Since the device hierarchy domain was added by commit c98c1822ee13
("irqchip/mips-gic: Add device hierarchy domain"), GIC local interrupts
have been broken.
Users attempting to setup a per-cpu local IRQ, for example the GIC timer
clock events code in drivers/clocksource/mips-gic-timer.c, the
setup_percpu_irq function would refuse with -EINVAL because the GIC
irqchip driver never called irq_set_percpu_devid so the
IRQ_PER_CPU_DEVID flag was never set for the IRQ. This happens because
irq_set_percpu_devid was being called from the gic_irq_domain_map
function which is no longer called.
Doing only that runs into further problems because gic_dev_domain_alloc
set the struct irq_chip for all interrupts, local or shared, to
gic_level_irq_controller despite that only being suitable for shared
interrupts. The typical outcome of this is that gic_level_irq_controller
callback functions are called for local interrupts, and then hwirq
number calculations overflow & the driver ends up attempting to access
some invalid register with an address calculated from an invalid hwirq
number. Best case scenario is that this then leads to a bus error. This
is fixed by abstracting the setup of the hwirq & chip to a new function
gic_setup_dev_chip which is used by both the root GIC IRQ domain & the
device domain.
Finally, decoding local interrupts failed because gic_dev_domain_alloc
only called irq_domain_alloc_irqs_parent for shared interrupts. Local
ones were therefore never associated with hwirqs in the root GIC IRQ
domain and the virq in gic_handle_local_int would always be 0. This is
fixed by calling irq_domain_alloc_irqs_parent unconditionally & having
gic_irq_domain_alloc handle both local & shared interrupts, which is
easy due to the aforementioned abstraction of chip setup into
gic_setup_dev_chip.
This fixes use of the MIPS GIC timer for clock events, which has been
broken since c98c1822ee13 ("irqchip/mips-gic: Add device hierarchy
domain") but hadn't been noticed due to a silent fallback to the MIPS
coprocessor 0 count/compare clock events device.
Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
Fixes: c98c1822ee13 ("irqchip/mips-gic: Add device hierarchy domain")
Cc: stable <stable@xxxxxxxxxxxxxxx> # v4.6+
Cc: Qais Yousef <qsyousef@xxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Jason Cooper <jason@xxxxxxxxxxxxxx>
Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-mips@xxxxxxxxxxxxxx
---
drivers/irqchip/irq-mips-gic.c | 105 ++++++++++++++++++++---------------------
1 file changed, 50 insertions(+), 55 deletions(-)
diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c
index 83f4983..61856964 100644
--- a/drivers/irqchip/irq-mips-gic.c
+++ b/drivers/irqchip/irq-mips-gic.c
@@ -638,27 +638,6 @@ static int gic_local_irq_domain_map(struct irq_domain *d, unsigned int virq,
if (!gic_local_irq_is_routable(intr))
return -EPERM;
- /*
- * HACK: These are all really percpu interrupts, but the rest
- * of the MIPS kernel code does not use the percpu IRQ API for
- * the CP0 timer and performance counter interrupts.
- */
- switch (intr) {
- case GIC_LOCAL_INT_TIMER:
- case GIC_LOCAL_INT_PERFCTR:
- case GIC_LOCAL_INT_FDC:
- irq_set_chip_and_handler(virq,
- &gic_all_vpes_local_irq_controller,
- handle_percpu_irq);
- break;
- default:
- irq_set_chip_and_handler(virq,
- &gic_local_irq_controller,
- handle_percpu_devid_irq);
- irq_set_percpu_devid(virq);
- break;
- }
-
spin_lock_irqsave(&gic_lock, flags);
for (i = 0; i < gic_vpes; i++) {
u32 val = GIC_MAP_TO_PIN_MSK | gic_cpu_pin;
@@ -724,16 +703,42 @@ static int gic_shared_irq_domain_map(struct irq_domain *d, unsigned int virq,
return 0;
}
-static int gic_irq_domain_map(struct irq_domain *d, unsigned int virq,
- irq_hw_number_t hw)
+static int gic_setup_dev_chip(struct irq_domain *d, unsigned int virq,
+ unsigned int hwirq)
{
- if (GIC_HWIRQ_TO_LOCAL(hw) < GIC_NUM_LOCAL_INTRS)
- return gic_local_irq_domain_map(d, virq, hw);
+ struct irq_chip *chip;
+ int err;
- irq_set_chip_and_handler(virq, &gic_level_irq_controller,
- handle_level_irq);
+ if (hwirq >= GIC_SHARED_HWIRQ_BASE) {
+ err = irq_domain_set_hwirq_and_chip(d, virq, hwirq,
+ &gic_level_irq_controller,
+ NULL);
+ } else {
+ switch (GIC_HWIRQ_TO_LOCAL(hwirq)) {
+ case GIC_LOCAL_INT_TIMER:
+ case GIC_LOCAL_INT_PERFCTR:
+ case GIC_LOCAL_INT_FDC:
+ /*
+ * HACK: These are all really percpu interrupts, but
+ * the rest of the MIPS kernel code does not use the
+ * percpu IRQ API for them.
+ */
+ chip = &gic_all_vpes_local_irq_controller;
+ irq_set_handler(virq, handle_percpu_irq);
+ break;
- return gic_shared_irq_domain_map(d, virq, hw, 0);
+ default:
+ chip = &gic_local_irq_controller;
+ irq_set_handler(virq, handle_percpu_devid_irq);
+ irq_set_percpu_devid(virq);
+ break;
+ }
+
+ err = irq_domain_set_hwirq_and_chip(d, virq, hwirq,
+ chip, NULL);
+ }
+
+ return err;
}
static int gic_irq_domain_alloc(struct irq_domain *d, unsigned int virq,
@@ -744,15 +749,12 @@ static int gic_irq_domain_alloc(struct irq_domain *d, unsigned int virq,
int cpu, ret, i;
if (spec->type == GIC_DEVICE) {
- /* verify that it doesn't conflict with an IPI irq */
- if (test_bit(spec->hwirq, ipi_resrv))
+ /* verify that shared irqs don't conflict with an IPI irq */
+ if ((spec->hwirq >= GIC_SHARED_HWIRQ_BASE) &&
+ test_bit(GIC_HWIRQ_TO_SHARED(spec->hwirq), ipi_resrv))
return -EBUSY;
- hwirq = GIC_SHARED_TO_HWIRQ(spec->hwirq);
-
- return irq_domain_set_hwirq_and_chip(d, virq, hwirq,
- &gic_level_irq_controller,
- NULL);
+ return gic_setup_dev_chip(d, virq, spec->hwirq);
} else {
base_hwirq = find_first_bit(ipi_resrv, gic_shared_intrs);
if (base_hwirq == gic_shared_intrs) {
@@ -821,7 +823,6 @@ int gic_irq_domain_match(struct irq_domain *d, struct device_node *node,
}
static const struct irq_domain_ops gic_irq_domain_ops = {
- .map = gic_irq_domain_map,
.alloc = gic_irq_domain_alloc,
.free = gic_irq_domain_free,
.match = gic_irq_domain_match,
@@ -852,29 +853,20 @@ static int gic_dev_domain_alloc(struct irq_domain *d, unsigned int virq,
struct irq_fwspec *fwspec = arg;
struct gic_irq_spec spec = {
.type = GIC_DEVICE,
- .hwirq = fwspec->param[1],
};
int i, ret;
- bool is_shared = fwspec->param[0] == GIC_SHARED;
- if (is_shared) {
- ret = irq_domain_alloc_irqs_parent(d, virq, nr_irqs, &spec);
- if (ret)
- return ret;
- }
+ if (fwspec->param[0] == GIC_SHARED)
+ spec.hwirq = GIC_SHARED_TO_HWIRQ(fwspec->param[1]);
+ else
+ spec.hwirq = GIC_LOCAL_TO_HWIRQ(fwspec->param[1]);
+
+ ret = irq_domain_alloc_irqs_parent(d, virq, nr_irqs, &spec);
+ if (ret)
+ return ret;
for (i = 0; i < nr_irqs; i++) {
- irq_hw_number_t hwirq;
-
- if (is_shared)
- hwirq = GIC_SHARED_TO_HWIRQ(spec.hwirq + i);
- else
- hwirq = GIC_LOCAL_TO_HWIRQ(spec.hwirq + i);
-
- ret = irq_domain_set_hwirq_and_chip(d, virq + i,
- hwirq,
- &gic_level_irq_controller,
- NULL);
+ ret = gic_setup_dev_chip(d, virq + i, spec.hwirq + i);
if (ret)
goto error;
}
@@ -896,7 +888,10 @@ void gic_dev_domain_free(struct irq_domain *d, unsigned int virq,
static void gic_dev_domain_activate(struct irq_domain *domain,
struct irq_data *d)
{
- gic_shared_irq_domain_map(domain, d->irq, d->hwirq, 0);
+ if (GIC_HWIRQ_TO_LOCAL(d->hwirq) < GIC_NUM_LOCAL_INTRS)
+ gic_local_irq_domain_map(domain, d->irq, d->hwirq);
+ else
+ gic_shared_irq_domain_map(domain, d->irq, d->hwirq, 0);
}
static struct irq_domain_ops gic_dev_domain_ops = {
--
2.9.3
--
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