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001 /* Copyright (C) 2005 David Decotigny 001 /* Copyright (C) 2005 David Decotigny 002 002 003 This program is free software; you can redi 003 This program is free software; you can redistribute it and/or 004 modify it under the terms of the GNU Genera 004 modify it under the terms of the GNU General Public License 005 as published by the Free Software Foundatio 005 as published by the Free Software Foundation; either version 2 006 of the License, or (at your option) any lat 006 of the License, or (at your option) any later version. 007 007 008 This program is distributed in the hope tha 008 This program is distributed in the hope that it will be useful, 009 but WITHOUT ANY WARRANTY; without even the 009 but WITHOUT ANY WARRANTY; without even the implied warranty of 010 MERCHANTABILITY or FITNESS FOR A PARTICULAR 010 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 011 GNU General Public License for more details 011 GNU General Public License for more details. 012 012 013 You should have received a copy of the GNU 013 You should have received a copy of the GNU General Public License 014 along with this program; if not, write to t 014 along with this program; if not, write to the Free Software 015 Foundation, Inc., 59 Temple Place - Suite 3 015 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 016 USA. 016 USA. 017 */ 017 */ 018 018 019 #include <sos/assert.h> 019 #include <sos/assert.h> 020 #include <sos/kmalloc.h> 020 #include <sos/kmalloc.h> 021 #include <sos/physmem.h> 021 #include <sos/physmem.h> 022 #include <hwcore/paging.h> 022 #include <hwcore/paging.h> 023 #include <sos/kmem_slab.h> 023 #include <sos/kmem_slab.h> 024 #include <sos/list.h> 024 #include <sos/list.h> 025 #include <hwcore/paging.h> 025 #include <hwcore/paging.h> 026 026 027 #include "zero.h" 027 #include "zero.h" 028 028 029 029 030 /** 030 /** 031 * A mapped page for a shared mapping of /dev/ 031 * A mapped page for a shared mapping of /dev/zero 032 */ 032 */ 033 struct zero_mapped_page 033 struct zero_mapped_page 034 { 034 { 035 sos_uoffset_t page_id; 035 sos_uoffset_t page_id; 036 sos_paddr_t ppage_paddr; 036 sos_paddr_t ppage_paddr; 037 037 038 struct zero_mapped_page *prev, *next; 038 struct zero_mapped_page *prev, *next; 039 }; 039 }; 040 /** The Slab cache of shared mapped pages */ 040 /** The Slab cache of shared mapped pages */ 041 struct sos_kslab_cache * cache_of_zero_mapped_ 041 struct sos_kslab_cache * cache_of_zero_mapped_pages; 042 042 043 043 044 /** 044 /** 045 * A mapped /dev/zero resource 045 * A mapped /dev/zero resource 046 */ 046 */ 047 struct zero_mapped_resource 047 struct zero_mapped_resource 048 { 048 { 049 int ref_cnt; 049 int ref_cnt; 050 050 051 /** 051 /** 052 * For shared mappings: the list of shared p 052 * For shared mappings: the list of shared pages mapped inside one 053 * or multiple VRs 053 * or multiple VRs 054 */ 054 */ 055 struct zero_mapped_page *list_mapped_pages; 055 struct zero_mapped_page *list_mapped_pages; 056 056 057 struct sos_umem_vmm_mapped_resource mr; 057 struct sos_umem_vmm_mapped_resource mr; 058 }; 058 }; 059 059 060 060 061 /** Helper function to insert the given physic 061 /** Helper function to insert the given physical page in the list of 062 physical pages used for shared anonymous m 062 physical pages used for shared anonymous mappings */ 063 static sos_ret_t insert_anonymous_physpage(str 063 static sos_ret_t insert_anonymous_physpage(struct zero_mapped_resource *mr, 064 sos 064 sos_paddr_t ppage_paddr, 065 sos 065 sos_uoffset_t page_id); 066 066 067 067 068 /** Helper function to insert the given physic 068 /** Helper function to insert the given physical page in the list of 069 physical pages used for shared anonymous m 069 physical pages used for shared anonymous mappings */ 070 static sos_paddr_t lookup_anonymous_physpage(s 070 static sos_paddr_t lookup_anonymous_physpage(struct zero_mapped_resource *mr, 071 s 071 sos_uoffset_t page_id); 072 072 073 073 074 sos_ret_t sos_dev_zero_subsystem_setup() 074 sos_ret_t sos_dev_zero_subsystem_setup() 075 { 075 { 076 cache_of_zero_mapped_pages = 076 cache_of_zero_mapped_pages = 077 sos_kmem_cache_create("shared anonymous ma 077 sos_kmem_cache_create("shared anonymous mappings", 078 sizeof(struct zero_m 078 sizeof(struct zero_mapped_page), 079 1, 0, 079 1, 0, 080 SOS_KSLAB_CREATE_MAP 080 SOS_KSLAB_CREATE_MAP | SOS_KSLAB_CREATE_ZERO); 081 if (! cache_of_zero_mapped_pages) 081 if (! cache_of_zero_mapped_pages) 082 return -SOS_ENOMEM; 082 return -SOS_ENOMEM; 083 083 084 return SOS_OK; 084 return SOS_OK; 085 } 085 } 086 086 087 087 088 /** Called after the virtual region has been i 088 /** Called after the virtual region has been inserted inside its 089 address space */ 089 address space */ 090 static void zero_ref(struct sos_umem_vmm_vr * 090 static void zero_ref(struct sos_umem_vmm_vr * vr) 091 { 091 { 092 /* Retrieve the 'zero' structure associated 092 /* Retrieve the 'zero' structure associated with the mapped resource */ 093 struct zero_mapped_resource * zero_resource; 093 struct zero_mapped_resource * zero_resource; 094 zero_resource 094 zero_resource 095 = (struct zero_mapped_resource*) 095 = (struct zero_mapped_resource*) 096 sos_umem_vmm_get_mapped_resource_of_vr(vr) 096 sos_umem_vmm_get_mapped_resource_of_vr(vr)->custom_data; 097 097 098 /* Increment ref counter */ 098 /* Increment ref counter */ 099 zero_resource->ref_cnt ++; 099 zero_resource->ref_cnt ++; 100 } 100 } 101 101 102 102 103 /** Called when the virtual region is removed 103 /** Called when the virtual region is removed from its address 104 space */ 104 space */ 105 static void zero_unref(struct sos_umem_vmm_vr 105 static void zero_unref(struct sos_umem_vmm_vr * vr) 106 { 106 { 107 /* Retrieve the 'zero' structure associated 107 /* Retrieve the 'zero' structure associated with the mapped resource */ 108 struct zero_mapped_resource * zero_resource; 108 struct zero_mapped_resource * zero_resource; 109 zero_resource 109 zero_resource 110 = (struct zero_mapped_resource*) 110 = (struct zero_mapped_resource*) 111 sos_umem_vmm_get_mapped_resource_of_vr(vr) 111 sos_umem_vmm_get_mapped_resource_of_vr(vr)->custom_data; 112 !! 112 113 /* Decrement ref coutner */ 113 /* Decrement ref coutner */ 114 SOS_ASSERT_FATAL(zero_resource->ref_cnt > 0) 114 SOS_ASSERT_FATAL(zero_resource->ref_cnt > 0); 115 zero_resource->ref_cnt --; 115 zero_resource->ref_cnt --; 116 116 117 /* Free the resource if it becomes unused */ 117 /* Free the resource if it becomes unused */ 118 if (zero_resource->ref_cnt == 0) 118 if (zero_resource->ref_cnt == 0) 119 { 119 { 120 /* Delete the list of anonymous shared m 120 /* Delete the list of anonymous shared mappings */ 121 struct zero_mapped_page *zmp; 121 struct zero_mapped_page *zmp; 122 list_collapse(zero_resource->list_mapped 122 list_collapse(zero_resource->list_mapped_pages, zmp) 123 { 123 { 124 /* No need to free the underlying ph !! 124 /* Unreference the underlying physical page */ 125 should have been unmapped just be !! 125 sos_physmem_unref_physpage(zmp->ppage_paddr); 126 called */ << 127 sos_kfree((sos_vaddr_t)zmp); 126 sos_kfree((sos_vaddr_t)zmp); 128 } 127 } 129 128 130 sos_kfree((sos_vaddr_t)zero_resource); 129 sos_kfree((sos_vaddr_t)zero_resource); 131 } 130 } 132 } 131 } 133 132 134 133 135 /** MOST IMPORTANT callback ! Called when a th 134 /** MOST IMPORTANT callback ! Called when a thread page faults on the 136 resource's mapping */ 135 resource's mapping */ 137 static sos_ret_t zero_page_in(struct sos_umem_ 136 static sos_ret_t zero_page_in(struct sos_umem_vmm_vr * vr, 138 sos_uaddr_t uadd 137 sos_uaddr_t uaddr, 139 sos_bool_t write 138 sos_bool_t write_access) 140 { 139 { 141 sos_ret_t retval = SOS_OK; 140 sos_ret_t retval = SOS_OK; 142 sos_paddr_t ppage_paddr; 141 sos_paddr_t ppage_paddr; 143 sos_uoffset_t required_page_id; 142 sos_uoffset_t required_page_id; 144 struct zero_mapped_resource * zero_resource; 143 struct zero_mapped_resource * zero_resource; 145 sos_ui32_t vr_prot, vr_flags; 144 sos_ui32_t vr_prot, vr_flags; 146 145 147 /* Retrieve the 'zero' structure associated 146 /* Retrieve the 'zero' structure associated with the mapped resource */ 148 zero_resource 147 zero_resource 149 = (struct zero_mapped_resource*) 148 = (struct zero_mapped_resource*) 150 sos_umem_vmm_get_mapped_resource_of_vr(vr) 149 sos_umem_vmm_get_mapped_resource_of_vr(vr)->custom_data; 151 150 152 /* Retrieve access rights/flags of the VR */ 151 /* Retrieve access rights/flags of the VR */ 153 vr_prot = sos_umem_vmm_get_prot_of_vr(vr); 152 vr_prot = sos_umem_vmm_get_prot_of_vr(vr); 154 vr_flags = sos_umem_vmm_get_flags_of_vr(vr); 153 vr_flags = sos_umem_vmm_get_flags_of_vr(vr); 155 154 156 /* Identifies the page in the mapping that's 155 /* Identifies the page in the mapping that's being paged-in */ 157 required_page_id = SOS_PAGE_ALIGN_INF(uaddr) 156 required_page_id = SOS_PAGE_ALIGN_INF(uaddr) 158 - sos_umem_vmm_get_start_of_vr(vr) 157 - sos_umem_vmm_get_start_of_vr(vr) 159 + sos_umem_vmm_get_offset_in_resource(vr); 158 + sos_umem_vmm_get_offset_in_resource(vr); 160 159 161 /* For shared mappings, check if there is a 160 /* For shared mappings, check if there is a page already mapping the 162 required address */ 161 required address */ 163 if (vr_flags & SOS_VR_MAP_SHARED) 162 if (vr_flags & SOS_VR_MAP_SHARED) 164 { 163 { 165 ppage_paddr = lookup_anonymous_physpage( 164 ppage_paddr = lookup_anonymous_physpage(zero_resource, required_page_id); 166 if (NULL != (void*)ppage_paddr) 165 if (NULL != (void*)ppage_paddr) 167 { 166 { 168 retval = sos_paging_map(ppage_paddr, 167 retval = sos_paging_map(ppage_paddr, 169 SOS_PAGE_ALI 168 SOS_PAGE_ALIGN_INF(uaddr), 170 TRUE, 169 TRUE, 171 vr_prot); 170 vr_prot); >> 171 172 return retval; 172 return retval; 173 } 173 } 174 } 174 } 175 175 176 /* For write accesses, directly maps a new p 176 /* For write accesses, directly maps a new page. For read accesses, 177 simply map in the zero_page (and wait for 177 simply map in the zero_page (and wait for COW to handle the next 178 write accesses) */ 178 write accesses) */ 179 if (write_access) 179 if (write_access) 180 { 180 { 181 /* Allocate a new page for the virtual a 181 /* Allocate a new page for the virtual address */ 182 ppage_paddr = sos_physmem_ref_physpage_n 182 ppage_paddr = sos_physmem_ref_physpage_new(FALSE); 183 if (! ppage_paddr) 183 if (! ppage_paddr) 184 return -SOS_ENOMEM; 184 return -SOS_ENOMEM; 185 !! 185 186 retval = sos_paging_map(ppage_paddr, 186 retval = sos_paging_map(ppage_paddr, 187 SOS_PAGE_ALIGN_I 187 SOS_PAGE_ALIGN_INF(uaddr), 188 TRUE, 188 TRUE, 189 vr_prot); 189 vr_prot); 190 if (SOS_OK != retval) 190 if (SOS_OK != retval) 191 { 191 { 192 sos_physmem_unref_physpage(ppage_pad 192 sos_physmem_unref_physpage(ppage_paddr); 193 return retval; 193 return retval; 194 } 194 } 195 195 196 memset((void*)SOS_PAGE_ALIGN_INF(uaddr), 196 memset((void*)SOS_PAGE_ALIGN_INF(uaddr), 0x0, SOS_PAGE_SIZE); 197 197 198 /* For shared mappings, add the page in 198 /* For shared mappings, add the page in the list of shared 199 mapped pages */ 199 mapped pages */ 200 if (vr_flags & SOS_VR_MAP_SHARED) 200 if (vr_flags & SOS_VR_MAP_SHARED) 201 insert_anonymous_physpage(zero_resourc 201 insert_anonymous_physpage(zero_resource, ppage_paddr, 202 required_pag 202 required_page_id); 203 203 204 sos_physmem_unref_physpage(ppage_paddr); 204 sos_physmem_unref_physpage(ppage_paddr); 205 } 205 } 206 else 206 else 207 { 207 { 208 /* Map-in the zero page in READ ONLY wha 208 /* Map-in the zero page in READ ONLY whatever the access_rights 209 or the type (shared/private) of the V 209 or the type (shared/private) of the VR to activate COW */ 210 retval = sos_paging_map(sos_zero_page, 210 retval = sos_paging_map(sos_zero_page, 211 SOS_PAGE_ALIGN_I 211 SOS_PAGE_ALIGN_INF(uaddr), 212 TRUE, 212 TRUE, 213 SOS_VM_MAP_PROT_ 213 SOS_VM_MAP_PROT_READ); 214 } 214 } 215 215 216 return retval; 216 return retval; 217 } 217 } 218 218 219 219 220 /** The callbacks for a mapped /dev/zero resou 220 /** The callbacks for a mapped /dev/zero resource */ 221 static struct sos_umem_vmm_vr_ops zero_ops = ( 221 static struct sos_umem_vmm_vr_ops zero_ops = (struct sos_umem_vmm_vr_ops) 222 { 222 { 223 .ref = zero_ref, 223 .ref = zero_ref, 224 .unref = zero_unref, 224 .unref = zero_unref, 225 .page_in = zero_page_in, 225 .page_in = zero_page_in, 226 .unmap = NULL 226 .unmap = NULL 227 }; 227 }; 228 228 229 229 230 /** The callback that gets called when the res 230 /** The callback that gets called when the resource gets mapped */ 231 static sos_ret_t zero_mmap(struct sos_umem_vmm 231 static sos_ret_t zero_mmap(struct sos_umem_vmm_vr *vr) 232 { 232 { 233 return sos_umem_vmm_set_ops_of_vr(vr, &zero_ 233 return sos_umem_vmm_set_ops_of_vr(vr, &zero_ops); 234 } 234 } 235 235 236 236 237 /** The function responsible for mapping the / 237 /** The function responsible for mapping the /dev/zero resource in 238 user space */ 238 user space */ 239 sos_ret_t sos_dev_zero_map(struct sos_umem_vmm 239 sos_ret_t sos_dev_zero_map(struct sos_umem_vmm_as * dest_as, 240 sos_uaddr_t *uaddr, 240 sos_uaddr_t *uaddr, 241 sos_size_t size, 241 sos_size_t size, 242 sos_ui32_t access_r 242 sos_ui32_t access_rights, 243 sos_ui32_t flags) 243 sos_ui32_t flags) 244 { 244 { 245 sos_ret_t retval; 245 sos_ret_t retval; 246 struct zero_mapped_resource * zero_resource; 246 struct zero_mapped_resource * zero_resource; 247 247 248 zero_resource 248 zero_resource 249 = (struct zero_mapped_resource*) sos_kmall 249 = (struct zero_mapped_resource*) sos_kmalloc(sizeof(*zero_resource), 0); 250 if (! zero_resource) 250 if (! zero_resource) 251 return -SOS_ENOMEM; 251 return -SOS_ENOMEM; 252 252 253 memset(zero_resource, 0x0, sizeof(*zero_reso 253 memset(zero_resource, 0x0, sizeof(*zero_resource)); 254 zero_resource->mr.allowed_access_rights 254 zero_resource->mr.allowed_access_rights 255 = SOS_VM_MAP_PROT_READ 255 = SOS_VM_MAP_PROT_READ 256 | SOS_VM_MAP_PROT_WRITE 256 | SOS_VM_MAP_PROT_WRITE 257 | SOS_VM_MAP_PROT_EXEC; 257 | SOS_VM_MAP_PROT_EXEC; 258 zero_resource->mr.flags |= SOS_MAPPE 258 zero_resource->mr.flags |= SOS_MAPPED_RESOURCE_ANONYMOUS; 259 zero_resource->mr.custom_data = zero_reso 259 zero_resource->mr.custom_data = zero_resource; 260 zero_resource->mr.mmap = zero_mmap 260 zero_resource->mr.mmap = zero_mmap; 261 261 262 retval = sos_umem_vmm_map(dest_as, uaddr, si 262 retval = sos_umem_vmm_map(dest_as, uaddr, size, 263 access_rights, fla 263 access_rights, flags, 264 &zero_resource->mr 264 &zero_resource->mr, 0); 265 if (SOS_OK != retval) 265 if (SOS_OK != retval) 266 { 266 { 267 sos_kfree((sos_vaddr_t)zero_resource); 267 sos_kfree((sos_vaddr_t)zero_resource); 268 return retval; 268 return retval; 269 } 269 } 270 270 271 return SOS_OK; 271 return SOS_OK; 272 } 272 } 273 273 274 274 275 static sos_ret_t insert_anonymous_physpage(str 275 static sos_ret_t insert_anonymous_physpage(struct zero_mapped_resource *mr, 276 sos 276 sos_paddr_t ppage_paddr, 277 sos 277 sos_uoffset_t page_id) 278 { 278 { 279 struct zero_mapped_page * zmp 279 struct zero_mapped_page * zmp 280 = (struct zero_mapped_page*)sos_kmem_cache 280 = (struct zero_mapped_page*)sos_kmem_cache_alloc(cache_of_zero_mapped_pages, 281 281 0); 282 if (! zmp) 282 if (! zmp) 283 return -SOS_ENOMEM; 283 return -SOS_ENOMEM; 284 284 285 zmp->page_id = page_id; 285 zmp->page_id = page_id; 286 zmp->ppage_paddr = ppage_paddr; 286 zmp->ppage_paddr = ppage_paddr; 287 287 288 list_add_head(mr->list_mapped_pages, zmp); 288 list_add_head(mr->list_mapped_pages, zmp); >> 289 sos_physmem_ref_physpage_at(ppage_paddr); 289 return SOS_OK; 290 return SOS_OK; 290 } 291 } 291 292 292 293 293 static sos_paddr_t lookup_anonymous_physpage(s 294 static sos_paddr_t lookup_anonymous_physpage(struct zero_mapped_resource *mr, 294 so 295 sos_uoffset_t page_id) 295 { 296 { 296 struct zero_mapped_page * zmp; 297 struct zero_mapped_page * zmp; 297 int nb_elts; 298 int nb_elts; 298 299 299 list_foreach_forward(mr->list_mapped_pages, 300 list_foreach_forward(mr->list_mapped_pages, zmp, nb_elts) 300 { 301 { 301 if (zmp->page_id == page_id) 302 if (zmp->page_id == page_id) 302 return zmp->ppage_paddr; 303 return zmp->ppage_paddr; 303 } 304 } 304 305 305 return (sos_paddr_t)NULL; 306 return (sos_paddr_t)NULL; 306 } 307 }
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