cregit-Linux how code gets into the kernel

Release 4.8 arch/arc/include/asm/atomic.h

/*
 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#ifndef _ASM_ARC_ATOMIC_H

#define _ASM_ARC_ATOMIC_H

#ifndef __ASSEMBLY__

#include <linux/types.h>
#include <linux/compiler.h>
#include <asm/cmpxchg.h>
#include <asm/barrier.h>
#include <asm/smp.h>

#ifndef CONFIG_ARC_PLAT_EZNPS


#define atomic_read(v)  READ_ONCE((v)->counter)

#ifdef CONFIG_ARC_HAS_LLSC


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


#define ATOMIC_OP(op, c_op, asm_op)					\
static inline void atomic_##op(int i, atomic_t *v)                      \
{                                                                       \
        unsigned int val;                                               \
                                                                        \
        __asm__ __volatile__(                                           \
        "1:     llock   %[val], [%[ctr]]                \n"             \
        "       " #asm_op " %[val], %[val], %[i]        \n"             \
        "       scond   %[val], [%[ctr]]                \n"             \
        "       bnz     1b                              \n"             \
        : [val] "=&r"   (val) /* Early clobber to prevent reg reuse */	\
        : [ctr] "r"     (&v->counter), /* Not "m": llock only supports reg direct addr mode */	\
          [i]   "ir"    (i)                                             \
        : "cc");                                                        \
}                                                                       \

#define ATOMIC_OP_RETURN(op, c_op, asm_op)                              \
static inline int atomic_##op##_return(int i, atomic_t *v)              \
{                                                                       \
        unsigned int val;                                               \
                                                                        \
	/*                                                              \
         * Explicit full memory barrier needed before/after as          \
         * LLOCK/SCOND thmeselves don't provide any such semantics      \
         */								\
        smp_mb();                                                       \
                                                                        \
        __asm__ __volatile__(                                           \
        "1:     llock   %[val], [%[ctr]]                \n"             \
        "       " #asm_op " %[val], %[val], %[i]        \n"             \
        "       scond   %[val], [%[ctr]]                \n"             \
        "       bnz     1b                              \n"             \
        : [val] "=&r"   (val)                                           \
        : [ctr] "r"     (&v->counter),                                  \
          [i]   "ir"    (i)                                             \
        : "cc");                                                        \
                                                                        \
        smp_mb();                                                       \
                                                                        \
        return val;                                                     \
}


#define ATOMIC_FETCH_OP(op, c_op, asm_op)				\
static inline int atomic_fetch_##op(int i, atomic_t *v)                 \
{                                                                       \
        unsigned int val, orig;                                         \
                                                                        \
	/*                                                              \
         * Explicit full memory barrier needed before/after as          \
         * LLOCK/SCOND thmeselves don't provide any such semantics      \
         */								\
        smp_mb();                                                       \
                                                                        \
        __asm__ __volatile__(                                           \
        "1:     llock   %[orig], [%[ctr]]               \n"             \
        "       " #asm_op " %[val], %[orig], %[i]       \n"             \
        "       scond   %[val], [%[ctr]]                \n"             \
        "                                               \n"             \
        : [val] "=&r"   (val),                                          \
          [orig] "=&r" (orig)                                           \
        : [ctr] "r"     (&v->counter),                                  \
          [i]   "ir"    (i)                                             \
        : "cc");                                                        \
                                                                        \
        smp_mb();                                                       \
                                                                        \
        return orig;                                                    \
}

#else	/* !CONFIG_ARC_HAS_LLSC */

#ifndef CONFIG_SMP

 /* violating atomic_xxx API locking protocol in UP for optimization sake */

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

#else


static inline void atomic_set(atomic_t *v, int i) { /* * Independent of hardware support, all of the atomic_xxx() APIs need * to follow the same locking rules to make sure that a "hardware" * atomic insn (e.g. LD) doesn't clobber an "emulated" atomic insn * sequence * * Thus atomic_set() despite being 1 insn (and seemingly atomic) * requires the locking. */ unsigned long flags; atomic_ops_lock(flags); WRITE_ONCE(v->counter, i); atomic_ops_unlock(flags); }

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vineet guptavineet gupta3489.47%150.00%
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#endif /* * Non hardware assisted Atomic-R-M-W * Locking would change to irq-disabling only (UP) and spinlocks (SMP) */ #define ATOMIC_OP(op, c_op, asm_op) \ static inline void atomic_##op(int i, atomic_t *v) \ { \ unsigned long flags; \ \ atomic_ops_lock(flags); \ v->counter c_op i; \ atomic_ops_unlock(flags); \ } #define ATOMIC_OP_RETURN(op, c_op, asm_op) \ static inline int atomic_##op##_return(int i, atomic_t *v) \ { \ unsigned long flags; \ unsigned long temp; \ \ /* \ * spin lock/unlock provides the needed smp_mb() before/after \ */ \ atomic_ops_lock(flags); \ temp = v->counter; \ temp c_op i; \ v->counter = temp; \ atomic_ops_unlock(flags); \ \ return temp; \ } #define ATOMIC_FETCH_OP(op, c_op, asm_op) \ static inline int atomic_fetch_##op(int i, atomic_t *v) \ { \ unsigned long flags; \ unsigned long orig; \ \ /* \ * spin lock/unlock provides the needed smp_mb() before/after \ */ \ atomic_ops_lock(flags); \ orig = v->counter; \ v->counter c_op i; \ atomic_ops_unlock(flags); \ \ return orig; \ } #endif /* !CONFIG_ARC_HAS_LLSC */ #define ATOMIC_OPS(op, c_op, asm_op) \ ATOMIC_OP(op, c_op, asm_op) \ ATOMIC_OP_RETURN(op, c_op, asm_op) \ ATOMIC_FETCH_OP(op, c_op, asm_op) ATOMIC_OPS(add, +=, add) ATOMIC_OPS(sub, -=, sub) #define atomic_andnot atomic_andnot #undef ATOMIC_OPS #define ATOMIC_OPS(op, c_op, asm_op) \ ATOMIC_OP(op, c_op, asm_op) \ ATOMIC_FETCH_OP(op, c_op, asm_op) ATOMIC_OPS(and, &=, and) ATOMIC_OPS(andnot, &= ~, bic) ATOMIC_OPS(or, |=, or) ATOMIC_OPS(xor, ^=, xor) #else /* CONFIG_ARC_PLAT_EZNPS */
static inline int atomic_read(const atomic_t *v) { int temp; __asm__ __volatile__( " ld.di %0, [%1]" : "=r"(temp) : "r"(&v->counter) : "memory"); return temp; }

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static inline void atomic_set(atomic_t *v, int i) { __asm__ __volatile__( " st.di %0,[%1]" : : "r"(i), "r"(&v->counter) : "memory"); }

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noam camusnoam camus17100.00%1100.00%
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#define ATOMIC_OP(op, c_op, asm_op) \ static inline void atomic_##op(int i, atomic_t *v) \ { \ __asm__ __volatile__( \ " mov r2, %0\n" \ " mov r3, %1\n" \ " .word %2\n" \ : \ : "r"(i), "r"(&v->counter), "i"(asm_op) \ : "r2", "r3", "memory"); \ } \ #define ATOMIC_OP_RETURN(op, c_op, asm_op) \ static inline int atomic_##op##_return(int i, atomic_t *v) \ { \ unsigned int temp = i; \ \ /* Explicit full memory barrier needed before/after */ \ smp_mb(); \ \ __asm__ __volatile__( \ " mov r2, %0\n" \ " mov r3, %1\n" \ " .word %2\n" \ " mov %0, r2" \ : "+r"(temp) \ : "r"(&v->counter), "i"(asm_op) \ : "r2", "r3", "memory"); \ \ smp_mb(); \ \ temp c_op i; \ \ return temp; \ } #define ATOMIC_FETCH_OP(op, c_op, asm_op) \ static inline int atomic_fetch_##op(int i, atomic_t *v) \ { \ unsigned int temp = i; \ \ /* Explicit full memory barrier needed before/after */ \ smp_mb(); \ \ __asm__ __volatile__( \ " mov r2, %0\n" \ " mov r3, %1\n" \ " .word %2\n" \ " mov %0, r2" \ : "+r"(temp) \ : "r"(&v->counter), "i"(asm_op) \ : "r2", "r3", "memory"); \ \ smp_mb(); \ \ return temp; \ } #define ATOMIC_OPS(op, c_op, asm_op) \ ATOMIC_OP(op, c_op, asm_op) \ ATOMIC_OP_RETURN(op, c_op, asm_op) \ ATOMIC_FETCH_OP(op, c_op, asm_op) ATOMIC_OPS(add, +=, CTOP_INST_AADD_DI_R2_R2_R3) #define atomic_sub(i, v) atomic_add(-(i), (v)) #define atomic_sub_return(i, v) atomic_add_return(-(i), (v)) #undef ATOMIC_OPS #define ATOMIC_OPS(op, c_op, asm_op) \ ATOMIC_OP(op, c_op, asm_op) \ ATOMIC_FETCH_OP(op, c_op, asm_op) ATOMIC_OPS(and, &=, CTOP_INST_AAND_DI_R2_R2_R3) #define atomic_andnot(mask, v) atomic_and(~(mask), (v)) ATOMIC_OPS(or, |=, CTOP_INST_AOR_DI_R2_R2_R3) ATOMIC_OPS(xor, ^=, CTOP_INST_AXOR_DI_R2_R2_R3) #endif /* CONFIG_ARC_PLAT_EZNPS */ #undef ATOMIC_OPS #undef ATOMIC_FETCH_OP #undef ATOMIC_OP_RETURN #undef ATOMIC_OP /** * __atomic_add_unless - add unless the number is a given value * @v: pointer of type atomic_t * @a: the amount to add to v... * @u: ...unless v is equal to u. * * Atomically adds @a to @v, so long as it was not @u. * Returns the old value of @v */ #define __atomic_add_unless(v, a, u) \ ({ \ int c, old; \ \ /* \ * Explicit full memory barrier needed before/after as \ * LLOCK/SCOND thmeselves don't provide any such semantics \ */ \ smp_mb(); \ \ c = atomic_read(v); \ while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c)\ c = old; \ \ smp_mb(); \ \ c; \ }) #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) #define atomic_inc(v) atomic_add(1, v) #define atomic_dec(v) atomic_sub(1, v) #define atomic_inc_and_test(v) (atomic_add_return(1, v) == 0) #define atomic_dec_and_test(v) (atomic_sub_return(1, v) == 0) #define atomic_inc_return(v) atomic_add_return(1, (v)) #define atomic_dec_return(v) atomic_sub_return(1, (v)) #define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0) #define atomic_add_negative(i, v) (atomic_add_return(i, v) < 0) #define ATOMIC_INIT(i) { (i) } #include <asm-generic/atomic64.h> #endif #endif

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peter zijlstrapeter zijlstra16631.56%541.67%
noam camusnoam camus13124.90%18.33%
Total526100.00%12100.00%
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