diff options
Diffstat (limited to 'arch/x86/kernel/irq_32.c')
-rw-r--r-- | arch/x86/kernel/irq_32.c | 74 |
1 files changed, 31 insertions, 43 deletions
diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c index f135cc2ff30..988dc8bcaeb 100644 --- a/arch/x86/kernel/irq_32.c +++ b/arch/x86/kernel/irq_32.c @@ -55,16 +55,8 @@ static inline int check_stack_overflow(void) { return 0; } static inline void print_stack_overflow(void) { } #endif -/* - * per-CPU IRQ handling contexts (thread information and stack) - */ -union irq_ctx { - struct thread_info tinfo; - u32 stack[THREAD_SIZE/sizeof(u32)]; -} __attribute__((aligned(THREAD_SIZE))); - -static DEFINE_PER_CPU(union irq_ctx *, hardirq_ctx); -static DEFINE_PER_CPU(union irq_ctx *, softirq_ctx); +DEFINE_PER_CPU(struct irq_stack *, hardirq_stack); +DEFINE_PER_CPU(struct irq_stack *, softirq_stack); static void call_on_stack(void *func, void *stack) { @@ -77,14 +69,22 @@ static void call_on_stack(void *func, void *stack) : "memory", "cc", "edx", "ecx", "eax"); } +/* how to get the current stack pointer from C */ +register unsigned long current_stack_pointer asm("esp") __used; + +static inline void *current_stack(void) +{ + return (void *)(current_stack_pointer & ~(THREAD_SIZE - 1)); +} + static inline int execute_on_irq_stack(int overflow, struct irq_desc *desc, int irq) { - union irq_ctx *curctx, *irqctx; + struct irq_stack *curstk, *irqstk; u32 *isp, *prev_esp, arg1, arg2; - curctx = (union irq_ctx *) current_thread_info(); - irqctx = __this_cpu_read(hardirq_ctx); + curstk = (struct irq_stack *) current_stack(); + irqstk = __this_cpu_read(hardirq_stack); /* * this is where we switch to the IRQ stack. However, if we are @@ -92,15 +92,13 @@ execute_on_irq_stack(int overflow, struct irq_desc *desc, int irq) * handler) we can't do that and just have to keep using the * current stack (which is the irq stack already after all) */ - if (unlikely(curctx == irqctx)) + if (unlikely(curstk == irqstk)) return 0; - /* build the stack frame on the IRQ stack */ - isp = (u32 *) ((char *)irqctx + sizeof(*irqctx)); - irqctx->tinfo.task = curctx->tinfo.task; - /* Save the next esp after thread_info */ - prev_esp = (u32 *) ((char *)irqctx + sizeof(struct thread_info) - - sizeof(long)); + isp = (u32 *) ((char *)irqstk + sizeof(*irqstk)); + + /* Save the next esp at the bottom of the stack */ + prev_esp = (u32 *)irqstk; *prev_esp = current_stack_pointer; if (unlikely(overflow)) @@ -121,49 +119,39 @@ execute_on_irq_stack(int overflow, struct irq_desc *desc, int irq) */ void irq_ctx_init(int cpu) { - union irq_ctx *irqctx; + struct irq_stack *irqstk; - if (per_cpu(hardirq_ctx, cpu)) + if (per_cpu(hardirq_stack, cpu)) return; - irqctx = page_address(alloc_pages_node(cpu_to_node(cpu), + irqstk = page_address(alloc_pages_node(cpu_to_node(cpu), THREADINFO_GFP, THREAD_SIZE_ORDER)); - memset(&irqctx->tinfo, 0, sizeof(struct thread_info)); - irqctx->tinfo.cpu = cpu; - irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); + per_cpu(hardirq_stack, cpu) = irqstk; - per_cpu(hardirq_ctx, cpu) = irqctx; - - irqctx = page_address(alloc_pages_node(cpu_to_node(cpu), + irqstk = page_address(alloc_pages_node(cpu_to_node(cpu), THREADINFO_GFP, THREAD_SIZE_ORDER)); - memset(&irqctx->tinfo, 0, sizeof(struct thread_info)); - irqctx->tinfo.cpu = cpu; - irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); - - per_cpu(softirq_ctx, cpu) = irqctx; + per_cpu(softirq_stack, cpu) = irqstk; printk(KERN_DEBUG "CPU %u irqstacks, hard=%p soft=%p\n", - cpu, per_cpu(hardirq_ctx, cpu), per_cpu(softirq_ctx, cpu)); + cpu, per_cpu(hardirq_stack, cpu), per_cpu(softirq_stack, cpu)); } void do_softirq_own_stack(void) { - struct thread_info *curctx; - union irq_ctx *irqctx; + struct thread_info *curstk; + struct irq_stack *irqstk; u32 *isp, *prev_esp; - curctx = current_thread_info(); - irqctx = __this_cpu_read(softirq_ctx); - irqctx->tinfo.task = curctx->task; + curstk = current_stack(); + irqstk = __this_cpu_read(softirq_stack); /* build the stack frame on the softirq stack */ - isp = (u32 *) ((char *)irqctx + sizeof(*irqctx)); + isp = (u32 *) ((char *)irqstk + sizeof(*irqstk)); /* Push the previous esp onto the stack */ - prev_esp = (u32 *) ((char *)irqctx + sizeof(struct thread_info) - - sizeof(long)); + prev_esp = (u32 *)irqstk; *prev_esp = current_stack_pointer; call_on_stack(__do_softirq, isp); |