diff options
Diffstat (limited to 'kernel/arch/mips/include/asm/cmpxchg.h')
| -rw-r--r-- | kernel/arch/mips/include/asm/cmpxchg.h | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/kernel/arch/mips/include/asm/cmpxchg.h b/kernel/arch/mips/include/asm/cmpxchg.h new file mode 100644 index 000000000..412f945f1 --- /dev/null +++ b/kernel/arch/mips/include/asm/cmpxchg.h @@ -0,0 +1,250 @@ +/* + * 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) 2003, 06, 07 by Ralf Baechle (ralf@linux-mips.org) + */ +#ifndef __ASM_CMPXCHG_H +#define __ASM_CMPXCHG_H + +#include <linux/bug.h> +#include <linux/irqflags.h> +#include <asm/compiler.h> +#include <asm/war.h> + +static inline unsigned long __xchg_u32(volatile int * m, unsigned int val) +{ + __u32 retval; + + smp_mb__before_llsc(); + + if (kernel_uses_llsc && R10000_LLSC_WAR) { + unsigned long dummy; + + __asm__ __volatile__( + " .set arch=r4000 \n" + "1: ll %0, %3 # xchg_u32 \n" + " .set mips0 \n" + " move %2, %z4 \n" + " .set arch=r4000 \n" + " sc %2, %1 \n" + " beqzl %2, 1b \n" + " .set mips0 \n" + : "=&r" (retval), "=" GCC_OFF_SMALL_ASM() (*m), "=&r" (dummy) + : GCC_OFF_SMALL_ASM() (*m), "Jr" (val) + : "memory"); + } else if (kernel_uses_llsc) { + unsigned long dummy; + + do { + __asm__ __volatile__( + " .set "MIPS_ISA_ARCH_LEVEL" \n" + " ll %0, %3 # xchg_u32 \n" + " .set mips0 \n" + " move %2, %z4 \n" + " .set "MIPS_ISA_ARCH_LEVEL" \n" + " sc %2, %1 \n" + " .set mips0 \n" + : "=&r" (retval), "=" GCC_OFF_SMALL_ASM() (*m), + "=&r" (dummy) + : GCC_OFF_SMALL_ASM() (*m), "Jr" (val) + : "memory"); + } while (unlikely(!dummy)); + } else { + unsigned long flags; + + raw_local_irq_save(flags); + retval = *m; + *m = val; + raw_local_irq_restore(flags); /* implies memory barrier */ + } + + smp_llsc_mb(); + + return retval; +} + +#ifdef CONFIG_64BIT +static inline __u64 __xchg_u64(volatile __u64 * m, __u64 val) +{ + __u64 retval; + + smp_mb__before_llsc(); + + if (kernel_uses_llsc && R10000_LLSC_WAR) { + unsigned long dummy; + + __asm__ __volatile__( + " .set arch=r4000 \n" + "1: lld %0, %3 # xchg_u64 \n" + " move %2, %z4 \n" + " scd %2, %1 \n" + " beqzl %2, 1b \n" + " .set mips0 \n" + : "=&r" (retval), "=" GCC_OFF_SMALL_ASM() (*m), "=&r" (dummy) + : GCC_OFF_SMALL_ASM() (*m), "Jr" (val) + : "memory"); + } else if (kernel_uses_llsc) { + unsigned long dummy; + + do { + __asm__ __volatile__( + " .set "MIPS_ISA_ARCH_LEVEL" \n" + " lld %0, %3 # xchg_u64 \n" + " move %2, %z4 \n" + " scd %2, %1 \n" + " .set mips0 \n" + : "=&r" (retval), "=" GCC_OFF_SMALL_ASM() (*m), + "=&r" (dummy) + : GCC_OFF_SMALL_ASM() (*m), "Jr" (val) + : "memory"); + } while (unlikely(!dummy)); + } else { + unsigned long flags; + + raw_local_irq_save(flags); + retval = *m; + *m = val; + raw_local_irq_restore(flags); /* implies memory barrier */ + } + + smp_llsc_mb(); + + return retval; +} +#else +extern __u64 __xchg_u64_unsupported_on_32bit_kernels(volatile __u64 * m, __u64 val); +#define __xchg_u64 __xchg_u64_unsupported_on_32bit_kernels +#endif + +static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size) +{ + switch (size) { + case 4: + return __xchg_u32(ptr, x); + case 8: + return __xchg_u64(ptr, x); + } + + return x; +} + +#define xchg(ptr, x) \ +({ \ + BUILD_BUG_ON(sizeof(*(ptr)) & ~0xc); \ + \ + ((__typeof__(*(ptr))) \ + __xchg((unsigned long)(x), (ptr), sizeof(*(ptr)))); \ +}) + +#define __HAVE_ARCH_CMPXCHG 1 + +#define __cmpxchg_asm(ld, st, m, old, new) \ +({ \ + __typeof(*(m)) __ret; \ + \ + if (kernel_uses_llsc && R10000_LLSC_WAR) { \ + __asm__ __volatile__( \ + " .set push \n" \ + " .set noat \n" \ + " .set arch=r4000 \n" \ + "1: " ld " %0, %2 # __cmpxchg_asm \n" \ + " bne %0, %z3, 2f \n" \ + " .set mips0 \n" \ + " move $1, %z4 \n" \ + " .set arch=r4000 \n" \ + " " st " $1, %1 \n" \ + " beqzl $1, 1b \n" \ + "2: \n" \ + " .set pop \n" \ + : "=&r" (__ret), "=" GCC_OFF_SMALL_ASM() (*m) \ + : GCC_OFF_SMALL_ASM() (*m), "Jr" (old), "Jr" (new) \ + : "memory"); \ + } else if (kernel_uses_llsc) { \ + __asm__ __volatile__( \ + " .set push \n" \ + " .set noat \n" \ + " .set "MIPS_ISA_ARCH_LEVEL" \n" \ + "1: " ld " %0, %2 # __cmpxchg_asm \n" \ + " bne %0, %z3, 2f \n" \ + " .set mips0 \n" \ + " move $1, %z4 \n" \ + " .set "MIPS_ISA_ARCH_LEVEL" \n" \ + " " st " $1, %1 \n" \ + " beqz $1, 1b \n" \ + " .set pop \n" \ + "2: \n" \ + : "=&r" (__ret), "=" GCC_OFF_SMALL_ASM() (*m) \ + : GCC_OFF_SMALL_ASM() (*m), "Jr" (old), "Jr" (new) \ + : "memory"); \ + } else { \ + unsigned long __flags; \ + \ + raw_local_irq_save(__flags); \ + __ret = *m; \ + if (__ret == old) \ + *m = new; \ + raw_local_irq_restore(__flags); \ + } \ + \ + __ret; \ +}) + +/* + * This function doesn't exist, so you'll get a linker error + * if something tries to do an invalid cmpxchg(). + */ +extern void __cmpxchg_called_with_bad_pointer(void); + +#define __cmpxchg(ptr, old, new, pre_barrier, post_barrier) \ +({ \ + __typeof__(ptr) __ptr = (ptr); \ + __typeof__(*(ptr)) __old = (old); \ + __typeof__(*(ptr)) __new = (new); \ + __typeof__(*(ptr)) __res = 0; \ + \ + pre_barrier; \ + \ + switch (sizeof(*(__ptr))) { \ + case 4: \ + __res = __cmpxchg_asm("ll", "sc", __ptr, __old, __new); \ + break; \ + case 8: \ + if (sizeof(long) == 8) { \ + __res = __cmpxchg_asm("lld", "scd", __ptr, \ + __old, __new); \ + break; \ + } \ + default: \ + __cmpxchg_called_with_bad_pointer(); \ + break; \ + } \ + \ + post_barrier; \ + \ + __res; \ +}) + +#define cmpxchg(ptr, old, new) __cmpxchg(ptr, old, new, smp_mb__before_llsc(), smp_llsc_mb()) +#define cmpxchg_local(ptr, old, new) __cmpxchg(ptr, old, new, , ) + +#ifdef CONFIG_64BIT +#define cmpxchg64_local(ptr, o, n) \ + ({ \ + BUILD_BUG_ON(sizeof(*(ptr)) != 8); \ + cmpxchg_local((ptr), (o), (n)); \ + }) + +#define cmpxchg64(ptr, o, n) \ + ({ \ + BUILD_BUG_ON(sizeof(*(ptr)) != 8); \ + cmpxchg((ptr), (o), (n)); \ + }) +#else +#include <asm-generic/cmpxchg-local.h> +#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) +#define cmpxchg64(ptr, o, n) cmpxchg64_local((ptr), (o), (n)) +#endif + +#endif /* __ASM_CMPXCHG_H */ |