+++ /dev/null
-/*
- * linux/arch/arm26/kernel/fiq.c
- *
- * Copyright (C) 1998 Russell King
- * Copyright (C) 1998, 1999 Phil Blundell
- * Copyright (C) 2003 Ian Molton
- *
- * 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/mm.h>
-#include <linux/mman.h>
-#include <linux/init.h>
-#include <linux/seq_file.h>
-
-#include <asm/fiq.h>
-#include <asm/io.h>
-#include <asm/irq.h>
-#include <asm/pgalloc.h>
-#include <asm/system.h>
-#include <asm/uaccess.h>
-
-#define FIQ_VECTOR (vectors_base() + 0x1c)
-
-static unsigned long no_fiq_insn;
-
-#define unprotect_page_0()
-#define protect_page_0()
-
-/* Default reacquire function
- * - we always relinquish FIQ control
- * - we always reacquire FIQ control
- */
-static int fiq_def_op(void *ref, int relinquish)
-{
- if (!relinquish) {
- unprotect_page_0();
- *(unsigned long *)FIQ_VECTOR = no_fiq_insn;
- protect_page_0();
- }
-
- 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)
-{
- unprotect_page_0();
-
- memcpy((void *)FIQ_VECTOR, start, length);
-
- protect_page_0();
-}
-
-/*
- * Taking an interrupt in FIQ mode is death, so both these functions
- * disable irqs for the duration.
- */
-void set_fiq_regs(struct pt_regs *regs)
-{
- register unsigned long tmp, tmp2;
- __asm__ volatile (
- "mov %0, pc \n"
- "bic %1, %0, #0x3 \n"
- "orr %1, %1, %3 \n"
- "teqp %1, #0 @ select FIQ mode \n"
- "mov r0, r0 \n"
- "ldmia %2, {r8 - r14} \n"
- "teqp %0, #0 @ return to SVC mode \n"
- "mov r0, r0 "
- : "=&r" (tmp), "=&r" (tmp2)
- : "r" (®s->ARM_r8), "I" (PSR_I_BIT | PSR_F_BIT | MODE_FIQ26)
- /* These registers aren't modified by the above code in a way
- visible to the compiler, but we mark them as clobbers anyway
- so that GCC won't put any of the input or output operands in
- them. */
- : "r8", "r9", "r10", "r11", "r12", "r13", "r14");
-}
-
-void get_fiq_regs(struct pt_regs *regs)
-{
- register unsigned long tmp, tmp2;
- __asm__ volatile (
- "mov %0, pc \n"
- "bic %1, %0, #0x3 \n"
- "orr %1, %1, %3 \n"
- "teqp %1, #0 @ select FIQ mode \n"
- "mov r0, r0 \n"
- "stmia %2, {r8 - r14} \n"
- "teqp %0, #0 @ return to SVC mode \n"
- "mov r0, r0 "
- : "=&r" (tmp), "=&r" (tmp2)
- : "r" (®s->ARM_r8), "I" (PSR_I_BIT | PSR_F_BIT | MODE_FIQ26)
- /* These registers aren't modified by the above code in a way
- visible to the compiler, but we mark them as clobbers anyway
- so that GCC won't put any of the input or output operands in
- them. */
- : "r8", "r9", "r10", "r11", "r12", "r13", "r14");
-}
-
-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);
-#ifdef CONFIG_DEBUG_ERRORS
- __backtrace();
-#endif
- 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 *)FIQ_VECTOR;
- set_fs(get_fs());
-}
git.openpandora.org / pandora-kernel.git / blobdiff