linux/arch/mips/lib/mips-atomic.c
Al Cooper f93a1a00f2 MIPS: Fix crash that occurs when function tracing is enabled
A recent patch changed some irq routines from inlines to functions.
These routines are called by the tracer code. Now that they're functions,
if they are compiled for function tracing they will call the tracer
and crash the system due to infinite recursion. The fix disables
tracing in these functions by using "notrace" in the function
definition.

Signed-off-by: Al Cooper <alcooperx@gmail.com>
Reviewed-by: David Daney <david.daney@cavium.com>
Pathchwork: https://patchwork.linux-mips.org/patch/4564/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2012-11-23 18:44:38 +01:00

177 lines
4.3 KiB
C

/*
* 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.
*
* Copyright (C) 1994, 95, 96, 97, 98, 99, 2003 by Ralf Baechle
* Copyright (C) 1996 by Paul M. Antoine
* Copyright (C) 1999 Silicon Graphics
* Copyright (C) 2000 MIPS Technologies, Inc.
*/
#include <asm/irqflags.h>
#include <asm/hazards.h>
#include <linux/compiler.h>
#include <linux/preempt.h>
#include <linux/export.h>
#if !defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_MIPS_MT_SMTC)
/*
* For cli() we have to insert nops to make sure that the new value
* has actually arrived in the status register before the end of this
* macro.
* R4000/R4400 need three nops, the R4600 two nops and the R10000 needs
* no nops at all.
*/
/*
* For TX49, operating only IE bit is not enough.
*
* If mfc0 $12 follows store and the mfc0 is last instruction of a
* page and fetching the next instruction causes TLB miss, the result
* of the mfc0 might wrongly contain EXL bit.
*
* ERT-TX49H2-027, ERT-TX49H3-012, ERT-TX49HL3-006, ERT-TX49H4-008
*
* Workaround: mask EXL bit of the result or place a nop before mfc0.
*/
__asm__(
" .macro arch_local_irq_disable\n"
" .set push \n"
" .set noat \n"
#ifdef CONFIG_MIPS_MT_SMTC
" mfc0 $1, $2, 1 \n"
" ori $1, 0x400 \n"
" .set noreorder \n"
" mtc0 $1, $2, 1 \n"
#elif defined(CONFIG_CPU_MIPSR2)
/* see irqflags.h for inline function */
#else
" mfc0 $1,$12 \n"
" ori $1,0x1f \n"
" xori $1,0x1f \n"
" .set noreorder \n"
" mtc0 $1,$12 \n"
#endif
" irq_disable_hazard \n"
" .set pop \n"
" .endm \n");
notrace void arch_local_irq_disable(void)
{
preempt_disable();
__asm__ __volatile__(
"arch_local_irq_disable"
: /* no outputs */
: /* no inputs */
: "memory");
preempt_enable();
}
EXPORT_SYMBOL(arch_local_irq_disable);
__asm__(
" .macro arch_local_irq_save result \n"
" .set push \n"
" .set reorder \n"
" .set noat \n"
#ifdef CONFIG_MIPS_MT_SMTC
" mfc0 \\result, $2, 1 \n"
" ori $1, \\result, 0x400 \n"
" .set noreorder \n"
" mtc0 $1, $2, 1 \n"
" andi \\result, \\result, 0x400 \n"
#elif defined(CONFIG_CPU_MIPSR2)
/* see irqflags.h for inline function */
#else
" mfc0 \\result, $12 \n"
" ori $1, \\result, 0x1f \n"
" xori $1, 0x1f \n"
" .set noreorder \n"
" mtc0 $1, $12 \n"
#endif
" irq_disable_hazard \n"
" .set pop \n"
" .endm \n");
notrace unsigned long arch_local_irq_save(void)
{
unsigned long flags;
preempt_disable();
asm volatile("arch_local_irq_save\t%0"
: "=r" (flags)
: /* no inputs */
: "memory");
preempt_enable();
return flags;
}
EXPORT_SYMBOL(arch_local_irq_save);
__asm__(
" .macro arch_local_irq_restore flags \n"
" .set push \n"
" .set noreorder \n"
" .set noat \n"
#ifdef CONFIG_MIPS_MT_SMTC
"mfc0 $1, $2, 1 \n"
"andi \\flags, 0x400 \n"
"ori $1, 0x400 \n"
"xori $1, 0x400 \n"
"or \\flags, $1 \n"
"mtc0 \\flags, $2, 1 \n"
#elif defined(CONFIG_CPU_MIPSR2) && defined(CONFIG_IRQ_CPU)
/* see irqflags.h for inline function */
#elif defined(CONFIG_CPU_MIPSR2)
/* see irqflags.h for inline function */
#else
" mfc0 $1, $12 \n"
" andi \\flags, 1 \n"
" ori $1, 0x1f \n"
" xori $1, 0x1f \n"
" or \\flags, $1 \n"
" mtc0 \\flags, $12 \n"
#endif
" irq_disable_hazard \n"
" .set pop \n"
" .endm \n");
notrace void arch_local_irq_restore(unsigned long flags)
{
unsigned long __tmp1;
#ifdef CONFIG_MIPS_MT_SMTC
/*
* SMTC kernel needs to do a software replay of queued
* IPIs, at the cost of branch and call overhead on each
* local_irq_restore()
*/
if (unlikely(!(flags & 0x0400)))
smtc_ipi_replay();
#endif
preempt_disable();
__asm__ __volatile__(
"arch_local_irq_restore\t%0"
: "=r" (__tmp1)
: "0" (flags)
: "memory");
preempt_enable();
}
EXPORT_SYMBOL(arch_local_irq_restore);
notrace void __arch_local_irq_restore(unsigned long flags)
{
unsigned long __tmp1;
preempt_disable();
__asm__ __volatile__(
"arch_local_irq_restore\t%0"
: "=r" (__tmp1)
: "0" (flags)
: "memory");
preempt_enable();
}
EXPORT_SYMBOL(__arch_local_irq_restore);
#endif /* !defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_MIPS_MT_SMTC) */