Provide a higher priority to be used for pseudo-NMIs. When such an interrupt is received, keep interrupts fully disabled at CPU level to prevent receiving other pseudo-NMIs while handling the current one.
Signed-off-by: Julien Thierry <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Jason Cooper <[email protected]> Cc: Marc Zyngier <[email protected]> --- drivers/irqchip/irq-gic-v3.c | 42 ++++++++++++++++++++++++++++++++++++------ 1 file changed, 36 insertions(+), 6 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index f833842..b9a00364 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -41,6 +41,8 @@ #include "irq-gic-common.h" +#define GICD_INT_NMI_PRI (GICD_INT_DEF_PRI & ~0x80) + struct redist_region { void __iomem *redist_base; phys_addr_t phys_base; @@ -375,12 +377,45 @@ static u64 gic_mpidr_to_affinity(unsigned long mpidr) return aff; } +static inline void gic_deactivate_unexpected_irq(u32 irqnr) +{ + if (static_branch_likely(&supports_deactivate_key)) { + if (irqnr < 8192) + gic_write_dir(irqnr); + } else { + gic_write_eoir(irqnr); + } +} + +static inline void gic_handle_nmi(u32 irqnr, struct pt_regs *regs) +{ + int err; + + if (static_branch_likely(&supports_deactivate_key)) + gic_write_eoir(irqnr); + /* + * Leave the PSR.I bit set to prevent other NMIs to be + * received while handling this one. + * PSR.I will be restored when we ERET to the + * interrupted context. + */ + err = handle_domain_nmi(gic_data.domain, irqnr, regs); + if (err) + gic_deactivate_unexpected_irq(irqnr); +} + static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs) { u32 irqnr; irqnr = gic_read_iar(); + if (gic_supports_nmi() && + unlikely(gic_read_rpr() == GICD_INT_NMI_PRI)) { + gic_handle_nmi(irqnr, regs); + return; + } + if (gic_prio_masking_enabled()) { gic_pmr_mask_irqs(); gic_arch_enable_irqs(); @@ -397,12 +432,7 @@ static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs err = handle_domain_irq(gic_data.domain, irqnr, regs); if (err) { WARN_ONCE(true, "Unexpected interrupt received!\n"); - if (static_branch_likely(&supports_deactivate_key)) { - if (irqnr < 8192) - gic_write_dir(irqnr); - } else { - gic_write_eoir(irqnr); - } + gic_deactivate_unexpected_irq(irqnr); } return; } -- 1.9.1
