diff options
| -rw-r--r-- | include/asm-generic/cmpxchg.h | 87 | ||||
| -rw-r--r-- | include/asm-generic/system.h | 70 |
2 files changed, 80 insertions, 77 deletions
diff --git a/include/asm-generic/cmpxchg.h b/include/asm-generic/cmpxchg.h index e0449af91f60..8a361834dc25 100644 --- a/include/asm-generic/cmpxchg.h +++ b/include/asm-generic/cmpxchg.h @@ -1,16 +1,87 @@ +/* + * Generic UP xchg and cmpxchg using interrupt disablement. Does not + * support SMP. + */ + #ifndef __ASM_GENERIC_CMPXCHG_H #define __ASM_GENERIC_CMPXCHG_H -/* - * Generic cmpxchg - * - * Uses the local cmpxchg. Does not support SMP. - */ #ifdef CONFIG_SMP #error "Cannot use generic cmpxchg on SMP" #endif -#include <asm-generic/cmpxchg-local.h> +#include <linux/irqflags.h> + +#ifndef xchg + +/* + * This function doesn't exist, so you'll get a linker error if + * something tries to do an invalidly-sized xchg(). + */ +extern void __xchg_called_with_bad_pointer(void); + +static inline +unsigned long __xchg(unsigned long x, volatile void *ptr, int size) +{ + unsigned long ret, flags; + + switch (size) { + case 1: +#ifdef __xchg_u8 + return __xchg_u8(x, ptr); +#else + local_irq_save(flags); + ret = *(volatile u8 *)ptr; + *(volatile u8 *)ptr = x; + local_irq_restore(flags); + return ret; +#endif /* __xchg_u8 */ + + case 2: +#ifdef __xchg_u16 + return __xchg_u16(x, ptr); +#else + local_irq_save(flags); + ret = *(volatile u16 *)ptr; + *(volatile u16 *)ptr = x; + local_irq_restore(flags); + return ret; +#endif /* __xchg_u16 */ + + case 4: +#ifdef __xchg_u32 + return __xchg_u32(x, ptr); +#else + local_irq_save(flags); + ret = *(volatile u32 *)ptr; + *(volatile u32 *)ptr = x; + local_irq_restore(flags); + return ret; +#endif /* __xchg_u32 */ + +#ifdef CONFIG_64BIT + case 8: +#ifdef __xchg_u64 + return __xchg_u64(x, ptr); +#else + local_irq_save(flags); + ret = *(volatile u64 *)ptr; + *(volatile u64 *)ptr = x; + local_irq_restore(flags); + return ret; +#endif /* __xchg_u64 */ +#endif /* CONFIG_64BIT */ + + default: + __xchg_called_with_bad_pointer(); + return x; + } +} + +#define xchg(ptr, x) \ + ((__typeof__(*(ptr))) __xchg((unsigned long)(x), (ptr), sizeof(*(ptr)))) + +#endif /* xchg */ /* * Atomic compare and exchange. @@ -18,7 +89,9 @@ * Do not define __HAVE_ARCH_CMPXCHG because we want to use it to check whether * a cmpxchg primitive faster than repeated local irq save/restore exists. */ +#include <asm-generic/cmpxchg-local.h> + #define cmpxchg(ptr, o, n) cmpxchg_local((ptr), (o), (n)) #define cmpxchg64(ptr, o, n) cmpxchg64_local((ptr), (o), (n)) -#endif +#endif /* __ASM_GENERIC_CMPXCHG_H */ diff --git a/include/asm-generic/system.h b/include/asm-generic/system.h index f98f693383c4..54cd124ea9a4 100644 --- a/include/asm-generic/system.h +++ b/include/asm-generic/system.h @@ -17,7 +17,6 @@ #ifndef __ASSEMBLY__ #include <linux/types.h> -#include <linux/irqflags.h> #include <asm/barrier.h> #include <asm/cmpxchg.h> @@ -34,75 +33,6 @@ extern struct task_struct *__switch_to(struct task_struct *, #define arch_align_stack(x) (x) -/* - * we make sure local_irq_enable() doesn't cause priority inversion - */ - -/* This function doesn't exist, so you'll get a linker error - * if something tries to do an invalid xchg(). */ -extern void __xchg_called_with_bad_pointer(void); - -static inline -unsigned long __xchg(unsigned long x, volatile void *ptr, int size) -{ - unsigned long ret, flags; - - switch (size) { - case 1: -#ifdef __xchg_u8 - return __xchg_u8(x, ptr); -#else - local_irq_save(flags); - ret = *(volatile u8 *)ptr; - *(volatile u8 *)ptr = x; - local_irq_restore(flags); - return ret; -#endif /* __xchg_u8 */ - - case 2: -#ifdef __xchg_u16 - return __xchg_u16(x, ptr); -#else - local_irq_save(flags); - ret = *(volatile u16 *)ptr; - *(volatile u16 *)ptr = x; - local_irq_restore(flags); - return ret; -#endif /* __xchg_u16 */ - - case 4: -#ifdef __xchg_u32 - return __xchg_u32(x, ptr); -#else - local_irq_save(flags); - ret = *(volatile u32 *)ptr; - *(volatile u32 *)ptr = x; - local_irq_restore(flags); - return ret; -#endif /* __xchg_u32 */ - -#ifdef CONFIG_64BIT - case 8: -#ifdef __xchg_u64 - return __xchg_u64(x, ptr); -#else - local_irq_save(flags); - ret = *(volatile u64 *)ptr; - *(volatile u64 *)ptr = x; - local_irq_restore(flags); - return ret; -#endif /* __xchg_u64 */ -#endif /* CONFIG_64BIT */ - - default: - __xchg_called_with_bad_pointer(); - return x; - } -} - -#define xchg(ptr, x) \ - ((__typeof__(*(ptr))) __xchg((unsigned long)(x), (ptr), sizeof(*(ptr)))) - #endif /* !__ASSEMBLY__ */ #endif /* __ASM_GENERIC_SYSTEM_H */ |