linux/arch/mips/include/asm/irqflags.h
Huacai Chen 1e820da3c9 MIPS: Loongson-3: Introduce CONFIG_LOONGSON3_ENHANCEMENT
New Loongson 3 CPU (since Loongson-3A R2, as opposed to Loongson-3A R1,
Loongson-3B R1 and Loongson-3B R2) has many enhancements, such as FTLB,
L1-VCache, EI/DI/Wait/Prefetch instruction, DSP/DSPv2 ASE, User Local
register, Read-Inhibit/Execute-Inhibit, SFB (Store Fill Buffer), Fast
TLB refill support, etc.

This patch introduce a config option, CONFIG_LOONGSON3_ENHANCEMENT, to
enable those enhancements which are not probed at run time. If you want
a generic kernel to run on all Loongson 3 machines, please say 'N'
here. If you want a high-performance kernel to run on new Loongson 3
machines only, please say 'Y' here.

Some additional explanations:
1) SFB locates between core and L1 cache, it causes memory access out
   of order, so writel/outl (and other similar functions) need a I/O
   reorder barrier.
2) Loongson 3 has a bug that di instruction can not save the irqflag,
   so arch_local_irq_save() is modified. Since CPU_MIPSR2 is selected
   by CONFIG_LOONGSON3_ENHANCEMENT, generic kernel doesn't use ei/di
   at all.
3) CPU_HAS_PREFETCH is selected by CONFIG_LOONGSON3_ENHANCEMENT, so
   MIPS_CPU_PREFETCH (used by uasm) probing is also put in this patch.

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J . Hill <sjhill@realitydiluted.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12755/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13 14:02:15 +02:00

181 lines
4.0 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 <linux/compiler.h>
#include <linux/stringify.h>
#include <asm/compiler.h>
#include <asm/hazards.h>
#if defined(CONFIG_CPU_MIPSR2) || defined (CONFIG_CPU_MIPSR6)
static inline void arch_local_irq_disable(void)
{
__asm__ __volatile__(
" .set push \n"
" .set noat \n"
" di \n"
" " __stringify(__irq_disable_hazard) " \n"
" .set pop \n"
: /* no outputs */
: /* no inputs */
: "memory");
}
static inline unsigned long arch_local_irq_save(void)
{
unsigned long flags;
asm __volatile__(
" .set push \n"
" .set reorder \n"
" .set noat \n"
#if defined(CONFIG_CPU_LOONGSON3)
" mfc0 %[flags], $12 \n"
" di \n"
#else
" di %[flags] \n"
#endif
" andi %[flags], 1 \n"
" " __stringify(__irq_disable_hazard) " \n"
" .set pop \n"
: [flags] "=r" (flags)
: /* no inputs */
: "memory");
return flags;
}
static inline void arch_local_irq_restore(unsigned long flags)
{
unsigned long __tmp1;
__asm__ __volatile__(
" .set push \n"
" .set noreorder \n"
" .set noat \n"
#if defined(CONFIG_IRQ_MIPS_CPU)
/*
* Slow, but doesn't suffer from a relatively unlikely race
* condition we're having since days 1.
*/
" beqz %[flags], 1f \n"
" di \n"
" ei \n"
"1: \n"
#else
/*
* Fast, dangerous. Life is fun, life is good.
*/
" mfc0 $1, $12 \n"
" ins $1, %[flags], 0, 1 \n"
" mtc0 $1, $12 \n"
#endif
" " __stringify(__irq_disable_hazard) " \n"
" .set pop \n"
: [flags] "=r" (__tmp1)
: "0" (flags)
: "memory");
}
#else
/* Functions that require preempt_{dis,en}able() are in mips-atomic.c */
void arch_local_irq_disable(void);
unsigned long arch_local_irq_save(void);
void arch_local_irq_restore(unsigned long flags);
#endif /* CONFIG_CPU_MIPSR2 || CONFIG_CPU_MIPSR6 */
static inline void arch_local_irq_enable(void)
{
__asm__ __volatile__(
" .set push \n"
" .set reorder \n"
" .set noat \n"
#if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6)
" ei \n"
#else
" mfc0 $1,$12 \n"
" ori $1,0x1f \n"
" xori $1,0x1e \n"
" mtc0 $1,$12 \n"
#endif
" " __stringify(__irq_enable_hazard) " \n"
" .set pop \n"
: /* no outputs */
: /* no inputs */
: "memory");
}
static inline unsigned long arch_local_save_flags(void)
{
unsigned long flags;
asm __volatile__(
" .set push \n"
" .set reorder \n"
" mfc0 %[flags], $12 \n"
" .set pop \n"
: [flags] "=r" (flags));
return flags;
}
static inline int arch_irqs_disabled_flags(unsigned long flags)
{
return !(flags & 1);
}
#endif /* #ifndef __ASSEMBLY__ */
/*
* 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 */