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author | Mark Rutland <mark.rutland@arm.com> | 2020-11-30 12:59:45 +0100 |
---|---|---|
committer | Will Deacon <will@kernel.org> | 2020-11-30 13:11:38 +0100 |
commit | 105fc3352077bba5faaf12cf39f7e3aad26fb70b (patch) | |
tree | 7ea4243d1adb728a97ea5fa2c545118dead8f339 | |
parent | arm64: entry: prepare ret_to_user for function call (diff) | |
download | linux-105fc3352077bba5faaf12cf39f7e3aad26fb70b.tar.xz linux-105fc3352077bba5faaf12cf39f7e3aad26fb70b.zip |
arm64: entry: move el1 irq/nmi logic to C
In preparation for reworking the EL1 irq/nmi entry code, move the
existing logic to C. We no longer need the asm_nmi_enter() and
asm_nmi_exit() wrappers, so these are removed. The new C functions are
marked noinstr, which prevents compiler instrumentation and runtime
probing.
In subsequent patches we'll want the new C helpers to be called in all
cases, so we don't bother wrapping the calls with ifdeferry. Even when
the new C functions are stubs the trivial calls are unlikely to have a
measurable impact on the IRQ or NMI paths anyway.
Prototypes are added to <asm/exception.h> as otherwise (in some
configurations) GCC will complain about the lack of a forward
declaration. We already do this for existing function, e.g.
enter_from_user_mode().
The new helpers are marked as noinstr (which prevents all
instrumentation, tracing, and kprobes). Otherwise, there should be no
functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201130115950.22492-7-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
-rw-r--r-- | arch/arm64/include/asm/exception.h | 2 | ||||
-rw-r--r-- | arch/arm64/kernel/entry-common.c | 16 | ||||
-rw-r--r-- | arch/arm64/kernel/entry.S | 34 | ||||
-rw-r--r-- | arch/arm64/kernel/irq.c | 15 |
4 files changed, 22 insertions, 45 deletions
diff --git a/arch/arm64/include/asm/exception.h b/arch/arm64/include/asm/exception.h index 99b9383cd036..d69d53dd7be7 100644 --- a/arch/arm64/include/asm/exception.h +++ b/arch/arm64/include/asm/exception.h @@ -31,6 +31,8 @@ static inline u32 disr_to_esr(u64 disr) return esr; } +asmlinkage void noinstr enter_el1_irq_or_nmi(struct pt_regs *regs); +asmlinkage void noinstr exit_el1_irq_or_nmi(struct pt_regs *regs); asmlinkage void enter_from_user_mode(void); void do_mem_abort(unsigned long addr, unsigned int esr, struct pt_regs *regs); void do_undefinstr(struct pt_regs *regs); diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c index 9a685e7686fe..920da254be1d 100644 --- a/arch/arm64/kernel/entry-common.c +++ b/arch/arm64/kernel/entry-common.c @@ -17,6 +17,22 @@ #include <asm/mmu.h> #include <asm/sysreg.h> +asmlinkage void noinstr enter_el1_irq_or_nmi(struct pt_regs *regs) +{ + if (IS_ENABLED(CONFIG_ARM64_PSEUDO_NMI) && !interrupts_enabled(regs)) + nmi_enter(); + + trace_hardirqs_off(); +} + +asmlinkage void noinstr exit_el1_irq_or_nmi(struct pt_regs *regs) +{ + if (IS_ENABLED(CONFIG_ARM64_PSEUDO_NMI) && !interrupts_enabled(regs)) + nmi_exit(); + else + trace_hardirqs_on(); +} + static void noinstr el1_abort(struct pt_regs *regs, unsigned long esr) { unsigned long far = read_sysreg(far_el1); diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 84aec600eeed..53e30750fc28 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -637,16 +637,8 @@ SYM_CODE_START_LOCAL_NOALIGN(el1_irq) gic_prio_irq_setup pmr=x20, tmp=x1 enable_da_f -#ifdef CONFIG_ARM64_PSEUDO_NMI - test_irqs_unmasked res=x0, pmr=x20 - cbz x0, 1f - bl asm_nmi_enter -1: -#endif - -#ifdef CONFIG_TRACE_IRQFLAGS - bl trace_hardirqs_off -#endif + mov x0, sp + bl enter_el1_irq_or_nmi irq_handler @@ -665,26 +657,8 @@ alternative_else_nop_endif 1: #endif -#ifdef CONFIG_ARM64_PSEUDO_NMI - /* - * When using IRQ priority masking, we can get spurious interrupts while - * PMR is set to GIC_PRIO_IRQOFF. An NMI might also have occurred in a - * section with interrupts disabled. Skip tracing in those cases. - */ - test_irqs_unmasked res=x0, pmr=x20 - cbz x0, 1f - bl asm_nmi_exit -1: -#endif - -#ifdef CONFIG_TRACE_IRQFLAGS -#ifdef CONFIG_ARM64_PSEUDO_NMI - test_irqs_unmasked res=x0, pmr=x20 - cbnz x0, 1f -#endif - bl trace_hardirqs_on -1: -#endif + mov x0, sp + bl exit_el1_irq_or_nmi kernel_exit 1 SYM_CODE_END(el1_irq) diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c index 9cf2fb87584a..60456a62da11 100644 --- a/arch/arm64/kernel/irq.c +++ b/arch/arm64/kernel/irq.c @@ -67,18 +67,3 @@ void __init init_IRQ(void) local_daif_restore(DAIF_PROCCTX_NOIRQ); } } - -/* - * Stubs to make nmi_enter/exit() code callable from ASM - */ -asmlinkage void notrace asm_nmi_enter(void) -{ - nmi_enter(); -} -NOKPROBE_SYMBOL(asm_nmi_enter); - -asmlinkage void notrace asm_nmi_exit(void) -{ - nmi_exit(); -} -NOKPROBE_SYMBOL(asm_nmi_exit); |