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703 | jermar | 1 | /* |
2 | * Copyright (C) 2001-2006 Jakub Jermar |
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3 | * All rights reserved. |
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4 | * |
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5 | * Redistribution and use in source and binary forms, with or without |
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6 | * modification, are permitted provided that the following conditions |
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7 | * are met: |
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8 | * |
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9 | * - Redistributions of source code must retain the above copyright |
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10 | * notice, this list of conditions and the following disclaimer. |
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11 | * - Redistributions in binary form must reproduce the above copyright |
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12 | * notice, this list of conditions and the following disclaimer in the |
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13 | * documentation and/or other materials provided with the distribution. |
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14 | * - The name of the author may not be used to endorse or promote products |
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15 | * derived from this software without specific prior written permission. |
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16 | * |
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17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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27 | */ |
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28 | |||
1248 | jermar | 29 | /** |
30 | * @file as.c |
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31 | * @brief Address space related functions. |
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32 | * |
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703 | jermar | 33 | * This file contains address space manipulation functions. |
34 | * Roughly speaking, this is a higher-level client of |
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35 | * Virtual Address Translation (VAT) subsystem. |
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1248 | jermar | 36 | * |
37 | * Functionality provided by this file allows one to |
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38 | * create address space and create, resize and share |
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39 | * address space areas. |
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40 | * |
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41 | * @see page.c |
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42 | * |
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703 | jermar | 43 | */ |
44 | |||
45 | #include <mm/as.h> |
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756 | jermar | 46 | #include <arch/mm/as.h> |
703 | jermar | 47 | #include <mm/page.h> |
48 | #include <mm/frame.h> |
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814 | palkovsky | 49 | #include <mm/slab.h> |
703 | jermar | 50 | #include <mm/tlb.h> |
51 | #include <arch/mm/page.h> |
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52 | #include <genarch/mm/page_pt.h> |
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1108 | jermar | 53 | #include <genarch/mm/page_ht.h> |
727 | jermar | 54 | #include <mm/asid.h> |
703 | jermar | 55 | #include <arch/mm/asid.h> |
56 | #include <synch/spinlock.h> |
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788 | jermar | 57 | #include <adt/list.h> |
1147 | jermar | 58 | #include <adt/btree.h> |
1235 | jermar | 59 | #include <proc/task.h> |
1288 | jermar | 60 | #include <proc/thread.h> |
1235 | jermar | 61 | #include <arch/asm.h> |
703 | jermar | 62 | #include <panic.h> |
63 | #include <debug.h> |
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1235 | jermar | 64 | #include <print.h> |
703 | jermar | 65 | #include <memstr.h> |
1070 | jermar | 66 | #include <macros.h> |
703 | jermar | 67 | #include <arch.h> |
1235 | jermar | 68 | #include <errno.h> |
69 | #include <config.h> |
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70 | #include <arch/types.h> |
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71 | #include <typedefs.h> |
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1288 | jermar | 72 | #include <syscall/copy.h> |
73 | #include <arch/interrupt.h> |
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703 | jermar | 74 | |
756 | jermar | 75 | as_operations_t *as_operations = NULL; |
703 | jermar | 76 | |
823 | jermar | 77 | /** Address space lock. It protects inactive_as_with_asid_head. */ |
78 | SPINLOCK_INITIALIZE(as_lock); |
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79 | |||
80 | /** |
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81 | * This list contains address spaces that are not active on any |
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82 | * processor and that have valid ASID. |
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83 | */ |
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84 | LIST_INITIALIZE(inactive_as_with_asid_head); |
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85 | |||
757 | jermar | 86 | /** Kernel address space. */ |
87 | as_t *AS_KERNEL = NULL; |
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88 | |||
1235 | jermar | 89 | static int area_flags_to_page_flags(int aflags); |
754 | jermar | 90 | static int get_area_flags(as_area_t *a); |
977 | jermar | 91 | static as_area_t *find_area_and_lock(as_t *as, __address va); |
1048 | jermar | 92 | static bool check_area_conflicts(as_t *as, __address va, size_t size, as_area_t *avoid_area); |
703 | jermar | 93 | |
756 | jermar | 94 | /** Initialize address space subsystem. */ |
95 | void as_init(void) |
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96 | { |
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97 | as_arch_init(); |
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789 | palkovsky | 98 | AS_KERNEL = as_create(FLAG_AS_KERNEL); |
756 | jermar | 99 | if (!AS_KERNEL) |
100 | panic("can't create kernel address space\n"); |
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101 | } |
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102 | |||
757 | jermar | 103 | /** Create address space. |
104 | * |
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105 | * @param flags Flags that influence way in wich the address space is created. |
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106 | */ |
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756 | jermar | 107 | as_t *as_create(int flags) |
703 | jermar | 108 | { |
109 | as_t *as; |
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110 | |||
822 | palkovsky | 111 | as = (as_t *) malloc(sizeof(as_t), 0); |
823 | jermar | 112 | link_initialize(&as->inactive_as_with_asid_link); |
822 | palkovsky | 113 | spinlock_initialize(&as->lock, "as_lock"); |
1147 | jermar | 114 | btree_create(&as->as_area_btree); |
822 | palkovsky | 115 | |
116 | if (flags & FLAG_AS_KERNEL) |
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117 | as->asid = ASID_KERNEL; |
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118 | else |
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119 | as->asid = ASID_INVALID; |
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120 | |||
823 | jermar | 121 | as->refcount = 0; |
822 | palkovsky | 122 | as->page_table = page_table_create(flags); |
703 | jermar | 123 | |
124 | return as; |
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125 | } |
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126 | |||
973 | palkovsky | 127 | /** Free Adress space */ |
128 | void as_free(as_t *as) |
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129 | { |
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130 | ASSERT(as->refcount == 0); |
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131 | |||
132 | /* TODO: free as_areas and other resources held by as */ |
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133 | /* TODO: free page table */ |
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134 | free(as); |
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135 | } |
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136 | |||
703 | jermar | 137 | /** Create address space area of common attributes. |
138 | * |
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139 | * The created address space area is added to the target address space. |
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140 | * |
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141 | * @param as Target address space. |
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1239 | jermar | 142 | * @param flags Flags of the area memory. |
1048 | jermar | 143 | * @param size Size of area. |
703 | jermar | 144 | * @param base Base address of area. |
1239 | jermar | 145 | * @param attrs Attributes of the area. |
703 | jermar | 146 | * |
147 | * @return Address space area on success or NULL on failure. |
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148 | */ |
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1239 | jermar | 149 | as_area_t *as_area_create(as_t *as, int flags, size_t size, __address base, int attrs) |
703 | jermar | 150 | { |
151 | ipl_t ipl; |
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152 | as_area_t *a; |
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153 | |||
154 | if (base % PAGE_SIZE) |
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1048 | jermar | 155 | return NULL; |
156 | |||
1233 | jermar | 157 | if (!size) |
158 | return NULL; |
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159 | |||
1048 | jermar | 160 | /* Writeable executable areas are not supported. */ |
161 | if ((flags & AS_AREA_EXEC) && (flags & AS_AREA_WRITE)) |
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162 | return NULL; |
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703 | jermar | 163 | |
164 | ipl = interrupts_disable(); |
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165 | spinlock_lock(&as->lock); |
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166 | |||
1048 | jermar | 167 | if (!check_area_conflicts(as, base, size, NULL)) { |
168 | spinlock_unlock(&as->lock); |
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169 | interrupts_restore(ipl); |
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170 | return NULL; |
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171 | } |
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703 | jermar | 172 | |
822 | palkovsky | 173 | a = (as_area_t *) malloc(sizeof(as_area_t), 0); |
703 | jermar | 174 | |
822 | palkovsky | 175 | spinlock_initialize(&a->lock, "as_area_lock"); |
176 | |||
1026 | jermar | 177 | a->flags = flags; |
1239 | jermar | 178 | a->attributes = attrs; |
1048 | jermar | 179 | a->pages = SIZE2FRAMES(size); |
822 | palkovsky | 180 | a->base = base; |
181 | |||
1147 | jermar | 182 | btree_insert(&as->as_area_btree, base, (void *) a, NULL); |
822 | palkovsky | 183 | |
703 | jermar | 184 | spinlock_unlock(&as->lock); |
185 | interrupts_restore(ipl); |
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704 | jermar | 186 | |
703 | jermar | 187 | return a; |
188 | } |
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189 | |||
1235 | jermar | 190 | /** Find address space area and change it. |
191 | * |
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192 | * @param as Address space. |
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193 | * @param address Virtual address belonging to the area to be changed. Must be page-aligned. |
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194 | * @param size New size of the virtual memory block starting at address. |
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195 | * @param flags Flags influencing the remap operation. Currently unused. |
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196 | * |
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1306 | jermar | 197 | * @return Zero on success or a value from @ref errno.h otherwise. |
1235 | jermar | 198 | */ |
1306 | jermar | 199 | int as_area_resize(as_t *as, __address address, size_t size, int flags) |
1235 | jermar | 200 | { |
1306 | jermar | 201 | as_area_t *area; |
1235 | jermar | 202 | ipl_t ipl; |
203 | size_t pages; |
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204 | |||
205 | ipl = interrupts_disable(); |
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206 | spinlock_lock(&as->lock); |
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207 | |||
208 | /* |
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209 | * Locate the area. |
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210 | */ |
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211 | area = find_area_and_lock(as, address); |
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212 | if (!area) { |
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213 | spinlock_unlock(&as->lock); |
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214 | interrupts_restore(ipl); |
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1306 | jermar | 215 | return ENOENT; |
1235 | jermar | 216 | } |
217 | |||
218 | if (area->flags & AS_AREA_DEVICE) { |
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219 | /* |
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220 | * Remapping of address space areas associated |
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221 | * with memory mapped devices is not supported. |
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222 | */ |
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223 | spinlock_unlock(&area->lock); |
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224 | spinlock_unlock(&as->lock); |
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225 | interrupts_restore(ipl); |
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1306 | jermar | 226 | return ENOTSUP; |
1235 | jermar | 227 | } |
228 | |||
229 | pages = SIZE2FRAMES((address - area->base) + size); |
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230 | if (!pages) { |
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231 | /* |
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232 | * Zero size address space areas are not allowed. |
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233 | */ |
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234 | spinlock_unlock(&area->lock); |
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235 | spinlock_unlock(&as->lock); |
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236 | interrupts_restore(ipl); |
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1306 | jermar | 237 | return EPERM; |
1235 | jermar | 238 | } |
239 | |||
240 | if (pages < area->pages) { |
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241 | int i; |
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242 | |||
243 | /* |
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244 | * Shrinking the area. |
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245 | * No need to check for overlaps. |
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246 | */ |
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247 | for (i = pages; i < area->pages; i++) { |
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248 | pte_t *pte; |
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249 | |||
250 | /* |
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251 | * Releasing physical memory. |
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252 | * This depends on the fact that the memory was allocated using frame_alloc(). |
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253 | */ |
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254 | page_table_lock(as, false); |
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255 | pte = page_mapping_find(as, area->base + i*PAGE_SIZE); |
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256 | if (pte && PTE_VALID(pte)) { |
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257 | __address frame; |
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258 | |||
259 | ASSERT(PTE_PRESENT(pte)); |
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260 | frame = PTE_GET_FRAME(pte); |
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261 | page_mapping_remove(as, area->base + i*PAGE_SIZE); |
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262 | page_table_unlock(as, false); |
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263 | |||
264 | frame_free(ADDR2PFN(frame)); |
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265 | } else { |
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266 | page_table_unlock(as, false); |
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267 | } |
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268 | } |
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269 | /* |
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270 | * Invalidate TLB's. |
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271 | */ |
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272 | tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages); |
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273 | tlb_invalidate_pages(AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages); |
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274 | tlb_shootdown_finalize(); |
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275 | } else { |
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276 | /* |
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277 | * Growing the area. |
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278 | * Check for overlaps with other address space areas. |
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279 | */ |
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280 | if (!check_area_conflicts(as, address, pages * PAGE_SIZE, area)) { |
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281 | spinlock_unlock(&area->lock); |
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282 | spinlock_unlock(&as->lock); |
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283 | interrupts_restore(ipl); |
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1306 | jermar | 284 | return EADDRNOTAVAIL; |
1235 | jermar | 285 | } |
286 | } |
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287 | |||
288 | area->pages = pages; |
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289 | |||
290 | spinlock_unlock(&area->lock); |
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291 | spinlock_unlock(&as->lock); |
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292 | interrupts_restore(ipl); |
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293 | |||
1306 | jermar | 294 | return 0; |
1235 | jermar | 295 | } |
296 | |||
1306 | jermar | 297 | /** Destroy address space area. |
298 | * |
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299 | * @param as Address space. |
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300 | * @param address Address withing the area to be deleted. |
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301 | * |
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302 | * @return Zero on success or a value from @ref errno.h on failure. |
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303 | */ |
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304 | int as_area_destroy(as_t *as, __address address) |
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305 | { |
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306 | as_area_t *area; |
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307 | __address base; |
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308 | ipl_t ipl; |
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309 | int i; |
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310 | |||
311 | ipl = interrupts_disable(); |
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312 | spinlock_lock(&as->lock); |
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313 | |||
314 | area = find_area_and_lock(as, address); |
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315 | if (!area) { |
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316 | spinlock_unlock(&as->lock); |
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317 | interrupts_restore(ipl); |
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318 | return ENOENT; |
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319 | } |
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320 | |||
321 | base = area->base; |
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322 | for (i = 0; i < area->pages; i++) { |
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323 | pte_t *pte; |
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324 | |||
325 | /* |
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326 | * Releasing physical memory. |
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327 | * Areas mapping memory-mapped devices are treated differently than |
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328 | * areas backing frame_alloc()'ed memory. |
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329 | */ |
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330 | page_table_lock(as, false); |
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331 | pte = page_mapping_find(as, area->base + i*PAGE_SIZE); |
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332 | if (pte && PTE_VALID(pte)) { |
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333 | ASSERT(PTE_PRESENT(pte)); |
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334 | page_mapping_remove(as, area->base + i*PAGE_SIZE); |
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335 | if (area->flags & AS_AREA_DEVICE) { |
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336 | __address frame; |
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337 | frame = PTE_GET_FRAME(pte); |
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338 | frame_free(ADDR2PFN(frame)); |
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339 | } |
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340 | page_table_unlock(as, false); |
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341 | } else { |
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342 | page_table_unlock(as, false); |
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343 | } |
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344 | } |
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345 | /* |
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346 | * Invalidate TLB's. |
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347 | */ |
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348 | tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base, area->pages); |
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349 | tlb_invalidate_pages(AS->asid, area->base, area->pages); |
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350 | tlb_shootdown_finalize(); |
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351 | |||
352 | spinlock_unlock(&area->lock); |
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353 | |||
354 | /* |
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355 | * Remove the empty area from address space. |
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356 | */ |
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357 | btree_remove(&AS->as_area_btree, base, NULL); |
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358 | |||
359 | spinlock_unlock(&AS->lock); |
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360 | interrupts_restore(ipl); |
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361 | return 0; |
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362 | } |
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363 | |||
1235 | jermar | 364 | /** Send address space area to another task. |
365 | * |
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366 | * Address space area is sent to the specified task. |
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367 | * If the destination task is willing to accept the |
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368 | * area, a new area is created according to the |
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369 | * source area. Moreover, any existing mapping |
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370 | * is copied as well, providing thus a mechanism |
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371 | * for sharing group of pages. The source address |
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372 | * space area and any associated mapping is preserved. |
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373 | * |
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1239 | jermar | 374 | * @param dst_id Task ID of the accepting task. |
375 | * @param src_base Base address of the source address space area. |
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1235 | jermar | 376 | * |
1306 | jermar | 377 | * @return Zero on success or ENOENT if there is no such task or |
1235 | jermar | 378 | * if there is no such address space area, |
379 | * EPERM if there was a problem in accepting the area or |
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380 | * ENOMEM if there was a problem in allocating destination |
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381 | * address space area. |
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382 | */ |
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1239 | jermar | 383 | int as_area_send(task_id_t dst_id, __address src_base) |
1235 | jermar | 384 | { |
385 | ipl_t ipl; |
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386 | task_t *t; |
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387 | count_t i; |
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1239 | jermar | 388 | as_t *dst_as; |
1235 | jermar | 389 | __address dst_base; |
1239 | jermar | 390 | int src_flags; |
391 | size_t src_size; |
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392 | as_area_t *src_area, *dst_area; |
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1235 | jermar | 393 | |
394 | ipl = interrupts_disable(); |
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395 | spinlock_lock(&tasks_lock); |
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396 | |||
1239 | jermar | 397 | t = task_find_by_id(dst_id); |
1235 | jermar | 398 | if (!NULL) { |
399 | spinlock_unlock(&tasks_lock); |
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400 | interrupts_restore(ipl); |
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401 | return ENOENT; |
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402 | } |
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403 | |||
404 | spinlock_lock(&t->lock); |
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405 | spinlock_unlock(&tasks_lock); |
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406 | |||
1239 | jermar | 407 | dst_as = t->as; |
1235 | jermar | 408 | dst_base = (__address) t->accept_arg.base; |
409 | |||
1239 | jermar | 410 | if (dst_as == AS) { |
1235 | jermar | 411 | /* |
412 | * The two tasks share the entire address space. |
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413 | * Return error since there is no point in continuing. |
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414 | */ |
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415 | spinlock_unlock(&t->lock); |
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416 | interrupts_restore(ipl); |
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417 | return EPERM; |
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418 | } |
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1238 | jermar | 419 | |
420 | spinlock_lock(&AS->lock); |
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1239 | jermar | 421 | src_area = find_area_and_lock(AS, src_base); |
422 | if (!src_area) { |
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1238 | jermar | 423 | /* |
424 | * Could not find the source address space area. |
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425 | */ |
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426 | spinlock_unlock(&t->lock); |
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427 | spinlock_unlock(&AS->lock); |
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428 | interrupts_restore(ipl); |
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429 | return ENOENT; |
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430 | } |
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1239 | jermar | 431 | src_size = src_area->pages * PAGE_SIZE; |
432 | src_flags = src_area->flags; |
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433 | spinlock_unlock(&src_area->lock); |
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1238 | jermar | 434 | spinlock_unlock(&AS->lock); |
1235 | jermar | 435 | |
1239 | jermar | 436 | if ((t->accept_arg.task_id != TASK->taskid) || (t->accept_arg.size != src_size) || |
437 | (t->accept_arg.flags != src_flags)) { |
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1235 | jermar | 438 | /* |
439 | * Discrepancy in either task ID, size or flags. |
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440 | */ |
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441 | spinlock_unlock(&t->lock); |
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442 | interrupts_restore(ipl); |
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443 | return EPERM; |
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444 | } |
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445 | |||
446 | /* |
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1239 | jermar | 447 | * Create copy of the source address space area. |
448 | * The destination area is created with AS_AREA_ATTR_PARTIAL |
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449 | * attribute set which prevents race condition with |
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450 | * preliminary as_page_fault() calls. |
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1235 | jermar | 451 | */ |
1239 | jermar | 452 | dst_area = as_area_create(dst_as, src_flags, src_size, dst_base, AS_AREA_ATTR_PARTIAL); |
453 | if (!dst_area) { |
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1235 | jermar | 454 | /* |
455 | * Destination address space area could not be created. |
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456 | */ |
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457 | spinlock_unlock(&t->lock); |
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458 | interrupts_restore(ipl); |
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459 | return ENOMEM; |
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460 | } |
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461 | |||
462 | memsetb((__address) &t->accept_arg, sizeof(as_area_acptsnd_arg_t), 0); |
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463 | spinlock_unlock(&t->lock); |
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464 | |||
465 | /* |
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466 | * Avoid deadlock by first locking the address space with lower address. |
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467 | */ |
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1239 | jermar | 468 | if (dst_as < AS) { |
469 | spinlock_lock(&dst_as->lock); |
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1235 | jermar | 470 | spinlock_lock(&AS->lock); |
471 | } else { |
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472 | spinlock_lock(&AS->lock); |
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1239 | jermar | 473 | spinlock_lock(&dst_as->lock); |
1235 | jermar | 474 | } |
475 | |||
1239 | jermar | 476 | for (i = 0; i < SIZE2FRAMES(src_size); i++) { |
1235 | jermar | 477 | pte_t *pte; |
478 | __address frame; |
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479 | |||
480 | page_table_lock(AS, false); |
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1239 | jermar | 481 | pte = page_mapping_find(AS, src_base + i*PAGE_SIZE); |
1235 | jermar | 482 | if (pte && PTE_VALID(pte)) { |
483 | ASSERT(PTE_PRESENT(pte)); |
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484 | frame = PTE_GET_FRAME(pte); |
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1239 | jermar | 485 | if (!(src_flags & AS_AREA_DEVICE)) |
1236 | jermar | 486 | frame_reference_add(ADDR2PFN(frame)); |
1235 | jermar | 487 | page_table_unlock(AS, false); |
488 | } else { |
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489 | page_table_unlock(AS, false); |
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490 | continue; |
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491 | } |
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492 | |||
1239 | jermar | 493 | page_table_lock(dst_as, false); |
494 | page_mapping_insert(dst_as, dst_base + i*PAGE_SIZE, frame, area_flags_to_page_flags(src_flags)); |
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495 | page_table_unlock(dst_as, false); |
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1235 | jermar | 496 | } |
1239 | jermar | 497 | |
498 | /* |
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499 | * Now the destination address space area has been |
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500 | * fully initialized. Clear the AS_AREA_ATTR_PARTIAL |
||
501 | * attribute. |
||
502 | */ |
||
503 | spinlock_lock(&dst_area->lock); |
||
504 | dst_area->attributes &= ~AS_AREA_ATTR_PARTIAL; |
||
505 | spinlock_unlock(&dst_area->lock); |
||
1235 | jermar | 506 | |
507 | spinlock_unlock(&AS->lock); |
||
1239 | jermar | 508 | spinlock_unlock(&dst_as->lock); |
1235 | jermar | 509 | interrupts_restore(ipl); |
510 | |||
511 | return 0; |
||
512 | } |
||
513 | |||
754 | jermar | 514 | /** Initialize mapping for one page of address space. |
703 | jermar | 515 | * |
754 | jermar | 516 | * This functions maps 'page' to 'frame' according |
517 | * to attributes of the address space area to |
||
518 | * wich 'page' belongs. |
||
703 | jermar | 519 | * |
840 | jermar | 520 | * @param as Target address space. |
754 | jermar | 521 | * @param page Virtual page within the area. |
522 | * @param frame Physical frame to which page will be mapped. |
||
703 | jermar | 523 | */ |
754 | jermar | 524 | void as_set_mapping(as_t *as, __address page, __address frame) |
703 | jermar | 525 | { |
977 | jermar | 526 | as_area_t *area; |
703 | jermar | 527 | ipl_t ipl; |
528 | |||
529 | ipl = interrupts_disable(); |
||
1044 | jermar | 530 | page_table_lock(as, true); |
703 | jermar | 531 | |
977 | jermar | 532 | area = find_area_and_lock(as, page); |
754 | jermar | 533 | if (!area) { |
534 | panic("page not part of any as_area\n"); |
||
535 | } |
||
536 | |||
756 | jermar | 537 | page_mapping_insert(as, page, frame, get_area_flags(area)); |
754 | jermar | 538 | |
539 | spinlock_unlock(&area->lock); |
||
1044 | jermar | 540 | page_table_unlock(as, true); |
703 | jermar | 541 | interrupts_restore(ipl); |
542 | } |
||
543 | |||
544 | /** Handle page fault within the current address space. |
||
545 | * |
||
546 | * This is the high-level page fault handler. |
||
547 | * Interrupts are assumed disabled. |
||
548 | * |
||
549 | * @param page Faulting page. |
||
1288 | jermar | 550 | * @param istate Pointer to interrupted state. |
703 | jermar | 551 | * |
1288 | jermar | 552 | * @return 0 on page fault, 1 on success or 2 if the fault was caused by copy_to_uspace() or copy_from_uspace(). |
703 | jermar | 553 | */ |
1288 | jermar | 554 | int as_page_fault(__address page, istate_t *istate) |
703 | jermar | 555 | { |
1044 | jermar | 556 | pte_t *pte; |
977 | jermar | 557 | as_area_t *area; |
703 | jermar | 558 | __address frame; |
559 | |||
560 | ASSERT(AS); |
||
1044 | jermar | 561 | |
703 | jermar | 562 | spinlock_lock(&AS->lock); |
977 | jermar | 563 | area = find_area_and_lock(AS, page); |
703 | jermar | 564 | if (!area) { |
565 | /* |
||
566 | * No area contained mapping for 'page'. |
||
567 | * Signal page fault to low-level handler. |
||
568 | */ |
||
569 | spinlock_unlock(&AS->lock); |
||
1288 | jermar | 570 | goto page_fault; |
703 | jermar | 571 | } |
572 | |||
1239 | jermar | 573 | if (area->attributes & AS_AREA_ATTR_PARTIAL) { |
574 | /* |
||
575 | * The address space area is not fully initialized. |
||
576 | * Avoid possible race by returning error. |
||
577 | */ |
||
578 | spinlock_unlock(&area->lock); |
||
579 | spinlock_unlock(&AS->lock); |
||
1288 | jermar | 580 | goto page_fault; |
1239 | jermar | 581 | } |
582 | |||
1179 | jermar | 583 | ASSERT(!(area->flags & AS_AREA_DEVICE)); |
584 | |||
1044 | jermar | 585 | page_table_lock(AS, false); |
586 | |||
703 | jermar | 587 | /* |
1044 | jermar | 588 | * To avoid race condition between two page faults |
589 | * on the same address, we need to make sure |
||
590 | * the mapping has not been already inserted. |
||
591 | */ |
||
592 | if ((pte = page_mapping_find(AS, page))) { |
||
593 | if (PTE_PRESENT(pte)) { |
||
594 | page_table_unlock(AS, false); |
||
595 | spinlock_unlock(&area->lock); |
||
596 | spinlock_unlock(&AS->lock); |
||
597 | return 1; |
||
598 | } |
||
599 | } |
||
600 | |||
601 | /* |
||
754 | jermar | 602 | * In general, there can be several reasons that |
603 | * can have caused this fault. |
||
604 | * |
||
605 | * - non-existent mapping: the area is a scratch |
||
606 | * area (e.g. stack) and so far has not been |
||
607 | * allocated a frame for the faulting page |
||
608 | * |
||
609 | * - non-present mapping: another possibility, |
||
610 | * currently not implemented, would be frame |
||
611 | * reuse; when this becomes a possibility, |
||
612 | * do not forget to distinguish between |
||
613 | * the different causes |
||
703 | jermar | 614 | */ |
814 | palkovsky | 615 | frame = PFN2ADDR(frame_alloc(ONE_FRAME, 0)); |
754 | jermar | 616 | memsetb(PA2KA(frame), FRAME_SIZE, 0); |
703 | jermar | 617 | |
618 | /* |
||
619 | * Map 'page' to 'frame'. |
||
620 | * Note that TLB shootdown is not attempted as only new information is being |
||
621 | * inserted into page tables. |
||
622 | */ |
||
756 | jermar | 623 | page_mapping_insert(AS, page, frame, get_area_flags(area)); |
1044 | jermar | 624 | page_table_unlock(AS, false); |
703 | jermar | 625 | |
626 | spinlock_unlock(&area->lock); |
||
627 | spinlock_unlock(&AS->lock); |
||
1288 | jermar | 628 | return AS_PF_OK; |
629 | |||
630 | page_fault: |
||
631 | if (!THREAD) |
||
632 | return AS_PF_FAULT; |
||
633 | |||
634 | if (THREAD->in_copy_from_uspace) { |
||
635 | THREAD->in_copy_from_uspace = false; |
||
636 | istate_set_retaddr(istate, (__address) &memcpy_from_uspace_failover_address); |
||
637 | } else if (THREAD->in_copy_to_uspace) { |
||
638 | THREAD->in_copy_to_uspace = false; |
||
639 | istate_set_retaddr(istate, (__address) &memcpy_to_uspace_failover_address); |
||
640 | } else { |
||
641 | return AS_PF_FAULT; |
||
642 | } |
||
643 | |||
644 | return AS_PF_DEFER; |
||
703 | jermar | 645 | } |
646 | |||
823 | jermar | 647 | /** Switch address spaces. |
703 | jermar | 648 | * |
823 | jermar | 649 | * @param old Old address space or NULL. |
650 | * @param new New address space. |
||
703 | jermar | 651 | */ |
823 | jermar | 652 | void as_switch(as_t *old, as_t *new) |
703 | jermar | 653 | { |
654 | ipl_t ipl; |
||
823 | jermar | 655 | bool needs_asid = false; |
703 | jermar | 656 | |
657 | ipl = interrupts_disable(); |
||
823 | jermar | 658 | spinlock_lock(&as_lock); |
703 | jermar | 659 | |
660 | /* |
||
823 | jermar | 661 | * First, take care of the old address space. |
662 | */ |
||
663 | if (old) { |
||
664 | spinlock_lock(&old->lock); |
||
665 | ASSERT(old->refcount); |
||
666 | if((--old->refcount == 0) && (old != AS_KERNEL)) { |
||
667 | /* |
||
668 | * The old address space is no longer active on |
||
669 | * any processor. It can be appended to the |
||
670 | * list of inactive address spaces with assigned |
||
671 | * ASID. |
||
672 | */ |
||
673 | ASSERT(old->asid != ASID_INVALID); |
||
674 | list_append(&old->inactive_as_with_asid_link, &inactive_as_with_asid_head); |
||
675 | } |
||
676 | spinlock_unlock(&old->lock); |
||
677 | } |
||
678 | |||
679 | /* |
||
680 | * Second, prepare the new address space. |
||
681 | */ |
||
682 | spinlock_lock(&new->lock); |
||
683 | if ((new->refcount++ == 0) && (new != AS_KERNEL)) { |
||
684 | if (new->asid != ASID_INVALID) |
||
685 | list_remove(&new->inactive_as_with_asid_link); |
||
686 | else |
||
687 | needs_asid = true; /* defer call to asid_get() until new->lock is released */ |
||
688 | } |
||
689 | SET_PTL0_ADDRESS(new->page_table); |
||
690 | spinlock_unlock(&new->lock); |
||
691 | |||
692 | if (needs_asid) { |
||
693 | /* |
||
694 | * Allocation of new ASID was deferred |
||
695 | * until now in order to avoid deadlock. |
||
696 | */ |
||
697 | asid_t asid; |
||
698 | |||
699 | asid = asid_get(); |
||
700 | spinlock_lock(&new->lock); |
||
701 | new->asid = asid; |
||
702 | spinlock_unlock(&new->lock); |
||
703 | } |
||
704 | spinlock_unlock(&as_lock); |
||
705 | interrupts_restore(ipl); |
||
706 | |||
707 | /* |
||
703 | jermar | 708 | * Perform architecture-specific steps. |
727 | jermar | 709 | * (e.g. write ASID to hardware register etc.) |
703 | jermar | 710 | */ |
823 | jermar | 711 | as_install_arch(new); |
703 | jermar | 712 | |
823 | jermar | 713 | AS = new; |
703 | jermar | 714 | } |
754 | jermar | 715 | |
1235 | jermar | 716 | /** Convert address space area flags to page flags. |
754 | jermar | 717 | * |
1235 | jermar | 718 | * @param aflags Flags of some address space area. |
754 | jermar | 719 | * |
1235 | jermar | 720 | * @return Flags to be passed to page_mapping_insert(). |
754 | jermar | 721 | */ |
1235 | jermar | 722 | int area_flags_to_page_flags(int aflags) |
754 | jermar | 723 | { |
724 | int flags; |
||
725 | |||
1178 | jermar | 726 | flags = PAGE_USER | PAGE_PRESENT; |
754 | jermar | 727 | |
1235 | jermar | 728 | if (aflags & AS_AREA_READ) |
1026 | jermar | 729 | flags |= PAGE_READ; |
730 | |||
1235 | jermar | 731 | if (aflags & AS_AREA_WRITE) |
1026 | jermar | 732 | flags |= PAGE_WRITE; |
733 | |||
1235 | jermar | 734 | if (aflags & AS_AREA_EXEC) |
1026 | jermar | 735 | flags |= PAGE_EXEC; |
736 | |||
1235 | jermar | 737 | if (!(aflags & AS_AREA_DEVICE)) |
1178 | jermar | 738 | flags |= PAGE_CACHEABLE; |
739 | |||
754 | jermar | 740 | return flags; |
741 | } |
||
756 | jermar | 742 | |
1235 | jermar | 743 | /** Compute flags for virtual address translation subsytem. |
744 | * |
||
745 | * The address space area must be locked. |
||
746 | * Interrupts must be disabled. |
||
747 | * |
||
748 | * @param a Address space area. |
||
749 | * |
||
750 | * @return Flags to be used in page_mapping_insert(). |
||
751 | */ |
||
752 | int get_area_flags(as_area_t *a) |
||
753 | { |
||
754 | return area_flags_to_page_flags(a->flags); |
||
755 | } |
||
756 | |||
756 | jermar | 757 | /** Create page table. |
758 | * |
||
759 | * Depending on architecture, create either address space |
||
760 | * private or global page table. |
||
761 | * |
||
762 | * @param flags Flags saying whether the page table is for kernel address space. |
||
763 | * |
||
764 | * @return First entry of the page table. |
||
765 | */ |
||
766 | pte_t *page_table_create(int flags) |
||
767 | { |
||
768 | ASSERT(as_operations); |
||
769 | ASSERT(as_operations->page_table_create); |
||
770 | |||
771 | return as_operations->page_table_create(flags); |
||
772 | } |
||
977 | jermar | 773 | |
1044 | jermar | 774 | /** Lock page table. |
775 | * |
||
776 | * This function should be called before any page_mapping_insert(), |
||
777 | * page_mapping_remove() and page_mapping_find(). |
||
778 | * |
||
779 | * Locking order is such that address space areas must be locked |
||
780 | * prior to this call. Address space can be locked prior to this |
||
781 | * call in which case the lock argument is false. |
||
782 | * |
||
783 | * @param as Address space. |
||
1248 | jermar | 784 | * @param lock If false, do not attempt to lock as->lock. |
1044 | jermar | 785 | */ |
786 | void page_table_lock(as_t *as, bool lock) |
||
787 | { |
||
788 | ASSERT(as_operations); |
||
789 | ASSERT(as_operations->page_table_lock); |
||
790 | |||
791 | as_operations->page_table_lock(as, lock); |
||
792 | } |
||
793 | |||
794 | /** Unlock page table. |
||
795 | * |
||
796 | * @param as Address space. |
||
1248 | jermar | 797 | * @param unlock If false, do not attempt to unlock as->lock. |
1044 | jermar | 798 | */ |
799 | void page_table_unlock(as_t *as, bool unlock) |
||
800 | { |
||
801 | ASSERT(as_operations); |
||
802 | ASSERT(as_operations->page_table_unlock); |
||
803 | |||
804 | as_operations->page_table_unlock(as, unlock); |
||
805 | } |
||
806 | |||
977 | jermar | 807 | |
808 | /** Find address space area and lock it. |
||
809 | * |
||
810 | * The address space must be locked and interrupts must be disabled. |
||
811 | * |
||
812 | * @param as Address space. |
||
813 | * @param va Virtual address. |
||
814 | * |
||
815 | * @return Locked address space area containing va on success or NULL on failure. |
||
816 | */ |
||
817 | as_area_t *find_area_and_lock(as_t *as, __address va) |
||
818 | { |
||
819 | as_area_t *a; |
||
1147 | jermar | 820 | btree_node_t *leaf, *lnode; |
821 | int i; |
||
977 | jermar | 822 | |
1147 | jermar | 823 | a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf); |
824 | if (a) { |
||
825 | /* va is the base address of an address space area */ |
||
977 | jermar | 826 | spinlock_lock(&a->lock); |
1147 | jermar | 827 | return a; |
828 | } |
||
829 | |||
830 | /* |
||
1150 | jermar | 831 | * Search the leaf node and the righmost record of its left neighbour |
1147 | jermar | 832 | * to find out whether this is a miss or va belongs to an address |
833 | * space area found there. |
||
834 | */ |
||
835 | |||
836 | /* First, search the leaf node itself. */ |
||
837 | for (i = 0; i < leaf->keys; i++) { |
||
838 | a = (as_area_t *) leaf->value[i]; |
||
839 | spinlock_lock(&a->lock); |
||
840 | if ((a->base <= va) && (va < a->base + a->pages * PAGE_SIZE)) { |
||
841 | return a; |
||
842 | } |
||
843 | spinlock_unlock(&a->lock); |
||
844 | } |
||
977 | jermar | 845 | |
1147 | jermar | 846 | /* |
1150 | jermar | 847 | * Second, locate the left neighbour and test its last record. |
1148 | jermar | 848 | * Because of its position in the B+tree, it must have base < va. |
1147 | jermar | 849 | */ |
1150 | jermar | 850 | if ((lnode = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) { |
1147 | jermar | 851 | a = (as_area_t *) lnode->value[lnode->keys - 1]; |
852 | spinlock_lock(&a->lock); |
||
853 | if (va < a->base + a->pages * PAGE_SIZE) { |
||
1048 | jermar | 854 | return a; |
1147 | jermar | 855 | } |
977 | jermar | 856 | spinlock_unlock(&a->lock); |
857 | } |
||
858 | |||
859 | return NULL; |
||
860 | } |
||
1048 | jermar | 861 | |
862 | /** Check area conflicts with other areas. |
||
863 | * |
||
864 | * The address space must be locked and interrupts must be disabled. |
||
865 | * |
||
866 | * @param as Address space. |
||
867 | * @param va Starting virtual address of the area being tested. |
||
868 | * @param size Size of the area being tested. |
||
869 | * @param avoid_area Do not touch this area. |
||
870 | * |
||
871 | * @return True if there is no conflict, false otherwise. |
||
872 | */ |
||
873 | bool check_area_conflicts(as_t *as, __address va, size_t size, as_area_t *avoid_area) |
||
874 | { |
||
875 | as_area_t *a; |
||
1147 | jermar | 876 | btree_node_t *leaf, *node; |
877 | int i; |
||
1048 | jermar | 878 | |
1070 | jermar | 879 | /* |
880 | * We don't want any area to have conflicts with NULL page. |
||
881 | */ |
||
882 | if (overlaps(va, size, NULL, PAGE_SIZE)) |
||
883 | return false; |
||
884 | |||
1147 | jermar | 885 | /* |
886 | * The leaf node is found in O(log n), where n is proportional to |
||
887 | * the number of address space areas belonging to as. |
||
888 | * The check for conflicts is then attempted on the rightmost |
||
1150 | jermar | 889 | * record in the left neighbour, the leftmost record in the right |
890 | * neighbour and all records in the leaf node itself. |
||
1147 | jermar | 891 | */ |
1048 | jermar | 892 | |
1147 | jermar | 893 | if ((a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf))) { |
894 | if (a != avoid_area) |
||
895 | return false; |
||
896 | } |
||
897 | |||
898 | /* First, check the two border cases. */ |
||
1150 | jermar | 899 | if ((node = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) { |
1147 | jermar | 900 | a = (as_area_t *) node->value[node->keys - 1]; |
901 | spinlock_lock(&a->lock); |
||
902 | if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) { |
||
903 | spinlock_unlock(&a->lock); |
||
904 | return false; |
||
905 | } |
||
906 | spinlock_unlock(&a->lock); |
||
907 | } |
||
1150 | jermar | 908 | if ((node = btree_leaf_node_right_neighbour(&as->as_area_btree, leaf))) { |
1147 | jermar | 909 | a = (as_area_t *) node->value[0]; |
910 | spinlock_lock(&a->lock); |
||
911 | if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) { |
||
912 | spinlock_unlock(&a->lock); |
||
913 | return false; |
||
914 | } |
||
915 | spinlock_unlock(&a->lock); |
||
916 | } |
||
917 | |||
918 | /* Second, check the leaf node. */ |
||
919 | for (i = 0; i < leaf->keys; i++) { |
||
920 | a = (as_area_t *) leaf->value[i]; |
||
921 | |||
1048 | jermar | 922 | if (a == avoid_area) |
923 | continue; |
||
1147 | jermar | 924 | |
1048 | jermar | 925 | spinlock_lock(&a->lock); |
1147 | jermar | 926 | if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) { |
927 | spinlock_unlock(&a->lock); |
||
928 | return false; |
||
929 | } |
||
1048 | jermar | 930 | spinlock_unlock(&a->lock); |
931 | } |
||
932 | |||
1070 | jermar | 933 | /* |
934 | * So far, the area does not conflict with other areas. |
||
935 | * Check if it doesn't conflict with kernel address space. |
||
936 | */ |
||
937 | if (!KERNEL_ADDRESS_SPACE_SHADOWED) { |
||
938 | return !overlaps(va, size, |
||
939 | KERNEL_ADDRESS_SPACE_START, KERNEL_ADDRESS_SPACE_END-KERNEL_ADDRESS_SPACE_START); |
||
940 | } |
||
941 | |||
1048 | jermar | 942 | return true; |
943 | } |
||
1235 | jermar | 944 | |
945 | /* |
||
946 | * Address space related syscalls. |
||
947 | */ |
||
948 | |||
949 | /** Wrapper for as_area_create(). */ |
||
950 | __native sys_as_area_create(__address address, size_t size, int flags) |
||
951 | { |
||
1239 | jermar | 952 | if (as_area_create(AS, flags, size, address, AS_AREA_ATTR_NONE)) |
1235 | jermar | 953 | return (__native) address; |
954 | else |
||
955 | return (__native) -1; |
||
956 | } |
||
957 | |||
958 | /** Wrapper for as_area_resize. */ |
||
959 | __native sys_as_area_resize(__address address, size_t size, int flags) |
||
960 | { |
||
1306 | jermar | 961 | return (__native) as_area_resize(AS, address, size, 0); |
1235 | jermar | 962 | } |
963 | |||
1306 | jermar | 964 | /** Wrapper for as_area_destroy. */ |
965 | __native sys_as_area_destroy(__address address) |
||
966 | { |
||
967 | return (__native) as_area_destroy(AS, address); |
||
968 | } |
||
969 | |||
1235 | jermar | 970 | /** Prepare task for accepting address space area from another task. |
971 | * |
||
972 | * @param uspace_accept_arg Accept structure passed from userspace. |
||
973 | * |
||
974 | * @return EPERM if the task ID encapsulated in @uspace_accept_arg references |
||
975 | * TASK. Otherwise zero is returned. |
||
976 | */ |
||
977 | __native sys_as_area_accept(as_area_acptsnd_arg_t *uspace_accept_arg) |
||
978 | { |
||
979 | as_area_acptsnd_arg_t arg; |
||
1288 | jermar | 980 | int rc; |
1235 | jermar | 981 | |
1288 | jermar | 982 | rc = copy_from_uspace(&arg, uspace_accept_arg, sizeof(as_area_acptsnd_arg_t)); |
983 | if (rc != 0) |
||
984 | return rc; |
||
1235 | jermar | 985 | |
986 | if (!arg.size) |
||
987 | return (__native) EPERM; |
||
988 | |||
989 | if (arg.task_id == TASK->taskid) { |
||
990 | /* |
||
991 | * Accepting from itself is not allowed. |
||
992 | */ |
||
993 | return (__native) EPERM; |
||
994 | } |
||
995 | |||
996 | memcpy(&TASK->accept_arg, &arg, sizeof(as_area_acptsnd_arg_t)); |
||
997 | |||
998 | return 0; |
||
999 | } |
||
1000 | |||
1001 | /** Wrapper for as_area_send. */ |
||
1002 | __native sys_as_area_send(as_area_acptsnd_arg_t *uspace_send_arg) |
||
1003 | { |
||
1004 | as_area_acptsnd_arg_t arg; |
||
1288 | jermar | 1005 | int rc; |
1235 | jermar | 1006 | |
1288 | jermar | 1007 | rc = copy_from_uspace(&arg, uspace_send_arg, sizeof(as_area_acptsnd_arg_t)); |
1008 | if (rc != 0) |
||
1009 | return rc; |
||
1235 | jermar | 1010 | |
1011 | if (!arg.size) |
||
1012 | return (__native) EPERM; |
||
1013 | |||
1014 | if (arg.task_id == TASK->taskid) { |
||
1015 | /* |
||
1016 | * Sending to itself is not allowed. |
||
1017 | */ |
||
1018 | return (__native) EPERM; |
||
1019 | } |
||
1020 | |||
1238 | jermar | 1021 | return (__native) as_area_send(arg.task_id, (__address) arg.base); |
1235 | jermar | 1022 | } |