Messages in this thread Patch in this message | | | From | Qi Zheng <> | Subject | [RFC PATCH 2/2] arm64: support HAVE_IRQ_EXIT_ON_IRQ_STACK | Date | Thu, 7 Jul 2022 19:05:11 +0800 |
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Since softirqs are handled on the per-CPU IRQ stack, let's support HAVE_IRQ_EXIT_ON_IRQ_STACK which causes the core code to invoke __do_softirq() directly without going through do_softirq_own_stack().
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/exception.h | 4 +++- arch/arm64/kernel/entry-common.c | 30 ++++++++++++++++++++---------- arch/arm64/kernel/entry.S | 6 ++++-- arch/arm64/kernel/irq.c | 5 +++-- 5 files changed, 31 insertions(+), 15 deletions(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 402e16fec02a..89f6368b705e 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -231,6 +231,7 @@ config ARM64 select TRACE_IRQFLAGS_SUPPORT select TRACE_IRQFLAGS_NMI_SUPPORT select HAVE_SOFTIRQ_ON_OWN_STACK + select HAVE_IRQ_EXIT_ON_IRQ_STACK help ARM 64-bit (AArch64) Linux support. diff --git a/arch/arm64/include/asm/exception.h b/arch/arm64/include/asm/exception.h index d94aecff9690..8bff0aa7ab50 100644 --- a/arch/arm64/include/asm/exception.h +++ b/arch/arm64/include/asm/exception.h @@ -54,7 +54,9 @@ asmlinkage void el0t_32_fiq_handler(struct pt_regs *regs); asmlinkage void el0t_32_error_handler(struct pt_regs *regs); asmlinkage void call_on_irq_stack(struct pt_regs *regs, - void (*func)(struct pt_regs *)); + void (*func)(struct pt_regs *), + void (*do_func)(struct pt_regs *, + void (*)(struct pt_regs *))); asmlinkage void asm_exit_to_user_mode(struct pt_regs *regs); void do_mem_abort(unsigned long far, unsigned long esr, struct pt_regs *regs); diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c index c75ca36b4a49..935d1ab150b5 100644 --- a/arch/arm64/kernel/entry-common.c +++ b/arch/arm64/kernel/entry-common.c @@ -266,14 +266,16 @@ static void __sched arm64_preempt_schedule_irq(void) } static void do_interrupt_handler(struct pt_regs *regs, - void (*handler)(struct pt_regs *)) + void (*handler)(struct pt_regs *), + void (*do_handler)(struct pt_regs *, + void (*)(struct pt_regs *))) { struct pt_regs *old_regs = set_irq_regs(regs); if (on_thread_stack()) - call_on_irq_stack(regs, handler); + call_on_irq_stack(regs, handler, do_handler); else - handler(regs); + do_handler(regs, handler); set_irq_regs(old_regs); } @@ -441,22 +443,32 @@ asmlinkage void noinstr el1h_64_sync_handler(struct pt_regs *regs) } } +static void nmi_handler(struct pt_regs *regs, void (*handler)(struct pt_regs *)) +{ + handler(regs); +} + static __always_inline void __el1_pnmi(struct pt_regs *regs, void (*handler)(struct pt_regs *)) { arm64_enter_nmi(regs); - do_interrupt_handler(regs, handler); + do_interrupt_handler(regs, handler, nmi_handler); arm64_exit_nmi(regs); } +static void irq_handler(struct pt_regs *regs, void (*handler)(struct pt_regs *)) +{ + irq_enter_rcu(); + handler(regs); + irq_exit_rcu(); +} + static __always_inline void __el1_irq(struct pt_regs *regs, void (*handler)(struct pt_regs *)) { enter_from_kernel_mode(regs); - irq_enter_rcu(); - do_interrupt_handler(regs, handler); - irq_exit_rcu(); + do_interrupt_handler(regs, handler, irq_handler); arm64_preempt_schedule_irq(); @@ -699,9 +711,7 @@ static void noinstr el0_interrupt(struct pt_regs *regs, if (regs->pc & BIT(55)) arm64_apply_bp_hardening(); - irq_enter_rcu(); - do_interrupt_handler(regs, handler); - irq_exit_rcu(); + do_interrupt_handler(regs, handler, irq_handler); exit_to_user_mode(regs); } diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 254fe31c03a0..1c351391f6bd 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -867,7 +867,9 @@ NOKPROBE(ret_from_fork) /* * void call_on_irq_stack(struct pt_regs *regs, - * void (*func)(struct pt_regs *)); + * void (*func)(struct pt_regs *) + * void (*do_func)(struct pt_regs *, + * void (*)(struct pt_regs *))); * * Calls func(regs) using this CPU's irq stack and shadow irq stack. */ @@ -886,7 +888,7 @@ SYM_FUNC_START(call_on_irq_stack) /* Move to the new stack and call the function there */ mov sp, x16 - blr x1 + blr x2 /* * Restore the SP from the FP, and restore the FP and LR from the frame diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c index e6aa37672fd4..54cd418d47ef 100644 --- a/arch/arm64/kernel/irq.c +++ b/arch/arm64/kernel/irq.c @@ -72,14 +72,15 @@ static void init_irq_stacks(void) } #endif -static void ____do_softirq(struct pt_regs *regs) +static void ____do_softirq(struct pt_regs *regs, + void (*handler)(struct pt_regs *)) { __do_softirq(); } void do_softirq_own_stack(void) { - call_on_irq_stack(NULL, ____do_softirq); + call_on_irq_stack(NULL, NULL, ____do_softirq); } static void default_handle_irq(struct pt_regs *regs) -- 2.20.1
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