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 <typedefs.h>
  51 #include <synch/spinlock.h>
  52 #include <synch/mutex.h>
  53 #include <adt/list.h>
  54 #include <adt/btree.h>
  55 #include <lib/elf.h>
  56
  57 /** Defined to be true if user address space and kernel address space shadow each other. */
  58 #define KERNEL_ADDRESS_SPACE_SHADOWED   KERNEL_ADDRESS_SPACE_SHADOWED_ARCH
  59
  60 #define KERNEL_ADDRESS_SPACE_START      KERNEL_ADDRESS_SPACE_START_ARCH
  61 #define KERNEL_ADDRESS_SPACE_END        KERNEL_ADDRESS_SPACE_END_ARCH
  62 #define USER_ADDRESS_SPACE_START        USER_ADDRESS_SPACE_START_ARCH
  63 #define USER_ADDRESS_SPACE_END          USER_ADDRESS_SPACE_END_ARCH
  64
  65 #define USTACK_ADDRESS  USTACK_ADDRESS_ARCH
  66
  67 #define FLAG_AS_KERNEL      (1 << 0)    /**< Kernel address space. */
  68
  69 /** Address space structure.
  70  *
  71  * as_t contains the list of as_areas of userspace accessible
  72  * pages for one or more tasks. Ranges of kernel memory pages are not
  73  * supposed to figure in the list as they are shared by all tasks and
  74  * set up during system initialization.
  75  */
  76 struct as {
  77         /** Protected by asidlock. */
  78         link_t inactive_as_with_asid_link;
  79
  80         mutex_t lock;
  81
  82         /** Number of references (i.e tasks that reference this as). */
  83         count_t refcount;
  84
  85         /** Number of processors on wich is this address space active. */
  86         count_t cpu_refcount;
  87
  88         /** B+tree of address space areas. */
  89         btree_t as_area_btree;
  90
  91         /** Page table pointer. Constant on architectures that use global page hash table. */
  92         pte_t *page_table;
  93
  94         /** Address space identifier. Constant on architectures that do not support ASIDs.*/
  95         asid_t asid;
  96
  97 #ifdef CONFIG_VIRT_IDX_DCACHE
  98         bool dcache_flush_on_install;
  99         bool dcache_flush_on_deinstall;
 100 #endif /* CONFIG_VIRT_IDX_DCACHE */
 101
 102         /** Architecture specific content. */
 103         as_arch_t arch;
 104 };
 105
 106 struct as_operations {
 107         pte_t *(* page_table_create)(int flags);
 108         void (* page_table_destroy)(pte_t *page_table);
 109         void (* page_table_lock)(as_t *as, bool lock);
 110         void (* page_table_unlock)(as_t *as, bool unlock);
 111 };
 112 typedef struct as_operations as_operations_t;
 113
 114 /** Address space area attributes. */
 115 #define AS_AREA_ATTR_NONE       0
 116 #define AS_AREA_ATTR_PARTIAL    1       /**< Not fully initialized area. */
 117
 118 #define AS_PF_FAULT             0       /**< The page fault was not resolved by as_page_fault(). */
 119 #define AS_PF_OK                1       /**< The page fault was resolved by as_page_fault(). */
 120 #define AS_PF_DEFER             2       /**< The page fault was caused by memcpy_from_uspace()
 121                                              or memcpy_to_uspace(). */
 122
 123 /** This structure contains information associated with the shared address space area. */
 124 typedef struct {
 125         mutex_t lock;           /**< This lock must be acquired only when the as_area lock is held. */
 126         count_t refcount;       /**< This structure can be deallocated if refcount drops to 0. */
 127         btree_t pagemap;        /**< B+tree containing complete map of anonymous pages of the shared area. */
 128 } share_info_t;
 129
 130 /** Address space area backend structure. */
 131 typedef struct {
 132         int (* page_fault)(as_area_t *area, uintptr_t addr, pf_access_t access);
 133         void (* frame_free)(as_area_t *area, uintptr_t page, uintptr_t frame);
 134         void (* share)(as_area_t *area);
 135 } mem_backend_t;
 136
 137 /** Backend data stored in address space area. */
 138 typedef union {
 139         struct {        /**< elf_backend members */
 140                 elf_header_t *elf;
 141                 elf_segment_header_t *segment;
 142         };
 143         struct {        /**< phys_backend members */
 144                 uintptr_t base;
 145                 count_t frames;
 146         };
 147 } mem_backend_data_t;
 148
 149 /** Address space area structure.
 150  *
 151  * Each as_area_t structure describes one contiguous area of virtual memory.
 152  * In the future, it should not be difficult to support shared areas.
 153  */
 154 struct as_area {
 155         mutex_t lock;
 156         as_t *as;               /**< Containing address space. */
 157         int flags;              /**< Flags related to the memory represented by the address space area. */
 158         int attributes;         /**< Attributes related to the address space area itself. */
 159         count_t pages;          /**< Size of this area in multiples of PAGE_SIZE. */
 160         uintptr_t base;         /**< Base address of this area. */
 161         btree_t used_space;     /**< Map of used space. */
 162         share_info_t *sh_info;  /**< If the address space area has been shared, this pointer will
 163                                      reference the share info structure. */
 164         mem_backend_t *backend; /**< Memory backend backing this address space area. */
 165
 166         /** Data to be used by the backend. */
 167         mem_backend_data_t backend_data;
 168
 169         /**
 170          * Virtual color of the original address space area that was at the beginning
 171          * of the share chain.
 172          */
 173         int orig_color;
 174 };
 175
 176 extern as_t *AS_KERNEL;
 177 extern as_operations_t *as_operations;
 178
 179 extern spinlock_t inactive_as_with_asid_lock;
 180 extern link_t inactive_as_with_asid_head;
 181
 182 extern void as_init(void);
 183
 184 extern as_t *as_create(int flags);
 185 extern void as_destroy(as_t *as);
 186 extern void as_switch(as_t *old, as_t *new);
 187 extern int as_page_fault(uintptr_t page, pf_access_t access, istate_t *istate);
 188
 189 extern as_area_t *as_area_create(as_t *as, int flags, size_t size, uintptr_t base, int attrs,
 190         mem_backend_t *backend, mem_backend_data_t *backend_data);
 191 extern int as_area_destroy(as_t *as, uintptr_t address);
 192 extern int as_area_resize(as_t *as, uintptr_t address, size_t size, int flags);
 193 int as_area_share(as_t *src_as, uintptr_t src_base, size_t acc_size,
 194                   as_t *dst_as, uintptr_t dst_base, int dst_flags_mask);
 195
 196 extern int as_area_get_flags(as_area_t *area);
 197 extern bool as_area_check_access(as_area_t *area, pf_access_t access);
 198 extern size_t as_get_size(uintptr_t base);
 199 extern int used_space_insert(as_area_t *a, uintptr_t page, count_t count);
 200 extern int used_space_remove(as_area_t *a, uintptr_t page, count_t count);
 201
 202
 203 /* Interface to be implemented by architectures. */
 204 #ifndef as_constructor_arch
 205 extern int as_constructor_arch(as_t *as, int flags);
 206 #endif /* !def as_constructor_arch */
 207 #ifndef as_destructor_arch
 208 extern int as_destructor_arch(as_t *as);
 209 #endif /* !def as_destructor_arch */
 210 #ifndef as_create_arch
 211 extern int as_create_arch(as_t *as, int flags);
 212 #endif /* !def as_create_arch */
 213 #ifndef as_install_arch
 214 extern void as_install_arch(as_t *as);
 215 #endif /* !def as_install_arch */
 216 #ifndef as_deinstall_arch
 217 extern void as_deinstall_arch(as_t *as);
 218 #endif /* !def as_deinstall_arch */
 219
 220 /* Backend declarations. */
 221 extern mem_backend_t anon_backend;
 222 extern mem_backend_t elf_backend;
 223 extern mem_backend_t phys_backend;
 224
 225 /* Address space area related syscalls. */
 226 extern unative_t sys_as_area_create(uintptr_t address, size_t size, int flags);
 227 extern unative_t sys_as_area_resize(uintptr_t address, size_t size, int flags);
 228 extern unative_t sys_as_area_destroy(uintptr_t address);
 229
 230 /* Introspection functions. */
 231 extern void as_print(as_t *as);
 232
 233 #endif /* KERNEL */
 234
 235 #endif
 236
 237 /** @}
 238  */