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.
121 lines
2.7 KiB
C
121 lines
2.7 KiB
C
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#define _SYSTEM 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/bitmap.h>
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#include <errno.h>
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#include <assert.h>
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#include <env.h>
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#include "glo.h"
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#include "proto.h"
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#include "util.h"
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#include "sanitycheck.h"
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PUBLIC void free_proc(struct vmproc *vmp)
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{
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map_free_proc(vmp);
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if(vmp->vm_flags & VMF_HASPT) {
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vmp->vm_flags &= ~VMF_HASPT;
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pt_free(&vmp->vm_pt);
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}
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vmp->vm_regions = NULL;
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#if VMSTATS
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vmp->vm_bytecopies = 0;
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#endif
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}
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PUBLIC void clear_proc(struct vmproc *vmp)
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{
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vmp->vm_regions = NULL;
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vmp->vm_callback = NULL; /* No pending vfs callback. */
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vmp->vm_flags = 0; /* Clear INUSE, so slot is free. */
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vmp->vm_heap = NULL;
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#if VMSTATS
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vmp->vm_bytecopies = 0;
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#endif
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}
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/*===========================================================================*
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* do_exit *
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*===========================================================================*/
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PUBLIC int do_exit(message *msg)
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{
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int proc;
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struct vmproc *vmp;
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SANITYCHECK(SCL_FUNCTIONS);
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if(vm_isokendpt(msg->VME_ENDPOINT, &proc) != OK) {
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printf("VM: bogus endpoint VM_EXIT %d\n", msg->VME_ENDPOINT);
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return EINVAL;
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}
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vmp = &vmproc[proc];
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if(!(vmp->vm_flags & VMF_EXITING)) {
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printf("VM: unannounced VM_EXIT %d\n", msg->VME_ENDPOINT);
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return EINVAL;
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}
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if(vmp->vm_flags & VMF_HAS_DMA) {
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release_dma(vmp);
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} else if(vmp->vm_flags & VMF_HASPT) {
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/* Free pagetable and pages allocated by pt code. */
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SANITYCHECK(SCL_DETAIL);
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free_proc(vmp);
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SANITYCHECK(SCL_DETAIL);
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} else {
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/* Free the data and stack segments. */
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free_mem(vmp->vm_arch.vm_seg[D].mem_phys,
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vmp->vm_arch.vm_seg[S].mem_vir +
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vmp->vm_arch.vm_seg[S].mem_len -
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vmp->vm_arch.vm_seg[D].mem_vir);
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if (find_share(vmp, vmp->vm_ino, vmp->vm_dev, vmp->vm_ctime) == NULL) {
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/* No other process shares the text segment,
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* so free it.
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*/
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free_mem(vmp->vm_arch.vm_seg[T].mem_phys,
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vmp->vm_arch.vm_seg[T].mem_len);
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}
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}
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SANITYCHECK(SCL_DETAIL);
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/* Reset process slot fields. */
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clear_proc(vmp);
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SANITYCHECK(SCL_FUNCTIONS);
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return OK;
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}
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/*===========================================================================*
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* do_willexit *
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*===========================================================================*/
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PUBLIC int do_willexit(message *msg)
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{
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int proc;
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struct vmproc *vmp;
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if(vm_isokendpt(msg->VMWE_ENDPOINT, &proc) != OK) {
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printf("VM: bogus endpoint VM_EXITING %d\n",
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msg->VMWE_ENDPOINT);
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return EINVAL;
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}
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vmp = &vmproc[proc];
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vmp->vm_flags |= VMF_EXITING;
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return OK;
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}
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