diff options
Diffstat (limited to 'arch/riscv/include/asm/cmpxchg.h')
| -rw-r--r-- | arch/riscv/include/asm/cmpxchg.h | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/cmpxchg.h b/arch/riscv/include/asm/cmpxchg.h index ac9d0eeb74e6..26cea2395aae 100644 --- a/arch/riscv/include/asm/cmpxchg.h +++ b/arch/riscv/include/asm/cmpxchg.h @@ -11,6 +11,31 @@ #include <asm/barrier.h> #include <asm/fence.h> +#define __arch_xchg_masked(prepend, append, r, p, n) \ +({ \ + u32 *__ptr32b = (u32 *)((ulong)(p) & ~0x3); \ + ulong __s = ((ulong)(p) & (0x4 - sizeof(*p))) * BITS_PER_BYTE; \ + ulong __mask = GENMASK(((sizeof(*p)) * BITS_PER_BYTE) - 1, 0) \ + << __s; \ + ulong __newx = (ulong)(n) << __s; \ + ulong __retx; \ + ulong __rc; \ + \ + __asm__ __volatile__ ( \ + prepend \ + "0: lr.w %0, %2\n" \ + " and %1, %0, %z4\n" \ + " or %1, %1, %z3\n" \ + " sc.w %1, %1, %2\n" \ + " bnez %1, 0b\n" \ + append \ + : "=&r" (__retx), "=&r" (__rc), "+A" (*(__ptr32b)) \ + : "rJ" (__newx), "rJ" (~__mask) \ + : "memory"); \ + \ + r = (__typeof__(*(p)))((__retx & __mask) >> __s); \ +}) + #define __arch_xchg(sfx, prepend, append, r, p, n) \ ({ \ __asm__ __volatile__ ( \ @@ -27,7 +52,13 @@ __typeof__(ptr) __ptr = (ptr); \ __typeof__(*(__ptr)) __new = (new); \ __typeof__(*(__ptr)) __ret; \ + \ switch (sizeof(*__ptr)) { \ + case 1: \ + case 2: \ + __arch_xchg_masked(prepend, append, \ + __ret, __ptr, __new); \ + break; \ case 4: \ __arch_xchg(".w" sfx, prepend, append, \ __ret, __ptr, __new); \ |