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author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
commit | 57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch) | |
tree | 5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/avr32/include/asm/cmpxchg.h |
Initial import
Diffstat (limited to 'arch/avr32/include/asm/cmpxchg.h')
-rw-r--r-- | arch/avr32/include/asm/cmpxchg.h | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/arch/avr32/include/asm/cmpxchg.h b/arch/avr32/include/asm/cmpxchg.h new file mode 100644 index 000000000..962a6aeab --- /dev/null +++ b/arch/avr32/include/asm/cmpxchg.h @@ -0,0 +1,117 @@ +/* + * Atomic operations that C can't guarantee us. Useful for + * resource counting etc. + * + * But use these as seldom as possible since they are slower than + * regular operations. + * + * Copyright (C) 2004-2006 Atmel Corporation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#ifndef __ASM_AVR32_CMPXCHG_H +#define __ASM_AVR32_CMPXCHG_H + +#define xchg(ptr,x) \ + ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)))) + +extern void __xchg_called_with_bad_pointer(void); + +static inline unsigned long xchg_u32(u32 val, volatile u32 *m) +{ + u32 ret; + + asm volatile("xchg %[ret], %[m], %[val]" + : [ret] "=&r"(ret), "=m"(*m) + : "m"(*m), [m] "r"(m), [val] "r"(val) + : "memory"); + return ret; +} + +static inline unsigned long __xchg(unsigned long x, + volatile void *ptr, + int size) +{ + switch(size) { + case 4: + return xchg_u32(x, ptr); + default: + __xchg_called_with_bad_pointer(); + return x; + } +} + +static inline unsigned long __cmpxchg_u32(volatile int *m, unsigned long old, + unsigned long new) +{ + __u32 ret; + + asm volatile( + "1: ssrf 5\n" + " ld.w %[ret], %[m]\n" + " cp.w %[ret], %[old]\n" + " brne 2f\n" + " stcond %[m], %[new]\n" + " brne 1b\n" + "2:\n" + : [ret] "=&r"(ret), [m] "=m"(*m) + : "m"(m), [old] "ir"(old), [new] "r"(new) + : "memory", "cc"); + return ret; +} + +extern unsigned long __cmpxchg_u64_unsupported_on_32bit_kernels( + volatile int * m, unsigned long old, unsigned long new); +#define __cmpxchg_u64 __cmpxchg_u64_unsupported_on_32bit_kernels + +/* 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 __HAVE_ARCH_CMPXCHG 1 + +static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old, + unsigned long new, int size) +{ + switch (size) { + case 4: + return __cmpxchg_u32(ptr, old, new); + case 8: + return __cmpxchg_u64(ptr, old, new); + } + + __cmpxchg_called_with_bad_pointer(); + return old; +} + +#define cmpxchg(ptr, old, new) \ + ((typeof(*(ptr)))__cmpxchg((ptr), (unsigned long)(old), \ + (unsigned long)(new), \ + sizeof(*(ptr)))) + +#include <asm-generic/cmpxchg-local.h> + +static inline unsigned long __cmpxchg_local(volatile void *ptr, + unsigned long old, + unsigned long new, int size) +{ + switch (size) { + case 4: + return __cmpxchg_u32(ptr, old, new); + default: + return __cmpxchg_local_generic(ptr, old, new, size); + } + + return old; +} + +#define cmpxchg_local(ptr, old, new) \ + ((typeof(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(old), \ + (unsigned long)(new), \ + sizeof(*(ptr)))) + +#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) + +#endif /* __ASM_AVR32_CMPXCHG_H */ |