#ifndef _M68K_SHM_H#define _M68K_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 /* _M68K_SHM_H */
