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![Dave Jones](/assets/img/avatar_default.png)
Since the x86 merge, lots of files that referenced their own filenames are no longer correct. Rather than keep them up to date, just delete them, as they add no real value. Additionally: - fix up comment formatting in scx200_32.c - Remove a credit from myself in setup_64.c from a time when we had no SCM - remove longwinded history from tsc_32.c which can be figured out from git. Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
339 lines
8.3 KiB
C
339 lines
8.3 KiB
C
/*
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* Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
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*
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* This file contains the lowest level x86-specific interrupt
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* entry, irq-stacks and irq statistics code. All the remaining
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* irq logic is done by the generic kernel/irq/ code and
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* by the x86-specific irq controller code. (e.g. i8259.c and
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* io_apic.c.)
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*/
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#include <linux/module.h>
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#include <linux/seq_file.h>
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#include <linux/interrupt.h>
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#include <linux/kernel_stat.h>
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#include <linux/notifier.h>
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#include <linux/cpu.h>
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#include <linux/delay.h>
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#include <asm/apic.h>
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#include <asm/uaccess.h>
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DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
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EXPORT_PER_CPU_SYMBOL(irq_stat);
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DEFINE_PER_CPU(struct pt_regs *, irq_regs);
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EXPORT_PER_CPU_SYMBOL(irq_regs);
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/*
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* 'what should we do if we get a hw irq event on an illegal vector'.
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* each architecture has to answer this themselves.
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*/
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void ack_bad_irq(unsigned int irq)
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{
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printk(KERN_ERR "unexpected IRQ trap at vector %02x\n", irq);
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#ifdef CONFIG_X86_LOCAL_APIC
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/*
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* Currently unexpected vectors happen only on SMP and APIC.
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* We _must_ ack these because every local APIC has only N
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* irq slots per priority level, and a 'hanging, unacked' IRQ
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* holds up an irq slot - in excessive cases (when multiple
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* unexpected vectors occur) that might lock up the APIC
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* completely.
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* But only ack when the APIC is enabled -AK
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*/
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if (cpu_has_apic)
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ack_APIC_irq();
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#endif
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}
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#ifdef CONFIG_4KSTACKS
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/*
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* per-CPU IRQ handling contexts (thread information and stack)
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*/
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union irq_ctx {
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struct thread_info tinfo;
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u32 stack[THREAD_SIZE/sizeof(u32)];
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};
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static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly;
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static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly;
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#endif
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/*
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* do_IRQ handles all normal device IRQ's (the special
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* SMP cross-CPU interrupts have their own specific
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* handlers).
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*/
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fastcall unsigned int do_IRQ(struct pt_regs *regs)
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{
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struct pt_regs *old_regs;
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/* high bit used in ret_from_ code */
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int irq = ~regs->orig_eax;
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struct irq_desc *desc = irq_desc + irq;
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#ifdef CONFIG_4KSTACKS
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union irq_ctx *curctx, *irqctx;
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u32 *isp;
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#endif
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if (unlikely((unsigned)irq >= NR_IRQS)) {
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printk(KERN_EMERG "%s: cannot handle IRQ %d\n",
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__FUNCTION__, irq);
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BUG();
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}
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old_regs = set_irq_regs(regs);
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irq_enter();
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#ifdef CONFIG_DEBUG_STACKOVERFLOW
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/* Debugging check for stack overflow: is there less than 1KB free? */
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{
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long esp;
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__asm__ __volatile__("andl %%esp,%0" :
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"=r" (esp) : "0" (THREAD_SIZE - 1));
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if (unlikely(esp < (sizeof(struct thread_info) + STACK_WARN))) {
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printk("do_IRQ: stack overflow: %ld\n",
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esp - sizeof(struct thread_info));
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dump_stack();
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}
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}
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#endif
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#ifdef CONFIG_4KSTACKS
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curctx = (union irq_ctx *) current_thread_info();
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irqctx = hardirq_ctx[smp_processor_id()];
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/*
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* this is where we switch to the IRQ stack. However, if we are
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* already using the IRQ stack (because we interrupted a hardirq
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* handler) we can't do that and just have to keep using the
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* current stack (which is the irq stack already after all)
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*/
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if (curctx != irqctx) {
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int arg1, arg2, ebx;
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/* build the stack frame on the IRQ stack */
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isp = (u32*) ((char*)irqctx + sizeof(*irqctx));
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irqctx->tinfo.task = curctx->tinfo.task;
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irqctx->tinfo.previous_esp = current_stack_pointer;
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/*
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* Copy the softirq bits in preempt_count so that the
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* softirq checks work in the hardirq context.
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*/
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irqctx->tinfo.preempt_count =
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(irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) |
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(curctx->tinfo.preempt_count & SOFTIRQ_MASK);
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asm volatile(
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" xchgl %%ebx,%%esp \n"
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" call *%%edi \n"
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" movl %%ebx,%%esp \n"
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: "=a" (arg1), "=d" (arg2), "=b" (ebx)
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: "0" (irq), "1" (desc), "2" (isp),
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"D" (desc->handle_irq)
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: "memory", "cc"
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);
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} else
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#endif
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desc->handle_irq(irq, desc);
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irq_exit();
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set_irq_regs(old_regs);
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return 1;
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}
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#ifdef CONFIG_4KSTACKS
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static char softirq_stack[NR_CPUS * THREAD_SIZE]
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__attribute__((__section__(".bss.page_aligned")));
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static char hardirq_stack[NR_CPUS * THREAD_SIZE]
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__attribute__((__section__(".bss.page_aligned")));
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/*
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* allocate per-cpu stacks for hardirq and for softirq processing
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*/
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void irq_ctx_init(int cpu)
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{
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union irq_ctx *irqctx;
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if (hardirq_ctx[cpu])
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return;
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irqctx = (union irq_ctx*) &hardirq_stack[cpu*THREAD_SIZE];
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irqctx->tinfo.task = NULL;
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irqctx->tinfo.exec_domain = NULL;
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irqctx->tinfo.cpu = cpu;
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irqctx->tinfo.preempt_count = HARDIRQ_OFFSET;
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irqctx->tinfo.addr_limit = MAKE_MM_SEG(0);
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hardirq_ctx[cpu] = irqctx;
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irqctx = (union irq_ctx*) &softirq_stack[cpu*THREAD_SIZE];
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irqctx->tinfo.task = NULL;
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irqctx->tinfo.exec_domain = NULL;
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irqctx->tinfo.cpu = cpu;
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irqctx->tinfo.preempt_count = 0;
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irqctx->tinfo.addr_limit = MAKE_MM_SEG(0);
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softirq_ctx[cpu] = irqctx;
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printk("CPU %u irqstacks, hard=%p soft=%p\n",
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cpu,hardirq_ctx[cpu],softirq_ctx[cpu]);
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}
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void irq_ctx_exit(int cpu)
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{
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hardirq_ctx[cpu] = NULL;
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}
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extern asmlinkage void __do_softirq(void);
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asmlinkage void do_softirq(void)
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{
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unsigned long flags;
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struct thread_info *curctx;
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union irq_ctx *irqctx;
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u32 *isp;
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if (in_interrupt())
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return;
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local_irq_save(flags);
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if (local_softirq_pending()) {
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curctx = current_thread_info();
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irqctx = softirq_ctx[smp_processor_id()];
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irqctx->tinfo.task = curctx->task;
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irqctx->tinfo.previous_esp = current_stack_pointer;
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/* build the stack frame on the softirq stack */
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isp = (u32*) ((char*)irqctx + sizeof(*irqctx));
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asm volatile(
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" xchgl %%ebx,%%esp \n"
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" call __do_softirq \n"
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" movl %%ebx,%%esp \n"
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: "=b"(isp)
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: "0"(isp)
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: "memory", "cc", "edx", "ecx", "eax"
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);
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/*
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* Shouldnt happen, we returned above if in_interrupt():
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*/
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WARN_ON_ONCE(softirq_count());
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}
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local_irq_restore(flags);
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}
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#endif
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/*
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* Interrupt statistics:
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*/
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atomic_t irq_err_count;
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/*
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* /proc/interrupts printing:
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*/
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int show_interrupts(struct seq_file *p, void *v)
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{
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int i = *(loff_t *) v, j;
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struct irqaction * action;
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unsigned long flags;
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if (i == 0) {
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seq_printf(p, " ");
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for_each_online_cpu(j)
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seq_printf(p, "CPU%-8d",j);
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seq_putc(p, '\n');
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}
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if (i < NR_IRQS) {
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spin_lock_irqsave(&irq_desc[i].lock, flags);
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action = irq_desc[i].action;
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if (!action)
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goto skip;
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seq_printf(p, "%3d: ",i);
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#ifndef CONFIG_SMP
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seq_printf(p, "%10u ", kstat_irqs(i));
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#else
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for_each_online_cpu(j)
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seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
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#endif
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seq_printf(p, " %8s", irq_desc[i].chip->name);
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seq_printf(p, "-%-8s", irq_desc[i].name);
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seq_printf(p, " %s", action->name);
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for (action=action->next; action; action = action->next)
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seq_printf(p, ", %s", action->name);
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seq_putc(p, '\n');
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skip:
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spin_unlock_irqrestore(&irq_desc[i].lock, flags);
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} else if (i == NR_IRQS) {
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seq_printf(p, "NMI: ");
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for_each_online_cpu(j)
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seq_printf(p, "%10u ", nmi_count(j));
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seq_putc(p, '\n');
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#ifdef CONFIG_X86_LOCAL_APIC
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seq_printf(p, "LOC: ");
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for_each_online_cpu(j)
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seq_printf(p, "%10u ",
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per_cpu(irq_stat,j).apic_timer_irqs);
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seq_putc(p, '\n');
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#endif
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seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
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#if defined(CONFIG_X86_IO_APIC)
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seq_printf(p, "MIS: %10u\n", atomic_read(&irq_mis_count));
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#endif
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}
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return 0;
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}
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#ifdef CONFIG_HOTPLUG_CPU
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#include <mach_apic.h>
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void fixup_irqs(cpumask_t map)
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{
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unsigned int irq;
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static int warned;
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for (irq = 0; irq < NR_IRQS; irq++) {
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cpumask_t mask;
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if (irq == 2)
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continue;
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cpus_and(mask, irq_desc[irq].affinity, map);
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if (any_online_cpu(mask) == NR_CPUS) {
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printk("Breaking affinity for irq %i\n", irq);
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mask = map;
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}
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if (irq_desc[irq].chip->set_affinity)
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irq_desc[irq].chip->set_affinity(irq, mask);
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else if (irq_desc[irq].action && !(warned++))
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printk("Cannot set affinity for irq %i\n", irq);
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}
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#if 0
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barrier();
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/* Ingo Molnar says: "after the IO-APIC masks have been redirected
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[note the nop - the interrupt-enable boundary on x86 is two
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instructions from sti] - to flush out pending hardirqs and
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IPIs. After this point nothing is supposed to reach this CPU." */
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__asm__ __volatile__("sti; nop; cli");
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barrier();
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#else
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/* That doesn't seem sufficient. Give it 1ms. */
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local_irq_enable();
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mdelay(1);
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local_irq_disable();
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#endif
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}
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#endif
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