lib: sbi: Remove xchg/cmpxchg implemented via lr/sc

lr/sc is part of the A extension. If the A extension is not supported,
lr/sc cannot be used. So remove xchg/cmpxchg.

Signed-off-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
This commit is contained in:
Xiang W 2023-11-08 11:28:16 +08:00 committed by Anup Patel
parent d162009612
commit 6b9a849482

View file

@ -12,6 +12,10 @@
#include <sbi/riscv_atomic.h>
#include <sbi/riscv_barrier.h>
#ifndef __riscv_atomic
#error "opensbi strongly relies on the A extension of RISC-V"
#endif
long atomic_read(atomic_t *atom)
{
long ret = atom->counter;
@ -79,131 +83,29 @@ long atomic_sub_return(atomic_t *atom, long value)
(__typeof__(*(ptr))) __axchg((ptr), _x_, sizeof(*(ptr))); \
})
#define __xchg(ptr, new, size) \
({ \
__typeof__(ptr) __ptr = (ptr); \
__typeof__(*(ptr)) __new = (new); \
__typeof__(*(ptr)) __ret; \
register unsigned int __rc; \
switch (size) { \
case 4: \
__asm__ __volatile__("0: lr.w %0, %2\n" \
" sc.w.rl %1, %z3, %2\n" \
" bnez %1, 0b\n" \
" fence rw, rw\n" \
: "=&r"(__ret), "=&r"(__rc), \
"+A"(*__ptr) \
: "rJ"(__new) \
: "memory"); \
break; \
case 8: \
__asm__ __volatile__("0: lr.d %0, %2\n" \
" sc.d.rl %1, %z3, %2\n" \
" bnez %1, 0b\n" \
" fence rw, rw\n" \
: "=&r"(__ret), "=&r"(__rc), \
"+A"(*__ptr) \
: "rJ"(__new) \
: "memory"); \
break; \
default: \
break; \
} \
__ret; \
})
#define xchg(ptr, n) \
({ \
__typeof__(*(ptr)) _n_ = (n); \
(__typeof__(*(ptr))) __xchg((ptr), _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"(__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: \
break; \
} \
__ret; \
})
#define cmpxchg(ptr, o, n) \
({ \
__typeof__(*(ptr)) _o_ = (o); \
__typeof__(*(ptr)) _n_ = (n); \
(__typeof__(*(ptr))) \
__cmpxchg((ptr), _o_, _n_, sizeof(*(ptr))); \
})
long atomic_cmpxchg(atomic_t *atom, long oldval, long newval)
{
#ifdef __riscv_atomic
return __sync_val_compare_and_swap(&atom->counter, oldval, newval);
#else
return cmpxchg(&atom->counter, oldval, newval);
#endif
}
long atomic_xchg(atomic_t *atom, long newval)
{
/* Atomically set new value and return old value. */
#ifdef __riscv_atomic
return axchg(&atom->counter, newval);
#else
return xchg(&atom->counter, newval);
#endif
}
unsigned int atomic_raw_xchg_uint(volatile unsigned int *ptr,
unsigned int newval)
{
/* Atomically set new value and return old value. */
#ifdef __riscv_atomic
return axchg(ptr, newval);
#else
return xchg(ptr, newval);
#endif
}
unsigned long atomic_raw_xchg_ulong(volatile unsigned long *ptr,
unsigned long newval)
{
/* Atomically set new value and return old value. */
#ifdef __riscv_atomic
return axchg(ptr, newval);
#else
return xchg(ptr, newval);
#endif
}
#if (__SIZEOF_POINTER__ == 8)