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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>
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#include <mm/tlb.h>
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#include <mm/heap.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>
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#include <list.h>
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#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();
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    AS_KERNEL = as_create(FLAG_AS_KERNEL);
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        if (!AS_KERNEL)
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                panic("can't create kernel address space\n");
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}
72
 
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
 
81
    as = (as_t *) malloc(sizeof(as_t));
82
    if (as) {
727 jermar 83
        list_initialize(&as->as_with_asid_link);
703 jermar 84
        spinlock_initialize(&as->lock, "as_lock");
85
        list_initialize(&as->as_area_head);
86
 
755 jermar 87
        if (flags & FLAG_AS_KERNEL)
727 jermar 88
            as->asid = ASID_KERNEL;
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        else
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            as->asid = ASID_INVALID;
703 jermar 91
 
756 jermar 92
        as->page_table = page_table_create(flags);
703 jermar 93
    }
94
 
95
    return as;
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}
97
 
98
/** 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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 *
102
 * @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.
108
 */
109
as_area_t *as_area_create(as_t *as, as_area_type_t type, size_t size, __address base)
110
{
111
    ipl_t ipl;
112
    as_area_t *a;
113
 
114
    if (base % PAGE_SIZE)
115
        panic("addr not aligned to a page boundary");
116
 
117
    ipl = interrupts_disable();
118
    spinlock_lock(&as->lock);
119
 
120
    /*
121
     * TODO: test as_area which is to be created doesn't overlap with an existing one.
122
     */
123
 
124
    a = (as_area_t *) malloc(sizeof(as_area_t));
754 jermar 125
    if (a) {   
703 jermar 126
        spinlock_initialize(&a->lock, "as_area_lock");
127
 
128
        link_initialize(&a->link);         
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        a->type = type;
130
        a->size = size;
131
        a->base = base;
132
 
133
        list_append(&a->link, &as->as_area_head);
134
    }
135
 
136
    spinlock_unlock(&as->lock);
137
    interrupts_restore(ipl);
704 jermar 138
 
703 jermar 139
    return a;
140
}
141
 
754 jermar 142
/** Initialize mapping for one page of address space.
703 jermar 143
 *
754 jermar 144
 * This functions maps 'page' to 'frame' according
145
 * to attributes of the address space area to
146
 * wich 'page' belongs.
703 jermar 147
 *
754 jermar 148
 * @param a Target address space.
149
 * @param page Virtual page within the area.
150
 * @param frame Physical frame to which page will be mapped.
703 jermar 151
 */
754 jermar 152
void as_set_mapping(as_t *as, __address page, __address frame)
703 jermar 153
{
754 jermar 154
    as_area_t *a, *area = NULL;
155
    link_t *cur;
703 jermar 156
    ipl_t ipl;
157
 
158
    ipl = interrupts_disable();
754 jermar 159
    spinlock_lock(&as->lock);
703 jermar 160
 
754 jermar 161
    /*
162
     * First, try locate an area.
163
     */
164
    for (cur = as->as_area_head.next; cur != &as->as_area_head; cur = cur->next) {
165
        a = list_get_instance(cur, as_area_t, link);
166
        spinlock_lock(&a->lock);
167
 
168
        if ((page >= a->base) && (page < a->base + a->size * PAGE_SIZE)) {
169
            area = a;
170
            break;
171
        }
172
 
173
        spinlock_unlock(&a->lock);
174
    }
718 decky 175
 
754 jermar 176
    if (!area) {
177
        panic("page not part of any as_area\n");
178
    }
179
 
180
    /*
181
     * Note: area->lock is held.
182
     */
183
 
756 jermar 184
    page_mapping_insert(as, page, frame, get_area_flags(area));
754 jermar 185
 
186
    spinlock_unlock(&area->lock);
187
    spinlock_unlock(&as->lock);
703 jermar 188
    interrupts_restore(ipl);
189
}
190
 
191
/** Handle page fault within the current address space.
192
 *
193
 * This is the high-level page fault handler.
194
 * Interrupts are assumed disabled.
195
 *
196
 * @param page Faulting page.
197
 *
704 jermar 198
 * @return 0 on page fault, 1 on success.
703 jermar 199
 */
200
int as_page_fault(__address page)
201
{
202
    link_t *cur;
203
    as_area_t *a, *area = NULL;
204
    __address frame;
205
 
206
    ASSERT(AS);
207
    spinlock_lock(&AS->lock);
208
 
209
    /*
210
     * Search this areas of this address space for presence of 'page'.
211
     */
212
    for (cur = AS->as_area_head.next; cur != &AS->as_area_head; cur = cur->next) {
213
        a = list_get_instance(cur, as_area_t, link);
214
        spinlock_lock(&a->lock);
215
 
216
        if ((page >= a->base) && (page < a->base + a->size * PAGE_SIZE)) {
217
 
218
            /*
219
             * We found the area containing 'page'.
220
             * TODO: access checking
221
             */
222
            area = a;
223
            break;
224
        }
225
 
226
        spinlock_unlock(&a->lock);
227
    }
228
 
229
    if (!area) {
230
        /*
231
         * No area contained mapping for 'page'.
232
         * Signal page fault to low-level handler.
233
         */
234
        spinlock_unlock(&AS->lock);
235
        return 0;
236
    }
237
 
238
    /*
239
     * Note: area->lock is held.
240
     */
241
 
242
    /*
754 jermar 243
     * In general, there can be several reasons that
244
     * can have caused this fault.
245
     *
246
     * - non-existent mapping: the area is a scratch
247
     *   area (e.g. stack) and so far has not been
248
     *   allocated a frame for the faulting page
249
     *
250
     * - non-present mapping: another possibility,
251
     *   currently not implemented, would be frame
252
     *   reuse; when this becomes a possibility,
253
     *   do not forget to distinguish between
254
     *   the different causes
703 jermar 255
     */
754 jermar 256
    frame = frame_alloc(0, ONE_FRAME, NULL);
257
    memsetb(PA2KA(frame), FRAME_SIZE, 0);
703 jermar 258
 
259
    /*
260
     * Map 'page' to 'frame'.
261
     * Note that TLB shootdown is not attempted as only new information is being
262
     * inserted into page tables.
263
     */
756 jermar 264
    page_mapping_insert(AS, page, frame, get_area_flags(area));
703 jermar 265
 
266
    spinlock_unlock(&area->lock);
267
    spinlock_unlock(&AS->lock);
268
 
269
    return 1;
270
}
271
 
272
/** Install address space on CPU.
273
 *
274
 * @param as Address space.
275
 */
276
void as_install(as_t *as)
277
{
278
    ipl_t ipl;
279
 
727 jermar 280
    asid_install(as);
281
 
703 jermar 282
    ipl = interrupts_disable();
283
    spinlock_lock(&as->lock);
756 jermar 284
    ASSERT(as->page_table);
285
    SET_PTL0_ADDRESS(as->page_table);
703 jermar 286
    spinlock_unlock(&as->lock);
287
    interrupts_restore(ipl);
288
 
289
    /*
290
     * Perform architecture-specific steps.
727 jermar 291
     * (e.g. write ASID to hardware register etc.)
703 jermar 292
     */
293
    as_install_arch(as);
294
 
295
    AS = as;
296
}
754 jermar 297
 
298
/** Compute flags for virtual address translation subsytem.
299
 *
300
 * The address space area must be locked.
301
 * Interrupts must be disabled.
302
 *
303
 * @param a Address space area.
304
 *
305
 * @return Flags to be used in page_mapping_insert().
306
 */
307
int get_area_flags(as_area_t *a)
308
{
309
    int flags;
310
 
311
    switch (a->type) {
312
        case AS_AREA_TEXT:
313
            flags = PAGE_EXEC | PAGE_READ | PAGE_USER | PAGE_PRESENT | PAGE_CACHEABLE;
314
            break;
315
        case AS_AREA_DATA:
316
        case AS_AREA_STACK:
317
            flags = PAGE_READ | PAGE_WRITE | PAGE_USER | PAGE_PRESENT | PAGE_CACHEABLE;
318
            break;
319
        default:
320
            panic("unexpected as_area_type_t %d", a->type);
321
    }
322
 
323
    return flags;
324
}
756 jermar 325
 
326
/** Create page table.
327
 *
328
 * Depending on architecture, create either address space
329
 * private or global page table.
330
 *
331
 * @param flags Flags saying whether the page table is for kernel address space.
332
 *
333
 * @return First entry of the page table.
334
 */
335
pte_t *page_table_create(int flags)
336
{
337
        ASSERT(as_operations);
338
        ASSERT(as_operations->page_table_create);
339
 
340
        return as_operations->page_table_create(flags);
341
}