linux/arch/m68k/sun3/sun3ints.c
Finn Thain 1efdd4bd25 m68k: Call timer_interrupt() with interrupts disabled
Some platforms execute their timer handler with the interrupt priority
level set below 6. That means the handler could be interrupted by another
driver and this could lead to re-entry of the timer core.

Avoid this by use of local_irq_save/restore for timer interrupt dispatch.
This provides mutual exclusion around the timer interrupt flag access
which is needed later in this series for the clocksource conversion.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1811131407120.2697@nanos.tec.linutronix.de
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2019-03-25 10:22:24 +01:00

103 lines
2.2 KiB
C

/*
* linux/arch/m68k/sun3/sun3ints.c -- Sun-3(x) Linux interrupt handling code
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of this archive
* for more details.
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/kernel_stat.h>
#include <linux/interrupt.h>
#include <asm/segment.h>
#include <asm/intersil.h>
#include <asm/oplib.h>
#include <asm/sun3ints.h>
#include <asm/irq_regs.h>
#include <linux/seq_file.h>
extern void sun3_leds (unsigned char);
void sun3_disable_interrupts(void)
{
sun3_disable_irq(0);
}
void sun3_enable_interrupts(void)
{
sun3_enable_irq(0);
}
static int led_pattern[8] = {
~(0x80), ~(0x01),
~(0x40), ~(0x02),
~(0x20), ~(0x04),
~(0x10), ~(0x08)
};
volatile unsigned char* sun3_intreg;
void sun3_enable_irq(unsigned int irq)
{
*sun3_intreg |= (1 << irq);
}
void sun3_disable_irq(unsigned int irq)
{
*sun3_intreg &= ~(1 << irq);
}
static irqreturn_t sun3_int7(int irq, void *dev_id)
{
unsigned int cnt;
cnt = kstat_irqs_cpu(irq, 0);
if (!(cnt % 2000))
sun3_leds(led_pattern[cnt % 16000 / 2000]);
return IRQ_HANDLED;
}
static irqreturn_t sun3_int5(int irq, void *dev_id)
{
unsigned long flags;
unsigned int cnt;
local_irq_save(flags);
#ifdef CONFIG_SUN3
intersil_clear();
#endif
sun3_disable_irq(5);
sun3_enable_irq(5);
#ifdef CONFIG_SUN3
intersil_clear();
#endif
xtime_update(1);
update_process_times(user_mode(get_irq_regs()));
cnt = kstat_irqs_cpu(irq, 0);
if (!(cnt % 20))
sun3_leds(led_pattern[cnt % 160 / 20]);
local_irq_restore(flags);
return IRQ_HANDLED;
}
static irqreturn_t sun3_vec255(int irq, void *dev_id)
{
return IRQ_HANDLED;
}
void __init sun3_init_IRQ(void)
{
*sun3_intreg = 1;
m68k_setup_user_interrupt(VEC_USER, 128);
if (request_irq(IRQ_AUTO_5, sun3_int5, 0, "clock", NULL))
pr_err("Couldn't register %s interrupt\n", "int5");
if (request_irq(IRQ_AUTO_7, sun3_int7, 0, "nmi", NULL))
pr_err("Couldn't register %s interrupt\n", "int7");
if (request_irq(IRQ_USER+127, sun3_vec255, 0, "vec255", NULL))
pr_err("Couldn't register %s interrupt\n", "vec255");
}