freebsd-skq/sys/arm/arm/stdatomic.c
Zbigniew Bodek e4b318d69c Fix GCC build for all ARMs. Revert bug introduced in r255613.
Previous change applied in r255613 fixed build for ARMv6 but
broke it for previous architecture revisions. This commit
eventually fixes GCC build for all ARM revisions.

Approved by:	cognet (mentor)
Approved by:	re (kib)
2013-09-20 20:44:32 +00:00

890 lines
28 KiB
C

/*-
* Copyright (c) 2013 Ed Schouten <ed@FreeBSD.org>
* 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/param.h>
#include <sys/stdatomic.h>
#include <sys/types.h>
#include <machine/cpufunc.h>
#include <machine/sysarch.h>
#ifdef _KERNEL
#include "opt_global.h"
#endif
/*
* Executing statements with interrupts disabled.
*/
#if defined(_KERNEL) && !defined(SMP)
#define WITHOUT_INTERRUPTS(s) do { \
register_t regs; \
\
regs = intr_disable(); \
do s while (0); \
intr_restore(regs); \
} while (0)
#endif /* _KERNEL && !SMP */
/*
* 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.
*/
#if defined(_KERNEL) && !defined(SMP)
static inline void
do_sync(void)
{
__asm volatile ("" : : : "memory");
}
#elif defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__)
static inline void
do_sync(void)
{
__asm volatile ("dmb" : : : "memory");
}
#elif defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || \
defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || \
defined(__ARM_ARCH_6ZK__)
static inline void
do_sync(void)
{
__asm volatile ("mcr p15, 0, %0, c7, c10, 5" : : "r" (0) : "memory");
}
#endif
#if defined(__CLANG_ATOMICS) || defined(__GNUC_ATOMICS)
/*
* New C11 __atomic_* API.
*/
#if defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || \
defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || \
defined(__ARM_ARCH_6ZK__) || \
defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__)
/* These systems should be supported by the compiler. */
#else /* __ARM_ARCH_5__ */
/* Clang doesn't allow us to reimplement builtins without this. */
#ifdef __clang__
#pragma redefine_extname __sync_synchronize_ext __sync_synchronize
#define __sync_synchronize __sync_synchronize_ext
#endif
void
__sync_synchronize(void)
{
}
#ifdef _KERNEL
#ifdef SMP
#error "On SMP systems we should have proper atomic operations."
#endif
/*
* On uniprocessor systems, we can perform the atomic operations by
* disabling interrupts.
*/
#define EMIT_LOAD_N(N, uintN_t) \
uintN_t \
__atomic_load_##N(uintN_t *mem, int model __unused) \
{ \
uintN_t ret; \
\
WITHOUT_INTERRUPTS({ \
ret = *mem; \
}); \
return (ret); \
}
#define EMIT_STORE_N(N, uintN_t) \
void \
__atomic_store_##N(uintN_t *mem, uintN_t val, int model __unused) \
{ \
\
WITHOUT_INTERRUPTS({ \
*mem = val; \
}); \
}
#define EMIT_COMPARE_EXCHANGE_N(N, uintN_t) \
_Bool \
__atomic_compare_exchange_##N(uintN_t *mem, uintN_t *expected, \
uintN_t desired, int success __unused, int failure __unused) \
{ \
_Bool ret; \
\
WITHOUT_INTERRUPTS({ \
if (*mem == *expected) { \
*mem = desired; \
ret = 1; \
} else { \
*expected = *mem; \
ret = 0; \
} \
}); \
return (ret); \
}
#define EMIT_FETCH_OP_N(N, uintN_t, name, op) \
uintN_t \
__atomic_##name##_##N(uintN_t *mem, uintN_t val, int model __unused) \
{ \
uintN_t ret; \
\
WITHOUT_INTERRUPTS({ \
ret = *mem; \
*mem op val; \
}); \
return (ret); \
}
#define EMIT_ALL_OPS_N(N, uintN_t) \
EMIT_LOAD_N(N, uintN_t) \
EMIT_STORE_N(N, uintN_t) \
EMIT_COMPARE_EXCHANGE_N(N, uintN_t) \
EMIT_FETCH_OP_N(N, uintN_t, exchange, =) \
EMIT_FETCH_OP_N(N, uintN_t, fetch_add, +=) \
EMIT_FETCH_OP_N(N, uintN_t, fetch_and, &=) \
EMIT_FETCH_OP_N(N, uintN_t, fetch_or, |=) \
EMIT_FETCH_OP_N(N, uintN_t, fetch_sub, -=) \
EMIT_FETCH_OP_N(N, uintN_t, fetch_xor, ^=)
EMIT_ALL_OPS_N(1, uint8_t)
EMIT_ALL_OPS_N(2, uint16_t)
EMIT_ALL_OPS_N(4, uint32_t)
EMIT_ALL_OPS_N(8, uint64_t)
#undef EMIT_ALL_OPS_N
#else /* !_KERNEL */
/*
* For userspace on uniprocessor systems, we can implement the atomic
* operations by using a Restartable Atomic Sequence. This makes the
* kernel restart the code from the beginning when interrupted.
*/
#define EMIT_LOAD_N(N, uintN_t) \
uintN_t \
__atomic_load_##N(uintN_t *mem, int model __unused) \
{ \
\
return (*mem); \
}
#define EMIT_STORE_N(N, uintN_t) \
void \
__atomic_store_##N(uintN_t *mem, uintN_t val, int model __unused) \
{ \
\
*mem = val; \
}
#define EMIT_EXCHANGE_N(N, uintN_t, ldr, str) \
uintN_t \
__atomic_exchange_##N(uintN_t *mem, uintN_t val, int model __unused) \
{ \
uint32_t old, temp, ras_start; \
\
ras_start = ARM_RAS_START; \
__asm volatile ( \
/* Set up Restartable Atomic Sequence. */ \
"1:" \
"\tadr %2, 1b\n" \
"\tstr %2, [%5]\n" \
"\tadr %2, 2f\n" \
"\tstr %2, [%5, #4]\n" \
\
"\t"ldr" %0, %4\n" /* Load old value. */ \
"\t"str" %3, %1\n" /* Store new value. */ \
\
/* Tear down Restartable Atomic Sequence. */ \
"2:" \
"\tmov %2, #0x00000000\n" \
"\tstr %2, [%5]\n" \
"\tmov %2, #0xffffffff\n" \
"\tstr %2, [%5, #4]\n" \
: "=&r" (old), "=m" (*mem), "=&r" (temp) \
: "r" (val), "m" (*mem), "r" (ras_start)); \
return (old); \
}
#define EMIT_COMPARE_EXCHANGE_N(N, uintN_t, ldr, streq) \
_Bool \
__atomic_compare_exchange_##N(uintN_t *mem, uintN_t *pexpected, \
uintN_t desired, int success __unused, int failure __unused) \
{ \
uint32_t expected, old, temp, ras_start; \
\
expected = *pexpected; \
ras_start = ARM_RAS_START; \
__asm volatile ( \
/* Set up Restartable Atomic Sequence. */ \
"1:" \
"\tadr %2, 1b\n" \
"\tstr %2, [%6]\n" \
"\tadr %2, 2f\n" \
"\tstr %2, [%6, #4]\n" \
\
"\t"ldr" %0, %5\n" /* Load old value. */ \
"\tcmp %0, %3\n" /* Compare to expected value. */\
"\t"streq" %4, %1\n" /* Store new value. */ \
\
/* Tear down Restartable Atomic Sequence. */ \
"2:" \
"\tmov %2, #0x00000000\n" \
"\tstr %2, [%6]\n" \
"\tmov %2, #0xffffffff\n" \
"\tstr %2, [%6, #4]\n" \
: "=&r" (old), "=m" (*mem), "=&r" (temp) \
: "r" (expected), "r" (desired), "m" (*mem), \
"r" (ras_start)); \
if (old == expected) { \
return (1); \
} else { \
*pexpected = old; \
return (0); \
} \
}
#define EMIT_FETCH_OP_N(N, uintN_t, ldr, str, name, op) \
uintN_t \
__atomic_##name##_##N(uintN_t *mem, uintN_t val, int model __unused) \
{ \
uint32_t old, temp, ras_start; \
\
ras_start = ARM_RAS_START; \
__asm volatile ( \
/* Set up Restartable Atomic Sequence. */ \
"1:" \
"\tadr %2, 1b\n" \
"\tstr %2, [%5]\n" \
"\tadr %2, 2f\n" \
"\tstr %2, [%5, #4]\n" \
\
"\t"ldr" %0, %4\n" /* Load old value. */ \
"\t"op" %2, %0, %3\n" /* Calculate new value. */ \
"\t"str" %2, %1\n" /* Store new value. */ \
\
/* Tear down Restartable Atomic Sequence. */ \
"2:" \
"\tmov %2, #0x00000000\n" \
"\tstr %2, [%5]\n" \
"\tmov %2, #0xffffffff\n" \
"\tstr %2, [%5, #4]\n" \
: "=&r" (old), "=m" (*mem), "=&r" (temp) \
: "r" (val), "m" (*mem), "r" (ras_start)); \
return (old); \
}
#define EMIT_ALL_OPS_N(N, uintN_t, ldr, str, streq) \
EMIT_LOAD_N(N, uintN_t) \
EMIT_STORE_N(N, uintN_t) \
EMIT_EXCHANGE_N(N, uintN_t, ldr, str) \
EMIT_COMPARE_EXCHANGE_N(N, uintN_t, ldr, streq) \
EMIT_FETCH_OP_N(N, uintN_t, ldr, str, fetch_add, "add") \
EMIT_FETCH_OP_N(N, uintN_t, ldr, str, fetch_and, "and") \
EMIT_FETCH_OP_N(N, uintN_t, ldr, str, fetch_or, "orr") \
EMIT_FETCH_OP_N(N, uintN_t, ldr, str, fetch_sub, "sub") \
EMIT_FETCH_OP_N(N, uintN_t, ldr, str, fetch_xor, "eor")
EMIT_ALL_OPS_N(1, uint8_t, "ldrb", "strb", "strbeq")
EMIT_ALL_OPS_N(2, uint16_t, "ldrh", "strh", "strheq")
EMIT_ALL_OPS_N(4, uint32_t, "ldr", "str", "streq")
#undef EMIT_ALL_OPS_N
#endif /* _KERNEL */
#endif
#endif /* __CLANG_ATOMICS || __GNUC_ATOMICS */
#if defined(__SYNC_ATOMICS) || defined(EMIT_SYNC_ATOMICS)
#ifdef __clang__
#pragma redefine_extname __sync_lock_test_and_set_1_c __sync_lock_test_and_set_1
#pragma redefine_extname __sync_lock_test_and_set_2_c __sync_lock_test_and_set_2
#pragma redefine_extname __sync_lock_test_and_set_4_c __sync_lock_test_and_set_4
#pragma redefine_extname __sync_val_compare_and_swap_1_c __sync_val_compare_and_swap_1
#pragma redefine_extname __sync_val_compare_and_swap_2_c __sync_val_compare_and_swap_2
#pragma redefine_extname __sync_val_compare_and_swap_4_c __sync_val_compare_and_swap_4
#pragma redefine_extname __sync_fetch_and_add_1_c __sync_fetch_and_add_1
#pragma redefine_extname __sync_fetch_and_add_2_c __sync_fetch_and_add_2
#pragma redefine_extname __sync_fetch_and_add_4_c __sync_fetch_and_add_4
#pragma redefine_extname __sync_fetch_and_and_1_c __sync_fetch_and_and_1
#pragma redefine_extname __sync_fetch_and_and_2_c __sync_fetch_and_and_2
#pragma redefine_extname __sync_fetch_and_and_4_c __sync_fetch_and_and_4
#pragma redefine_extname __sync_fetch_and_or_1_c __sync_fetch_and_or_1
#pragma redefine_extname __sync_fetch_and_or_2_c __sync_fetch_and_or_2
#pragma redefine_extname __sync_fetch_and_or_4_c __sync_fetch_and_or_4
#pragma redefine_extname __sync_fetch_and_xor_1_c __sync_fetch_and_xor_1
#pragma redefine_extname __sync_fetch_and_xor_2_c __sync_fetch_and_xor_2
#pragma redefine_extname __sync_fetch_and_xor_4_c __sync_fetch_and_xor_4
#pragma redefine_extname __sync_fetch_and_sub_1_c __sync_fetch_and_sub_1
#pragma redefine_extname __sync_fetch_and_sub_2_c __sync_fetch_and_sub_2
#pragma redefine_extname __sync_fetch_and_sub_4_c __sync_fetch_and_sub_4
#endif
/*
* Old __sync_* API.
*/
#if defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || \
defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || \
defined(__ARM_ARCH_6ZK__) || \
defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__)
/* Implementations for old GCC versions, lacking support for atomics. */
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##_c(uintN_t *mem, uintN_t val) \
{ \
uint32_t *mem32; \
reg_t val32, negmask, old; \
uint32_t temp1, temp2; \
\
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:" \
"\tldrex %0, %6\n" /* Load old value. */ \
"\tand %2, %5, %0\n" /* Remove the old value. */ \
"\torr %2, %2, %4\n" /* Put in the new value. */ \
"\tstrex %3, %2, %1\n" /* Attempt to store. */ \
"\tcmp %3, #0\n" /* Did it succeed? */ \
"\tbne 1b\n" /* Spin if failed. */ \
: "=&r" (old.v32), "=m" (*mem32), "=&r" (temp1), \
"=&r" (temp2) \
: "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##_c(uintN_t *mem, uintN_t expected, \
uintN_t desired) \
{ \
uint32_t *mem32; \
reg_t expected32, desired32, posmask, old; \
uint32_t negmask, temp1, temp2; \
\
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:" \
"\tldrex %0, %8\n" /* Load old value. */ \
"\tand %2, %6, %0\n" /* Isolate the old value. */ \
"\tcmp %2, %4\n" /* Compare to expected value. */\
"\tbne 2f\n" /* Values are unequal. */ \
"\tand %2, %7, %0\n" /* Remove the old value. */ \
"\torr %2, %5\n" /* Put in the new value. */ \
"\tstrex %3, %2, %1\n" /* Attempt to store. */ \
"\tcmp %3, #0\n" /* Did it succeed? */ \
"\tbne 1b\n" /* Spin if failed. */ \
"2:" \
: "=&r" (old), "=m" (*mem32), "=&r" (temp1), \
"=&r" (temp2) \
: "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##_c(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:" \
"\tldrex %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. */ \
"\torr %2, %2, %3\n" /* Put in the new value. */ \
"\tstrex %3, %2, %1\n" /* Attempt to store. */ \
"\tcmp %3, #0\n" /* Did it succeed? */ \
"\tbne 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, "add")
EMIT_ARITHMETIC_FETCH_AND_OP_N(1, uint8_t, fetch_and_sub, "sub")
EMIT_ARITHMETIC_FETCH_AND_OP_N(2, uint16_t, fetch_and_add, "add")
EMIT_ARITHMETIC_FETCH_AND_OP_N(2, uint16_t, fetch_and_sub, "sub")
#define EMIT_BITWISE_FETCH_AND_OP_N(N, uintN_t, name, op, idempotence) \
uintN_t \
__sync_##name##_##N##_c(uintN_t *mem, uintN_t val) \
{ \
uint32_t *mem32; \
reg_t val32, old; \
uint32_t temp1, temp2; \
\
mem32 = round_to_word(mem); \
val32.v32 = idempotence ? 0xffffffff : 0x00000000; \
put_##N(&val32, mem, val); \
\
do_sync(); \
__asm volatile ( \
"1:" \
"\tldrex %0, %5\n" /* Load old value. */ \
"\t"op" %2, %4, %0\n" /* Calculate new value. */ \
"\tstrex %3, %2, %1\n" /* Attempt to store. */ \
"\tcmp %3, #0\n" /* Did it succeed? */ \
"\tbne 1b\n" /* Spin if failed. */ \
: "=&r" (old.v32), "=m" (*mem32), "=&r" (temp1), \
"=&r" (temp2) \
: "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, "orr", 0)
EMIT_BITWISE_FETCH_AND_OP_N(1, uint8_t, fetch_and_xor, "eor", 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, "orr", 0)
EMIT_BITWISE_FETCH_AND_OP_N(2, uint16_t, fetch_and_xor, "eor", 0)
/*
* 32-bit routines.
*/
uint32_t
__sync_lock_test_and_set_4_c(uint32_t *mem, uint32_t val)
{
uint32_t old, temp;
do_sync();
__asm volatile (
"1:"
"\tldrex %0, %4\n" /* Load old value. */
"\tstrex %2, %3, %1\n" /* Attempt to store. */
"\tcmp %2, #0\n" /* Did it succeed? */
"\tbne 1b\n" /* Spin if failed. */
: "=&r" (old), "=m" (*mem), "=&r" (temp)
: "r" (val), "m" (*mem));
return (old);
}
uint32_t
__sync_val_compare_and_swap_4_c(uint32_t *mem, uint32_t expected,
uint32_t desired)
{
uint32_t old, temp;
do_sync();
__asm volatile (
"1:"
"\tldrex %0, %5\n" /* Load old value. */
"\tcmp %0, %3\n" /* Compare to expected value. */
"\tbne 2f\n" /* Values are unequal. */
"\tstrex %2, %4, %1\n" /* Attempt to store. */
"\tcmp %2, #0\n" /* Did it succeed? */
"\tbne 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##_c(uint32_t *mem, uint32_t val) \
{ \
uint32_t old, temp1, temp2; \
\
do_sync(); \
__asm volatile ( \
"1:" \
"\tldrex %0, %5\n" /* Load old value. */ \
"\t"op" %2, %0, %4\n" /* Calculate new value. */ \
"\tstrex %3, %2, %1\n" /* Attempt to store. */ \
"\tcmp %3, #0\n" /* Did it succeed? */ \
"\tbne 1b\n" /* Spin if failed. */ \
: "=&r" (old), "=m" (*mem), "=&r" (temp1), \
"=&r" (temp2) \
: "r" (val), "m" (*mem)); \
return (old); \
}
EMIT_FETCH_AND_OP_4(fetch_and_add, "add")
EMIT_FETCH_AND_OP_4(fetch_and_and, "and")
EMIT_FETCH_AND_OP_4(fetch_and_or, "orr")
EMIT_FETCH_AND_OP_4(fetch_and_sub, "sub")
EMIT_FETCH_AND_OP_4(fetch_and_xor, "eor")
#ifndef __clang__
__strong_reference(__sync_lock_test_and_set_1_c, __sync_lock_test_and_set_1);
__strong_reference(__sync_lock_test_and_set_2_c, __sync_lock_test_and_set_2);
__strong_reference(__sync_lock_test_and_set_4_c, __sync_lock_test_and_set_4);
__strong_reference(__sync_val_compare_and_swap_1_c, __sync_val_compare_and_swap_1);
__strong_reference(__sync_val_compare_and_swap_2_c, __sync_val_compare_and_swap_2);
__strong_reference(__sync_val_compare_and_swap_4_c, __sync_val_compare_and_swap_4);
__strong_reference(__sync_fetch_and_add_1_c, __sync_fetch_and_add_1);
__strong_reference(__sync_fetch_and_add_2_c, __sync_fetch_and_add_2);
__strong_reference(__sync_fetch_and_add_4_c, __sync_fetch_and_add_4);
__strong_reference(__sync_fetch_and_and_1_c, __sync_fetch_and_and_1);
__strong_reference(__sync_fetch_and_and_2_c, __sync_fetch_and_and_2);
__strong_reference(__sync_fetch_and_and_4_c, __sync_fetch_and_and_4);
__strong_reference(__sync_fetch_and_sub_1_c, __sync_fetch_and_sub_1);
__strong_reference(__sync_fetch_and_sub_2_c, __sync_fetch_and_sub_2);
__strong_reference(__sync_fetch_and_sub_4_c, __sync_fetch_and_sub_4);
__strong_reference(__sync_fetch_and_or_1_c, __sync_fetch_and_or_1);
__strong_reference(__sync_fetch_and_or_2_c, __sync_fetch_and_or_2);
__strong_reference(__sync_fetch_and_or_4_c, __sync_fetch_and_or_4);
__strong_reference(__sync_fetch_and_xor_1_c, __sync_fetch_and_xor_1);
__strong_reference(__sync_fetch_and_xor_2_c, __sync_fetch_and_xor_2);
__strong_reference(__sync_fetch_and_xor_4_c, __sync_fetch_and_xor_4);
#endif
#else /* __ARM_ARCH_5__ */
#ifdef _KERNEL
#ifdef SMP
#error "On SMP systems we should have proper atomic operations."
#endif
/*
* On uniprocessor systems, we can perform the atomic operations by
* disabling interrupts.
*/
#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) \
{ \
uintN_t ret; \
\
WITHOUT_INTERRUPTS({ \
ret = *mem; \
if (*mem == expected) \
*mem = desired; \
}); \
return (ret); \
}
#define EMIT_FETCH_AND_OP_N(N, uintN_t, name, op) \
uintN_t \
__sync_##name##_##N(uintN_t *mem, uintN_t val) \
{ \
uintN_t ret; \
\
WITHOUT_INTERRUPTS({ \
ret = *mem; \
*mem op val; \
}); \
return (ret); \
}
#define EMIT_ALL_OPS_N(N, uintN_t) \
EMIT_VAL_COMPARE_AND_SWAP_N(N, uintN_t) \
EMIT_FETCH_AND_OP_N(N, uintN_t, lock_test_and_set, =) \
EMIT_FETCH_AND_OP_N(N, uintN_t, fetch_and_add, +=) \
EMIT_FETCH_AND_OP_N(N, uintN_t, fetch_and_and, &=) \
EMIT_FETCH_AND_OP_N(N, uintN_t, fetch_and_or, |=) \
EMIT_FETCH_AND_OP_N(N, uintN_t, fetch_and_sub, -=) \
EMIT_FETCH_AND_OP_N(N, uintN_t, fetch_and_xor, ^=)
EMIT_ALL_OPS_N(1, uint8_t)
EMIT_ALL_OPS_N(2, uint16_t)
EMIT_ALL_OPS_N(4, uint32_t)
EMIT_ALL_OPS_N(8, uint64_t)
#undef EMIT_ALL_OPS_N
#else /* !_KERNEL */
/*
* For userspace on uniprocessor systems, we can implement the atomic
* operations by using a Restartable Atomic Sequence. This makes the
* kernel restart the code from the beginning when interrupted.
*/
#define EMIT_LOCK_TEST_AND_SET_N(N, uintN_t, ldr, str) \
uintN_t \
__sync_lock_test_and_set_##N##_c(uintN_t *mem, uintN_t val) \
{ \
uint32_t old, temp, ras_start; \
\
ras_start = ARM_RAS_START; \
__asm volatile ( \
/* Set up Restartable Atomic Sequence. */ \
"1:" \
"\tadr %2, 1b\n" \
"\tstr %2, [%5]\n" \
"\tadr %2, 2f\n" \
"\tstr %2, [%5, #4]\n" \
\
"\t"ldr" %0, %4\n" /* Load old value. */ \
"\t"str" %3, %1\n" /* Store new value. */ \
\
/* Tear down Restartable Atomic Sequence. */ \
"2:" \
"\tmov %2, #0x00000000\n" \
"\tstr %2, [%5]\n" \
"\tmov %2, #0xffffffff\n" \
"\tstr %2, [%5, #4]\n" \
: "=&r" (old), "=m" (*mem), "=&r" (temp) \
: "r" (val), "m" (*mem), "r" (ras_start)); \
return (old); \
}
#define EMIT_VAL_COMPARE_AND_SWAP_N(N, uintN_t, ldr, streq) \
uintN_t \
__sync_val_compare_and_swap_##N##_c(uintN_t *mem, uintN_t expected, \
uintN_t desired) \
{ \
uint32_t old, temp, ras_start; \
\
ras_start = ARM_RAS_START; \
__asm volatile ( \
/* Set up Restartable Atomic Sequence. */ \
"1:" \
"\tadr %2, 1b\n" \
"\tstr %2, [%6]\n" \
"\tadr %2, 2f\n" \
"\tstr %2, [%6, #4]\n" \
\
"\t"ldr" %0, %5\n" /* Load old value. */ \
"\tcmp %0, %3\n" /* Compare to expected value. */\
"\t"streq" %4, %1\n" /* Store new value. */ \
\
/* Tear down Restartable Atomic Sequence. */ \
"2:" \
"\tmov %2, #0x00000000\n" \
"\tstr %2, [%6]\n" \
"\tmov %2, #0xffffffff\n" \
"\tstr %2, [%6, #4]\n" \
: "=&r" (old), "=m" (*mem), "=&r" (temp) \
: "r" (expected), "r" (desired), "m" (*mem), \
"r" (ras_start)); \
return (old); \
}
#define EMIT_FETCH_AND_OP_N(N, uintN_t, ldr, str, name, op) \
uintN_t \
__sync_##name##_##N##_c(uintN_t *mem, uintN_t val) \
{ \
uint32_t old, temp, ras_start; \
\
ras_start = ARM_RAS_START; \
__asm volatile ( \
/* Set up Restartable Atomic Sequence. */ \
"1:" \
"\tadr %2, 1b\n" \
"\tstr %2, [%5]\n" \
"\tadr %2, 2f\n" \
"\tstr %2, [%5, #4]\n" \
\
"\t"ldr" %0, %4\n" /* Load old value. */ \
"\t"op" %2, %0, %3\n" /* Calculate new value. */ \
"\t"str" %2, %1\n" /* Store new value. */ \
\
/* Tear down Restartable Atomic Sequence. */ \
"2:" \
"\tmov %2, #0x00000000\n" \
"\tstr %2, [%5]\n" \
"\tmov %2, #0xffffffff\n" \
"\tstr %2, [%5, #4]\n" \
: "=&r" (old), "=m" (*mem), "=&r" (temp) \
: "r" (val), "m" (*mem), "r" (ras_start)); \
return (old); \
}
#define EMIT_ALL_OPS_N(N, uintN_t, ldr, str, streq) \
EMIT_LOCK_TEST_AND_SET_N(N, uintN_t, ldr, str) \
EMIT_VAL_COMPARE_AND_SWAP_N(N, uintN_t, ldr, streq) \
EMIT_FETCH_AND_OP_N(N, uintN_t, ldr, str, fetch_and_add, "add") \
EMIT_FETCH_AND_OP_N(N, uintN_t, ldr, str, fetch_and_and, "and") \
EMIT_FETCH_AND_OP_N(N, uintN_t, ldr, str, fetch_and_or, "orr") \
EMIT_FETCH_AND_OP_N(N, uintN_t, ldr, str, fetch_and_sub, "sub") \
EMIT_FETCH_AND_OP_N(N, uintN_t, ldr, str, fetch_and_xor, "eor")
EMIT_ALL_OPS_N(1, uint8_t, "ldrb", "strb", "streqb")
EMIT_ALL_OPS_N(2, uint16_t, "ldrh", "strh", "streqh")
EMIT_ALL_OPS_N(4, uint32_t, "ldr", "str", "streq")
#ifndef __clang__
__strong_reference(__sync_lock_test_and_set_1_c, __sync_lock_test_and_set_1);
__strong_reference(__sync_lock_test_and_set_2_c, __sync_lock_test_and_set_2);
__strong_reference(__sync_lock_test_and_set_4_c, __sync_lock_test_and_set_4);
__strong_reference(__sync_val_compare_and_swap_1_c, __sync_val_compare_and_swap_1);
__strong_reference(__sync_val_compare_and_swap_2_c, __sync_val_compare_and_swap_2);
__strong_reference(__sync_val_compare_and_swap_4_c, __sync_val_compare_and_swap_4);
__strong_reference(__sync_fetch_and_add_1_c, __sync_fetch_and_add_1);
__strong_reference(__sync_fetch_and_add_2_c, __sync_fetch_and_add_2);
__strong_reference(__sync_fetch_and_add_4_c, __sync_fetch_and_add_4);
__strong_reference(__sync_fetch_and_and_1_c, __sync_fetch_and_and_1);
__strong_reference(__sync_fetch_and_and_2_c, __sync_fetch_and_and_2);
__strong_reference(__sync_fetch_and_and_4_c, __sync_fetch_and_and_4);
__strong_reference(__sync_fetch_and_sub_1_c, __sync_fetch_and_sub_1);
__strong_reference(__sync_fetch_and_sub_2_c, __sync_fetch_and_sub_2);
__strong_reference(__sync_fetch_and_sub_4_c, __sync_fetch_and_sub_4);
__strong_reference(__sync_fetch_and_or_1_c, __sync_fetch_and_or_1);
__strong_reference(__sync_fetch_and_or_2_c, __sync_fetch_and_or_2);
__strong_reference(__sync_fetch_and_or_4_c, __sync_fetch_and_or_4);
__strong_reference(__sync_fetch_and_xor_1_c, __sync_fetch_and_xor_1);
__strong_reference(__sync_fetch_and_xor_2_c, __sync_fetch_and_xor_2);
__strong_reference(__sync_fetch_and_xor_4_c, __sync_fetch_and_xor_4);
#endif
#endif /* _KERNEL */
#endif
#endif /* __SYNC_ATOMICS */