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Diffstat (limited to 'sys/sys/mapmem.h')
| -rw-r--r-- | sys/sys/mapmem.h | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/sys/sys/mapmem.h b/sys/sys/mapmem.h new file mode 100644 index 000000000000..10735780f33f --- /dev/null +++ b/sys/sys/mapmem.h @@ -0,0 +1,112 @@ +/* + * Copyright (c) 1988 University of Utah. + * Copyright (c) 1990 The Regents of the University of California. + * All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * the Systems Programming Group of the University of Utah Computer + * Science Department. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * from: Utah $Hdr: mmap.h 1.4 89/08/14$ + * from: @(#)mapmem.h 7.2 (Berkeley) 6/6/90 + * $Id: mapmem.h,v 1.2 1993/10/16 17:17:06 rgrimes Exp $ + */ + +/* + * Mapped memory descriptors. + * + * A process has one of these for every "mapped" memory region. + * Mapped memory is characterized by: + * - Corresponding physical memory is neither paged nor swapped. + * - User PTEs have both pg_v and pg_fod set. + * - Has no backing swap space unless mapped over existing data. + * - If mapped over existing data, original data is lost when + * segment is unmapped. (i.e. pages are reinitialized to ZFOD) + * Operations: + * (*mm_fork)(mp, ischild) struct mapmem *mp; int ischild; + * Called during fork in both parent and child. Parent + * call can be used for maintaining reference counts and + * should NEVER destroy the region. Child call should be + * used for unmapping regions not inherited across forks. + * (*mm_vfork)(mp, fup, tup) struct mapmem *mp; struct user *fup, *tup; + * Called twice during vfork (always in parent context) + * after exchanging resources (including u_mmap chains). + * `fup' is the donor and `tup' the recipient of the + * "parent" (full) context. Needed for maintaining + * reference counts or if the underlying object contains + * references to owning process. Routine should NEVER + * destroy the region. + * (*mm_exec)(mp) struct mapmem *mp; + * Called during exec before releasing old address space. + * Used for graceful cleanup of underlying object. Resources + * will be freed regardless of what this routine does. + * Need to add a post-exec call to re-establish mappings + * in the new address space for regions inherited across execs. + * (*mm_exit)(mp) struct mapmem *mp; + * Called during exit just before releasing address space. + * Used for graceful cleanup of underlying object. Resources + * will be freed regardless of what this routine does. + * The default semantics for a region with routine addresses of zero are + * that it is inherited across forks, stays with the "active" process during + * vforks, and is destroyed by execs and exit. + */ + +struct mapmem { + struct mapmem *mm_next; /* next descriptor */ + int mm_id; /* identifier (e.g. fd, shmid) */ + caddr_t mm_uva; /* user VA at which region is mapped */ + int mm_size; /* size of mapped region */ + int mm_prot; /* attributes of region */ + struct mapmemops { /* operations */ + int (*mm_fork)(); + int (*mm_vfork)(); + int (*mm_exec)(); + int (*mm_exit)(); + } *mm_ops; +}; + +#define MMNIL ((struct mapmem *)0) + +/* attributes */ +#define MM_RW 0x00 /* region is read-write */ +#define MM_RO 0x01 /* region is read-only */ +#define MM_CI 0x02 /* caching is inhibited on region */ +#define MM_NOCORE 0x04 /* cannot write region to core file; + e.g. mapped framebuffer hardware */ + +#ifdef KERNEL +#define MMALLOC(mp) \ + (mp) = (struct mapmem *)malloc((u_long)sizeof(struct mapmem), \ + M_MAPMEM, M_WAITOK) + +#define MMFREE(mp) \ + free((caddr_t)(mp), M_MAPMEM) +#endif |