Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar |
| 3 | * |
| 4 | * This file contains the lowest level x86-specific interrupt |
| 5 | * entry, irq-stacks and irq statistics code. All the remaining |
| 6 | * irq logic is done by the generic kernel/irq/ code and |
| 7 | * by the x86-specific irq controller code. (e.g. i8259.c and |
| 8 | * io_apic.c.) |
| 9 | */ |
| 10 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | #include <linux/module.h> |
| 12 | #include <linux/seq_file.h> |
| 13 | #include <linux/interrupt.h> |
| 14 | #include <linux/kernel_stat.h> |
Zwane Mwaikambo | f370513 | 2005-06-25 14:54:50 -0700 | [diff] [blame] | 15 | #include <linux/notifier.h> |
| 16 | #include <linux/cpu.h> |
| 17 | #include <linux/delay.h> |
Jaswinder Singh Rajput | 72ade5f | 2009-01-04 16:32:36 +0530 | [diff] [blame] | 18 | #include <linux/uaccess.h> |
Lai Jiangshan | 42f8fae | 2009-02-17 11:46:42 +0800 | [diff] [blame] | 19 | #include <linux/percpu.h> |
Eric Dumazet | 5c1eb08 | 2010-10-28 16:40:54 +0200 | [diff] [blame] | 20 | #include <linux/mm.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | |
Thomas Gleixner | e05d723 | 2007-02-16 01:27:58 -0800 | [diff] [blame] | 22 | #include <asm/apic.h> |
Thomas Gleixner | e05d723 | 2007-02-16 01:27:58 -0800 | [diff] [blame] | 23 | |
Thomas Gleixner | de9b10a | 2008-05-05 15:58:15 +0200 | [diff] [blame] | 24 | #ifdef CONFIG_DEBUG_STACKOVERFLOW |
Ingo Molnar | 53b5650 | 2011-12-05 12:25:44 +0100 | [diff] [blame] | 25 | |
| 26 | int sysctl_panic_on_stackoverflow __read_mostly; |
| 27 | |
Thomas Gleixner | de9b10a | 2008-05-05 15:58:15 +0200 | [diff] [blame] | 28 | /* Debugging check for stack overflow: is there less than 1KB free? */ |
| 29 | static int check_stack_overflow(void) |
| 30 | { |
| 31 | long sp; |
| 32 | |
| 33 | __asm__ __volatile__("andl %%esp,%0" : |
| 34 | "=r" (sp) : "0" (THREAD_SIZE - 1)); |
| 35 | |
| 36 | return sp < (sizeof(struct thread_info) + STACK_WARN); |
| 37 | } |
| 38 | |
| 39 | static void print_stack_overflow(void) |
| 40 | { |
| 41 | printk(KERN_WARNING "low stack detected by irq handler\n"); |
| 42 | dump_stack(); |
Mitsuo Hayasaka | 55af779 | 2011-11-29 15:08:36 +0900 | [diff] [blame] | 43 | if (sysctl_panic_on_stackoverflow) |
| 44 | panic("low stack detected by irq handler - check messages\n"); |
Thomas Gleixner | de9b10a | 2008-05-05 15:58:15 +0200 | [diff] [blame] | 45 | } |
| 46 | |
| 47 | #else |
| 48 | static inline int check_stack_overflow(void) { return 0; } |
| 49 | static inline void print_stack_overflow(void) { } |
| 50 | #endif |
| 51 | |
Steven Rostedt | 198d208 | 2014-02-06 09:41:31 -0500 | [diff] [blame] | 52 | DEFINE_PER_CPU(struct irq_stack *, hardirq_stack); |
| 53 | DEFINE_PER_CPU(struct irq_stack *, softirq_stack); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | |
Thomas Gleixner | 403d8ef | 2008-05-05 18:13:50 +0200 | [diff] [blame] | 55 | static void call_on_stack(void *func, void *stack) |
| 56 | { |
| 57 | asm volatile("xchgl %%ebx,%%esp \n" |
| 58 | "call *%%edi \n" |
| 59 | "movl %%ebx,%%esp \n" |
| 60 | : "=b" (stack) |
| 61 | : "0" (stack), |
| 62 | "D"(func) |
| 63 | : "memory", "cc", "edx", "ecx", "eax"); |
Andi Kleen | 04b361a | 2008-05-05 12:36:38 +0200 | [diff] [blame] | 64 | } |
| 65 | |
Steven Rostedt | 198d208 | 2014-02-06 09:41:31 -0500 | [diff] [blame] | 66 | static inline void *current_stack(void) |
| 67 | { |
Andy Lutomirski | 83653c1 | 2014-11-13 15:57:07 -0800 | [diff] [blame] | 68 | return (void *)(current_stack_pointer() & ~(THREAD_SIZE - 1)); |
Steven Rostedt | 198d208 | 2014-02-06 09:41:31 -0500 | [diff] [blame] | 69 | } |
| 70 | |
Thomas Gleixner | de9b10a | 2008-05-05 15:58:15 +0200 | [diff] [blame] | 71 | static inline int |
| 72 | execute_on_irq_stack(int overflow, struct irq_desc *desc, int irq) |
| 73 | { |
Steven Rostedt | 198d208 | 2014-02-06 09:41:31 -0500 | [diff] [blame] | 74 | struct irq_stack *curstk, *irqstk; |
Steven Rostedt | 0788aa6 | 2014-02-06 09:41:30 -0500 | [diff] [blame] | 75 | u32 *isp, *prev_esp, arg1, arg2; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | |
Steven Rostedt | 198d208 | 2014-02-06 09:41:31 -0500 | [diff] [blame] | 77 | curstk = (struct irq_stack *) current_stack(); |
| 78 | irqstk = __this_cpu_read(hardirq_stack); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | |
| 80 | /* |
| 81 | * this is where we switch to the IRQ stack. However, if we are |
| 82 | * already using the IRQ stack (because we interrupted a hardirq |
| 83 | * handler) we can't do that and just have to keep using the |
| 84 | * current stack (which is the irq stack already after all) |
| 85 | */ |
Steven Rostedt | 198d208 | 2014-02-06 09:41:31 -0500 | [diff] [blame] | 86 | if (unlikely(curstk == irqstk)) |
Thomas Gleixner | de9b10a | 2008-05-05 15:58:15 +0200 | [diff] [blame] | 87 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | |
Steven Rostedt | 198d208 | 2014-02-06 09:41:31 -0500 | [diff] [blame] | 89 | isp = (u32 *) ((char *)irqstk + sizeof(*irqstk)); |
| 90 | |
| 91 | /* Save the next esp at the bottom of the stack */ |
| 92 | prev_esp = (u32 *)irqstk; |
Andy Lutomirski | 83653c1 | 2014-11-13 15:57:07 -0800 | [diff] [blame] | 93 | *prev_esp = current_stack_pointer(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | |
Thomas Gleixner | de9b10a | 2008-05-05 15:58:15 +0200 | [diff] [blame] | 95 | if (unlikely(overflow)) |
Thomas Gleixner | 403d8ef | 2008-05-05 18:13:50 +0200 | [diff] [blame] | 96 | call_on_stack(print_stack_overflow, isp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 97 | |
Thomas Gleixner | 403d8ef | 2008-05-05 18:13:50 +0200 | [diff] [blame] | 98 | asm volatile("xchgl %%ebx,%%esp \n" |
| 99 | "call *%%edi \n" |
| 100 | "movl %%ebx,%%esp \n" |
| 101 | : "=a" (arg1), "=d" (arg2), "=b" (isp) |
| 102 | : "0" (irq), "1" (desc), "2" (isp), |
| 103 | "D" (desc->handle_irq) |
| 104 | : "memory", "cc", "ecx"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 105 | return 1; |
| 106 | } |
| 107 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | /* |
| 109 | * allocate per-cpu stacks for hardirq and for softirq processing |
| 110 | */ |
Paul Gortmaker | 148f9bb | 2013-06-18 18:23:59 -0400 | [diff] [blame] | 111 | void irq_ctx_init(int cpu) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | { |
Steven Rostedt | 198d208 | 2014-02-06 09:41:31 -0500 | [diff] [blame] | 113 | struct irq_stack *irqstk; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | |
Steven Rostedt | 198d208 | 2014-02-06 09:41:31 -0500 | [diff] [blame] | 115 | if (per_cpu(hardirq_stack, cpu)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | return; |
| 117 | |
Steven Rostedt | 198d208 | 2014-02-06 09:41:31 -0500 | [diff] [blame] | 118 | irqstk = page_address(alloc_pages_node(cpu_to_node(cpu), |
Thomas Gleixner | 38e7c57 | 2012-05-05 15:05:42 +0000 | [diff] [blame] | 119 | THREADINFO_GFP, |
| 120 | THREAD_SIZE_ORDER)); |
Steven Rostedt | 198d208 | 2014-02-06 09:41:31 -0500 | [diff] [blame] | 121 | per_cpu(hardirq_stack, cpu) = irqstk; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | |
Steven Rostedt | 198d208 | 2014-02-06 09:41:31 -0500 | [diff] [blame] | 123 | irqstk = page_address(alloc_pages_node(cpu_to_node(cpu), |
Thomas Gleixner | 38e7c57 | 2012-05-05 15:05:42 +0000 | [diff] [blame] | 124 | THREADINFO_GFP, |
| 125 | THREAD_SIZE_ORDER)); |
Steven Rostedt | 198d208 | 2014-02-06 09:41:31 -0500 | [diff] [blame] | 126 | per_cpu(softirq_stack, cpu) = irqstk; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | |
Thomas Gleixner | 403d8ef | 2008-05-05 18:13:50 +0200 | [diff] [blame] | 128 | printk(KERN_DEBUG "CPU %u irqstacks, hard=%p soft=%p\n", |
Steven Rostedt | 198d208 | 2014-02-06 09:41:31 -0500 | [diff] [blame] | 129 | cpu, per_cpu(hardirq_stack, cpu), per_cpu(softirq_stack, cpu)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | } |
| 131 | |
Frederic Weisbecker | 7d65f4a | 2013-09-05 15:49:45 +0200 | [diff] [blame] | 132 | void do_softirq_own_stack(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | { |
Steven Rostedt | 198d208 | 2014-02-06 09:41:31 -0500 | [diff] [blame] | 134 | struct thread_info *curstk; |
| 135 | struct irq_stack *irqstk; |
Steven Rostedt | 0788aa6 | 2014-02-06 09:41:30 -0500 | [diff] [blame] | 136 | u32 *isp, *prev_esp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 137 | |
Steven Rostedt | 198d208 | 2014-02-06 09:41:31 -0500 | [diff] [blame] | 138 | curstk = current_stack(); |
| 139 | irqstk = __this_cpu_read(softirq_stack); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | |
Frederic Weisbecker | 7d65f4a | 2013-09-05 15:49:45 +0200 | [diff] [blame] | 141 | /* build the stack frame on the softirq stack */ |
Steven Rostedt | 198d208 | 2014-02-06 09:41:31 -0500 | [diff] [blame] | 142 | isp = (u32 *) ((char *)irqstk + sizeof(*irqstk)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | |
Steven Rostedt | 0788aa6 | 2014-02-06 09:41:30 -0500 | [diff] [blame] | 144 | /* Push the previous esp onto the stack */ |
Steven Rostedt | 198d208 | 2014-02-06 09:41:31 -0500 | [diff] [blame] | 145 | prev_esp = (u32 *)irqstk; |
Andy Lutomirski | 83653c1 | 2014-11-13 15:57:07 -0800 | [diff] [blame] | 146 | *prev_esp = current_stack_pointer(); |
Steven Rostedt | 0788aa6 | 2014-02-06 09:41:30 -0500 | [diff] [blame] | 147 | |
Frederic Weisbecker | 7d65f4a | 2013-09-05 15:49:45 +0200 | [diff] [blame] | 148 | call_on_stack(__do_softirq, isp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 149 | } |
Thomas Gleixner | 403d8ef | 2008-05-05 18:13:50 +0200 | [diff] [blame] | 150 | |
Thomas Gleixner | a782a7e | 2015-08-02 20:38:27 +0000 | [diff] [blame] | 151 | bool handle_irq(struct irq_desc *desc, struct pt_regs *regs) |
Jeremy Fitzhardinge | 9b2b76a | 2009-02-06 14:09:40 -0800 | [diff] [blame] | 152 | { |
Thomas Gleixner | a47d457 | 2015-08-28 10:30:15 +0200 | [diff] [blame] | 153 | unsigned int irq; |
Jeremy Fitzhardinge | 9b2b76a | 2009-02-06 14:09:40 -0800 | [diff] [blame] | 154 | int overflow; |
| 155 | |
| 156 | overflow = check_stack_overflow(); |
| 157 | |
Thomas Gleixner | a782a7e | 2015-08-02 20:38:27 +0000 | [diff] [blame] | 158 | if (IS_ERR_OR_NULL(desc)) |
Jeremy Fitzhardinge | 9b2b76a | 2009-02-06 14:09:40 -0800 | [diff] [blame] | 159 | return false; |
| 160 | |
Thomas Gleixner | a47d457 | 2015-08-28 10:30:15 +0200 | [diff] [blame] | 161 | irq = irq_desc_get_irq(desc); |
Andy Lutomirski | f39b6f0 | 2015-03-18 18:33:33 -0700 | [diff] [blame] | 162 | if (user_mode(regs) || !execute_on_irq_stack(overflow, desc, irq)) { |
Jeremy Fitzhardinge | 9b2b76a | 2009-02-06 14:09:40 -0800 | [diff] [blame] | 163 | if (unlikely(overflow)) |
| 164 | print_stack_overflow(); |
Thomas Gleixner | a782a7e | 2015-08-02 20:38:27 +0000 | [diff] [blame] | 165 | generic_handle_irq_desc(irq, desc); |
Jeremy Fitzhardinge | 9b2b76a | 2009-02-06 14:09:40 -0800 | [diff] [blame] | 166 | } |
| 167 | |
| 168 | return true; |
| 169 | } |