cregit-Linux how code gets into the kernel

Release 4.14 arch/tile/include/asm/atomic_64.h

/*
 * Copyright 2011 Tilera Corporation. All Rights Reserved.
 *
 *   This program is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU General Public License
 *   as published by the Free Software Foundation, version 2.
 *
 *   This program is distributed in the hope that it will be useful, but
 *   WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 *   NON INFRINGEMENT.  See the GNU General Public License for
 *   more details.
 *
 * Do not include directly; use <linux/atomic.h>.
 */

#ifndef _ASM_TILE_ATOMIC_64_H

#define _ASM_TILE_ATOMIC_64_H

#ifndef __ASSEMBLY__

#include <asm/barrier.h>
#include <arch/spr_def.h>

/* First, the 32-bit atomic ops that are "real" on our 64-bit platform. */


#define atomic_set(v, i) WRITE_ONCE((v)->counter, (i))

/*
 * The smp_mb() operations throughout are to support the fact that
 * Linux requires memory barriers before and after the operation,
 * on any routine which updates memory and returns a value.
 */

/*
 * Note a subtlety of the locking here.  We are required to provide a
 * full memory barrier before and after the operation.  However, we
 * only provide an explicit mb before the operation.  After the
 * operation, we use barrier() to get a full mb for free, because:
 *
 * (1) The barrier directive to the compiler prohibits any instructions
 * being statically hoisted before the barrier;
 * (2) the microarchitecture will not issue any further instructions
 * until the fetchadd result is available for the "+ i" add instruction;
 * (3) the smb_mb before the fetchadd ensures that no other memory
 * operations are in flight at this point.
 */

static inline int atomic_add_return(int i, atomic_t *v) { int val; smp_mb(); /* barrier for proper semantics */ val = __insn_fetchadd4((void *)&v->counter, i) + i; barrier(); /* equivalent to smp_mb(); see block comment above */ return val; }

Contributors

PersonTokensPropCommitsCommitProp
Chris Metcalf46100.00%2100.00%
Total46100.00%2100.00%

#define ATOMIC_OPS(op) \ static inline int atomic_fetch_##op(int i, atomic_t *v) \ { \ int val; \ smp_mb(); \ val = __insn_fetch##op##4((void *)&v->counter, i); \ smp_mb(); \ return val; \ } \ static inline void atomic_##op(int i, atomic_t *v) \ { \ __insn_fetch##op##4((void *)&v->counter, i); \ } ATOMIC_OPS(add) ATOMIC_OPS(and) ATOMIC_OPS(or) #undef ATOMIC_OPS
static inline int atomic_fetch_xor(int i, atomic_t *v) { int guess, oldval = v->counter; smp_mb(); do { guess = oldval; __insn_mtspr(SPR_CMPEXCH_VALUE, guess); oldval = __insn_cmpexch4(&v->counter, guess ^ i); } while (guess != oldval); smp_mb(); return oldval; }

Contributors

PersonTokensPropCommitsCommitProp
Chris Metcalf4770.15%266.67%
Peter Zijlstra2029.85%133.33%
Total67100.00%3100.00%


static inline void atomic_xor(int i, atomic_t *v) { int guess, oldval = v->counter; do { guess = oldval; __insn_mtspr(SPR_CMPEXCH_VALUE, guess); oldval = __insn_cmpexch4(&v->counter, guess ^ i); } while (guess != oldval); }

Contributors

PersonTokensPropCommitsCommitProp
Peter Zijlstra3051.72%150.00%
Chris Metcalf2848.28%150.00%
Total58100.00%2100.00%


static inline int __atomic_add_unless(atomic_t *v, int a, int u) { int guess, oldval = v->counter; do { if (oldval == u) break; guess = oldval; oldval = cmpxchg(&v->counter, guess, guess + a); } while (guess != oldval); return oldval; }

Contributors

PersonTokensPropCommitsCommitProp
Chris Metcalf4365.15%150.00%
Peter Zijlstra2334.85%150.00%
Total66100.00%2100.00%

/* Now the true 64-bit operations. */ #define ATOMIC64_INIT(i) { (i) } #define atomic64_read(v) READ_ONCE((v)->counter) #define atomic64_set(v, i) WRITE_ONCE((v)->counter, (i))
static inline long atomic64_add_return(long i, atomic64_t *v) { int val; smp_mb(); /* barrier for proper semantics */ val = __insn_fetchadd((void *)&v->counter, i) + i; barrier(); /* equivalent to smp_mb; see atomic_add_return() */ return val; }

Contributors

PersonTokensPropCommitsCommitProp
Chris Metcalf46100.00%2100.00%
Total46100.00%2100.00%

#define ATOMIC64_OPS(op) \ static inline long atomic64_fetch_##op(long i, atomic64_t *v) \ { \ long val; \ smp_mb(); \ val = __insn_fetch##op((void *)&v->counter, i); \ smp_mb(); \ return val; \ } \ static inline void atomic64_##op(long i, atomic64_t *v) \ { \ __insn_fetch##op((void *)&v->counter, i); \ } ATOMIC64_OPS(add) ATOMIC64_OPS(and) ATOMIC64_OPS(or) #undef ATOMIC64_OPS
static inline long atomic64_fetch_xor(long i, atomic64_t *v) { long guess, oldval = v->counter; smp_mb(); do { guess = oldval; __insn_mtspr(SPR_CMPEXCH_VALUE, guess); oldval = __insn_cmpexch(&v->counter, guess ^ i); } while (guess != oldval); smp_mb(); return oldval; }

Contributors

PersonTokensPropCommitsCommitProp
Chris Metcalf4770.15%266.67%
Peter Zijlstra2029.85%133.33%
Total67100.00%3100.00%


static inline void atomic64_xor(long i, atomic64_t *v) { long guess, oldval = v->counter; do { guess = oldval; __insn_mtspr(SPR_CMPEXCH_VALUE, guess); oldval = __insn_cmpexch(&v->counter, guess ^ i); } while (guess != oldval); }

Contributors

PersonTokensPropCommitsCommitProp
Peter Zijlstra3051.72%150.00%
Chris Metcalf2848.28%150.00%
Total58100.00%2100.00%


static inline long atomic64_add_unless(atomic64_t *v, long a, long u) { long guess, oldval = v->counter; do { if (oldval == u) break; guess = oldval; oldval = cmpxchg(&v->counter, guess, guess + a); } while (guess != oldval); return oldval != u; }

Contributors

PersonTokensPropCommitsCommitProp
Chris Metcalf4363.24%150.00%
Peter Zijlstra2536.76%150.00%
Total68100.00%2100.00%

#define atomic64_sub_return(i, v) atomic64_add_return(-(i), (v)) #define atomic64_fetch_sub(i, v) atomic64_fetch_add(-(i), (v)) #define atomic64_sub(i, v) atomic64_add(-(i), (v)) #define atomic64_inc_return(v) atomic64_add_return(1, (v)) #define atomic64_dec_return(v) atomic64_sub_return(1, (v)) #define atomic64_inc(v) atomic64_add(1, (v)) #define atomic64_dec(v) atomic64_sub(1, (v)) #define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0) #define atomic64_dec_and_test(v) (atomic64_dec_return(v) == 0) #define atomic64_sub_and_test(i, v) (atomic64_sub_return((i), (v)) == 0) #define atomic64_add_negative(i, v) (atomic64_add_return((i), (v)) < 0) #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0) #endif /* !__ASSEMBLY__ */ #endif /* _ASM_TILE_ATOMIC_64_H */

Overall Contributors

PersonTokensPropCommitsCommitProp
Chris Metcalf46468.84%450.00%
Peter Zijlstra20630.56%225.00%
David Howells30.45%112.50%
Arun Sharma10.15%112.50%
Total674100.00%8100.00%
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.