diff options
Diffstat (limited to 'arch/arm/include')
| -rw-r--r-- | arch/arm/include/asm/futex.h | 137 |
1 files changed, 90 insertions, 47 deletions
diff --git a/arch/arm/include/asm/futex.h b/arch/arm/include/asm/futex.h index 199a6b6de7f..8c73900da9e 100644 --- a/arch/arm/include/asm/futex.h +++ b/arch/arm/include/asm/futex.h @@ -3,16 +3,74 @@ #ifdef __KERNEL__ +#if defined(CONFIG_CPU_USE_DOMAINS) && defined(CONFIG_SMP) +/* ARM doesn't provide unprivileged exclusive memory accessors */ +#include <asm-generic/futex.h> +#else + +#include <linux/futex.h> +#include <linux/uaccess.h> +#include <asm/errno.h> + +#define __futex_atomic_ex_table(err_reg) \ + "3:\n" \ + " .pushsection __ex_table,\"a\"\n" \ + " .align 3\n" \ + " .long 1b, 4f, 2b, 4f\n" \ + " .popsection\n" \ + " .pushsection .fixup,\"ax\"\n" \ + "4: mov %0, " err_reg "\n" \ + " b 3b\n" \ + " .popsection" + #ifdef CONFIG_SMP -#include <asm-generic/futex.h> +#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \ + smp_mb(); \ + __asm__ __volatile__( \ + "1: ldrex %1, [%2]\n" \ + " " insn "\n" \ + "2: strex %1, %0, [%2]\n" \ + " teq %1, #0\n" \ + " bne 1b\n" \ + " mov %0, #0\n" \ + __futex_atomic_ex_table("%4") \ + : "=&r" (ret), "=&r" (oldval) \ + : "r" (uaddr), "r" (oparg), "Ir" (-EFAULT) \ + : "cc", "memory") + +static inline int +futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, + u32 oldval, u32 newval) +{ + int ret; + u32 val; + + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) + return -EFAULT; + + smp_mb(); + __asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n" + "1: ldrex %1, [%4]\n" + " teq %1, %2\n" + " ite eq @ explicit IT needed for the 2b label\n" + "2: strexeq %0, %3, [%4]\n" + " movne %0, #0\n" + " teq %0, #0\n" + " bne 1b\n" + __futex_atomic_ex_table("%5") + : "=&r" (ret), "=&r" (val) + : "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT) + : "cc", "memory"); + smp_mb(); + + *uval = val; + return ret; +} #else /* !SMP, we can work around lack of atomic ops by disabling preemption */ -#include <linux/futex.h> #include <linux/preempt.h> -#include <linux/uaccess.h> -#include <asm/errno.h> #include <asm/domain.h> #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \ @@ -21,20 +79,38 @@ " " insn "\n" \ "2: " T(str) " %0, [%2]\n" \ " mov %0, #0\n" \ - "3:\n" \ - " .pushsection __ex_table,\"a\"\n" \ - " .align 3\n" \ - " .long 1b, 4f, 2b, 4f\n" \ - " .popsection\n" \ - " .pushsection .fixup,\"ax\"\n" \ - "4: mov %0, %4\n" \ - " b 3b\n" \ - " .popsection" \ + __futex_atomic_ex_table("%4") \ : "=&r" (ret), "=&r" (oldval) \ : "r" (uaddr), "r" (oparg), "Ir" (-EFAULT) \ : "cc", "memory") static inline int +futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, + u32 oldval, u32 newval) +{ + int ret = 0; + u32 val; + + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) + return -EFAULT; + + __asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n" + "1: " T(ldr) " %1, [%4]\n" + " teq %1, %2\n" + " it eq @ explicit IT needed for the 2b label\n" + "2: " T(streq) " %3, [%4]\n" + __futex_atomic_ex_table("%5") + : "+r" (ret), "=&r" (val) + : "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT) + : "cc", "memory"); + + *uval = val; + return ret; +} + +#endif /* !SMP */ + +static inline int futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr) { int op = (encoded_op >> 28) & 7; @@ -87,39 +163,6 @@ futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr) return ret; } -static inline int -futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, - u32 oldval, u32 newval) -{ - int ret = 0; - u32 val; - - if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) - return -EFAULT; - - __asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n" - "1: " T(ldr) " %1, [%4]\n" - " teq %1, %2\n" - " it eq @ explicit IT needed for the 2b label\n" - "2: " T(streq) " %3, [%4]\n" - "3:\n" - " .pushsection __ex_table,\"a\"\n" - " .align 3\n" - " .long 1b, 4f, 2b, 4f\n" - " .popsection\n" - " .pushsection .fixup,\"ax\"\n" - "4: mov %0, %5\n" - " b 3b\n" - " .popsection" - : "+r" (ret), "=&r" (val) - : "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT) - : "cc", "memory"); - - *uval = val; - return ret; -} - -#endif /* !SMP */ - +#endif /* !(CPU_USE_DOMAINS && SMP) */ #endif /* __KERNEL__ */ #endif /* _ASM_ARM_FUTEX_H */ |