diff options
Diffstat (limited to 'arch/hexagon/include/asm/futex.h')
-rw-r--r-- | arch/hexagon/include/asm/futex.h | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/arch/hexagon/include/asm/futex.h b/arch/hexagon/include/asm/futex.h new file mode 100644 index 00000000000..7e597f8434d --- /dev/null +++ b/arch/hexagon/include/asm/futex.h @@ -0,0 +1,137 @@ +#ifndef _ASM_HEXAGON_FUTEX_H +#define _ASM_HEXAGON_FUTEX_H + +#ifdef __KERNEL__ + +#include <linux/futex.h> +#include <linux/uaccess.h> +#include <asm/errno.h> + +/* XXX TODO-- need to add sync barriers! */ + +#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \ + __asm__ __volatile( \ + "1: %0 = memw_locked(%3);\n" \ + /* For example: %1 = %4 */ \ + insn \ + "2: memw_locked(%3,p2) = %1;\n" \ + " if !p2 jump 1b;\n" \ + " %1 = #0;\n" \ + "3:\n" \ + ".section .fixup,\"ax\"\n" \ + "4: %1 = #%5;\n" \ + " jump 3b\n" \ + ".previous\n" \ + ".section __ex_table,\"a\"\n" \ + ".long 1b,4b,2b,4b\n" \ + ".previous\n" \ + : "=&r" (oldval), "=&r" (ret), "+m" (*uaddr) \ + : "r" (uaddr), "r" (oparg), "i" (-EFAULT) \ + : "p2", "memory") + + +static inline int +futex_atomic_op_inuser(int encoded_op, int __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(int))) + return -EFAULT; + + pagefault_disable(); + + switch (op) { + case FUTEX_OP_SET: + __futex_atomic_op("%1 = %4\n", ret, oldval, uaddr, oparg); + break; + case FUTEX_OP_ADD: + __futex_atomic_op("%1 = add(%0,%4)\n", ret, oldval, uaddr, + oparg); + break; + case FUTEX_OP_OR: + __futex_atomic_op("%1 = or(%0,%4)\n", ret, oldval, uaddr, + oparg); + break; + case FUTEX_OP_ANDN: + __futex_atomic_op("%1 = not(%4); %1 = and(%0,%1)\n", ret, + oldval, uaddr, oparg); + break; + case FUTEX_OP_XOR: + __futex_atomic_op("%1 = xor(%0,%4)\n", 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 prev; + int ret; + + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) + return -EFAULT; + + __asm__ __volatile__ ( + "1: %1 = memw_locked(%3)\n" + " {\n" + " p2 = cmp.eq(%1,%4)\n" + " if !p2.new jump:NT 3f\n" + " }\n" + "2: memw_locked(%3,p2) = %5\n" + " if !p2 jump 1b\n" + "3:\n" + ".section .fixup,\"ax\"\n" + "4: %0 = #%6\n" + " jump 3b\n" + ".previous\n" + ".section __ex_table,\"a\"\n" + ".long 1b,4b,2b,4b\n" + ".previous\n" + : "+r" (ret), "=&r" (prev), "+m" (*uaddr) + : "r" (uaddr), "r" (oldval), "r" (newval), "i"(-EFAULT) + : "p2", "memory"); + + *uval = prev; + return ret; +} + +#endif /* __KERNEL__ */ +#endif /* _ASM_HEXAGON_FUTEX_H */ |