linux/arch/arm/kernel/fiq.c
Thomas Gleixner 4a2581a080 [ARM] 3692/1: ARM: coswitch irq handling to the generic implementation
Patch from Thomas Gleixner

From: Thomas Gleixner <tglx@linutronix.de>

Switch the ARM irq core handling to the generic implementation. The
ARM specific header files now contain mostly migration stubs and
helper macros. Note that each machine type must be converted after
this step seperately. This was seperated out from the patch for easier
review.

The main changes for the machine type code is the conversion of the
type handlers to a 'type flow' and 'chip' model. This affects only the
multiplex interrupt handlers. A conversion macro needs to be added to
those implementations, which defines the data structure which is
registered by the set_irq_chained_handler() macro.

Some minor fixups of include files and the conversion of data
structure access is necessary all over the place.

The mostly macro based conversion was provided to allow an easy
migration of the existing implementations.

The code compiles on all defconfigs available in arch/arm/configs
except those which were broken also before applying the conversion
patches.

The code has been boot and runtime tested on most ARM platforms. The
results of an extensive testing and bugfixing series can be found
at: http://www.linutronix.de/index.php?page=testing

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-07-01 22:30:09 +01:00

182 lines
4 KiB
C

/*
* linux/arch/arm/kernel/fiq.c
*
* Copyright (C) 1998 Russell King
* Copyright (C) 1998, 1999 Phil Blundell
*
* FIQ support written by Philip Blundell <philb@gnu.org>, 1998.
*
* FIQ support re-written by Russell King to be more generic
*
* We now properly support a method by which the FIQ handlers can
* be stacked onto the vector. We still do not support sharing
* the FIQ vector itself.
*
* Operation is as follows:
* 1. Owner A claims FIQ:
* - default_fiq relinquishes control.
* 2. Owner A:
* - inserts code.
* - sets any registers,
* - enables FIQ.
* 3. Owner B claims FIQ:
* - if owner A has a relinquish function.
* - disable FIQs.
* - saves any registers.
* - returns zero.
* 4. Owner B:
* - inserts code.
* - sets any registers,
* - enables FIQ.
* 5. Owner B releases FIQ:
* - Owner A is asked to reacquire FIQ:
* - inserts code.
* - restores saved registers.
* - enables FIQ.
* 6. Goto 3
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/seq_file.h>
#include <asm/cacheflush.h>
#include <asm/fiq.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <asm/uaccess.h>
static unsigned long no_fiq_insn;
/* Default reacquire function
* - we always relinquish FIQ control
* - we always reacquire FIQ control
*/
static int fiq_def_op(void *ref, int relinquish)
{
if (!relinquish)
set_fiq_handler(&no_fiq_insn, sizeof(no_fiq_insn));
return 0;
}
static struct fiq_handler default_owner = {
.name = "default",
.fiq_op = fiq_def_op,
};
static struct fiq_handler *current_fiq = &default_owner;
int show_fiq_list(struct seq_file *p, void *v)
{
if (current_fiq != &default_owner)
seq_printf(p, "FIQ: %s\n", current_fiq->name);
return 0;
}
void set_fiq_handler(void *start, unsigned int length)
{
memcpy((void *)0xffff001c, start, length);
flush_icache_range(0xffff001c, 0xffff001c + length);
if (!vectors_high())
flush_icache_range(0x1c, 0x1c + length);
}
/*
* Taking an interrupt in FIQ mode is death, so both these functions
* disable irqs for the duration. Note - these functions are almost
* entirely coded in assembly.
*/
void __attribute__((naked)) set_fiq_regs(struct pt_regs *regs)
{
register unsigned long tmp;
asm volatile (
"mov ip, sp\n\
stmfd sp!, {fp, ip, lr, pc}\n\
sub fp, ip, #4\n\
mrs %0, cpsr\n\
msr cpsr_c, %2 @ select FIQ mode\n\
mov r0, r0\n\
ldmia %1, {r8 - r14}\n\
msr cpsr_c, %0 @ return to SVC mode\n\
mov r0, r0\n\
ldmfd sp, {fp, sp, pc}"
: "=&r" (tmp)
: "r" (&regs->ARM_r8), "I" (PSR_I_BIT | PSR_F_BIT | FIQ_MODE));
}
void __attribute__((naked)) get_fiq_regs(struct pt_regs *regs)
{
register unsigned long tmp;
asm volatile (
"mov ip, sp\n\
stmfd sp!, {fp, ip, lr, pc}\n\
sub fp, ip, #4\n\
mrs %0, cpsr\n\
msr cpsr_c, %2 @ select FIQ mode\n\
mov r0, r0\n\
stmia %1, {r8 - r14}\n\
msr cpsr_c, %0 @ return to SVC mode\n\
mov r0, r0\n\
ldmfd sp, {fp, sp, pc}"
: "=&r" (tmp)
: "r" (&regs->ARM_r8), "I" (PSR_I_BIT | PSR_F_BIT | FIQ_MODE));
}
int claim_fiq(struct fiq_handler *f)
{
int ret = 0;
if (current_fiq) {
ret = -EBUSY;
if (current_fiq->fiq_op != NULL)
ret = current_fiq->fiq_op(current_fiq->dev_id, 1);
}
if (!ret) {
f->next = current_fiq;
current_fiq = f;
}
return ret;
}
void release_fiq(struct fiq_handler *f)
{
if (current_fiq != f) {
printk(KERN_ERR "%s FIQ trying to release %s FIQ\n",
f->name, current_fiq->name);
dump_stack();
return;
}
do
current_fiq = current_fiq->next;
while (current_fiq->fiq_op(current_fiq->dev_id, 0));
}
void enable_fiq(int fiq)
{
enable_irq(fiq + FIQ_START);
}
void disable_fiq(int fiq)
{
disable_irq(fiq + FIQ_START);
}
EXPORT_SYMBOL(set_fiq_handler);
EXPORT_SYMBOL(set_fiq_regs);
EXPORT_SYMBOL(get_fiq_regs);
EXPORT_SYMBOL(claim_fiq);
EXPORT_SYMBOL(release_fiq);
EXPORT_SYMBOL(enable_fiq);
EXPORT_SYMBOL(disable_fiq);
void __init init_FIQ(void)
{
no_fiq_insn = *(unsigned long *)0xffff001c;
}