f-stack/freebsd/mips/mips/stdatomic.c

393 lines
11 KiB
C

/*-
* Copyright (c) 2013 Ed Schouten <ed@FreeBSD.org>
* All rights reserved.
*
* Copyright (c) 1998 Doug Rabson
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/stdatomic.h>
#include <sys/types.h>
#if defined(__SYNC_ATOMICS)
/*
* Memory barriers.
*
* It turns out __sync_synchronize() does not emit any code when used
* with GCC 4.2. Implement our own version that does work reliably.
*
* Although __sync_lock_test_and_set() should only perform an acquire
* barrier, make it do a full barrier like the other functions. This
* should make <stdatomic.h>'s atomic_exchange_explicit() work reliably.
*/
static inline void
do_sync(void)
{
__asm volatile (
#if !defined(_KERNEL) || defined(SMP)
".set noreorder\n"
"\tsync\n"
"\tnop\n"
"\tnop\n"
"\tnop\n"
"\tnop\n"
"\tnop\n"
"\tnop\n"
"\tnop\n"
"\tnop\n"
".set reorder\n"
#else /* _KERNEL && !SMP */
""
#endif /* !KERNEL || SMP */
: : : "memory");
}
typedef union {
uint8_t v8[4];
uint32_t v32;
} reg_t;
/*
* Given a memory address pointing to an 8-bit or 16-bit integer, return
* the address of the 32-bit word containing it.
*/
static inline uint32_t *
round_to_word(void *ptr)
{
return ((uint32_t *)((intptr_t)ptr & ~3));
}
/*
* Utility functions for loading and storing 8-bit and 16-bit integers
* in 32-bit words at an offset corresponding with the location of the
* atomic variable.
*/
static inline void
put_1(reg_t *r, const uint8_t *offset_ptr, uint8_t val)
{
size_t offset;
offset = (intptr_t)offset_ptr & 3;
r->v8[offset] = val;
}
static inline uint8_t
get_1(const reg_t *r, const uint8_t *offset_ptr)
{
size_t offset;
offset = (intptr_t)offset_ptr & 3;
return (r->v8[offset]);
}
static inline void
put_2(reg_t *r, const uint16_t *offset_ptr, uint16_t val)
{
size_t offset;
union {
uint16_t in;
uint8_t out[2];
} bytes;
offset = (intptr_t)offset_ptr & 3;
bytes.in = val;
r->v8[offset] = bytes.out[0];
r->v8[offset + 1] = bytes.out[1];
}
static inline uint16_t
get_2(const reg_t *r, const uint16_t *offset_ptr)
{
size_t offset;
union {
uint8_t in[2];
uint16_t out;
} bytes;
offset = (intptr_t)offset_ptr & 3;
bytes.in[0] = r->v8[offset];
bytes.in[1] = r->v8[offset + 1];
return (bytes.out);
}
/*
* 8-bit and 16-bit routines.
*
* These operations are not natively supported by the CPU, so we use
* some shifting and bitmasking on top of the 32-bit instructions.
*/
#define EMIT_LOCK_TEST_AND_SET_N(N, uintN_t) \
uintN_t \
__sync_lock_test_and_set_##N(uintN_t *mem, uintN_t val) \
{ \
uint32_t *mem32; \
reg_t val32, negmask, old; \
uint32_t temp; \
\
mem32 = round_to_word(mem); \
val32.v32 = 0x00000000; \
put_##N(&val32, mem, val); \
negmask.v32 = 0xffffffff; \
put_##N(&negmask, mem, 0); \
\
do_sync(); \
__asm volatile ( \
"1:" \
"\tll %0, %5\n" /* Load old value. */ \
"\tand %2, %4, %0\n" /* Remove the old value. */ \
"\tor %2, %3\n" /* Put in the new value. */ \
"\tsc %2, %1\n" /* Attempt to store. */ \
"\tbeqz %2, 1b\n" /* Spin if failed. */ \
: "=&r" (old.v32), "=m" (*mem32), "=&r" (temp) \
: "r" (val32.v32), "r" (negmask.v32), "m" (*mem32)); \
return (get_##N(&old, mem)); \
}
EMIT_LOCK_TEST_AND_SET_N(1, uint8_t)
EMIT_LOCK_TEST_AND_SET_N(2, uint16_t)
#define EMIT_VAL_COMPARE_AND_SWAP_N(N, uintN_t) \
uintN_t \
__sync_val_compare_and_swap_##N(uintN_t *mem, uintN_t expected, \
uintN_t desired) \
{ \
uint32_t *mem32; \
reg_t expected32, desired32, posmask, old; \
uint32_t negmask, temp; \
\
mem32 = round_to_word(mem); \
expected32.v32 = 0x00000000; \
put_##N(&expected32, mem, expected); \
desired32.v32 = 0x00000000; \
put_##N(&desired32, mem, desired); \
posmask.v32 = 0x00000000; \
put_##N(&posmask, mem, ~0); \
negmask = ~posmask.v32; \
\
do_sync(); \
__asm volatile ( \
"1:" \
"\tll %0, %7\n" /* Load old value. */ \
"\tand %2, %5, %0\n" /* Isolate the old value. */ \
"\tbne %2, %3, 2f\n" /* Compare to expected value. */\
"\tand %2, %6, %0\n" /* Remove the old value. */ \
"\tor %2, %4\n" /* Put in the new value. */ \
"\tsc %2, %1\n" /* Attempt to store. */ \
"\tbeqz %2, 1b\n" /* Spin if failed. */ \
"2:" \
: "=&r" (old), "=m" (*mem32), "=&r" (temp) \
: "r" (expected32.v32), "r" (desired32.v32), \
"r" (posmask.v32), "r" (negmask), "m" (*mem32)); \
return (get_##N(&old, mem)); \
}
EMIT_VAL_COMPARE_AND_SWAP_N(1, uint8_t)
EMIT_VAL_COMPARE_AND_SWAP_N(2, uint16_t)
#define EMIT_ARITHMETIC_FETCH_AND_OP_N(N, uintN_t, name, op) \
uintN_t \
__sync_##name##_##N(uintN_t *mem, uintN_t val) \
{ \
uint32_t *mem32; \
reg_t val32, posmask, old; \
uint32_t negmask, temp1, temp2; \
\
mem32 = round_to_word(mem); \
val32.v32 = 0x00000000; \
put_##N(&val32, mem, val); \
posmask.v32 = 0x00000000; \
put_##N(&posmask, mem, ~0); \
negmask = ~posmask.v32; \
\
do_sync(); \
__asm volatile ( \
"1:" \
"\tll %0, %7\n" /* Load old value. */ \
"\t"op" %2, %0, %4\n" /* Calculate new value. */ \
"\tand %2, %5\n" /* Isolate the new value. */ \
"\tand %3, %6, %0\n" /* Remove the old value. */ \
"\tor %2, %3\n" /* Put in the new value. */ \
"\tsc %2, %1\n" /* Attempt to store. */ \
"\tbeqz %2, 1b\n" /* Spin if failed. */ \
: "=&r" (old.v32), "=m" (*mem32), "=&r" (temp1), \
"=&r" (temp2) \
: "r" (val32.v32), "r" (posmask.v32), "r" (negmask), \
"m" (*mem32)); \
return (get_##N(&old, mem)); \
}
EMIT_ARITHMETIC_FETCH_AND_OP_N(1, uint8_t, fetch_and_add, "addu")
EMIT_ARITHMETIC_FETCH_AND_OP_N(1, uint8_t, fetch_and_sub, "subu")
EMIT_ARITHMETIC_FETCH_AND_OP_N(2, uint16_t, fetch_and_add, "addu")
EMIT_ARITHMETIC_FETCH_AND_OP_N(2, uint16_t, fetch_and_sub, "subu")
#define EMIT_BITWISE_FETCH_AND_OP_N(N, uintN_t, name, op, idempotence) \
uintN_t \
__sync_##name##_##N(uintN_t *mem, uintN_t val) \
{ \
uint32_t *mem32; \
reg_t val32, old; \
uint32_t temp; \
\
mem32 = round_to_word(mem); \
val32.v32 = idempotence ? 0xffffffff : 0x00000000; \
put_##N(&val32, mem, val); \
\
do_sync(); \
__asm volatile ( \
"1:" \
"\tll %0, %4\n" /* Load old value. */ \
"\t"op" %2, %3, %0\n" /* Calculate new value. */ \
"\tsc %2, %1\n" /* Attempt to store. */ \
"\tbeqz %2, 1b\n" /* Spin if failed. */ \
: "=&r" (old.v32), "=m" (*mem32), "=&r" (temp) \
: "r" (val32.v32), "m" (*mem32)); \
return (get_##N(&old, mem)); \
}
EMIT_BITWISE_FETCH_AND_OP_N(1, uint8_t, fetch_and_and, "and", 1)
EMIT_BITWISE_FETCH_AND_OP_N(1, uint8_t, fetch_and_or, "or", 0)
EMIT_BITWISE_FETCH_AND_OP_N(1, uint8_t, fetch_and_xor, "xor", 0)
EMIT_BITWISE_FETCH_AND_OP_N(2, uint16_t, fetch_and_and, "and", 1)
EMIT_BITWISE_FETCH_AND_OP_N(2, uint16_t, fetch_and_or, "or", 0)
EMIT_BITWISE_FETCH_AND_OP_N(2, uint16_t, fetch_and_xor, "xor", 0)
/*
* 32-bit routines.
*/
uint32_t
__sync_val_compare_and_swap_4(uint32_t *mem, uint32_t expected,
uint32_t desired)
{
uint32_t old, temp;
do_sync();
__asm volatile (
"1:"
"\tll %0, %5\n" /* Load old value. */
"\tbne %0, %3, 2f\n" /* Compare to expected value. */
"\tmove %2, %4\n" /* Value to store. */
"\tsc %2, %1\n" /* Attempt to store. */
"\tbeqz %2, 1b\n" /* Spin if failed. */
"2:"
: "=&r" (old), "=m" (*mem), "=&r" (temp)
: "r" (expected), "r" (desired), "m" (*mem));
return (old);
}
#define EMIT_FETCH_AND_OP_4(name, op) \
uint32_t \
__sync_##name##_4(uint32_t *mem, uint32_t val) \
{ \
uint32_t old, temp; \
\
do_sync(); \
__asm volatile ( \
"1:" \
"\tll %0, %4\n" /* Load old value. */ \
"\t"op"\n" /* Calculate new value. */ \
"\tsc %2, %1\n" /* Attempt to store. */ \
"\tbeqz %2, 1b\n" /* Spin if failed. */ \
: "=&r" (old), "=m" (*mem), "=&r" (temp) \
: "r" (val), "m" (*mem)); \
return (old); \
}
EMIT_FETCH_AND_OP_4(lock_test_and_set, "move %2, %3")
EMIT_FETCH_AND_OP_4(fetch_and_add, "addu %2, %0, %3")
EMIT_FETCH_AND_OP_4(fetch_and_and, "and %2, %0, %3")
EMIT_FETCH_AND_OP_4(fetch_and_or, "or %2, %0, %3")
EMIT_FETCH_AND_OP_4(fetch_and_sub, "subu %2, %0, %3")
EMIT_FETCH_AND_OP_4(fetch_and_xor, "xor %2, %0, %3")
/*
* 64-bit routines.
*
* Note: All the 64-bit atomic operations are only atomic when running
* in 64-bit mode. It is assumed that code compiled for n32 and n64 fits
* into this definition and no further safeties are needed.
*/
#if defined(__mips_n32) || defined(__mips_n64)
uint64_t
__sync_val_compare_and_swap_8(uint64_t *mem, uint64_t expected,
uint64_t desired)
{
uint64_t old, temp;
do_sync();
__asm volatile (
"1:"
"\tlld %0, %5\n" /* Load old value. */
"\tbne %0, %3, 2f\n" /* Compare to expected value. */
"\tmove %2, %4\n" /* Value to store. */
"\tscd %2, %1\n" /* Attempt to store. */
"\tbeqz %2, 1b\n" /* Spin if failed. */
"2:"
: "=&r" (old), "=m" (*mem), "=&r" (temp)
: "r" (expected), "r" (desired), "m" (*mem));
return (old);
}
#define EMIT_FETCH_AND_OP_8(name, op) \
uint64_t \
__sync_##name##_8(uint64_t *mem, uint64_t val) \
{ \
uint64_t old, temp; \
\
do_sync(); \
__asm volatile ( \
"1:" \
"\tlld %0, %4\n" /* Load old value. */ \
"\t"op"\n" /* Calculate new value. */ \
"\tscd %2, %1\n" /* Attempt to store. */ \
"\tbeqz %2, 1b\n" /* Spin if failed. */ \
: "=&r" (old), "=m" (*mem), "=&r" (temp) \
: "r" (val), "m" (*mem)); \
return (old); \
}
EMIT_FETCH_AND_OP_8(lock_test_and_set, "move %2, %3")
EMIT_FETCH_AND_OP_8(fetch_and_add, "daddu %2, %0, %3")
EMIT_FETCH_AND_OP_8(fetch_and_and, "and %2, %0, %3")
EMIT_FETCH_AND_OP_8(fetch_and_or, "or %2, %0, %3")
EMIT_FETCH_AND_OP_8(fetch_and_sub, "dsubu %2, %0, %3")
EMIT_FETCH_AND_OP_8(fetch_and_xor, "xor %2, %0, %3")
#endif /* __mips_n32 || __mips_n64 */
#endif /* __SYNC_ATOMICS */