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author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-04-01 10:17:18 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-04-01 10:17:18 -0700 |
commit | 99f7b025bfadd7fac5216dcfb2a08312804674c0 (patch) | |
tree | b5318d3acc933eb21676e48e3bf7b428295347c2 /arch/x86/kernel/irq_32.c | |
parent | a21e40877ad130de837b0394583e4f68dc2ab6c5 (diff) | |
parent | 6cce16f99d7be23cec7cabdf32a8166eec6e5393 (diff) | |
download | linux-99f7b025bfadd7fac5216dcfb2a08312804674c0.tar.gz linux-99f7b025bfadd7fac5216dcfb2a08312804674c0.tar.bz2 linux-99f7b025bfadd7fac5216dcfb2a08312804674c0.zip |
Merge branch 'x86-threadinfo-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 threadinfo changes from Ingo Molnar:
"The main change here is the consolidation/unification of 32 and 64 bit
thread_info handling methods, from Steve Rostedt"
* 'x86-threadinfo-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, threadinfo: Redo "x86: Use inline assembler to get sp"
x86: Clean up dumpstack_64.c code
x86: Keep thread_info on thread stack in x86_32
x86: Prepare removal of previous_esp from i386 thread_info structure
x86: Nuke GET_THREAD_INFO_WITH_ESP() macro for i386
x86: Nuke the supervisor_stack field in i386 thread_info
Diffstat (limited to 'arch/x86/kernel/irq_32.c')
-rw-r--r-- | arch/x86/kernel/irq_32.c | 83 |
1 files changed, 41 insertions, 42 deletions
diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c index d7fcbedc9c43..63ce838e5a54 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 +69,26 @@ static void call_on_stack(void *func, void *stack) : "memory", "cc", "edx", "ecx", "eax"); } +/* how to get the current stack pointer from C */ +#define current_stack_pointer ({ \ + unsigned long sp; \ + asm("mov %%esp,%0" : "=g" (sp)); \ + sp; \ +}) + +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; - u32 *isp, arg1, arg2; + 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 @@ -92,13 +96,14 @@ 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; - irqctx->tinfo.previous_esp = current_stack_pointer; + 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)) call_on_stack(print_stack_overflow, isp); @@ -118,46 +123,40 @@ 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_ctx, cpu) = irqctx; + per_cpu(hardirq_stack, cpu) = irqstk; - 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; - u32 *isp; + 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; - irqctx->tinfo.previous_esp = current_stack_pointer; + 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 *)irqstk; + *prev_esp = current_stack_pointer; call_on_stack(__do_softirq, isp); } |