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author | James Morris <jmorris@namei.org> | 2008-08-28 10:47:34 +1000 |
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committer | James Morris <jmorris@namei.org> | 2008-08-28 10:47:34 +1000 |
commit | 86d688984deefa3ae5a802880c11f2b408b5d6cf (patch) | |
tree | 7ea5e8189b0a774626d3ed7c3c87df2495a4c4a0 /arch/h8300/include/asm/shm.h | |
parent | 93c06cbbf9fea5d5be1778febb7fa9ab1a74e5f5 (diff) | |
parent | 4c246edd2550304df5b766cc841584b2bb058843 (diff) |
Merge branch 'master' into next
Diffstat (limited to 'arch/h8300/include/asm/shm.h')
-rw-r--r-- | arch/h8300/include/asm/shm.h | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/arch/h8300/include/asm/shm.h b/arch/h8300/include/asm/shm.h new file mode 100644 index 00000000000..ed6623c0545 --- /dev/null +++ b/arch/h8300/include/asm/shm.h @@ -0,0 +1,31 @@ +#ifndef _H8300_SHM_H +#define _H8300_SHM_H + + +/* format of page table entries that correspond to shared memory pages + currently out in swap space (see also mm/swap.c): + bits 0-1 (PAGE_PRESENT) is = 0 + bits 8..2 (SWP_TYPE) are = SHM_SWP_TYPE + bits 31..9 are used like this: + bits 15..9 (SHM_ID) the id of the shared memory segment + bits 30..16 (SHM_IDX) the index of the page within the shared memory segment + (actually only bits 25..16 get used since SHMMAX is so low) + bit 31 (SHM_READ_ONLY) flag whether the page belongs to a read-only attach +*/ +/* on the m68k both bits 0 and 1 must be zero */ +/* format on the sun3 is similar, but bits 30, 31 are set to zero and all + others are reduced by 2. --m */ + +#ifndef CONFIG_SUN3 +#define SHM_ID_SHIFT 9 +#else +#define SHM_ID_SHIFT 7 +#endif +#define _SHM_ID_BITS 7 +#define SHM_ID_MASK ((1<<_SHM_ID_BITS)-1) + +#define SHM_IDX_SHIFT (SHM_ID_SHIFT+_SHM_ID_BITS) +#define _SHM_IDX_BITS 15 +#define SHM_IDX_MASK ((1<<_SHM_IDX_BITS)-1) + +#endif /* _H8300_SHM_H */ |