kernel/generic/include/mm/as.h

   1 /*
   2  * Copyright (c) 2001-2004 Jakub Jermar
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * - Redistributions of source code must retain the above copyright
  10  *   notice, this list of conditions and the following disclaimer.
  11  * - Redistributions in binary form must reproduce the above copyright
  12  *   notice, this list of conditions and the following disclaimer in the
  13  *   documentation and/or other materials provided with the distribution.
  14  * - The name of the author may not be used to endorse or promote products
  15  *   derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /** @addtogroup genericmm
  30  * @{
  31  */
  32 /** @file
  33  */
  34
  35 #ifndef KERN_AS_H_
  36 #define KERN_AS_H_
  37
  38 /** Address space area flags. */
  39 #define AS_AREA_READ            1
  40 #define AS_AREA_WRITE           2
  41 #define AS_AREA_EXEC            4
  42 #define AS_AREA_CACHEABLE       8
  43
  44 #ifdef KERNEL
  45
  46 #include <arch/mm/page.h>
  47 #include <arch/mm/as.h>
  48 #include <arch/mm/asid.h>
  49 #include <arch/types.h>
  50 #include <synch/spinlock.h>
  51 #include <synch/mutex.h>
  52 #include <adt/list.h>
  53 #include <adt/btree.h>
  54 #include <lib/elf.h>
  55
  56 /**
  57  * Defined to be true if user address space and kernel address space shadow each
  58  * other.
  59  */
  60 #define KERNEL_ADDRESS_SPACE_SHADOWED   KERNEL_ADDRESS_SPACE_SHADOWED_ARCH
  61
  62 #define KERNEL_ADDRESS_SPACE_START      KERNEL_ADDRESS_SPACE_START_ARCH
  63 #define KERNEL_ADDRESS_SPACE_END        KERNEL_ADDRESS_SPACE_END_ARCH
  64 #define USER_ADDRESS_SPACE_START        USER_ADDRESS_SPACE_START_ARCH
  65 #define USER_ADDRESS_SPACE_END          USER_ADDRESS_SPACE_END_ARCH
  66
  67 #define USTACK_ADDRESS                  USTACK_ADDRESS_ARCH
  68
  69 /** Kernel address space. */
  70 #define FLAG_AS_KERNEL                  (1 << 0)
  71
  72 /* Address space area attributes. */
  73 #define AS_AREA_ATTR_NONE       0
  74 #define AS_AREA_ATTR_PARTIAL    1       /**< Not fully initialized area. */
  75
  76 /** The page fault was not resolved by as_page_fault(). */
  77 #define AS_PF_FAULT             0
  78 /** The page fault was resolved by as_page_fault(). */
  79 #define AS_PF_OK                1
  80 /** The page fault was caused by memcpy_from_uspace() or memcpy_to_uspace(). */
  81 #define AS_PF_DEFER             2
  82
  83 /** Address space structure.
  84  *
  85  * as_t contains the list of as_areas of userspace accessible
  86  * pages for one or more tasks. Ranges of kernel memory pages are not
  87  * supposed to figure in the list as they are shared by all tasks and
  88  * set up during system initialization.
  89  */
  90 typedef struct as {
  91         /** Protected by asidlock. */
  92         link_t inactive_as_with_asid_link;
  93
  94         mutex_t lock;
  95
  96         /** Number of references (i.e tasks that reference this as). */
  97         count_t refcount;
  98
  99         /** Number of processors on wich is this address space active. */
 100         count_t cpu_refcount;
 101
 102         /** B+tree of address space areas. */
 103         btree_t as_area_btree;
 104
 105         /**
 106          *  Address space identifier.
 107          *  Constant on architectures that do not support ASIDs.
 108          */
 109         asid_t asid;
 110
 111         /** Non-generic content. */
 112         as_genarch_t genarch;
 113
 114         /** Architecture specific content. */
 115         as_arch_t arch;
 116 } as_t;
 117
 118 typedef struct {
 119         pte_t *(* page_table_create)(int flags);
 120         void (* page_table_destroy)(pte_t *page_table);
 121         void (* page_table_lock)(as_t *as, bool lock);
 122         void (* page_table_unlock)(as_t *as, bool unlock);
 123 } as_operations_t;
 124
 125 /**
 126  * This structure contains information associated with the shared address space
 127  * area.
 128  */
 129 typedef struct {
 130         /** This lock must be acquired only when the as_area lock is held. */
 131         mutex_t lock;
 132         /** This structure can be deallocated if refcount drops to 0. */
 133         count_t refcount;
 134         /**
 135          * B+tree containing complete map of anonymous pages of the shared area.
 136          */
 137         btree_t pagemap;
 138 } share_info_t;
 139
 140 /** Page fault access type. */
 141 typedef enum {
 142         PF_ACCESS_READ,
 143         PF_ACCESS_WRITE,
 144         PF_ACCESS_EXEC
 145 } pf_access_t;
 146
 147 struct mem_backend;
 148
 149 /** Backend data stored in address space area. */
 150 typedef union mem_backend_data {
 151         struct {        /**< elf_backend members */
 152                 elf_header_t *elf;
 153                 elf_segment_header_t *segment;
 154         };
 155         struct {        /**< phys_backend members */
 156                 uintptr_t base;
 157                 count_t frames;
 158         };
 159 } mem_backend_data_t;
 160
 161 /** Address space area structure.
 162  *
 163  * Each as_area_t structure describes one contiguous area of virtual memory.
 164  * In the future, it should not be difficult to support shared areas.
 165  */
 166 typedef struct {
 167         mutex_t lock;
 168         /** Containing address space. */
 169         as_t *as;
 170         /** Flags related to the memory represented by the address space area. */
 171         int flags;
 172         /** Attributes related to the address space area itself. */
 173         int attributes;
 174         /** Size of this area in multiples of PAGE_SIZE. */
 175         count_t pages;
 176         /** Base address of this area. */
 177         uintptr_t base;
 178         /** Map of used space. */
 179         btree_t used_space;
 180
 181         /**
 182          * If the address space area has been shared, this pointer will reference
 183          * the share info structure.
 184          */
 185         share_info_t *sh_info;
 186
 187         /** Memory backend backing this address space area. */
 188         struct mem_backend *backend;
 189
 190         /** Data to be used by the backend. */
 191         mem_backend_data_t backend_data;
 192 } as_area_t;
 193
 194 /** Address space area backend structure. */
 195 typedef struct mem_backend {
 196         int (* page_fault)(as_area_t *area, uintptr_t addr, pf_access_t access);
 197         void (* frame_free)(as_area_t *area, uintptr_t page, uintptr_t frame);
 198         void (* share)(as_area_t *area);
 199 } mem_backend_t;
 200
 201 extern as_t *AS_KERNEL;
 202 extern as_operations_t *as_operations;
 203
 204 SPINLOCK_EXTERN(inactive_as_with_asid_lock);
 205 extern link_t inactive_as_with_asid_head;
 206
 207 extern void as_init(void);
 208
 209 extern as_t *as_create(int flags);
 210 extern void as_destroy(as_t *as);
 211 extern void as_switch(as_t *old_as, as_t *new_as);
 212 extern int as_page_fault(uintptr_t page, pf_access_t access, istate_t *istate);
 213
 214 extern as_area_t *as_area_create(as_t *as, int flags, size_t size,
 215     uintptr_t base, int attrs, mem_backend_t *backend,
 216     mem_backend_data_t *backend_data);
 217 extern int as_area_destroy(as_t *as, uintptr_t address);
 218 extern int as_area_resize(as_t *as, uintptr_t address, size_t size, int flags);
 219 int as_area_share(as_t *src_as, uintptr_t src_base, size_t acc_size,
 220     as_t *dst_as, uintptr_t dst_base, int dst_flags_mask);
 221
 222 extern int as_area_get_flags(as_area_t *area);
 223 extern bool as_area_check_access(as_area_t *area, pf_access_t access);
 224 extern size_t as_get_size(uintptr_t base);
 225 extern int used_space_insert(as_area_t *a, uintptr_t page, count_t count);
 226 extern int used_space_remove(as_area_t *a, uintptr_t page, count_t count);
 227
 228
 229 /* Interface to be implemented by architectures. */
 230 #ifndef as_constructor_arch
 231 extern int as_constructor_arch(as_t *as, int flags);
 232 #endif /* !def as_constructor_arch */
 233 #ifndef as_destructor_arch
 234 extern int as_destructor_arch(as_t *as);
 235 #endif /* !def as_destructor_arch */
 236 #ifndef as_create_arch
 237 extern int as_create_arch(as_t *as, int flags);
 238 #endif /* !def as_create_arch */
 239 #ifndef as_install_arch
 240 extern void as_install_arch(as_t *as);
 241 #endif /* !def as_install_arch */
 242 #ifndef as_deinstall_arch
 243 extern void as_deinstall_arch(as_t *as);
 244 #endif /* !def as_deinstall_arch */
 245
 246 /* Backend declarations and functions. */
 247 extern mem_backend_t anon_backend;
 248 extern mem_backend_t elf_backend;
 249 extern mem_backend_t phys_backend;
 250
 251 extern int elf_load(elf_header_t *header, as_t *as);
 252
 253 /* Address space area related syscalls. */
 254 extern unative_t sys_as_area_create(uintptr_t address, size_t size, int flags);
 255 extern unative_t sys_as_area_resize(uintptr_t address, size_t size, int flags);
 256 extern unative_t sys_as_area_destroy(uintptr_t address);
 257
 258 /* Introspection functions. */
 259 extern void as_print(as_t *as);
 260
 261 #endif /* KERNEL */
 262
 263 #endif
 264
 265 /** @}
 266  */