kernel-ark/include/asm-mips/irqflags.h
Ralf Baechle ac8be95504 [MIPS] SMTC: Instant IPI replay.
SMTC pseudo-interrupts between TCs are deferred and queued if the target
TC is interrupt-inhibited (IXMT). In the first SMTC prototypes, these
queued IPIs were serviced on return to user mode, or on entry into the
kernel idle loop. The INSTANT_REPLAY option dispatches them as part of
local_irq_restore() processing, which adds runtime overhead (hence the
option to turn it off), but ensures that IPIs are handled promptly even
under heavy I/O interrupt load.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-01-23 18:26:47 +00:00

273 lines
6.4 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.
*/
#ifndef _ASM_IRQFLAGS_H
#define _ASM_IRQFLAGS_H
#ifndef __ASSEMBLY__
#include <asm/hazards.h>
/*
* CONFIG_MIPS_MT_SMTC_INSTANT_REPLAY does prompt replay of deferred IPIs,
* at the cost of branch and call overhead on each local_irq_restore()
*/
#ifdef CONFIG_MIPS_MT_SMTC_INSTANT_REPLAY
extern void smtc_ipi_replay(void);
#define irq_restore_epilog(flags) \
do { \
if (!(flags & 0x0400)) \
smtc_ipi_replay(); \
} while (0)
#else
#define irq_restore_epilog(ignore) do { } while (0)
#endif /* CONFIG_MIPS_MT_SMTC_INSTANT_REPLAY */
__asm__ (
" .macro raw_local_irq_enable \n"
" .set push \n"
" .set reorder \n"
" .set noat \n"
#ifdef CONFIG_MIPS_MT_SMTC
" mfc0 $1, $2, 1 # SMTC - clear TCStatus.IXMT \n"
" ori $1, 0x400 \n"
" xori $1, 0x400 \n"
" mtc0 $1, $2, 1 \n"
#elif defined(CONFIG_CPU_MIPSR2)
" ei \n"
#else
" mfc0 $1,$12 \n"
" ori $1,0x1f \n"
" xori $1,0x1e \n"
" mtc0 $1,$12 \n"
#endif
" irq_enable_hazard \n"
" .set pop \n"
" .endm");
static inline void raw_local_irq_enable(void)
{
__asm__ __volatile__(
"raw_local_irq_enable"
: /* no outputs */
: /* no inputs */
: "memory");
}
/*
* 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 raw_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)
" di \n"
#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");
static inline void raw_local_irq_disable(void)
{
__asm__ __volatile__(
"raw_local_irq_disable"
: /* no outputs */
: /* no inputs */
: "memory");
}
__asm__ (
" .macro raw_local_save_flags flags \n"
" .set push \n"
" .set reorder \n"
#ifdef CONFIG_MIPS_MT_SMTC
" mfc0 \\flags, $2, 1 \n"
#else
" mfc0 \\flags, $12 \n"
#endif
" .set pop \n"
" .endm \n");
#define raw_local_save_flags(x) \
__asm__ __volatile__( \
"raw_local_save_flags %0" \
: "=r" (x))
__asm__ (
" .macro raw_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)
" di \\result \n"
" andi \\result, 1 \n"
#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");
#define raw_local_irq_save(x) \
__asm__ __volatile__( \
"raw_local_irq_save\t%0" \
: "=r" (x) \
: /* no inputs */ \
: "memory")
__asm__ (
" .macro raw_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)
/*
* Slow, but doesn't suffer from a relativly unlikely race
* condition we're having since days 1.
*/
" beqz \\flags, 1f \n"
" di \n"
" ei \n"
"1: \n"
#elif defined(CONFIG_CPU_MIPSR2)
/*
* Fast, dangerous. Life is fun, life is good.
*/
" mfc0 $1, $12 \n"
" ins $1, \\flags, 0, 1 \n"
" mtc0 $1, $12 \n"
#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");
#define raw_local_irq_restore(flags) \
do { \
unsigned long __tmp1; \
\
__asm__ __volatile__( \
"raw_local_irq_restore\t%0" \
: "=r" (__tmp1) \
: "0" (flags) \
: "memory"); \
irq_restore_epilog(flags); \
} while(0)
static inline int raw_irqs_disabled_flags(unsigned long flags)
{
#ifdef CONFIG_MIPS_MT_SMTC
/*
* SMTC model uses TCStatus.IXMT to disable interrupts for a thread/CPU
*/
return flags & 0x400;
#else
return !(flags & 1);
#endif
}
#endif
/*
* Do the CPU's IRQ-state tracing from assembly code.
*/
#ifdef CONFIG_TRACE_IRQFLAGS
/* Reload some registers clobbered by trace_hardirqs_on */
#ifdef CONFIG_64BIT
# define TRACE_IRQS_RELOAD_REGS \
LONG_L $11, PT_R11(sp); \
LONG_L $10, PT_R10(sp); \
LONG_L $9, PT_R9(sp); \
LONG_L $8, PT_R8(sp); \
LONG_L $7, PT_R7(sp); \
LONG_L $6, PT_R6(sp); \
LONG_L $5, PT_R5(sp); \
LONG_L $4, PT_R4(sp); \
LONG_L $2, PT_R2(sp)
#else
# define TRACE_IRQS_RELOAD_REGS \
LONG_L $7, PT_R7(sp); \
LONG_L $6, PT_R6(sp); \
LONG_L $5, PT_R5(sp); \
LONG_L $4, PT_R4(sp); \
LONG_L $2, PT_R2(sp)
#endif
# define TRACE_IRQS_ON \
CLI; /* make sure trace_hardirqs_on() is called in kernel level */ \
jal trace_hardirqs_on
# define TRACE_IRQS_ON_RELOAD \
TRACE_IRQS_ON; \
TRACE_IRQS_RELOAD_REGS
# define TRACE_IRQS_OFF \
jal trace_hardirqs_off
#else
# define TRACE_IRQS_ON
# define TRACE_IRQS_ON_RELOAD
# define TRACE_IRQS_OFF
#endif
#endif /* _ASM_IRQFLAGS_H */