186 lines
4.3 KiB
C
186 lines
4.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
/*
|
|
* Atomic operations for the Hexagon architecture
|
|
*
|
|
* Copyright (c) 2010-2013, The Linux Foundation. All rights reserved.
|
|
*/
|
|
|
|
#ifndef _ASM_ATOMIC_H
|
|
#define _ASM_ATOMIC_H
|
|
|
|
#include <linux/types.h>
|
|
#include <asm/cmpxchg.h>
|
|
#include <asm/barrier.h>
|
|
|
|
/* Normal writes in our arch don't clear lock reservations */
|
|
|
|
static inline void arch_atomic_set(atomic_t *v, int new)
|
|
{
|
|
asm volatile(
|
|
"1: r6 = memw_locked(%0);\n"
|
|
" memw_locked(%0,p0) = %1;\n"
|
|
" if (!P0) jump 1b;\n"
|
|
:
|
|
: "r" (&v->counter), "r" (new)
|
|
: "memory", "p0", "r6"
|
|
);
|
|
}
|
|
|
|
#define arch_atomic_set_release(v, i) arch_atomic_set((v), (i))
|
|
|
|
/**
|
|
* arch_atomic_read - reads a word, atomically
|
|
* @v: pointer to atomic value
|
|
*
|
|
* Assumes all word reads on our architecture are atomic.
|
|
*/
|
|
#define arch_atomic_read(v) READ_ONCE((v)->counter)
|
|
|
|
/**
|
|
* arch_atomic_xchg - atomic
|
|
* @v: pointer to memory to change
|
|
* @new: new value (technically passed in a register -- see xchg)
|
|
*/
|
|
#define arch_atomic_xchg(v, new) (arch_xchg(&((v)->counter), (new)))
|
|
|
|
|
|
/**
|
|
* arch_atomic_cmpxchg - atomic compare-and-exchange values
|
|
* @v: pointer to value to change
|
|
* @old: desired old value to match
|
|
* @new: new value to put in
|
|
*
|
|
* Parameters are then pointer, value-in-register, value-in-register,
|
|
* and the output is the old value.
|
|
*
|
|
* Apparently this is complicated for archs that don't support
|
|
* the memw_locked like we do (or it's broken or whatever).
|
|
*
|
|
* Kind of the lynchpin of the rest of the generically defined routines.
|
|
* Remember V2 had that bug with dotnew predicate set by memw_locked.
|
|
*
|
|
* "old" is "expected" old val, __oldval is actual old value
|
|
*/
|
|
static inline int arch_atomic_cmpxchg(atomic_t *v, int old, int new)
|
|
{
|
|
int __oldval;
|
|
|
|
asm volatile(
|
|
"1: %0 = memw_locked(%1);\n"
|
|
" { P0 = cmp.eq(%0,%2);\n"
|
|
" if (!P0.new) jump:nt 2f; }\n"
|
|
" memw_locked(%1,P0) = %3;\n"
|
|
" if (!P0) jump 1b;\n"
|
|
"2:\n"
|
|
: "=&r" (__oldval)
|
|
: "r" (&v->counter), "r" (old), "r" (new)
|
|
: "memory", "p0"
|
|
);
|
|
|
|
return __oldval;
|
|
}
|
|
|
|
#define ATOMIC_OP(op) \
|
|
static inline void arch_atomic_##op(int i, atomic_t *v) \
|
|
{ \
|
|
int output; \
|
|
\
|
|
__asm__ __volatile__ ( \
|
|
"1: %0 = memw_locked(%1);\n" \
|
|
" %0 = "#op "(%0,%2);\n" \
|
|
" memw_locked(%1,P3)=%0;\n" \
|
|
" if (!P3) jump 1b;\n" \
|
|
: "=&r" (output) \
|
|
: "r" (&v->counter), "r" (i) \
|
|
: "memory", "p3" \
|
|
); \
|
|
} \
|
|
|
|
#define ATOMIC_OP_RETURN(op) \
|
|
static inline int arch_atomic_##op##_return(int i, atomic_t *v) \
|
|
{ \
|
|
int output; \
|
|
\
|
|
__asm__ __volatile__ ( \
|
|
"1: %0 = memw_locked(%1);\n" \
|
|
" %0 = "#op "(%0,%2);\n" \
|
|
" memw_locked(%1,P3)=%0;\n" \
|
|
" if (!P3) jump 1b;\n" \
|
|
: "=&r" (output) \
|
|
: "r" (&v->counter), "r" (i) \
|
|
: "memory", "p3" \
|
|
); \
|
|
return output; \
|
|
}
|
|
|
|
#define ATOMIC_FETCH_OP(op) \
|
|
static inline int arch_atomic_fetch_##op(int i, atomic_t *v) \
|
|
{ \
|
|
int output, val; \
|
|
\
|
|
__asm__ __volatile__ ( \
|
|
"1: %0 = memw_locked(%2);\n" \
|
|
" %1 = "#op "(%0,%3);\n" \
|
|
" memw_locked(%2,P3)=%1;\n" \
|
|
" if (!P3) jump 1b;\n" \
|
|
: "=&r" (output), "=&r" (val) \
|
|
: "r" (&v->counter), "r" (i) \
|
|
: "memory", "p3" \
|
|
); \
|
|
return output; \
|
|
}
|
|
|
|
#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op) ATOMIC_FETCH_OP(op)
|
|
|
|
ATOMIC_OPS(add)
|
|
ATOMIC_OPS(sub)
|
|
|
|
#undef ATOMIC_OPS
|
|
#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_FETCH_OP(op)
|
|
|
|
ATOMIC_OPS(and)
|
|
ATOMIC_OPS(or)
|
|
ATOMIC_OPS(xor)
|
|
|
|
#undef ATOMIC_OPS
|
|
#undef ATOMIC_FETCH_OP
|
|
#undef ATOMIC_OP_RETURN
|
|
#undef ATOMIC_OP
|
|
|
|
/**
|
|
* arch_atomic_fetch_add_unless - add unless the number is a given value
|
|
* @v: pointer to value
|
|
* @a: amount to add
|
|
* @u: unless value is equal to u
|
|
*
|
|
* Returns old value.
|
|
*
|
|
*/
|
|
|
|
static inline int arch_atomic_fetch_add_unless(atomic_t *v, int a, int u)
|
|
{
|
|
int __oldval;
|
|
register int tmp;
|
|
|
|
asm volatile(
|
|
"1: %0 = memw_locked(%2);"
|
|
" {"
|
|
" p3 = cmp.eq(%0, %4);"
|
|
" if (p3.new) jump:nt 2f;"
|
|
" %1 = add(%0, %3);"
|
|
" }"
|
|
" memw_locked(%2, p3) = %1;"
|
|
" {"
|
|
" if (!p3) jump 1b;"
|
|
" }"
|
|
"2:"
|
|
: "=&r" (__oldval), "=&r" (tmp)
|
|
: "r" (v), "r" (a), "r" (u)
|
|
: "memory", "p3"
|
|
);
|
|
return __oldval;
|
|
}
|
|
#define arch_atomic_fetch_add_unless arch_atomic_fetch_add_unless
|
|
|
|
#endif
|