cregit-Linux how code gets into the kernel

Release 4.14 arch/frv/include/asm/cmpxchg.h

/* xchg and cmpxchg operation emulation for FR-V
 *
 * For an explanation of how atomic ops work in this arch, see:
 *   Documentation/frv/atomic-ops.txt
 *
 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * 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; either version
 * 2 of the License, or (at your option) any later version.
 */
#ifndef _ASM_CMPXCHG_H

#define _ASM_CMPXCHG_H

#include <linux/types.h>

/*****************************************************************************/
/*
 * exchange value with memory
 */
extern uint64_t __xchg_64(uint64_t i, volatile void *v);

#ifndef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS


#define xchg(ptr, x)								\
({                                                                              \
        __typeof__(ptr) __xg_ptr = (ptr);                                       \
        __typeof__(*(ptr)) __xg_orig;                                           \
                                                                                \
        switch (sizeof(__xg_orig)) {                                            \
        case 4:                                                                 \
                asm volatile(                                                   \
                        "swap%I0 %M0,%1"                                        \
                        : "+m"(*__xg_ptr), "=r"(__xg_orig)                      \
                        : "1"(x)                                                \
                        : "memory"                                              \
                        );                                                      \
                break;                                                          \
                                                                                \
        default:                                                                \
                __xg_orig = (__typeof__(__xg_orig))0;                           \
                asm volatile("break");                                          \
                break;                                                          \
        }                                                                       \
                                                                                \
        __xg_orig;                                                              \
})

#else

extern uint32_t __xchg_32(uint32_t i, volatile void *v);


#define xchg(ptr, x)										\
({                                                                                              \
        __typeof__(ptr) __xg_ptr = (ptr);                                                       \
        __typeof__(*(ptr)) __xg_orig;                                                           \
                                                                                                \
        switch (sizeof(__xg_orig)) {                                                            \
        case 4: __xg_orig = (__typeof__(*(ptr))) __xchg_32((uint32_t) x, __xg_ptr);     break;  \
        default:                                                                                \
                __xg_orig = (__typeof__(__xg_orig))0;                                                                   \
                asm volatile("break");                                                          \
                break;                                                                          \
        }                                                                                       \
        __xg_orig;                                                                              \
})

#endif

/*****************************************************************************/
/*
 * compare and conditionally exchange value with memory
 * - if (*ptr == test) then orig = *ptr; *ptr = test;
 * - if (*ptr != test) then orig = *ptr;
 */
extern uint64_t __cmpxchg_64(uint64_t test, uint64_t new, volatile uint64_t *v);

#define cmpxchg64(p, o, n)	__cmpxchg_64((o), (n), (p))

#ifndef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS


#define cmpxchg(ptr, test, new)							\
({                                                                              \
        __typeof__(ptr) __xg_ptr = (ptr);                                       \
        __typeof__(*(ptr)) __xg_orig, __xg_tmp;                                 \
        __typeof__(*(ptr)) __xg_test = (test);                                  \
        __typeof__(*(ptr)) __xg_new = (new);                                    \
                                                                                \
        switch (sizeof(__xg_orig)) {                                            \
        case 4:                                                                 \
                asm volatile(                                                   \
                        "0:                                             \n"     \
                        "       orcc            gr0,gr0,gr0,icc3        \n"     \
                        "       ckeq            icc3,cc7                \n"     \
                        "       ld.p            %M0,%1                  \n"     \
                        "       orcr            cc7,cc7,cc3             \n"     \
                        "       sub%I4cc        %1,%4,%2,icc0           \n"     \
                        "       bne             icc0,#0,1f              \n"     \
                        "       cst.p           %3,%M0          ,cc3,#1 \n"     \
                        "       corcc           gr29,gr29,gr0   ,cc3,#1 \n"     \
                        "       beq             icc3,#0,0b              \n"     \
                        "1:                                             \n"     \
                        : "+U"(*__xg_ptr), "=&r"(__xg_orig), "=&r"(__xg_tmp)    \
                        : "r"(__xg_new), "NPr"(__xg_test)                       \
                        : "memory", "cc7", "cc3", "icc3", "icc0"                \
                        );                                                      \
                break;                                                          \
                                                                                \
        default:                                                                \
                __xg_orig = (__typeof__(__xg_orig))0;                           \
                asm volatile("break");                                          \
                break;                                                          \
        }                                                                       \
                                                                                \
        __xg_orig;                                                              \
})

#else

extern uint32_t __cmpxchg_32(uint32_t *v, uint32_t test, uint32_t new);


#define cmpxchg(ptr, test, new)							\
({                                                                              \
        __typeof__(ptr) __xg_ptr = (ptr);                                       \
        __typeof__(*(ptr)) __xg_orig;                                           \
        __typeof__(*(ptr)) __xg_test = (test);                                  \
        __typeof__(*(ptr)) __xg_new = (new);                                    \
                                                                                \
        switch (sizeof(__xg_orig)) {                                            \
        case 4: __xg_orig = (__force __typeof__(*ptr))                          \
                        __cmpxchg_32((__force uint32_t *)__xg_ptr,              \
                                         (__force uint32_t)__xg_test,           \
                                         (__force uint32_t)__xg_new); break;    \
        default:                                                                \
                __xg_orig = (__typeof__(__xg_orig))0;                           \
                asm volatile("break");                                          \
                break;                                                          \
        }                                                                       \
                                                                                \
        __xg_orig;                                                              \
})

#endif

#include <asm-generic/cmpxchg-local.h>


static inline unsigned long __cmpxchg_local(volatile void *ptr, unsigned long old, unsigned long new, int size) { switch (size) { case 4: return cmpxchg((unsigned long *)ptr, old, new); default: return __cmpxchg_local_generic(ptr, old, new, size); } return old; }

Contributors

PersonTokensPropCommitsCommitProp
David Howells64100.00%1100.00%
Total64100.00%1100.00%

/* * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make * them available. */ #define cmpxchg_local(ptr, o, n) \ ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \ (unsigned long)(n), sizeof(*(ptr)))) #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) #endif /* _ASM_CMPXCHG_H */

Overall Contributors

PersonTokensPropCommitsCommitProp
David Howells22395.30%150.00%
Will Deacon114.70%150.00%
Total234100.00%2100.00%
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