From d3ebdc1772c0714faca14eec789ff082f6e00535 Mon Sep 17 00:00:00 2001 From: Vladimir Murzin Date: Mon, 27 Jul 2026 17:34:14 +0100 Subject: [PATCH] arm64: suspend: Initialize PMR on resume When we resume from cpu_suspend() context tracking, specially, ct_idle_exit() performs IRQ save/restore sequence. It doesn't cause any functional issues since we have masked all exceptions prior suspend and have not restored them. However, in case of pseudo-NMI PMR can be set by firmware to arbitrary value, thus IRQ save/restore routines manipulates this arbitrary value. Again, it doesn't cause any issues since PMR variant of IRQ save helper carries a __pmr_irqs_disabled_flags() guard. Going forward __pmr_irqs_disabled_flags() guard will be gone and we will call __pmr_local_irq_disable() unconditionally - that would cause warning in case CONFIG_ARM64_DEBUG_PRIORITY_MASKING is set. Initialize PMR to a value known to Linux on resume until the normal exception restore path restores the saved DAIF and PMR state. Signed-off-by: Vladimir Murzin Signed-off-by: Will Deacon --- arch/arm64/mm/proc.S | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index 22866b49be37..06c8bc9a85d6 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -169,6 +169,13 @@ alternative_if ARM64_HAS_RAS_EXTN msr_s SYS_DISR_EL1, xzr alternative_else_nop_endif +#ifdef CONFIG_ARM64_PSEUDO_NMI +alternative_if ARM64_HAS_GIC_PRIO_MASKING + mov x1, #GIC_PRIO_IRQON + msr_s SYS_ICC_PMR_EL1, x1 +alternative_else_nop_endif +#endif + ptrauth_keys_install_kernel_nosync x14, x1, x2, x3 isb ret