim->virq_base = irq_alloc_descs(-1, 0, num_irqs, 0);
> > > + if (sim->virq_base < 0)
> > > + return sim->virq_base;
> > > +
> > > + sim->domain = irq_domain_add_legacy(NULL, num_irqs, sim->virq_base,
> > > + 0, &irq_sim_domain_ops, sim);
> >
> > Why do you need a legacy domain? As far as I can tell, this is new
> > code, hence it has no legacy.
> >
> > > + if (!sim->domain) {
> > > + irq_free_descs(sim->virq_base, num_irqs);
> > > return -ENOMEM;
> > > -
> > > - sim->irq_base = irq_alloc_descs(-1, 0, num_irqs, 0);
> > > - if (sim->irq_base < 0) {
> > > - kfree(sim->irqs);
> > > - return sim->irq_base;
> > > }
> > >
> > > sim->chip.name = "irq_sim";
> > > @@ -74,25 +110,15 @@ int irq_sim_init(struct irq_sim *sim, unsigned int num_irqs)
> > >
> > > 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);
> > > + irq_domain_remove(sim->domain);
> > > + irq_free_descs(sim->virq_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;
> > > - irq_set_chip(sim->irq_base + i, &sim->chip);
> > > - irq_set_chip_data(sim->irq_base + i, &sim->irqs[i]);
> > > - irq_set_handler(sim->irq_base + i, &handle_simple_irq);
> > > - irq_modify_status(sim->irq_base + i,
> > > - IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE);
> > > - }
> > > -
> > > init_irq_work(&sim->work_ctx.work, irq_sim_handle_irq);
> > > sim->irq_count = num_irqs;
> > >
> > > - return sim->irq_base;
> > > + return sim->virq_base;
> > > }
> > > EXPORT_SYMBOL_GPL(irq_sim_init);
> > >
> > > @@ -106,8 +132,8 @@ 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);
> > > + irq_domain_free_irqs(sim->virq_base, sim->irq_count);
> > > + irq_domain_remove(sim->domain);
> > > }
> > > EXPORT_SYMBOL_GPL(irq_sim_fini);
> > >
> > > @@ -151,6 +177,20 @@ int devm_irq_sim_init(struct device *dev, struct irq_sim *sim,
> > > }
> > > EXPORT_SYMBOL_GPL(devm_irq_sim_init);
> > >
> > > +static struct irq_sim_irq_ctx *
> > > +irq_sim_get_ctx(struct irq_sim *sim, unsigned int offset)
> > > +{
> > > + struct irq_sim_irq_ctx *ctx;
> > > + struct irq_data *irq;
> > > + int virq;
> > > +
> > > + virq = irq_find_mapping(sim->domain, offset);
> > > + irq = irq_domain_get_irq_data(sim->domain, virq);
> > > + ctx = irq_data_get_irq_chip_data(irq);
> > > +
> > > + return ctx;
> > > +}
> > > +
> > > /**
> > > * irq_sim_fire - Enqueue an interrupt.
> > > *
> > > @@ -159,7 +199,9 @@ EXPORT_SYMBOL_GPL(devm_irq_sim_init);
> > > */
> > > void irq_sim_fire(struct irq_sim *sim, unsigned int offset)
> > > {
> > > - if (sim->irqs[offset].enabled) {
> > > + struct irq_sim_irq_ctx *ctx = irq_sim_get_ctx(sim, offset);
> > > +
> > > + if (ctx->enabled) {
> > > set_bit(offset, sim->work_ctx.pending);
> > > irq_work_queue(&sim->work_ctx.work);
> > > }
> > > @@ -175,6 +217,6 @@ EXPORT_SYMBOL_GPL(irq_sim_fire);
> > > */
> > > int irq_sim_irqnum(struct irq_sim *sim, unsigned int offset)
> > > {
> > > - return sim->irqs[offset].irqnum;
> > > + return irq_find_mapping(sim->domain, offset);
> > > }
> > > EXPORT_SYMBOL_GPL(irq_sim_irqnum);
> >
> >
> > Thanks,
> >
> > M.
> > --
> > Without deviation from the norm, progress is not possible.
>
> Hi Marc,
>
> since we're so late in the release cycle and I really only need patch
> 3/9 from this series - I'll drop this patch and 1/9 as well in v3. We
> can come back to this in the next cycle.

Then this series doesn't even compile once you remove these two
patches (just removing patch #1 breaks everything). Please repost a
fixed series that can be reviewed in the light of your new, reduced
requirements.

I'd also appreciate if you could answer the questions I have above, as
it appears that you intend to bring this patch back in the future.

Thanks,

M.

--
Jazz is not dead, it just smell funny.
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