minix/servers/vm/mem_anon_contig.c

   1
   2 /* This file implements the methods of physically contiguous anonymous memory. */
   3
   4 #include <assert.h>
   5
   6 #include "proto.h"
   7 #include "vm.h"
   8 #include "region.h"
   9 #include "glo.h"
  10
  11 static int anon_contig_reference(struct phys_region *, struct phys_region *);
  12 static int anon_contig_unreference(struct phys_region *pr);
  13 static int anon_contig_pagefault(struct vmproc *vmp, struct vir_region *region,
  14         struct phys_region *ph, int write, vfs_callback_t cb, void *state,
  15         int len, int *io);
  16 static int anon_contig_sanitycheck(struct phys_region *pr, const char *file, int line);
  17 static int anon_contig_writable(struct phys_region *pr);
  18 static int anon_contig_resize(struct vmproc *vmp, struct vir_region *vr, vir_bytes l);
  19 static int anon_contig_new(struct vir_region *vr);
  20 static int anon_contig_pt_flags(struct vir_region *vr);
  21
  22 struct mem_type mem_type_anon_contig = {
  23         .name = "anonymous memory (physically contiguous)",
  24         .ev_new = anon_contig_new,
  25         .ev_reference = anon_contig_reference,
  26         .ev_unreference = anon_contig_unreference,
  27         .ev_pagefault = anon_contig_pagefault,
  28         .ev_resize = anon_contig_resize,
  29         .ev_sanitycheck = anon_contig_sanitycheck,
  30         .writable = anon_contig_writable,
  31         .pt_flags = anon_contig_pt_flags,
  32 };
  33
  34 static int anon_contig_pt_flags(struct vir_region *vr){
  35 #if defined(__arm__)
  36         return  ARM_VM_PTE_DEVICE;
  37 #else
  38         return  0;
  39 #endif
  40 }
  41
  42 static int anon_contig_pagefault(struct vmproc *vmp, struct vir_region *region,
  43         struct phys_region *ph, int write, vfs_callback_t cb, void *state,
  44         int len, int *io)
  45 {
  46         panic("anon_contig_pagefault: pagefault cannot happen");
  47 }
  48
  49 static int anon_contig_new(struct vir_region *region)
  50 {
  51         u32_t allocflags;
  52         phys_bytes new_pages, new_page_cl, cur_ph;
  53         phys_bytes p, pages;
  54
  55         allocflags = vrallocflags(region->flags);
  56
  57         pages = region->length/VM_PAGE_SIZE;
  58
  59         assert(physregions(region) == 0);
  60
  61         for(p = 0; p < pages; p++) {
  62                 struct phys_block *pb = pb_new(MAP_NONE);
  63                 struct phys_region *pr = NULL;
  64                 if(pb)
  65                         pr = pb_reference(pb, p * VM_PAGE_SIZE, region, &mem_type_anon_contig);
  66                 if(!pr) {
  67                         if(pb) pb_free(pb);
  68                         map_free(region);
  69                         return ENOMEM;
  70                 }
  71         }
  72
  73         assert(physregions(region) == pages);
  74
  75         if((new_page_cl = alloc_mem(pages, allocflags)) == NO_MEM) {
  76                 map_free(region);
  77                 return ENOMEM;
  78         }
  79
  80         cur_ph = new_pages = CLICK2ABS(new_page_cl);
  81
  82         for(p = 0; p < pages; p++) {
  83                 struct phys_region *pr = physblock_get(region, p * VM_PAGE_SIZE);
  84                 assert(pr);
  85                 assert(pr->ph);
  86                 assert(pr->ph->phys == MAP_NONE);
  87                 assert(pr->offset == p * VM_PAGE_SIZE);
  88                 pr->ph->phys = cur_ph + pr->offset;
  89         }
  90
  91         return OK;
  92 }
  93
  94 static int anon_contig_resize(struct vmproc *vmp, struct vir_region *vr, vir_bytes l)
  95 {
  96         printf("VM: cannot resize physically contiguous memory.\n");
  97         return ENOMEM;
  98 }
  99
 100 static int anon_contig_reference(struct phys_region *pr,
 101         struct phys_region *newpr)
 102 {
 103         printf("VM: cannot fork with physically contig memory.\n");
 104         return ENOMEM;
 105 }
 106
 107 /* Methods inherited from the anonymous memory methods. */
 108
 109 static int anon_contig_unreference(struct phys_region *pr)
 110 {
 111         return mem_type_anon.ev_unreference(pr);
 112 }
 113
 114 static int anon_contig_sanitycheck(struct phys_region *pr, const char *file, int line)
 115 {
 116         return mem_type_anon.ev_sanitycheck(pr, file, line);
 117 }
 118
 119 static int anon_contig_writable(struct phys_region *pr)
 120 {
 121         return mem_type_anon.writable(pr);
 122 }
 123