projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| b688fc87 WJ |
1 | /* |
| 2 | * Copyright (c) 1988 University of Utah. | |
| 3 | * Copyright (c) 1990 The Regents of the University of California. | |
| 4 | * All rights reserved. | |
| 5 | * | |
| 6 | * This code is derived from software contributed to Berkeley by | |
| 7 | * the Systems Programming Group of the University of Utah Computer | |
| 8 | * Science Department. | |
| 9 | * | |
| 10 | * Redistribution and use in source and binary forms, with or without | |
| 11 | * modification, are permitted provided that the following conditions | |
| 12 | * are met: | |
| 13 | * 1. Redistributions of source code must retain the above copyright | |
| 14 | * notice, this list of conditions and the following disclaimer. | |
| 15 | * 2. Redistributions in binary form must reproduce the above copyright | |
| 16 | * notice, this list of conditions and the following disclaimer in the | |
| 17 | * documentation and/or other materials provided with the distribution. | |
| 18 | * 3. All advertising materials mentioning features or use of this software | |
| 19 | * must display the following acknowledgement: | |
| 20 | * This product includes software developed by the University of | |
| 21 | * California, Berkeley and its contributors. | |
| 22 | * 4. Neither the name of the University nor the names of its contributors | |
| 23 | * may be used to endorse or promote products derived from this software | |
| 24 | * without specific prior written permission. | |
| 25 | * | |
| 26 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
| 27 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| 28 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
| 29 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
| 30 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
| 31 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
| 32 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
| 33 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
| 34 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
| 35 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
| 36 | * SUCH DAMAGE. | |
| 37 | * | |
| 38 | * from: Utah $Hdr: mmap.h 1.4 89/08/14$ | |
| 39 | * | |
| 40 | * @(#)mapmem.h 7.2 (Berkeley) 6/6/90 | |
| 41 | */ | |
| 42 | ||
| 43 | /* | |
| 44 | * Mapped memory descriptors. | |
| 45 | * | |
| 46 | * A process has one of these for every "mapped" memory region. | |
| 47 | * Mapped memory is characterized by: | |
| 48 | * - Corresponding physical memory is neither paged nor swapped. | |
| 49 | * - User PTEs have both pg_v and pg_fod set. | |
| 50 | * - Has no backing swap space unless mapped over existing data. | |
| 51 | * - If mapped over existing data, original data is lost when | |
| 52 | * segment is unmapped. (i.e. pages are reinitialized to ZFOD) | |
| 53 | * Operations: | |
| 54 | * (*mm_fork)(mp, ischild) struct mapmem *mp; int ischild; | |
| 55 | * Called during fork in both parent and child. Parent | |
| 56 | * call can be used for maintaining reference counts and | |
| 57 | * should NEVER destroy the region. Child call should be | |
| 58 | * used for unmapping regions not inherited across forks. | |
| 59 | * (*mm_vfork)(mp, fup, tup) struct mapmem *mp; struct user *fup, *tup; | |
| 60 | * Called twice during vfork (always in parent context) | |
| 61 | * after exchanging resources (including u_mmap chains). | |
| 62 | * `fup' is the donor and `tup' the recipient of the | |
| 63 | * "parent" (full) context. Needed for maintaining | |
| 64 | * reference counts or if the underlying object contains | |
| 65 | * references to owning process. Routine should NEVER | |
| 66 | * destroy the region. | |
| 67 | * (*mm_exec)(mp) struct mapmem *mp; | |
| 68 | * Called during exec before releasing old address space. | |
| 69 | * Used for graceful cleanup of underlying object. Resources | |
| 70 | * will be freed regardless of what this routine does. | |
| 71 | * Need to add a post-exec call to re-establish mappings | |
| 72 | * in the new address space for regions inherited across execs. | |
| 73 | * (*mm_exit)(mp) struct mapmem *mp; | |
| 74 | * Called during exit just before releasing address space. | |
| 75 | * Used for graceful cleanup of underlying object. Resources | |
| 76 | * will be freed regardless of what this routine does. | |
| 77 | * The default semantics for a region with routine addresses of zero are | |
| 78 | * that it is inherited across forks, stays with the "active" process during | |
| 79 | * vforks, and is destroyed by execs and exit. | |
| 80 | */ | |
| 81 | ||
| 82 | struct mapmem { | |
| 83 | struct mapmem *mm_next; /* next descriptor */ | |
| 84 | int mm_id; /* identifier (e.g. fd, shmid) */ | |
| 85 | caddr_t mm_uva; /* user VA at which region is mapped */ | |
| 86 | int mm_size; /* size of mapped region */ | |
| 87 | int mm_prot; /* attributes of region */ | |
| 88 | struct mapmemops { /* operations */ | |
| 89 | int (*mm_fork)(); | |
| 90 | int (*mm_vfork)(); | |
| 91 | int (*mm_exec)(); | |
| 92 | int (*mm_exit)(); | |
| 93 | } *mm_ops; | |
| 94 | }; | |
| 95 | ||
| 96 | #define MMNIL ((struct mapmem *)0) | |
| 97 | ||
| 98 | /* attributes */ | |
| 99 | #define MM_RW 0x00 /* region is read-write */ | |
| 100 | #define MM_RO 0x01 /* region is read-only */ | |
| 101 | #define MM_CI 0x02 /* caching is inhibited on region */ | |
| 102 | #define MM_NOCORE 0x04 /* cannot write region to core file; | |
| 103 | e.g. mapped framebuffer hardware */ | |
| 104 | ||
| 105 | #ifdef KERNEL | |
| 106 | #define MMALLOC(mp) \ | |
| 107 | (mp) = (struct mapmem *)malloc((u_long)sizeof(struct mapmem), \ | |
| 108 | M_MAPMEM, M_WAITOK) | |
| 109 | ||
| 110 | #define MMFREE(mp) \ | |
| 111 | free((caddr_t)(mp), M_MAPMEM) | |
| 112 | #endif |