linux_dsm_epyc7002/arch/riscv/include/asm/cmpxchg.h
Nathan Huckleberry 6c58f25e69
riscv/atomic: Fix sign extension for RV64I
The argument passed to cmpxchg is not guaranteed to be sign
extended, but lr.w sign extends on RV64I. This makes cmpxchg
fail on clang built kernels when __old is negative.

To fix this, we just cast __old to long which sign extends on
RV64I. With this fix, clang built RISC-V kernels now boot.

Link: https://github.com/ClangBuiltLinux/linux/issues/867
Signed-off-by: Nathan Huckleberry <nhuck@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-12 12:07:58 -07:00

376 lines
9.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2014 Regents of the University of California
*/
#ifndef _ASM_RISCV_CMPXCHG_H
#define _ASM_RISCV_CMPXCHG_H
#include <linux/bug.h>
#include <asm/barrier.h>
#include <asm/fence.h>
#define __xchg_relaxed(ptr, new, size) \
({ \
__typeof__(ptr) __ptr = (ptr); \
__typeof__(new) __new = (new); \
__typeof__(*(ptr)) __ret; \
switch (size) { \
case 4: \
__asm__ __volatile__ ( \
" amoswap.w %0, %2, %1\n" \
: "=r" (__ret), "+A" (*__ptr) \
: "r" (__new) \
: "memory"); \
break; \
case 8: \
__asm__ __volatile__ ( \
" amoswap.d %0, %2, %1\n" \
: "=r" (__ret), "+A" (*__ptr) \
: "r" (__new) \
: "memory"); \
break; \
default: \
BUILD_BUG(); \
} \
__ret; \
})
#define xchg_relaxed(ptr, x) \
({ \
__typeof__(*(ptr)) _x_ = (x); \
(__typeof__(*(ptr))) __xchg_relaxed((ptr), \
_x_, sizeof(*(ptr))); \
})
#define __xchg_acquire(ptr, new, size) \
({ \
__typeof__(ptr) __ptr = (ptr); \
__typeof__(new) __new = (new); \
__typeof__(*(ptr)) __ret; \
switch (size) { \
case 4: \
__asm__ __volatile__ ( \
" amoswap.w %0, %2, %1\n" \
RISCV_ACQUIRE_BARRIER \
: "=r" (__ret), "+A" (*__ptr) \
: "r" (__new) \
: "memory"); \
break; \
case 8: \
__asm__ __volatile__ ( \
" amoswap.d %0, %2, %1\n" \
RISCV_ACQUIRE_BARRIER \
: "=r" (__ret), "+A" (*__ptr) \
: "r" (__new) \
: "memory"); \
break; \
default: \
BUILD_BUG(); \
} \
__ret; \
})
#define xchg_acquire(ptr, x) \
({ \
__typeof__(*(ptr)) _x_ = (x); \
(__typeof__(*(ptr))) __xchg_acquire((ptr), \
_x_, sizeof(*(ptr))); \
})
#define __xchg_release(ptr, new, size) \
({ \
__typeof__(ptr) __ptr = (ptr); \
__typeof__(new) __new = (new); \
__typeof__(*(ptr)) __ret; \
switch (size) { \
case 4: \
__asm__ __volatile__ ( \
RISCV_RELEASE_BARRIER \
" amoswap.w %0, %2, %1\n" \
: "=r" (__ret), "+A" (*__ptr) \
: "r" (__new) \
: "memory"); \
break; \
case 8: \
__asm__ __volatile__ ( \
RISCV_RELEASE_BARRIER \
" amoswap.d %0, %2, %1\n" \
: "=r" (__ret), "+A" (*__ptr) \
: "r" (__new) \
: "memory"); \
break; \
default: \
BUILD_BUG(); \
} \
__ret; \
})
#define xchg_release(ptr, x) \
({ \
__typeof__(*(ptr)) _x_ = (x); \
(__typeof__(*(ptr))) __xchg_release((ptr), \
_x_, sizeof(*(ptr))); \
})
#define __xchg(ptr, new, size) \
({ \
__typeof__(ptr) __ptr = (ptr); \
__typeof__(new) __new = (new); \
__typeof__(*(ptr)) __ret; \
switch (size) { \
case 4: \
__asm__ __volatile__ ( \
" amoswap.w.aqrl %0, %2, %1\n" \
: "=r" (__ret), "+A" (*__ptr) \
: "r" (__new) \
: "memory"); \
break; \
case 8: \
__asm__ __volatile__ ( \
" amoswap.d.aqrl %0, %2, %1\n" \
: "=r" (__ret), "+A" (*__ptr) \
: "r" (__new) \
: "memory"); \
break; \
default: \
BUILD_BUG(); \
} \
__ret; \
})
#define xchg(ptr, x) \
({ \
__typeof__(*(ptr)) _x_ = (x); \
(__typeof__(*(ptr))) __xchg((ptr), _x_, sizeof(*(ptr))); \
})
#define xchg32(ptr, x) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 4); \
xchg((ptr), (x)); \
})
#define xchg64(ptr, x) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
xchg((ptr), (x)); \
})
/*
* Atomic compare and exchange. Compare OLD with MEM, if identical,
* store NEW in MEM. Return the initial value in MEM. Success is
* indicated by comparing RETURN with OLD.
*/
#define __cmpxchg_relaxed(ptr, old, new, size) \
({ \
__typeof__(ptr) __ptr = (ptr); \
__typeof__(*(ptr)) __old = (old); \
__typeof__(*(ptr)) __new = (new); \
__typeof__(*(ptr)) __ret; \
register unsigned int __rc; \
switch (size) { \
case 4: \
__asm__ __volatile__ ( \
"0: lr.w %0, %2\n" \
" bne %0, %z3, 1f\n" \
" sc.w %1, %z4, %2\n" \
" bnez %1, 0b\n" \
"1:\n" \
: "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \
: "rJ" ((long)__old), "rJ" (__new) \
: "memory"); \
break; \
case 8: \
__asm__ __volatile__ ( \
"0: lr.d %0, %2\n" \
" bne %0, %z3, 1f\n" \
" sc.d %1, %z4, %2\n" \
" bnez %1, 0b\n" \
"1:\n" \
: "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \
: "rJ" (__old), "rJ" (__new) \
: "memory"); \
break; \
default: \
BUILD_BUG(); \
} \
__ret; \
})
#define cmpxchg_relaxed(ptr, o, n) \
({ \
__typeof__(*(ptr)) _o_ = (o); \
__typeof__(*(ptr)) _n_ = (n); \
(__typeof__(*(ptr))) __cmpxchg_relaxed((ptr), \
_o_, _n_, sizeof(*(ptr))); \
})
#define __cmpxchg_acquire(ptr, old, new, size) \
({ \
__typeof__(ptr) __ptr = (ptr); \
__typeof__(*(ptr)) __old = (old); \
__typeof__(*(ptr)) __new = (new); \
__typeof__(*(ptr)) __ret; \
register unsigned int __rc; \
switch (size) { \
case 4: \
__asm__ __volatile__ ( \
"0: lr.w %0, %2\n" \
" bne %0, %z3, 1f\n" \
" sc.w %1, %z4, %2\n" \
" bnez %1, 0b\n" \
RISCV_ACQUIRE_BARRIER \
"1:\n" \
: "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \
: "rJ" ((long)__old), "rJ" (__new) \
: "memory"); \
break; \
case 8: \
__asm__ __volatile__ ( \
"0: lr.d %0, %2\n" \
" bne %0, %z3, 1f\n" \
" sc.d %1, %z4, %2\n" \
" bnez %1, 0b\n" \
RISCV_ACQUIRE_BARRIER \
"1:\n" \
: "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \
: "rJ" (__old), "rJ" (__new) \
: "memory"); \
break; \
default: \
BUILD_BUG(); \
} \
__ret; \
})
#define cmpxchg_acquire(ptr, o, n) \
({ \
__typeof__(*(ptr)) _o_ = (o); \
__typeof__(*(ptr)) _n_ = (n); \
(__typeof__(*(ptr))) __cmpxchg_acquire((ptr), \
_o_, _n_, sizeof(*(ptr))); \
})
#define __cmpxchg_release(ptr, old, new, size) \
({ \
__typeof__(ptr) __ptr = (ptr); \
__typeof__(*(ptr)) __old = (old); \
__typeof__(*(ptr)) __new = (new); \
__typeof__(*(ptr)) __ret; \
register unsigned int __rc; \
switch (size) { \
case 4: \
__asm__ __volatile__ ( \
RISCV_RELEASE_BARRIER \
"0: lr.w %0, %2\n" \
" bne %0, %z3, 1f\n" \
" sc.w %1, %z4, %2\n" \
" bnez %1, 0b\n" \
"1:\n" \
: "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \
: "rJ" ((long)__old), "rJ" (__new) \
: "memory"); \
break; \
case 8: \
__asm__ __volatile__ ( \
RISCV_RELEASE_BARRIER \
"0: lr.d %0, %2\n" \
" bne %0, %z3, 1f\n" \
" sc.d %1, %z4, %2\n" \
" bnez %1, 0b\n" \
"1:\n" \
: "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \
: "rJ" (__old), "rJ" (__new) \
: "memory"); \
break; \
default: \
BUILD_BUG(); \
} \
__ret; \
})
#define cmpxchg_release(ptr, o, n) \
({ \
__typeof__(*(ptr)) _o_ = (o); \
__typeof__(*(ptr)) _n_ = (n); \
(__typeof__(*(ptr))) __cmpxchg_release((ptr), \
_o_, _n_, sizeof(*(ptr))); \
})
#define __cmpxchg(ptr, old, new, size) \
({ \
__typeof__(ptr) __ptr = (ptr); \
__typeof__(*(ptr)) __old = (old); \
__typeof__(*(ptr)) __new = (new); \
__typeof__(*(ptr)) __ret; \
register unsigned int __rc; \
switch (size) { \
case 4: \
__asm__ __volatile__ ( \
"0: lr.w %0, %2\n" \
" bne %0, %z3, 1f\n" \
" sc.w.rl %1, %z4, %2\n" \
" bnez %1, 0b\n" \
" fence rw, rw\n" \
"1:\n" \
: "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \
: "rJ" ((long)__old), "rJ" (__new) \
: "memory"); \
break; \
case 8: \
__asm__ __volatile__ ( \
"0: lr.d %0, %2\n" \
" bne %0, %z3, 1f\n" \
" sc.d.rl %1, %z4, %2\n" \
" bnez %1, 0b\n" \
" fence rw, rw\n" \
"1:\n" \
: "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \
: "rJ" (__old), "rJ" (__new) \
: "memory"); \
break; \
default: \
BUILD_BUG(); \
} \
__ret; \
})
#define cmpxchg(ptr, o, n) \
({ \
__typeof__(*(ptr)) _o_ = (o); \
__typeof__(*(ptr)) _n_ = (n); \
(__typeof__(*(ptr))) __cmpxchg((ptr), \
_o_, _n_, sizeof(*(ptr))); \
})
#define cmpxchg_local(ptr, o, n) \
(__cmpxchg_relaxed((ptr), (o), (n), sizeof(*(ptr))))
#define cmpxchg32(ptr, o, n) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 4); \
cmpxchg((ptr), (o), (n)); \
})
#define cmpxchg32_local(ptr, o, n) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 4); \
cmpxchg_relaxed((ptr), (o), (n)) \
})
#define cmpxchg64(ptr, o, n) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
cmpxchg((ptr), (o), (n)); \
})
#define cmpxchg64_local(ptr, o, n) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
cmpxchg_relaxed((ptr), (o), (n)); \
})
#endif /* _ASM_RISCV_CMPXCHG_H */