diff options
Diffstat (limited to 'kernel/arch/microblaze/include/asm/futex.h')
| -rw-r--r-- | kernel/arch/microblaze/include/asm/futex.h | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/kernel/arch/microblaze/include/asm/futex.h b/kernel/arch/microblaze/include/asm/futex.h new file mode 100644 index 000000000..01848f056 --- /dev/null +++ b/kernel/arch/microblaze/include/asm/futex.h @@ -0,0 +1,129 @@ +#ifndef _ASM_MICROBLAZE_FUTEX_H +#define _ASM_MICROBLAZE_FUTEX_H + +#ifdef __KERNEL__ + +#include <linux/futex.h> +#include <linux/uaccess.h> +#include <asm/errno.h> + +#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \ +({ \ + __asm__ __volatile__ ( \ + "1: lwx %0, %2, r0; " \ + insn \ + "2: swx %1, %2, r0; \ + addic %1, r0, 0; \ + bnei %1, 1b; \ + 3: \ + .section .fixup,\"ax\"; \ + 4: brid 3b; \ + addik %1, r0, %3; \ + .previous; \ + .section __ex_table,\"a\"; \ + .word 1b,4b,2b,4b; \ + .previous;" \ + : "=&r" (oldval), "=&r" (ret) \ + : "r" (uaddr), "i" (-EFAULT), "r" (oparg) \ + ); \ +}) + +static inline int +futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr) +{ + int op = (encoded_op >> 28) & 7; + int cmp = (encoded_op >> 24) & 15; + int oparg = (encoded_op << 8) >> 20; + int cmparg = (encoded_op << 20) >> 20; + int oldval = 0, ret; + if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) + oparg = 1 << oparg; + + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) + return -EFAULT; + + pagefault_disable(); + + switch (op) { + case FUTEX_OP_SET: + __futex_atomic_op("or %1,%4,%4;", ret, oldval, uaddr, oparg); + break; + case FUTEX_OP_ADD: + __futex_atomic_op("add %1,%0,%4;", ret, oldval, uaddr, oparg); + break; + case FUTEX_OP_OR: + __futex_atomic_op("or %1,%0,%4;", ret, oldval, uaddr, oparg); + break; + case FUTEX_OP_ANDN: + __futex_atomic_op("andn %1,%0,%4;", ret, oldval, uaddr, oparg); + break; + case FUTEX_OP_XOR: + __futex_atomic_op("xor %1,%0,%4;", ret, oldval, uaddr, oparg); + break; + default: + ret = -ENOSYS; + } + + pagefault_enable(); + + if (!ret) { + switch (cmp) { + case FUTEX_OP_CMP_EQ: + ret = (oldval == cmparg); + break; + case FUTEX_OP_CMP_NE: + ret = (oldval != cmparg); + break; + case FUTEX_OP_CMP_LT: + ret = (oldval < cmparg); + break; + case FUTEX_OP_CMP_GE: + ret = (oldval >= cmparg); + break; + case FUTEX_OP_CMP_LE: + ret = (oldval <= cmparg); + break; + case FUTEX_OP_CMP_GT: + ret = (oldval > cmparg); + break; + default: + ret = -ENOSYS; + } + } + return ret; +} + +static inline int +futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, + u32 oldval, u32 newval) +{ + int ret = 0, cmp; + u32 prev; + + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) + return -EFAULT; + + __asm__ __volatile__ ("1: lwx %1, %3, r0; \ + cmp %2, %1, %4; \ + bnei %2, 3f; \ + 2: swx %5, %3, r0; \ + addic %2, r0, 0; \ + bnei %2, 1b; \ + 3: \ + .section .fixup,\"ax\"; \ + 4: brid 3b; \ + addik %0, r0, %6; \ + .previous; \ + .section __ex_table,\"a\"; \ + .word 1b,4b,2b,4b; \ + .previous;" \ + : "+r" (ret), "=&r" (prev), "=&r"(cmp) \ + : "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT)); + + *uval = prev; + return ret; +} + +#endif /* __KERNEL__ */ + +#endif |