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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/riscv/include/asm/futex.h | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/riscv/include/asm/futex.h')
-rw-r--r-- | arch/riscv/include/asm/futex.h | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/futex.h b/arch/riscv/include/asm/futex.h new file mode 100644 index 000000000..fc8130f99 --- /dev/null +++ b/arch/riscv/include/asm/futex.h @@ -0,0 +1,104 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (c) 2006 Ralf Baechle (ralf@linux-mips.org) + * Copyright (c) 2018 Jim Wilson (jimw@sifive.com) + */ + +#ifndef _ASM_RISCV_FUTEX_H +#define _ASM_RISCV_FUTEX_H + +#include <linux/futex.h> +#include <linux/uaccess.h> +#include <linux/errno.h> +#include <asm/asm.h> +#include <asm/asm-extable.h> + +/* We don't even really need the extable code, but for now keep it simple */ +#ifndef CONFIG_MMU +#define __enable_user_access() do { } while (0) +#define __disable_user_access() do { } while (0) +#endif + +#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \ +{ \ + __enable_user_access(); \ + __asm__ __volatile__ ( \ + "1: " insn " \n" \ + "2: \n" \ + _ASM_EXTABLE_UACCESS_ERR(1b, 2b, %[r]) \ + : [r] "+r" (ret), [ov] "=&r" (oldval), \ + [u] "+m" (*uaddr) \ + : [op] "Jr" (oparg) \ + : "memory"); \ + __disable_user_access(); \ +} + +static inline int +arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr) +{ + int oldval = 0, ret = 0; + + if (!access_ok(uaddr, sizeof(u32))) + return -EFAULT; + + switch (op) { + case FUTEX_OP_SET: + __futex_atomic_op("amoswap.w.aqrl %[ov],%z[op],%[u]", + ret, oldval, uaddr, oparg); + break; + case FUTEX_OP_ADD: + __futex_atomic_op("amoadd.w.aqrl %[ov],%z[op],%[u]", + ret, oldval, uaddr, oparg); + break; + case FUTEX_OP_OR: + __futex_atomic_op("amoor.w.aqrl %[ov],%z[op],%[u]", + ret, oldval, uaddr, oparg); + break; + case FUTEX_OP_ANDN: + __futex_atomic_op("amoand.w.aqrl %[ov],%z[op],%[u]", + ret, oldval, uaddr, ~oparg); + break; + case FUTEX_OP_XOR: + __futex_atomic_op("amoxor.w.aqrl %[ov],%z[op],%[u]", + ret, oldval, uaddr, oparg); + break; + default: + ret = -ENOSYS; + } + + if (!ret) + *oval = oldval; + + return ret; +} + +static inline int +futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, + u32 oldval, u32 newval) +{ + int ret = 0; + u32 val; + uintptr_t tmp; + + if (!access_ok(uaddr, sizeof(u32))) + return -EFAULT; + + __enable_user_access(); + __asm__ __volatile__ ( + "1: lr.w.aqrl %[v],%[u] \n" + " bne %[v],%z[ov],3f \n" + "2: sc.w.aqrl %[t],%z[nv],%[u] \n" + " bnez %[t],1b \n" + "3: \n" + _ASM_EXTABLE_UACCESS_ERR(1b, 3b, %[r]) \ + _ASM_EXTABLE_UACCESS_ERR(2b, 3b, %[r]) \ + : [r] "+r" (ret), [v] "=&r" (val), [u] "+m" (*uaddr), [t] "=&r" (tmp) + : [ov] "Jr" (oldval), [nv] "Jr" (newval) + : "memory"); + __disable_user_access(); + + *uval = val; + return ret; +} + +#endif /* _ASM_RISCV_FUTEX_H */ |