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703 jermar 1
/*
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 * Copyright (C) 2001-2006 Jakub Jermar
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 * All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 *
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 * - Redistributions of source code must retain the above copyright
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 *   notice, this list of conditions and the following disclaimer.
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 * - Redistributions in binary form must reproduce the above copyright
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 *   notice, this list of conditions and the following disclaimer in the
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 *   documentation and/or other materials provided with the distribution.
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 * - The name of the author may not be used to endorse or promote products
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 *   derived from this software without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 */
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/*
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 * This file contains address space manipulation functions.
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 * Roughly speaking, this is a higher-level client of
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 * Virtual Address Translation (VAT) subsystem.
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 */
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#include <mm/as.h>
756 jermar 36
#include <arch/mm/as.h>
703 jermar 37
#include <mm/page.h>
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#include <mm/frame.h>
814 palkovsky 39
#include <mm/slab.h>
703 jermar 40
#include <mm/tlb.h>
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#include <arch/mm/page.h>
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#include <genarch/mm/page_pt.h>
727 jermar 43
#include <mm/asid.h>
703 jermar 44
#include <arch/mm/asid.h>
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#include <arch/types.h>
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#include <typedefs.h>
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#include <synch/spinlock.h>
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#include <config.h>
788 jermar 49
#include <adt/list.h>
703 jermar 50
#include <panic.h>
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#include <arch/asm.h>
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#include <debug.h>
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#include <memstr.h>
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#include <arch.h>
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#include <print.h>
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756 jermar 57
as_operations_t *as_operations = NULL;
703 jermar 58
 
757 jermar 59
/** Kernel address space. */
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as_t *AS_KERNEL = NULL;
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754 jermar 62
static int get_area_flags(as_area_t *a);
703 jermar 63
 
756 jermar 64
/** Initialize address space subsystem. */
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void as_init(void)
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{
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    as_arch_init();
789 palkovsky 68
    AS_KERNEL = as_create(FLAG_AS_KERNEL);
756 jermar 69
        if (!AS_KERNEL)
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                panic("can't create kernel address space\n");
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}
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757 jermar 73
/** Create address space.
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 *
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 * @param flags Flags that influence way in wich the address space is created.
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 */
756 jermar 77
as_t *as_create(int flags)
703 jermar 78
{
79
    as_t *as;
80
 
822 palkovsky 81
    as = (as_t *) malloc(sizeof(as_t), 0);
703 jermar 82
 
822 palkovsky 83
    list_initialize(&as->as_with_asid_link);
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    spinlock_initialize(&as->lock, "as_lock");
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    list_initialize(&as->as_area_head);
86
 
87
    if (flags & FLAG_AS_KERNEL)
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        as->asid = ASID_KERNEL;
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    else
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        as->asid = ASID_INVALID;
91
 
92
    as->page_table = page_table_create(flags);
703 jermar 93
 
94
    return as;
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}
96
 
97
/** Create address space area of common attributes.
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 *
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 * The created address space area is added to the target address space.
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 *
101
 * @param as Target address space.
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 * @param type Type of area.
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 * @param size Size of area in multiples of PAGE_SIZE.
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 * @param base Base address of area.
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 *
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 * @return Address space area on success or NULL on failure.
107
 */
108
as_area_t *as_area_create(as_t *as, as_area_type_t type, size_t size, __address base)
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{
110
    ipl_t ipl;
111
    as_area_t *a;
112
 
113
    if (base % PAGE_SIZE)
114
        panic("addr not aligned to a page boundary");
115
 
116
    ipl = interrupts_disable();
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    spinlock_lock(&as->lock);
118
 
119
    /*
120
     * TODO: test as_area which is to be created doesn't overlap with an existing one.
121
     */
122
 
822 palkovsky 123
    a = (as_area_t *) malloc(sizeof(as_area_t), 0);
703 jermar 124
 
822 palkovsky 125
    spinlock_initialize(&a->lock, "as_area_lock");
126
 
127
    link_initialize(&a->link);         
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    a->type = type;
129
    a->size = size;
130
    a->base = base;
131
 
132
    list_append(&a->link, &as->as_area_head);
133
 
703 jermar 134
    spinlock_unlock(&as->lock);
135
    interrupts_restore(ipl);
704 jermar 136
 
703 jermar 137
    return a;
138
}
139
 
754 jermar 140
/** Initialize mapping for one page of address space.
703 jermar 141
 *
754 jermar 142
 * This functions maps 'page' to 'frame' according
143
 * to attributes of the address space area to
144
 * wich 'page' belongs.
703 jermar 145
 *
754 jermar 146
 * @param a Target address space.
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 * @param page Virtual page within the area.
148
 * @param frame Physical frame to which page will be mapped.
703 jermar 149
 */
754 jermar 150
void as_set_mapping(as_t *as, __address page, __address frame)
703 jermar 151
{
754 jermar 152
    as_area_t *a, *area = NULL;
153
    link_t *cur;
703 jermar 154
    ipl_t ipl;
155
 
156
    ipl = interrupts_disable();
754 jermar 157
    spinlock_lock(&as->lock);
703 jermar 158
 
754 jermar 159
    /*
160
     * First, try locate an area.
161
     */
162
    for (cur = as->as_area_head.next; cur != &as->as_area_head; cur = cur->next) {
163
        a = list_get_instance(cur, as_area_t, link);
164
        spinlock_lock(&a->lock);
165
 
166
        if ((page >= a->base) && (page < a->base + a->size * PAGE_SIZE)) {
167
            area = a;
168
            break;
169
        }
170
 
171
        spinlock_unlock(&a->lock);
172
    }
718 decky 173
 
754 jermar 174
    if (!area) {
175
        panic("page not part of any as_area\n");
176
    }
177
 
178
    /*
179
     * Note: area->lock is held.
180
     */
181
 
756 jermar 182
    page_mapping_insert(as, page, frame, get_area_flags(area));
754 jermar 183
 
184
    spinlock_unlock(&area->lock);
185
    spinlock_unlock(&as->lock);
703 jermar 186
    interrupts_restore(ipl);
187
}
188
 
189
/** Handle page fault within the current address space.
190
 *
191
 * This is the high-level page fault handler.
192
 * Interrupts are assumed disabled.
193
 *
194
 * @param page Faulting page.
195
 *
704 jermar 196
 * @return 0 on page fault, 1 on success.
703 jermar 197
 */
198
int as_page_fault(__address page)
199
{
200
    link_t *cur;
201
    as_area_t *a, *area = NULL;
202
    __address frame;
203
 
204
    ASSERT(AS);
205
    spinlock_lock(&AS->lock);
206
 
207
    /*
208
     * Search this areas of this address space for presence of 'page'.
209
     */
210
    for (cur = AS->as_area_head.next; cur != &AS->as_area_head; cur = cur->next) {
211
        a = list_get_instance(cur, as_area_t, link);
212
        spinlock_lock(&a->lock);
213
 
214
        if ((page >= a->base) && (page < a->base + a->size * PAGE_SIZE)) {
215
 
216
            /*
217
             * We found the area containing 'page'.
218
             * TODO: access checking
219
             */
220
            area = a;
221
            break;
222
        }
223
 
224
        spinlock_unlock(&a->lock);
225
    }
226
 
227
    if (!area) {
228
        /*
229
         * No area contained mapping for 'page'.
230
         * Signal page fault to low-level handler.
231
         */
232
        spinlock_unlock(&AS->lock);
233
        return 0;
234
    }
235
 
236
    /*
237
     * Note: area->lock is held.
238
     */
239
 
240
    /*
754 jermar 241
     * In general, there can be several reasons that
242
     * can have caused this fault.
243
     *
244
     * - non-existent mapping: the area is a scratch
245
     *   area (e.g. stack) and so far has not been
246
     *   allocated a frame for the faulting page
247
     *
248
     * - non-present mapping: another possibility,
249
     *   currently not implemented, would be frame
250
     *   reuse; when this becomes a possibility,
251
     *   do not forget to distinguish between
252
     *   the different causes
703 jermar 253
     */
814 palkovsky 254
    frame = PFN2ADDR(frame_alloc(ONE_FRAME, 0));
754 jermar 255
    memsetb(PA2KA(frame), FRAME_SIZE, 0);
703 jermar 256
 
257
    /*
258
     * Map 'page' to 'frame'.
259
     * Note that TLB shootdown is not attempted as only new information is being
260
     * inserted into page tables.
261
     */
756 jermar 262
    page_mapping_insert(AS, page, frame, get_area_flags(area));
703 jermar 263
 
264
    spinlock_unlock(&area->lock);
265
    spinlock_unlock(&AS->lock);
266
 
267
    return 1;
268
}
269
 
270
/** Install address space on CPU.
271
 *
272
 * @param as Address space.
273
 */
274
void as_install(as_t *as)
275
{
276
    ipl_t ipl;
277
 
727 jermar 278
    asid_install(as);
279
 
703 jermar 280
    ipl = interrupts_disable();
281
    spinlock_lock(&as->lock);
756 jermar 282
    SET_PTL0_ADDRESS(as->page_table);
703 jermar 283
    spinlock_unlock(&as->lock);
284
    interrupts_restore(ipl);
285
 
286
    /*
287
     * Perform architecture-specific steps.
727 jermar 288
     * (e.g. write ASID to hardware register etc.)
703 jermar 289
     */
290
    as_install_arch(as);
291
 
292
    AS = as;
293
}
754 jermar 294
 
295
/** Compute flags for virtual address translation subsytem.
296
 *
297
 * The address space area must be locked.
298
 * Interrupts must be disabled.
299
 *
300
 * @param a Address space area.
301
 *
302
 * @return Flags to be used in page_mapping_insert().
303
 */
304
int get_area_flags(as_area_t *a)
305
{
306
    int flags;
307
 
308
    switch (a->type) {
309
        case AS_AREA_TEXT:
310
            flags = PAGE_EXEC | PAGE_READ | PAGE_USER | PAGE_PRESENT | PAGE_CACHEABLE;
311
            break;
312
        case AS_AREA_DATA:
313
        case AS_AREA_STACK:
314
            flags = PAGE_READ | PAGE_WRITE | PAGE_USER | PAGE_PRESENT | PAGE_CACHEABLE;
315
            break;
316
        default:
317
            panic("unexpected as_area_type_t %d", a->type);
318
    }
319
 
320
    return flags;
321
}
756 jermar 322
 
323
/** Create page table.
324
 *
325
 * Depending on architecture, create either address space
326
 * private or global page table.
327
 *
328
 * @param flags Flags saying whether the page table is for kernel address space.
329
 *
330
 * @return First entry of the page table.
331
 */
332
pte_t *page_table_create(int flags)
333
{
334
        ASSERT(as_operations);
335
        ASSERT(as_operations->page_table_create);
336
 
337
        return as_operations->page_table_create(flags);
338
}