f78d8e74fd
A new call to vm lets processes yield a part of their memory to vm, together with an id, getting newly allocated memory in return. vm is allowed to forget about it if it runs out of memory. processes can ask for it back using the same id. (These two operations are normally combined in a single call.) It can be used as a as-big-as-memory-will-allow block cache for filesystems, which is how mfs now uses it.
70 lines
1.8 KiB
C
70 lines
1.8 KiB
C
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#ifndef _REGION_H
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#define _REGION_H 1
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#include <minix/callnr.h>
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#include <minix/com.h>
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#include <minix/config.h>
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#include <minix/const.h>
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#include <minix/ds.h>
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#include <minix/endpoint.h>
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#include <minix/keymap.h>
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#include <minix/minlib.h>
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#include <minix/type.h>
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#include <minix/ipc.h>
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#include <minix/sysutil.h>
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#include <minix/syslib.h>
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#include <minix/const.h>
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#include "phys_region.h"
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#include "physravl.h"
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struct phys_block {
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#if SANITYCHECKS
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u32_t seencount;
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#endif
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vir_bytes length; /* no. of contiguous bytes */
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phys_bytes phys; /* physical memory */
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u8_t refcount; /* Refcount of these pages */
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#define PBSH_COW 1
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#define PBSH_SMAP 2
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u8_t share_flag; /* PBSH_COW or PBSH_SMAP */
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/* first in list of phys_regions that reference this block */
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struct phys_region *firstregion;
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};
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struct vir_region {
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struct vir_region *next; /* next virtual region in this process */
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vir_bytes vaddr; /* virtual address, offset from pagetable */
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vir_bytes length; /* length in bytes */
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physr_avl *phys; /* avl tree of physical memory blocks */
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u16_t flags;
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u32_t tag; /* Opaque to mapping code. */
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struct vmproc *parent; /* Process that owns this vir_region. */
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};
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/* Mapping flags: */
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#define VR_WRITABLE 0x001 /* Process may write here. */
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#define VR_NOPF 0x002 /* May not generate page faults. */
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#define VR_PHYS64K 0x004 /* Physical memory must be 64k aligned. */
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#define VR_LOWER16MB 0x008
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#define VR_LOWER1MB 0x010
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#define VR_CONTIG 0x020 /* Must be physically contiguous. */
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#define VR_SHARED 0x040
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/* Mapping type: */
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#define VR_ANON 0x100 /* Memory to be cleared and allocated */
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#define VR_DIRECT 0x200 /* Mapped, but not managed by VM */
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/* Tag values: */
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#define VRT_NONE 0xBEEF0000
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#define VRT_HEAP 0xBEEF0001
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#define VRT_TEXT 0xBEEF0002
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#define VRT_STACK 0xBEEF0003
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/* map_page_region flags */
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#define MF_PREALLOC 0x01
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#endif
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