Date: Wed, 22 Mar 2017 17:33:57 +0000 (UTC) From: Mark Johnston <markj@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r315719 - head/sys/compat/linuxkpi/common/include/asm Message-ID: <201703221733.v2MHXvUG023871@repo.freebsd.org>
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Author: markj Date: Wed Mar 22 17:33:57 2017 New Revision: 315719 URL: https://svnweb.freebsd.org/changeset/base/315719 Log: Extend cmpxchg() to support 8- and 16-bit values, and add xchg(). These are needed to support updated revisions of the DRM code. Reviewed by: hselasky (previous version) MFC after: 2 weeks Modified: head/sys/compat/linuxkpi/common/include/asm/atomic.h Modified: head/sys/compat/linuxkpi/common/include/asm/atomic.h ============================================================================== --- head/sys/compat/linuxkpi/common/include/asm/atomic.h Wed Mar 22 17:29:04 2017 (r315718) +++ head/sys/compat/linuxkpi/common/include/asm/atomic.h Wed Mar 22 17:33:57 2017 (r315719) @@ -28,11 +28,13 @@ * * $FreeBSD$ */ -#ifndef _ASM_ATOMIC_H_ + +#ifndef _ASM_ATOMIC_H_ #define _ASM_ATOMIC_H_ #include <sys/cdefs.h> #include <sys/types.h> + #include <machine/atomic.h> #define ATOMIC_INIT(x) { .counter = (x) } @@ -158,31 +160,47 @@ atomic_cmpxchg(atomic_t *v, int old, int } #define cmpxchg(ptr, old, new) ({ \ - __typeof(*(ptr)) __ret = (old); \ - CTASSERT(sizeof(__ret) == 4 || sizeof(__ret) == 8); \ - for (;;) { \ - if (sizeof(__ret) == 4) { \ - if (atomic_cmpset_int((volatile int *) \ - (ptr), (old), (new))) \ - break; \ - __ret = atomic_load_acq_int( \ - (volatile int *)(ptr)); \ - if (__ret != (old)) \ - break; \ - } else { \ - if (atomic_cmpset_64( \ - (volatile int64_t *)(ptr), \ - (old), (new))) \ - break; \ - __ret = atomic_load_acq_64( \ - (volatile int64_t *)(ptr)); \ - if (__ret != (old)) \ - break; \ - } \ + __typeof(*(ptr)) __ret; \ + \ + CTASSERT(sizeof(__ret) == 1 || sizeof(__ret) == 2 || \ + sizeof(__ret) == 4 || sizeof(__ret) == 8); \ + \ + __ret = (old); \ + switch (sizeof(__ret)) { \ + case 1: \ + while (!atomic_fcmpset_8((volatile int8_t *)(ptr), \ + (int8_t *)&__ret, (new)) && __ret == (old)) \ + ; \ + break; \ + case 2: \ + while (!atomic_fcmpset_16((volatile int16_t *)(ptr), \ + (int16_t *)&__ret, (new)) && __ret == (old)) \ + ; \ + break; \ + case 4: \ + while (!atomic_fcmpset_32((volatile int32_t *)(ptr), \ + (int32_t *)&__ret, (new)) && __ret == (old)) \ + ; \ + break; \ + case 8: \ + while (!atomic_fcmpset_64((volatile int64_t *)(ptr), \ + (int64_t *)&__ret, (new)) && __ret == (old)) \ + ; \ + break; \ } \ __ret; \ }) +#define cmpxchg_relaxed cmpxchg + +#define xchg(ptr, v) ({ \ + __typeof(*(ptr)) __ret; \ + \ + __ret = *(ptr); \ + *(ptr) = v; \ + __ret; \ +}) + #define LINUX_ATOMIC_OP(op, c_op) \ static inline void atomic_##op(int i, atomic_t *v) \ { \
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