/*
* linux/arch/sh/kernel/irq.c
*
* Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
*
*
* SuperH version: Copyright (C) 1999 Niibe Yutaka
*/
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/kernel_stat.h>
#include <linux/seq_file.h>
#include <asm/processor.h>
#include <asm/machvec.h>
#include <asm/uaccess.h>
#include <asm/thread_info.h>
#include <asm/cpu/mmu_context.h>
atomic_t irq_err_count;
/*
* 'what should we do if we get a hw irq event on an illegal vector'.
* each architecture has to answer this themselves, it doesn't deserve
* a generic callback i think.
*/
void ack_bad_irq(unsigned int irq)
{
atomic_inc(&irq_err_count);
printk("unexpected IRQ trap at vector %02x\n", irq);
}
#if defined(CONFIG_PROC_FS)
int show_interrupts(struct seq_file *p, void *v)
{
int i = *(loff_t *) v, j;
struct irqaction * action;
unsigned long flags;
if (i == 0) {
seq_puts(p, " ");
for_each_online_cpu(j)
seq_printf(p, "CPU%d ",j);
seq_putc(p, '\n');
}
if (i < sh_mv.mv_nr_irqs) {
spin_lock_irqsave(&irq_desc[i].lock, flags);
action = irq_desc[i].action;
if (!action)
goto unlock;
seq_printf(p, "%3d: ",i);
for_each_online_cpu(j)
seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
seq_printf(p, " %14s", irq_desc[i].chip->name);
seq_printf(p, "-%-8s", irq_desc[i].name);
seq_printf(p, " %s", action->name);
for (action=action->next; action; action = action->next)
seq_printf(p, ", %s", action->name);
seq_putc(p, '\n');
unlock:
spin_unlock_irqrestore(&irq_desc[i].lock, flags);
} else if (i == sh_mv.mv_nr_irqs)
seq_printf(p, "Err: %10u\n", atomic_read(&irq_err_count));
return 0;
}
#endif
#ifdef CONFIG_IRQSTACKS
/*
* per-CPU IRQ handling contexts (thread information and stack)
*/
union irq_ctx {
struct thread_info tinfo;
u32 stack[THREAD_SIZE/sizeof(u32)];
};
static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly;
static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly;
#endif
asmlinkage int do_IRQ(unsigned int irq, struct pt_regs *regs)
{
struct pt_regs *old_regs = set_irq_regs(regs);
#ifdef CONFIG_IRQSTACKS
union irq_ctx *curctx, *irqctx;
#endif
irq_enter();
#ifdef CONFIG_DEBUG_STACKOVERFLOW
/* Debugging check for stack overflow: is there less than 1KB free? */
{
long sp;
__asm__ __volatile__ ("and r15, %0" :
"=r" (sp) : "0" (THREAD_SIZE - 1));
if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
printk("do_IRQ: stack overflow: %ld\n",
sp - sizeof(struct thread_info));
dump_stack();
}
}
#endif
irq = irq_demux(evt2irq(irq));
#ifdef CONFIG_IRQSTACKS
curctx = (union irq_ctx *)current_thread_info();
irqctx = hardirq_ctx[smp_processor_id()];
/*
* this is where we switch to the IRQ stack. However, if we are
* already using the IRQ stack (because we interrupted a hardirq
* handler) we can't do that and just have to keep using the
* current stack (which is the irq stack already after all)
*/
if (curctx != irqctx) {
u32 *isp;
isp = (u32 *)((char *)irqctx + sizeof(*irqctx));
irqctx->tinfo.task = curctx->tinfo.task;
irqctx->tinfo.previous_sp = current_stack_pointer;
/*
* Copy the softirq bits in preempt_count so that the
* softirq checks work in the hardirq context.
*/
irqctx->tinfo.preempt_count =
(irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) |
(curctx->tinfo.preempt_count & SOFTIRQ_MASK);
__asm__ __volatile__ (
"mov %0, r4 \n"
"mov r15, r8 \n"
"jsr @%1 \n"
/* swith to the irq stack */
" mov %2, r15 \n"
/* restore the stack (ring zero) */
"mov r8, r15 \n"
: /* no outputs */
: "r" (irq), "r" (generic_handle_irq), "r" (isp)
: "memory", "r0", "r1", "r2", "r3", "r4",
"r5", "r6", "r7", "r8", "t", "pr"
);
} else
#endif
generic_handle_irq(irq);
irq_exit();
set_irq_regs(old_regs);
return 1;
}
#ifdef CONFIG_IRQSTACKS
static char softirq_stack[NR_CPUS * THREAD_SIZE]
__attribute__((__section__(".bss.page_aligned")));
static char hardirq_stack[NR_CPUS * THREAD_SIZE]
__attribute__((__section__(".bss.page_aligned")));
/*
* allocate per-cpu stacks for hardirq and for softirq processing
*/
void irq_ctx_init(int cpu)
{
union irq_ctx *irqctx;
if (hardirq_ctx[cpu])
return;
irqctx = (union irq_ctx *)&hardirq_stack[cpu * THREAD_SIZE];
irqctx->tinfo.task = NULL;
irqctx->tinfo.exec_domain = NULL;
irqctx->tinfo.cpu = cpu;
irqctx->tinfo.preempt_count = HARDIRQ_OFFSET;
irqctx->tinfo.addr_limit = MAKE_MM_SEG(0);
hardirq_ctx[cpu] = irqctx;
irqctx = (union irq_ctx *)&softirq_stack[cpu * THREAD_SIZE];
irqctx->tinfo.task = NULL;
irqctx->tinfo.exec_domain = NULL;
irqctx->tinfo.cpu = cpu;
irqctx->tinfo.preempt_count = 0;
irqctx->tinfo.addr_limit = MAKE_MM_SEG(0);
softirq_ctx[cpu] = irqctx;
printk("CPU %u irqstacks, hard=%p soft=%p\n",
cpu, hardirq_ctx[cpu], softirq_ctx[cpu]);
}
void irq_ctx_exit(int cpu)
{
hardirq_ctx[cpu] = NULL;
}
extern asmlinkage void __do_softirq(void);
asmlinkage void do_softirq(void)
{
unsigned long flags;
struct thread_info *curctx;
union irq_ctx *irqctx;
u32 *isp;
if (in_interrupt())
return;
local_irq_save(flags);
if (local_softirq_pending()) {
curctx = current_thread_info();
irqctx = softirq_ctx[smp_processor_id()];
irqctx->tinfo.task = curctx->task;
irqctx->tinfo.previous_sp = current_stack_pointer;
/* build the stack frame on the softirq stack */
isp = (u32 *)((char *)irqctx + sizeof(*irqctx));
__asm__ __volatile__ (
"mov r15, r9 \n"
"jsr @%0 \n"
/* switch to the softirq stack */
" mov %1, r15 \n"
/* restore the thread stack */
"mov r9, r15 \n"
: /* no outputs */
: "r" (__do_softirq), "r" (isp)
: "memory", "r0", "r1", "r2", "r3", "r4",
"r5", "r6", "r7", "r8", "r9", "r15", "t", "pr"
);
/*
* Shouldnt happen, we returned above if in_interrupt():
*/
WARN_ON_ONCE(softirq_count());
}
local_irq_restore(flags);
}
#endif
void __init init_IRQ(void)
{
plat_irq_setup();
/* Perform the machine specific initialisation */
if (sh_mv.mv_init_irq)
sh_mv.mv_init_irq();
irq_ctx_init(smp_processor_id());
}
