linux/arch/mips/lib/mips-atomic.c
Ralf Baechle b633648c5a MIPS: MT: Remove SMTC support
Nobody is maintaining SMTC anymore and there also seems to be no userbase.
Which is a pity - the SMTC technology primarily developed by Kevin D.
Kissell <kevink@paralogos.com> is an ingenious demonstration for the MT
ASE's power and elegance.

Based on Markos Chandras <Markos.Chandras@imgtec.com> patch
https://patchwork.linux-mips.org/patch/6719/ which while very similar did
no longer apply cleanly when I tried to merge it plus some additional
post-SMTC cleanup - SMTC was a feature as tricky to remove as it was to
merge once upon a time.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-24 00:07:01 +02:00

162 lines
3.7 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>
#include <linux/stringify.h>
#ifndef CONFIG_CPU_MIPSR2
/*
* 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.
*/
notrace void arch_local_irq_disable(void)
{
preempt_disable();
__asm__ __volatile__(
" .set push \n"
" .set noat \n"
#if 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
" " __stringify(__irq_disable_hazard) " \n"
" .set pop \n"
: /* no outputs */
: /* no inputs */
: "memory");
preempt_enable();
}
EXPORT_SYMBOL(arch_local_irq_disable);
notrace unsigned long arch_local_irq_save(void)
{
unsigned long flags;
preempt_disable();
__asm__ __volatile__(
" .set push \n"
" .set reorder \n"
" .set noat \n"
#if defined(CONFIG_CPU_MIPSR2)
/* see irqflags.h for inline function */
#else
" mfc0 %[flags], $12 \n"
" ori $1, %[flags], 0x1f \n"
" xori $1, 0x1f \n"
" .set noreorder \n"
" mtc0 $1, $12 \n"
#endif
" " __stringify(__irq_disable_hazard) " \n"
" .set pop \n"
: [flags] "=r" (flags)
: /* no inputs */
: "memory");
preempt_enable();
return flags;
}
EXPORT_SYMBOL(arch_local_irq_save);
notrace void arch_local_irq_restore(unsigned long flags)
{
unsigned long __tmp1;
preempt_disable();
__asm__ __volatile__(
" .set push \n"
" .set noreorder \n"
" .set noat \n"
#if 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
" " __stringify(__irq_disable_hazard) " \n"
" .set pop \n"
: [flags] "=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__(
" .set push \n"
" .set noreorder \n"
" .set noat \n"
#if 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
" " __stringify(__irq_disable_hazard) " \n"
" .set pop \n"
: [flags] "=r" (__tmp1)
: "0" (flags)
: "memory");
preempt_enable();
}
EXPORT_SYMBOL(__arch_local_irq_restore);
#endif /* !CONFIG_CPU_MIPSR2 */