diff options
| author | Julien Thierry <julien.thierry@arm.com> | 2019-06-11 12:38:11 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2019-06-21 17:50:23 +0300 |
| commit | 48ce8f80f5901f1f031b00be66d659d39f33b0a1 (patch) | |
| tree | cc0a9df40912c904f658cc063c2e2f230eb80489 | |
| parent | bd82d4bd21880b7c4d5f5756be435095d6ae07b5 (diff) | |
| download | linux-48ce8f80f5901f1f031b00be66d659d39f33b0a1.tar.xz | |
arm64: irqflags: Introduce explicit debugging for IRQ priorities
Using IRQ priority masking to enable/disable interrupts is a bit
sensitive as it requires to deal with both ICC_PMR_EL1 and PSR.I.
Introduce some validity checks to both highlight the states in which
functions dealing with IRQ enabling/disabling can (not) be called, and
bark a warning when called in an unexpected state.
Since these checks are done on hotpaths, introduce a build option to
choose whether to do the checking.
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
| -rw-r--r-- | arch/arm64/Kconfig | 11 | ||||
| -rw-r--r-- | arch/arm64/include/asm/cpufeature.h | 6 | ||||
| -rw-r--r-- | arch/arm64/include/asm/daifflags.h | 7 | ||||
| -rw-r--r-- | arch/arm64/include/asm/irqflags.h | 12 |
4 files changed, 36 insertions, 0 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index acd72e5f78ae..bd3915ae7b53 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1436,6 +1436,17 @@ config ARM64_PSEUDO_NMI If unsure, say N +if ARM64_PSEUDO_NMI +config ARM64_DEBUG_PRIORITY_MASKING + bool "Debug interrupt priority masking" + help + This adds runtime checks to functions enabling/disabling + interrupts when using priority masking. The additional checks verify + the validity of ICC_PMR_EL1 when calling concerned functions. + + If unsure, say N +endif + config RELOCATABLE bool help diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index bc895c869892..693a086e2148 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -617,6 +617,12 @@ static inline bool system_uses_irq_prio_masking(void) cpus_have_const_cap(ARM64_HAS_IRQ_PRIO_MASKING); } +static inline bool system_has_prio_mask_debugging(void) +{ + return IS_ENABLED(CONFIG_ARM64_DEBUG_PRIORITY_MASKING) && + system_uses_irq_prio_masking(); +} + #define ARM64_SSBD_UNKNOWN -1 #define ARM64_SSBD_FORCE_DISABLE 0 #define ARM64_SSBD_KERNEL 1 diff --git a/arch/arm64/include/asm/daifflags.h b/arch/arm64/include/asm/daifflags.h index f93204f319da..eca5bee1d85b 100644 --- a/arch/arm64/include/asm/daifflags.h +++ b/arch/arm64/include/asm/daifflags.h @@ -28,6 +28,10 @@ /* mask/save/unmask/restore all exceptions, including interrupts. */ static inline void local_daif_mask(void) { + WARN_ON(system_has_prio_mask_debugging() && + (read_sysreg_s(SYS_ICC_PMR_EL1) == (GIC_PRIO_IRQOFF | + GIC_PRIO_PSR_I_SET))); + asm volatile( "msr daifset, #0xf // local_daif_mask\n" : @@ -62,6 +66,9 @@ static inline void local_daif_restore(unsigned long flags) { bool irq_disabled = flags & PSR_I_BIT; + WARN_ON(system_has_prio_mask_debugging() && + !(read_sysreg(daif) & PSR_I_BIT)); + if (!irq_disabled) { trace_hardirqs_on(); diff --git a/arch/arm64/include/asm/irqflags.h b/arch/arm64/include/asm/irqflags.h index a1372722f12e..cac2d2a3c24e 100644 --- a/arch/arm64/include/asm/irqflags.h +++ b/arch/arm64/include/asm/irqflags.h @@ -40,6 +40,12 @@ */ static inline void arch_local_irq_enable(void) { + if (system_has_prio_mask_debugging()) { + u32 pmr = read_sysreg_s(SYS_ICC_PMR_EL1); + + WARN_ON_ONCE(pmr != GIC_PRIO_IRQON && pmr != GIC_PRIO_IRQOFF); + } + asm volatile(ALTERNATIVE( "msr daifclr, #2 // arch_local_irq_enable\n" "nop", @@ -53,6 +59,12 @@ static inline void arch_local_irq_enable(void) static inline void arch_local_irq_disable(void) { + if (system_has_prio_mask_debugging()) { + u32 pmr = read_sysreg_s(SYS_ICC_PMR_EL1); + + WARN_ON_ONCE(pmr != GIC_PRIO_IRQON && pmr != GIC_PRIO_IRQOFF); + } + asm volatile(ALTERNATIVE( "msr daifset, #2 // arch_local_irq_disable", __msr_s(SYS_ICC_PMR_EL1, "%0"), |