linux-stable-rt/arch/sh/kernel/cpu/irq/imask.c

86 lines
1.9 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 <linux/bitmap.h>
#include <asm/system.h>
#include <asm/irq.h>
/* Bitmap of IRQ masked */
#define IMASK_PRIORITY 15
static DECLARE_BITMAP(imask_mask, IMASK_PRIORITY);
static int interrupt_priority;
static inline void set_interrupt_registers(int ip)
{
unsigned long __dummy;
asm volatile(
#ifdef CONFIG_CPU_HAS_SR_RB
"ldc %2, r6_bank\n\t"
#endif
"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 mask_imask_irq(struct irq_data *data)
{
unsigned int irq = data->irq;
clear_bit(irq, imask_mask);
if (interrupt_priority < IMASK_PRIORITY - irq)
interrupt_priority = IMASK_PRIORITY - irq;
set_interrupt_registers(interrupt_priority);
}
static void unmask_imask_irq(struct irq_data *data)
{
unsigned int irq = data->irq;
set_bit(irq, imask_mask);
interrupt_priority = IMASK_PRIORITY -
find_first_zero_bit(imask_mask, IMASK_PRIORITY);
set_interrupt_registers(interrupt_priority);
}
static struct irq_chip imask_irq_chip = {
.name = "SR.IMASK",
.irq_mask = mask_imask_irq,
.irq_unmask = unmask_imask_irq,
.irq_mask_ack = mask_imask_irq,
};
void make_imask_irq(unsigned int irq)
{
irq_set_chip_and_handler_name(irq, &imask_irq_chip, handle_level_irq,
"level");
}