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Diffstat (limited to 'arch/mips/lib/mips-atomic.c')
| -rw-r--r-- | arch/mips/lib/mips-atomic.c | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/arch/mips/lib/mips-atomic.c b/arch/mips/lib/mips-atomic.c new file mode 100644 index 000000000000..e091430dbeb1 --- /dev/null +++ b/arch/mips/lib/mips-atomic.c @@ -0,0 +1,176 @@ +/* + * 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"); + +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"); + +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"); + +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); + + +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) */ |