Author: attilio
Date: Tue Oct 9 14:32:30 2012
New Revision: 241374
URL: http://svn.freebsd.org/changeset/base/241374
Log:
Add an unified macro to deny ability from the compiler to reorder
instruction loads/stores at its will.
The macro __compiler_membar() is currently supported for both gcc and
clang, but kernel compilation will fail otherwise.
Reviewed by: bde, kib
Discussed with: dim, theraven
MFC after: 2 weeks
Modified:
head/sys/amd64/include/atomic.h
head/sys/gnu/fs/xfs/FreeBSD/xfs_compat.h
head/sys/gnu/fs/xfs/FreeBSD/xfs_freebsd.h
head/sys/i386/include/atomic.h
head/sys/kern/kern_rmlock.c
head/sys/mips/include/cpufunc.h
head/sys/pc98/include/bus.h
head/sys/sparc64/include/atomic.h
head/sys/sys/cdefs.h
head/sys/x86/include/bus.h
Modified: head/sys/amd64/include/atomic.h
==============================================================================
--- head/sys/amd64/include/atomic.h Tue Oct 9 14:25:14 2012
(r241373)
+++ head/sys/amd64/include/atomic.h Tue Oct 9 14:32:30 2012
(r241374)
@@ -226,7 +226,7 @@ atomic_fetchadd_long(volatile u_long *p,
static __inline void \
atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
{ \
- __asm __volatile("" : : : "memory"); \
+ __compiler_membar(); \
*p = v; \
} \
struct __hack
@@ -240,7 +240,7 @@ atomic_load_acq_##TYPE(volatile u_##TYPE
u_##TYPE tmp; \
\
tmp = *p; \
- __asm __volatile("" : : : "memory"); \
+ __compiler_membar(); \
return (tmp); \
} \
struct __hack
Modified: head/sys/gnu/fs/xfs/FreeBSD/xfs_compat.h
==============================================================================
--- head/sys/gnu/fs/xfs/FreeBSD/xfs_compat.h Tue Oct 9 14:25:14 2012
(r241373)
+++ head/sys/gnu/fs/xfs/FreeBSD/xfs_compat.h Tue Oct 9 14:32:30 2012
(r241374)
@@ -129,10 +129,6 @@ typedef dev_t os_dev_t;
#define copy_from_user(dst, src, len) copyin((src), (dst), (len))
#endif
-#ifndef barrier
-#define barrier() __asm__ __volatile__("": : :"memory")
-#endif
-
/*
* Map simple global vairables to FreeBSD kernel equivalents
*/
Modified: head/sys/gnu/fs/xfs/FreeBSD/xfs_freebsd.h
==============================================================================
--- head/sys/gnu/fs/xfs/FreeBSD/xfs_freebsd.h Tue Oct 9 14:25:14 2012
(r241373)
+++ head/sys/gnu/fs/xfs/FreeBSD/xfs_freebsd.h Tue Oct 9 14:32:30 2012
(r241374)
@@ -162,7 +162,7 @@
*/
#define EFSCORRUPTED 990 /* Filesystem is corrupted */
-#define SYNCHRONIZE() barrier()
+#define SYNCHRONIZE() __compiler_membar()
#define __return_address __builtin_return_address(0)
/*
Modified: head/sys/i386/include/atomic.h
==============================================================================
--- head/sys/i386/include/atomic.h Tue Oct 9 14:25:14 2012
(r241373)
+++ head/sys/i386/include/atomic.h Tue Oct 9 14:32:30 2012
(r241374)
@@ -296,7 +296,7 @@ atomic_fetchadd_int(volatile u_int *p, u
static __inline void \
atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
{ \
- __asm __volatile("" : : : "memory"); \
+ __compiler_membar(); \
*p = v; \
} \
struct __hack
@@ -310,7 +310,7 @@ atomic_load_acq_##TYPE(volatile u_##TYPE
u_##TYPE tmp; \
\
tmp = *p; \
- __asm __volatile("" : : : "memory"); \
+ __compiler_membar(); \
return (tmp); \
} \
struct __hack
Modified: head/sys/kern/kern_rmlock.c
==============================================================================
--- head/sys/kern/kern_rmlock.c Tue Oct 9 14:25:14 2012 (r241373)
+++ head/sys/kern/kern_rmlock.c Tue Oct 9 14:32:30 2012 (r241374)
@@ -65,10 +65,6 @@ __FBSDID("$FreeBSD$");
* does not seem very useful
*/
-static __inline void compiler_memory_barrier(void) {
- __asm __volatile("":::"memory");
-}
-
static void assert_rm(const struct lock_object *lock, int what);
static void lock_rm(struct lock_object *lock, int how);
#ifdef KDTRACE_HOOKS
@@ -353,7 +349,7 @@ _rm_rlock(struct rmlock *rm, struct rm_p
td->td_critnest++; /* critical_enter(); */
- compiler_memory_barrier();
+ __compiler_membar();
pc = cpuid_to_pcpu[td->td_oncpu]; /* pcpu_find(td->td_oncpu); */
@@ -361,7 +357,7 @@ _rm_rlock(struct rmlock *rm, struct rm_p
sched_pin();
- compiler_memory_barrier();
+ __compiler_membar();
td->td_critnest--;
Modified: head/sys/mips/include/cpufunc.h
==============================================================================
--- head/sys/mips/include/cpufunc.h Tue Oct 9 14:25:14 2012
(r241373)
+++ head/sys/mips/include/cpufunc.h Tue Oct 9 14:32:30 2012
(r241374)
@@ -70,7 +70,7 @@ static __inline void
mips_barrier(void)
{
#if defined(CPU_CNMIPS) || defined(CPU_RMI) || defined(CPU_NLM)
- __asm __volatile("" : : : "memory");
+ __compiler_membar();
#else
__asm __volatile (".set noreorder\n\t"
"nop\n\t"
Modified: head/sys/pc98/include/bus.h
==============================================================================
--- head/sys/pc98/include/bus.h Tue Oct 9 14:25:14 2012 (r241373)
+++ head/sys/pc98/include/bus.h Tue Oct 9 14:32:30 2012 (r241374)
@@ -593,7 +593,7 @@ bus_space_barrier(bus_space_tag_t tag, b
if (flags & BUS_SPACE_BARRIER_READ)
__asm __volatile("lock; addl $0,0(%%esp)" : : : "memory");
else
- __asm __volatile("" : : : "memory");
+ __compiler_membar();
}
#ifdef BUS_SPACE_NO_LEGACY
Modified: head/sys/sparc64/include/atomic.h
==============================================================================
--- head/sys/sparc64/include/atomic.h Tue Oct 9 14:25:14 2012
(r241373)
+++ head/sys/sparc64/include/atomic.h Tue Oct 9 14:32:30 2012
(r241374)
@@ -97,7 +97,7 @@
#define atomic_cas_acq(p, e, s, sz) ({
\
itype(sz) v; \
v = atomic_cas((p), (e), (s), sz); \
- __asm __volatile("" : : : "memory"); \
+ __compiler_membar(); \
v; \
})
@@ -122,7 +122,7 @@
#define atomic_op_acq(p, op, v, sz) ({
\
itype(sz) t; \
t = atomic_op((p), op, (v), sz); \
- __asm __volatile("" : : : "memory"); \
+ __compiler_membar(); \
t; \
})
@@ -139,7 +139,7 @@
#define atomic_load_acq(p, sz) ({
\
itype(sz) v; \
v = atomic_load((p), sz); \
- __asm __volatile("" : : : "memory"); \
+ __compiler_membar(); \
v; \
})
Modified: head/sys/sys/cdefs.h
==============================================================================
--- head/sys/sys/cdefs.h Tue Oct 9 14:25:14 2012 (r241373)
+++ head/sys/sys/cdefs.h Tue Oct 9 14:32:30 2012 (r241374)
@@ -82,6 +82,13 @@
# define __GNUC_VA_LIST_COMPATIBILITY 1
#endif
+/*
+ * Compiler memory barriers, specific to gcc and clang.
+ */
+#if defined(__GNUC__)
+#define __compiler_membar() __asm __volatile(" " : : : "memory")
+#endif
+
#ifndef __INTEL_COMPILER
# define __GNUCLIKE_BUILTIN_NEXT_ARG 1
# define __GNUCLIKE_MATH_BUILTIN_RELOPS
Modified: head/sys/x86/include/bus.h
==============================================================================
--- head/sys/x86/include/bus.h Tue Oct 9 14:25:14 2012 (r241373)
+++ head/sys/x86/include/bus.h Tue Oct 9 14:32:30 2012 (r241374)
@@ -1014,7 +1014,7 @@ bus_space_barrier(bus_space_tag_t tag __
__asm __volatile("lock; addl $0,0(%%esp)" : : : "memory");
#endif
else
- __asm __volatile("" : : : "memory");
+ __compiler_membar();
#endif
}
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