original_kernel/arch/sh/kernel/cpu/irq/imask.c

111 lines
2.5 KiB
C

/*
* arch/sh/kernel/cpu/irq/imask.c
*
* Copyright (C) 1999, 2000 Niibe Yutaka
*
* Simple interrupt handling using IMASK of SR register.
*
*/
/* NOTE: Will not work on level 15 */
#include <linux/ptrace.h>
#include <linux/errno.h>
#include <linux/kernel_stat.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <linux/spinlock.h>
#include <linux/cache.h>
#include <linux/irq.h>
#include <asm/system.h>
#include <asm/irq.h>
/* Bitmap of IRQ masked */
static unsigned long imask_mask = 0x7fff;
static int interrupt_priority = 0;
static void enable_imask_irq(unsigned int irq);
static void disable_imask_irq(unsigned int irq);
static void shutdown_imask_irq(unsigned int irq);
static void mask_and_ack_imask(unsigned int);
static void end_imask_irq(unsigned int irq);
#define IMASK_PRIORITY 15
static unsigned int startup_imask_irq(unsigned int irq)
{
/* Nothing to do */
return 0; /* never anything pending */
}
static struct hw_interrupt_type imask_irq_type = {
.typename = "SR.IMASK",
.startup = startup_imask_irq,
.shutdown = shutdown_imask_irq,
.enable = enable_imask_irq,
.disable = disable_imask_irq,
.ack = mask_and_ack_imask,
.end = end_imask_irq
};
void static inline set_interrupt_registers(int ip)
{
unsigned long __dummy;
asm volatile("ldc %2, r6_bank\n\t"
"stc sr, %0\n\t"
"and #0xf0, %0\n\t"
"shlr2 %0\n\t"
"cmp/eq #0x3c, %0\n\t"
"bt/s 1f ! CLI-ed\n\t"
" stc sr, %0\n\t"
"and %1, %0\n\t"
"or %2, %0\n\t"
"ldc %0, sr\n"
"1:"
: "=&z" (__dummy)
: "r" (~0xf0), "r" (ip << 4)
: "t");
}
static void disable_imask_irq(unsigned int irq)
{
clear_bit(irq, &imask_mask);
if (interrupt_priority < IMASK_PRIORITY - irq)
interrupt_priority = IMASK_PRIORITY - irq;
set_interrupt_registers(interrupt_priority);
}
static void enable_imask_irq(unsigned int irq)
{
set_bit(irq, &imask_mask);
interrupt_priority = IMASK_PRIORITY - ffz(imask_mask);
set_interrupt_registers(interrupt_priority);
}
static void mask_and_ack_imask(unsigned int irq)
{
disable_imask_irq(irq);
}
static void end_imask_irq(unsigned int irq)
{
if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
enable_imask_irq(irq);
}
static void shutdown_imask_irq(unsigned int irq)
{
/* Nothing to do */
}
void make_imask_irq(unsigned int irq)
{
disable_irq_nosync(irq);
irq_desc[irq].handler = &imask_irq_type;
enable_irq(irq);
}