These 2 patches fix a couple of issues found with the MIPS GIC driver in
v4.14-rc1 as a result of my recent series. My apologies!
Thanks,
Paul
Paul Burton (2):
irqchip: mips-gic: Fix shifts to extract register fields
irqchip: mips-gic: Use effective affinity to unmask
drivers/irqchip/irq-mips-gic.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
--
2.14.1
The MIPS GIC driver is incorrectly using __fls to shift registers,
intending to shift to the least significant bit of a value based upon
its mask but instead shifting off all but the value's top bit. It should
actually be using __ffs to shift to the first, not last, bit of the
value.
Apparently the system I used when testing commit 3680746abd87
("irqchip: mips-gic: Convert remaining shared reg access to new
accessors") and commit b2b2e584ceab ("irqchip: mips-gic: Clean up mti,
reserved-cpu-vectors handling") managed to work correctly despite this
issue, but not all systems do...
Signed-off-by: Paul Burton <[email protected]>
Fixes: 3680746abd87 ("irqchip: mips-gic: Convert remaining shared reg access to new accessors")
Fixes: b2b2e584ceab ("irqchip: mips-gic: Clean up mti, reserved-cpu-vectors handling")
Cc: Jason Cooper <[email protected]>
Cc: Marc Zyngier <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
---
drivers/irqchip/irq-mips-gic.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c
index 40159ac12ac8..0022b31ad2c5 100644
--- a/drivers/irqchip/irq-mips-gic.c
+++ b/drivers/irqchip/irq-mips-gic.c
@@ -645,7 +645,7 @@ static int __init gic_of_init(struct device_node *node,
/* Find the first available CPU vector. */
i = 0;
- reserved = (C_SW0 | C_SW1) >> __fls(C_SW0);
+ reserved = (C_SW0 | C_SW1) >> __ffs(C_SW0);
while (!of_property_read_u32_index(node, "mti,reserved-cpu-vectors",
i++, &cpu_vec))
reserved |= BIT(cpu_vec);
@@ -684,11 +684,11 @@ static int __init gic_of_init(struct device_node *node,
gicconfig = read_gic_config();
gic_shared_intrs = gicconfig & GIC_CONFIG_NUMINTERRUPTS;
- gic_shared_intrs >>= __fls(GIC_CONFIG_NUMINTERRUPTS);
+ gic_shared_intrs >>= __ffs(GIC_CONFIG_NUMINTERRUPTS);
gic_shared_intrs = (gic_shared_intrs + 1) * 8;
gic_vpes = gicconfig & GIC_CONFIG_PVPS;
- gic_vpes >>= __fls(GIC_CONFIG_PVPS);
+ gic_vpes >>= __ffs(GIC_CONFIG_PVPS);
gic_vpes = gic_vpes + 1;
if (cpu_has_veic) {
--
2.14.1
Commit 7778c4b27cbe ("irqchip: mips-gic: Use pcpu_masks to avoid reading
GIC_SH_MASK*") adjusted the way we handle masking interrupts to set &
clear the interrupt's bit in each pcpu_mask. This allows us to avoid
needing to read the GIC mask registers and perform a bitwise and of
their values with the pending & pcpu_masks.
Unfortunately this didn't quite work for IPIs, which were mapped to a
particular CPU/VP during initialisation but never set the affinity or
effective_affinity fields of their struct irq_desc. This led to them
losing their affinity when gic_unmask_irq() was called for them, and
they'd all become affine to cpu0.
Fix this by:
1) Setting the effective affinity of interrupts in
gic_shared_irq_domain_map(), which is where we actually map an
interrupt to a CPU/VP. This ensures that the effective affinity mask
is always valid, not just after explicitly setting affinity.
2) Using an interrupt's effective affinity when unmasking it, which
prevents gic_unmask_irq() from unintentionally changing which
pcpu_mask includes an interrupt.
Signed-off-by: Paul Burton <[email protected]>
Fixes: 7778c4b27cbe ("irqchip: mips-gic: Use pcpu_masks to avoid reading GIC_SH_MASK*")
Cc: Jason Cooper <[email protected]>
Cc: Marc Zyngier <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
---
drivers/irqchip/irq-mips-gic.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c
index 0022b31ad2c5..c90976d7e53c 100644
--- a/drivers/irqchip/irq-mips-gic.c
+++ b/drivers/irqchip/irq-mips-gic.c
@@ -175,14 +175,13 @@ static void gic_mask_irq(struct irq_data *d)
static void gic_unmask_irq(struct irq_data *d)
{
- struct cpumask *affinity = irq_data_get_affinity_mask(d);
unsigned int intr = GIC_HWIRQ_TO_SHARED(d->hwirq);
unsigned int cpu;
write_gic_smask(intr);
gic_clear_pcpu_masks(intr);
- cpu = cpumask_first_and(affinity, cpu_online_mask);
+ cpu = cpumask_first(irq_data_get_effective_affinity_mask(d));
set_bit(intr, per_cpu_ptr(pcpu_masks, cpu));
}
@@ -420,13 +419,17 @@ static int gic_shared_irq_domain_map(struct irq_domain *d, unsigned int virq,
irq_hw_number_t hw, unsigned int cpu)
{
int intr = GIC_HWIRQ_TO_SHARED(hw);
+ struct irq_data *data;
unsigned long flags;
+ data = irq_get_irq_data(virq);
+
spin_lock_irqsave(&gic_lock, flags);
write_gic_map_pin(intr, GIC_MAP_PIN_MAP_TO_PIN | gic_cpu_pin);
write_gic_map_vp(intr, BIT(mips_cm_vp_id(cpu)));
gic_clear_pcpu_masks(intr);
set_bit(intr, per_cpu_ptr(pcpu_masks, cpu));
+ irq_data_update_effective_affinity(data, cpumask_of(cpu));
spin_unlock_irqrestore(&gic_lock, flags);
return 0;
--
2.14.1