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103 lines
2.4 KiB
103 lines
2.4 KiB
/* SPDX-License-Identifier: GPL-2.0 */ |
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#ifndef _ASM_POWERPC_FUTEX_H |
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#define _ASM_POWERPC_FUTEX_H |
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#ifdef __KERNEL__ |
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#include <linux/futex.h> |
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#include <linux/uaccess.h> |
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#include <asm/errno.h> |
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#include <asm/synch.h> |
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#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \ |
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__asm__ __volatile ( \ |
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PPC_ATOMIC_ENTRY_BARRIER \ |
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"1: lwarx %0,0,%2\n" \ |
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insn \ |
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"2: stwcx. %1,0,%2\n" \ |
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"bne- 1b\n" \ |
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PPC_ATOMIC_EXIT_BARRIER \ |
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"li %1,0\n" \ |
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"3: .section .fixup,\"ax\"\n" \ |
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"4: li %1,%3\n" \ |
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"b 3b\n" \ |
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".previous\n" \ |
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EX_TABLE(1b, 4b) \ |
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EX_TABLE(2b, 4b) \ |
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: "=&r" (oldval), "=&r" (ret) \ |
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: "b" (uaddr), "i" (-EFAULT), "r" (oparg) \ |
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: "cr0", "memory") |
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static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval, |
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u32 __user *uaddr) |
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{ |
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int oldval = 0, ret; |
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if (!access_ok(uaddr, sizeof(u32))) |
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return -EFAULT; |
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allow_read_write_user(uaddr, uaddr, sizeof(*uaddr)); |
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switch (op) { |
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case FUTEX_OP_SET: |
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__futex_atomic_op("mr %1,%4\n", ret, oldval, uaddr, oparg); |
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break; |
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case FUTEX_OP_ADD: |
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__futex_atomic_op("add %1,%0,%4\n", ret, oldval, uaddr, oparg); |
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break; |
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case FUTEX_OP_OR: |
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__futex_atomic_op("or %1,%0,%4\n", ret, oldval, uaddr, oparg); |
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break; |
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case FUTEX_OP_ANDN: |
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__futex_atomic_op("andc %1,%0,%4\n", ret, oldval, uaddr, oparg); |
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break; |
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case FUTEX_OP_XOR: |
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__futex_atomic_op("xor %1,%0,%4\n", ret, oldval, uaddr, oparg); |
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break; |
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default: |
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ret = -ENOSYS; |
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} |
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*oval = oldval; |
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prevent_read_write_user(uaddr, uaddr, sizeof(*uaddr)); |
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return ret; |
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} |
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static inline int |
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futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, |
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u32 oldval, u32 newval) |
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{ |
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int ret = 0; |
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u32 prev; |
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if (!access_ok(uaddr, sizeof(u32))) |
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return -EFAULT; |
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allow_read_write_user(uaddr, uaddr, sizeof(*uaddr)); |
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__asm__ __volatile__ ( |
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PPC_ATOMIC_ENTRY_BARRIER |
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"1: lwarx %1,0,%3 # futex_atomic_cmpxchg_inatomic\n\ |
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cmpw 0,%1,%4\n\ |
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bne- 3f\n" |
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"2: stwcx. %5,0,%3\n\ |
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bne- 1b\n" |
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PPC_ATOMIC_EXIT_BARRIER |
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"3: .section .fixup,\"ax\"\n\ |
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4: li %0,%6\n\ |
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b 3b\n\ |
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.previous\n" |
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EX_TABLE(1b, 4b) |
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EX_TABLE(2b, 4b) |
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: "+r" (ret), "=&r" (prev), "+m" (*uaddr) |
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: "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT) |
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: "cc", "memory"); |
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*uval = prev; |
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prevent_read_write_user(uaddr, uaddr, sizeof(*uaddr)); |
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return ret; |
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} |
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#endif /* __KERNEL__ */ |
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#endif /* _ASM_POWERPC_FUTEX_H */
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