MIPS: IRQ: Fix disable_irq on CPU IRQs

If the irq_chip does not define .irq_disable, any call to disable_irq
will defer disabling the IRQ until it fires while marked as disabled.
This assumes that the handler function checks for this condition, which
handle_percpu_irq does not. In this case, calling disable_irq leads to
an IRQ storm, if the interrupt fires while disabled.

This optimization is only useful when disabling the IRQ is slow, which
is not true for the MIPS CPU IRQ.

Disable this optimization by implementing .irq_disable and .irq_enable

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Cc: stable@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8949/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/arch/mips/kernel/irq_cpu.c b/arch/mips/kernel/irq_cpu.c
index 590c2c980fd38b6b3d3b3740d3987cadbfc78b76..6eb7a3f515fc82d97cb4cbbc1f1160dfb5d345d8 100644 (file)
--- a/arch/mips/kernel/irq_cpu.c
+++ b/arch/mips/kernel/irq_cpu.c
@@ -57,6 +57,8 @@ static struct irq_chip mips_cpu_irq_controller = {
        .irq_mask_ack   = mask_mips_irq,
        .irq_unmask     = unmask_mips_irq,
        .irq_eoi        = unmask_mips_irq,
+       .irq_disable    = mask_mips_irq,
+       .irq_enable     = unmask_mips_irq,
 };
 
 /*
@@ -93,6 +95,8 @@ static struct irq_chip mips_mt_cpu_irq_controller = {
        .irq_mask_ack   = mips_mt_cpu_irq_ack,
        .irq_unmask     = unmask_mips_irq,
        .irq_eoi        = unmask_mips_irq,
+       .irq_disable    = mask_mips_irq,
+       .irq_enable     = unmask_mips_irq,
 };
 
 asmlinkage void __weak plat_irq_dispatch(void)