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| author | nyan <nyan@FreeBSD.org> | 2000-05-31 10:47:55 +0000 |
|---|---|---|
| committer | nyan <nyan@FreeBSD.org> | 2000-05-31 10:47:55 +0000 |
| commit | b4451d2d3a5af7a66d95431e98f603bd4ef2efc4 (patch) | |
| tree | 5d55e18bf47f68435024590194866ccc11f73ea5 /sys/i386/include/bus_pc98.h | |
| parent | 27d9c9b35acce3c82ed7bfbf0d2fdbcf77d60b7a (diff) | |
| download | FreeBSD-src-b4451d2d3a5af7a66d95431e98f603bd4ef2efc4.zip FreeBSD-src-b4451d2d3a5af7a66d95431e98f603bd4ef2efc4.tar.gz | |
Sync with sys/i386/include/bus_at386.h revision 1.9.
Diffstat (limited to 'sys/i386/include/bus_pc98.h')
| -rw-r--r-- | sys/i386/include/bus_pc98.h | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/sys/i386/include/bus_pc98.h b/sys/i386/include/bus_pc98.h index d8a7c33..6aa457a 100644 --- a/sys/i386/include/bus_pc98.h +++ b/sys/i386/include/bus_pc98.h @@ -1436,14 +1436,25 @@ bus_space_copy_region_4(bus_space_tag_t tag, bus_space_handle_t bsh1, * void bus_space_barrier(bus_space_tag_t tag, bus_space_handle_t bsh, * bus_size_t offset, bus_size_t len, int flags); * - * Note: the i386 does not currently require barriers, but we must - * provide the flags to MI code. + * + * Note that BUS_SPACE_BARRIER_WRITE doesn't do anything other than + * prevent reordering by the compiler; all Intel x86 processors currently + * retire operations outside the CPU in program order. */ -#define bus_space_barrier(t, h, o, l, f) \ - ((void)((void)(t), (void)(h), (void)(o), (void)(l), (void)(f))) #define BUS_SPACE_BARRIER_READ 0x01 /* force read barrier */ #define BUS_SPACE_BARRIER_WRITE 0x02 /* force write barrier */ +static __inline void +bus_space_barrier(bus_space_tag_t tag, bus_space_handle_t bsh, + bus_size_t offset, bus_size_t len, int flags) +{ + if (flags & BUS_SPACE_BARRIER_READ) + __asm __volatile ("lock; addl $0,0(%esp)" : : : "memory"); + else + __asm __volatile ("" : : : "memory"); +} + + /* * Flags used in various bus DMA methods. */ |
