From: Brian Gerst Date: Mon, 3 Mar 2025 16:52:42 +0000 (-0500) Subject: x86/irq: Move irq stacks to percpu hot section X-Git-Tag: v6.15-rc1~216^2~78 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c6a0918072eaa97df268c00c05822ea982a321b6;p=thirdparty%2Flinux.git x86/irq: Move irq stacks to percpu hot section No functional change. Signed-off-by: Brian Gerst Signed-off-by: Ingo Molnar Acked-by: Uros Bizjak Cc: Linus Torvalds Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20250303165246.2175811-8-brgerst@gmail.com --- diff --git a/arch/x86/include/asm/current.h b/arch/x86/include/asm/current.h index f153c77853de1..6fad5a4c21d7c 100644 --- a/arch/x86/include/asm/current.h +++ b/arch/x86/include/asm/current.h @@ -15,12 +15,6 @@ struct task_struct; struct pcpu_hot { struct task_struct *current_task; unsigned long top_of_stack; - void *hardirq_stack_ptr; -#ifdef CONFIG_X86_64 - bool hardirq_stack_inuse; -#else - void *softirq_stack_ptr; -#endif }; DECLARE_PER_CPU_CACHE_HOT(struct pcpu_hot, pcpu_hot); diff --git a/arch/x86/include/asm/irq_stack.h b/arch/x86/include/asm/irq_stack.h index 562a547c29a5b..735c3a491f604 100644 --- a/arch/x86/include/asm/irq_stack.h +++ b/arch/x86/include/asm/irq_stack.h @@ -116,7 +116,7 @@ ASM_CALL_ARG2 #define call_on_irqstack(func, asm_call, argconstr...) \ - call_on_stack(__this_cpu_read(pcpu_hot.hardirq_stack_ptr), \ + call_on_stack(__this_cpu_read(hardirq_stack_ptr), \ func, asm_call, argconstr) /* Macros to assert type correctness for run_*_on_irqstack macros */ @@ -135,7 +135,7 @@ * User mode entry and interrupt on the irq stack do not \ * switch stacks. If from user mode the task stack is empty. \ */ \ - if (user_mode(regs) || __this_cpu_read(pcpu_hot.hardirq_stack_inuse)) { \ + if (user_mode(regs) || __this_cpu_read(hardirq_stack_inuse)) { \ irq_enter_rcu(); \ func(c_args); \ irq_exit_rcu(); \ @@ -146,9 +146,9 @@ * places. Invoke the stack switch macro with the call \ * sequence which matches the above direct invocation. \ */ \ - __this_cpu_write(pcpu_hot.hardirq_stack_inuse, true); \ + __this_cpu_write(hardirq_stack_inuse, true); \ call_on_irqstack(func, asm_call, constr); \ - __this_cpu_write(pcpu_hot.hardirq_stack_inuse, false); \ + __this_cpu_write(hardirq_stack_inuse, false); \ } \ } @@ -212,9 +212,9 @@ */ #define do_softirq_own_stack() \ { \ - __this_cpu_write(pcpu_hot.hardirq_stack_inuse, true); \ + __this_cpu_write(hardirq_stack_inuse, true); \ call_on_irqstack(__do_softirq, ASM_CALL_ARG0); \ - __this_cpu_write(pcpu_hot.hardirq_stack_inuse, false); \ + __this_cpu_write(hardirq_stack_inuse, false); \ } #endif diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index c241dbc1562c2..6bb6af0b54304 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -415,6 +415,13 @@ struct irq_stack { char stack[IRQ_STACK_SIZE]; } __aligned(IRQ_STACK_SIZE); +DECLARE_PER_CPU_CACHE_HOT(struct irq_stack *, hardirq_stack_ptr); +#ifdef CONFIG_X86_64 +DECLARE_PER_CPU_CACHE_HOT(bool, hardirq_stack_inuse); +#else +DECLARE_PER_CPU_CACHE_HOT(struct irq_stack *, softirq_stack_ptr); +#endif + #ifdef CONFIG_X86_64 static inline unsigned long cpu_kernelmode_gs_base(int cpu) { diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c index b4905d5173fd3..722fd712e1cf0 100644 --- a/arch/x86/kernel/dumpstack_32.c +++ b/arch/x86/kernel/dumpstack_32.c @@ -37,7 +37,7 @@ const char *stack_type_name(enum stack_type type) static bool in_hardirq_stack(unsigned long *stack, struct stack_info *info) { - unsigned long *begin = (unsigned long *)this_cpu_read(pcpu_hot.hardirq_stack_ptr); + unsigned long *begin = (unsigned long *)this_cpu_read(hardirq_stack_ptr); unsigned long *end = begin + (THREAD_SIZE / sizeof(long)); /* @@ -62,7 +62,7 @@ static bool in_hardirq_stack(unsigned long *stack, struct stack_info *info) static bool in_softirq_stack(unsigned long *stack, struct stack_info *info) { - unsigned long *begin = (unsigned long *)this_cpu_read(pcpu_hot.softirq_stack_ptr); + unsigned long *begin = (unsigned long *)this_cpu_read(softirq_stack_ptr); unsigned long *end = begin + (THREAD_SIZE / sizeof(long)); /* diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c index f05339fee7785..6c5defd6569a3 100644 --- a/arch/x86/kernel/dumpstack_64.c +++ b/arch/x86/kernel/dumpstack_64.c @@ -134,7 +134,7 @@ static __always_inline bool in_exception_stack(unsigned long *stack, struct stac static __always_inline bool in_irq_stack(unsigned long *stack, struct stack_info *info) { - unsigned long *end = (unsigned long *)this_cpu_read(pcpu_hot.hardirq_stack_ptr); + unsigned long *end = (unsigned long *)this_cpu_read(hardirq_stack_ptr); unsigned long *begin; /* diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c index 83a5252a473c3..81f9b78e0f7ba 100644 --- a/arch/x86/kernel/irq.c +++ b/arch/x86/kernel/irq.c @@ -36,6 +36,8 @@ EXPORT_PER_CPU_SYMBOL(irq_stat); DEFINE_PER_CPU_CACHE_HOT(u16, __softirq_pending); EXPORT_PER_CPU_SYMBOL(__softirq_pending); +DEFINE_PER_CPU_CACHE_HOT(struct irq_stack *, hardirq_stack_ptr); + atomic_t irq_err_count; /* diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c index d301208d35d02..c7a5d2960d575 100644 --- a/arch/x86/kernel/irq_32.c +++ b/arch/x86/kernel/irq_32.c @@ -49,6 +49,8 @@ static inline bool check_stack_overflow(void) { return false; } static inline void print_stack_overflow(void) { } #endif +DEFINE_PER_CPU_CACHE_HOT(struct irq_stack *, softirq_stack_ptr); + static void call_on_stack(void *func, void *stack) { asm volatile("xchgl %[sp], %%esp\n" @@ -70,7 +72,7 @@ static inline bool execute_on_irq_stack(bool overflow, struct irq_desc *desc) u32 *isp, *prev_esp; curstk = (struct irq_stack *) current_stack(); - irqstk = __this_cpu_read(pcpu_hot.hardirq_stack_ptr); + irqstk = __this_cpu_read(hardirq_stack_ptr); /* * this is where we switch to the IRQ stack. However, if we are @@ -107,7 +109,7 @@ int irq_init_percpu_irqstack(unsigned int cpu) int node = cpu_to_node(cpu); struct page *ph, *ps; - if (per_cpu(pcpu_hot.hardirq_stack_ptr, cpu)) + if (per_cpu(hardirq_stack_ptr, cpu)) return 0; ph = alloc_pages_node(node, THREADINFO_GFP, THREAD_SIZE_ORDER); @@ -119,8 +121,8 @@ int irq_init_percpu_irqstack(unsigned int cpu) return -ENOMEM; } - per_cpu(pcpu_hot.hardirq_stack_ptr, cpu) = page_address(ph); - per_cpu(pcpu_hot.softirq_stack_ptr, cpu) = page_address(ps); + per_cpu(hardirq_stack_ptr, cpu) = page_address(ph); + per_cpu(softirq_stack_ptr, cpu) = page_address(ps); return 0; } @@ -130,7 +132,7 @@ void do_softirq_own_stack(void) struct irq_stack *irqstk; u32 *isp, *prev_esp; - irqstk = __this_cpu_read(pcpu_hot.softirq_stack_ptr); + irqstk = __this_cpu_read(softirq_stack_ptr); /* build the stack frame on the softirq stack */ isp = (u32 *) ((char *)irqstk + sizeof(*irqstk)); diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c index 56bdeecd8ee02..ca78dce39361f 100644 --- a/arch/x86/kernel/irq_64.c +++ b/arch/x86/kernel/irq_64.c @@ -26,6 +26,7 @@ #include #include +DEFINE_PER_CPU_CACHE_HOT(bool, hardirq_stack_inuse); DEFINE_PER_CPU_PAGE_ALIGNED(struct irq_stack, irq_stack_backing_store) __visible; #ifdef CONFIG_VMAP_STACK @@ -50,7 +51,7 @@ static int map_irq_stack(unsigned int cpu) return -ENOMEM; /* Store actual TOS to avoid adjustment in the hotpath */ - per_cpu(pcpu_hot.hardirq_stack_ptr, cpu) = va + IRQ_STACK_SIZE - 8; + per_cpu(hardirq_stack_ptr, cpu) = va + IRQ_STACK_SIZE - 8; return 0; } #else @@ -63,14 +64,14 @@ static int map_irq_stack(unsigned int cpu) void *va = per_cpu_ptr(&irq_stack_backing_store, cpu); /* Store actual TOS to avoid adjustment in the hotpath */ - per_cpu(pcpu_hot.hardirq_stack_ptr, cpu) = va + IRQ_STACK_SIZE - 8; + per_cpu(hardirq_stack_ptr, cpu) = va + IRQ_STACK_SIZE - 8; return 0; } #endif int irq_init_percpu_irqstack(unsigned int cpu) { - if (per_cpu(pcpu_hot.hardirq_stack_ptr, cpu)) + if (per_cpu(hardirq_stack_ptr, cpu)) return 0; return map_irq_stack(cpu); } diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index f983d2a57ac3c..2f38416deb746 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -614,7 +614,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) int cpu = smp_processor_id(); WARN_ON_ONCE(IS_ENABLED(CONFIG_DEBUG_ENTRY) && - this_cpu_read(pcpu_hot.hardirq_stack_inuse)); + this_cpu_read(hardirq_stack_inuse)); if (!test_tsk_thread_flag(prev_p, TIF_NEED_FPU_LOAD)) switch_fpu_prepare(prev_p, cpu);