diff options
Diffstat (limited to 'arch/tile/include/asm/futex.h')
| -rw-r--r-- | arch/tile/include/asm/futex.h | 143 |
1 files changed, 98 insertions, 45 deletions
diff --git a/arch/tile/include/asm/futex.h b/arch/tile/include/asm/futex.h index d03ec124a598..5909ac3d7218 100644 --- a/arch/tile/include/asm/futex.h +++ b/arch/tile/include/asm/futex.h @@ -28,29 +28,81 @@ #include <linux/futex.h> #include <linux/uaccess.h> #include <linux/errno.h> +#include <asm/atomic.h> -extern struct __get_user futex_set(u32 __user *v, int i); -extern struct __get_user futex_add(u32 __user *v, int n); -extern struct __get_user futex_or(u32 __user *v, int n); -extern struct __get_user futex_andn(u32 __user *v, int n); -extern struct __get_user futex_cmpxchg(u32 __user *v, int o, int n); +/* + * Support macros for futex operations. Do not use these macros directly. + * They assume "ret", "val", "oparg", and "uaddr" in the lexical context. + * __futex_cmpxchg() additionally assumes "oldval". + */ + +#ifdef __tilegx__ + +#define __futex_asm(OP) \ + asm("1: {" #OP " %1, %3, %4; movei %0, 0 }\n" \ + ".pushsection .fixup,\"ax\"\n" \ + "0: { movei %0, %5; j 9f }\n" \ + ".section __ex_table,\"a\"\n" \ + ".quad 1b, 0b\n" \ + ".popsection\n" \ + "9:" \ + : "=r" (ret), "=r" (val), "+m" (*(uaddr)) \ + : "r" (uaddr), "r" (oparg), "i" (-EFAULT)) + +#define __futex_set() __futex_asm(exch4) +#define __futex_add() __futex_asm(fetchadd4) +#define __futex_or() __futex_asm(fetchor4) +#define __futex_andn() ({ oparg = ~oparg; __futex_asm(fetchand4); }) +#define __futex_cmpxchg() \ + ({ __insn_mtspr(SPR_CMPEXCH_VALUE, oldval); __futex_asm(cmpexch4); }) + +#define __futex_xor() \ + ({ \ + u32 oldval, n = oparg; \ + if ((ret = __get_user(oldval, uaddr)) == 0) { \ + do { \ + oparg = oldval ^ n; \ + __futex_cmpxchg(); \ + } while (ret == 0 && oldval != val); \ + } \ + }) + +/* No need to prefetch, since the atomic ops go to the home cache anyway. */ +#define __futex_prolog() -#ifndef __tilegx__ -extern struct __get_user futex_xor(u32 __user *v, int n); #else -static inline struct __get_user futex_xor(u32 __user *uaddr, int n) -{ - struct __get_user asm_ret = __get_user_4(uaddr); - if (!asm_ret.err) { - int oldval, newval; - do { - oldval = asm_ret.val; - newval = oldval ^ n; - asm_ret = futex_cmpxchg(uaddr, oldval, newval); - } while (asm_ret.err == 0 && oldval != asm_ret.val); + +#define __futex_call(FN) \ + { \ + struct __get_user gu = FN((u32 __force *)uaddr, lock, oparg); \ + val = gu.val; \ + ret = gu.err; \ } - return asm_ret; -} + +#define __futex_set() __futex_call(__atomic_xchg) +#define __futex_add() __futex_call(__atomic_xchg_add) +#define __futex_or() __futex_call(__atomic_or) +#define __futex_andn() __futex_call(__atomic_andn) +#define __futex_xor() __futex_call(__atomic_xor) + +#define __futex_cmpxchg() \ + { \ + struct __get_user gu = __atomic_cmpxchg((u32 __force *)uaddr, \ + lock, oldval, oparg); \ + val = gu.val; \ + ret = gu.err; \ + } + +/* + * Find the lock pointer for the atomic calls to use, and issue a + * prefetch to the user address to bring it into cache. Similar to + * __atomic_setup(), but we can't do a read into the L1 since it might + * fault; instead we do a prefetch into the L2. + */ +#define __futex_prolog() \ + int *lock; \ + __insn_prefetch(uaddr); \ + lock = __atomic_hashed_lock((int __force *)uaddr) #endif static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr) @@ -59,8 +111,12 @@ static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr) int cmp = (encoded_op >> 24) & 15; int oparg = (encoded_op << 8) >> 20; int cmparg = (encoded_op << 20) >> 20; - int ret; - struct __get_user asm_ret; + int uninitialized_var(val), ret; + + __futex_prolog(); + + /* The 32-bit futex code makes this assumption, so validate it here. */ + BUILD_BUG_ON(sizeof(atomic_t) != sizeof(int)); if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) oparg = 1 << oparg; @@ -71,46 +127,45 @@ static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr) pagefault_disable(); switch (op) { case FUTEX_OP_SET: - asm_ret = futex_set(uaddr, oparg); + __futex_set(); break; case FUTEX_OP_ADD: - asm_ret = futex_add(uaddr, oparg); + __futex_add(); break; case FUTEX_OP_OR: - asm_ret = futex_or(uaddr, oparg); + __futex_or(); break; case FUTEX_OP_ANDN: - asm_ret = futex_andn(uaddr, oparg); + __futex_andn(); break; case FUTEX_OP_XOR: - asm_ret = futex_xor(uaddr, oparg); + __futex_xor(); break; default: - asm_ret.err = -ENOSYS; + ret = -ENOSYS; + break; } pagefault_enable(); - ret = asm_ret.err; - if (!ret) { switch (cmp) { case FUTEX_OP_CMP_EQ: - ret = (asm_ret.val == cmparg); + ret = (val == cmparg); break; case FUTEX_OP_CMP_NE: - ret = (asm_ret.val != cmparg); + ret = (val != cmparg); break; case FUTEX_OP_CMP_LT: - ret = (asm_ret.val < cmparg); + ret = (val < cmparg); break; case FUTEX_OP_CMP_GE: - ret = (asm_ret.val >= cmparg); + ret = (val >= cmparg); break; case FUTEX_OP_CMP_LE: - ret = (asm_ret.val <= cmparg); + ret = (val <= cmparg); break; case FUTEX_OP_CMP_GT: - ret = (asm_ret.val > cmparg); + ret = (val > cmparg); break; default: ret = -ENOSYS; @@ -120,22 +175,20 @@ static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr) } static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, - u32 oldval, u32 newval) + u32 oldval, u32 oparg) { - struct __get_user asm_ret; + int ret, val; + + __futex_prolog(); if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; - asm_ret = futex_cmpxchg(uaddr, oldval, newval); - *uval = asm_ret.val; - return asm_ret.err; -} + __futex_cmpxchg(); -#ifndef __tilegx__ -/* Return failure from the atomic wrappers. */ -struct __get_user __atomic_bad_address(int __user *addr); -#endif + *uval = val; + return ret; +} #endif /* !__ASSEMBLY__ */ |