[PATCH v7 1/4] irqchip: gic: Support hierarchy irq domain.
Marc Zyngier
marc.zyngier at arm.com
Wed Nov 19 09:18:38 PST 2014
Hi Yingjoe,
On Wed, Nov 19 2014 at 2:14:08 pm GMT, Yingjoe Chen <yingjoe.chen at mediatek.com> wrote:
> Add support to use gic as a parent for stacked irq domain.
>
> Signed-off-by: Yingjoe Chen <yingjoe.chen at mediatek.com>
> ---
> drivers/irqchip/Kconfig | 1 +
> drivers/irqchip/irq-gic.c | 78 ++++++++++++++++++++++++++++++++---------------
> 2 files changed, 55 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index b21f12f..7f34138 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -5,6 +5,7 @@ config IRQCHIP
> config ARM_GIC
> bool
> select IRQ_DOMAIN
> + select IRQ_DOMAIN_HIERARCHY
> select MULTI_IRQ_HANDLER
>
> config GIC_NON_BANKED
> diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
> index 38493ff..464dd53 100644
> --- a/drivers/irqchip/irq-gic.c
> +++ b/drivers/irqchip/irq-gic.c
> @@ -788,17 +788,16 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
> {
> if (hw < 32) {
> irq_set_percpu_devid(irq);
> - irq_set_chip_and_handler(irq, &gic_chip,
> - handle_percpu_devid_irq);
> + irq_domain_set_info(d, irq, hw, &gic_chip, d->host_data,
> + handle_percpu_devid_irq, NULL, NULL);
> set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN);
> } else {
> - irq_set_chip_and_handler(irq, &gic_chip,
> - handle_fasteoi_irq);
> + irq_domain_set_info(d, irq, hw, &gic_chip, d->host_data,
> + handle_fasteoi_irq, NULL, NULL);
> set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
>
> gic_routable_irq_domain_ops->map(d, irq, hw);
> }
> - irq_set_chip_data(irq, d->host_data);
> return 0;
> }
>
> @@ -858,6 +857,31 @@ static struct notifier_block gic_cpu_notifier = {
> };
> #endif
>
> +static int gic_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
> + unsigned int nr_irqs, void *arg)
> +{
> + int i, ret;
> + irq_hw_number_t hwirq;
> + unsigned int type = IRQ_TYPE_NONE;
> + struct of_phandle_args *irq_data = arg;
> +
> + ret = gic_irq_domain_xlate(domain, irq_data->np, irq_data->args,
> + irq_data->args_count, &hwirq, &type);
> + if (ret)
> + return ret;
> +
> + for (i = 0; i < nr_irqs; i++)
> + gic_irq_domain_map(domain, virq+i, hwirq+i);
nit: spacing around '+'.
> +
> + return 0;
> +}
> +
> +static const struct irq_domain_ops gic_irq_domain_hierarchy_ops = {
> + .xlate = gic_irq_domain_xlate,
> + .alloc = gic_irq_domain_alloc,
> + .free = irq_domain_free_irqs_top,
I'm convinced that irq_domain_free_irqs_top is the wrong function to
call here, because you're calling it from the bottom, not the top-level
(it has no parent).
I cannot verify this with your code as I don't a working platform with
GICv2m, but if I enable something similar on GICv3, it dies a very
painful way:
Unable to handle kernel NULL pointer dereference at virtual address 00000018
pgd = ffffffc03d059000
[00000018] *pgd=0000000081356003, *pud=0000000081356003, *pmd=0000000000000000
Internal error: Oops: 96000006 [#1] SMP
Modules linked in:
CPU: 4 PID: 1052 Comm: sh Not tainted 3.18.0-rc4+ #3311
task: ffffffc03e320000 ti: ffffffc001390000 task.ti: ffffffc001390000
PC is at irq_domain_free_irqs_recursive+0x1c/0x80
LR is at irq_domain_free_irqs_common+0x88/0x9c
pc : [<ffffffc0000ed790>] lr : [<ffffffc0000ede20>] pstate: 60000145
[...]
[<ffffffc0000ed790>] irq_domain_free_irqs_recursive+0x1c/0x80
[<ffffffc0000ede1c>] irq_domain_free_irqs_common+0x84/0x9c
[<ffffffc0000ede98>] irq_domain_free_irqs_top+0x64/0x7c <-- gic_domain.free()
[<ffffffc0000ed798>] irq_domain_free_irqs_recursive+0x24/0x80
[<ffffffc0000ee468>] irq_domain_free_irqs_parent+0x14/0x20
[<ffffffc0003500b8>] its_irq_domain_free+0xc8/0x250
[<ffffffc0000ed798>] irq_domain_free_irqs_recursive+0x24/0x80
[<ffffffc0000ede1c>] irq_domain_free_irqs_common+0x84/0x9c
[<ffffffc0000ede98>] irq_domain_free_irqs_top+0x64/0x7c
[<ffffffc0000ef518>] msi_domain_free+0x70/0x88
[<ffffffc0000ed798>] irq_domain_free_irqs_recursive+0x24/0x80
[<ffffffc0000ee3ac>] irq_domain_free_irqs+0x108/0x17c
[<ffffffc0000efb68>] msi_domain_free_irqs+0x28/0x4c
[<ffffffc000369cac>] free_msi_irqs+0xb4/0x1c0
[<ffffffc00036adec>] pci_disable_msix+0x3c/0x4c
[...]
and I cannot see how this could work on the standard GIC either.
Thomas, Jiang: could you please confirm or infirm my suspicions? My
understanding is that irq_domain_free_irqs_top can only be called from
the top-level domain.
> +};
> +
> static const struct irq_domain_ops gic_irq_domain_ops = {
> .map = gic_irq_domain_map,
> .unmap = gic_irq_domain_unmap,
> @@ -948,18 +972,6 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start,
> gic_cpu_map[i] = 0xff;
>
> /*
> - * For primary GICs, skip over SGIs.
> - * For secondary GICs, skip over PPIs, too.
> - */
> - if (gic_nr == 0 && (irq_start & 31) > 0) {
> - hwirq_base = 16;
> - if (irq_start != -1)
> - irq_start = (irq_start & ~31) + 16;
> - } else {
> - hwirq_base = 32;
> - }
> -
> - /*
> * Find out how many interrupts are supported.
> * The GIC only supports up to 1020 interrupt sources.
> */
> @@ -969,10 +981,32 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start,
> gic_irqs = 1020;
> gic->gic_irqs = gic_irqs;
>
> - gic_irqs -= hwirq_base; /* calculate # of irqs to allocate */
> + if (node) { /* DT case */
> + const struct irq_domain_ops *ops =
> + &gic_irq_domain_hierarchy_ops;
nit: please put this on the same line, even if it is longer than 80
characters.
> +
> + if (!of_property_read_u32(node, "arm,routable-irqs",
> + &nr_routable_irqs)) {
> + ops = &gic_irq_domain_ops;
> + gic_irqs = nr_routable_irqs;
> + }
> +
> + gic->domain = irq_domain_add_linear(node, gic_irqs, ops, gic);
> + } else { /* Non-DT case */
> + /*
> + * For primary GICs, skip over SGIs.
> + * For secondary GICs, skip over PPIs, too.
> + */
> + if (gic_nr == 0 && (irq_start & 31) > 0) {
> + hwirq_base = 16;
> + if (irq_start != -1)
> + irq_start = (irq_start & ~31) + 16;
> + } else {
> + hwirq_base = 32;
> + }
> +
> + gic_irqs -= hwirq_base; /* calculate # of irqs to allocate */
>
> - if (of_property_read_u32(node, "arm,routable-irqs",
> - &nr_routable_irqs)) {
> irq_base = irq_alloc_descs(irq_start, 16, gic_irqs,
> numa_node_id());
> if (IS_ERR_VALUE(irq_base)) {
> @@ -983,10 +1017,6 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start,
>
> gic->domain = irq_domain_add_legacy(node, gic_irqs, irq_base,
> hwirq_base, &gic_irq_domain_ops, gic);
> - } else {
> - gic->domain = irq_domain_add_linear(node, nr_routable_irqs,
> - &gic_irq_domain_ops,
> - gic);
> }
>
> if (WARN_ON(!gic->domain))
Thanks,
M.
--
Jazz is not dead. It just smells funny.
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