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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>
727 jermar 36
#include <mm/asid.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/mm/as.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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#define KAS_START_INDEX     PTL0_INDEX(KERNEL_ADDRESS_SPACE_START)
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#define KAS_END_INDEX       PTL0_INDEX(KERNEL_ADDRESS_SPACE_END)
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#define KAS_INDICES     (1+(KAS_END_INDEX-KAS_START_INDEX))
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754 jermar 62
static int get_area_flags(as_area_t *a);
703 jermar 63
 
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/** Create address space. */
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/*
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 * FIXME: this interface must be meaningful for all possible VAT
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 *    (Virtual Address Translation) mechanisms.
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 */
727 jermar 69
as_t *as_create(pte_t *ptl0, int flags)
703 jermar 70
{
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    as_t *as;
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73
    as = (as_t *) malloc(sizeof(as_t));
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    if (as) {
727 jermar 75
        list_initialize(&as->as_with_asid_link);
703 jermar 76
        spinlock_initialize(&as->lock, "as_lock");
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        list_initialize(&as->as_area_head);
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755 jermar 79
        if (flags & FLAG_AS_KERNEL)
727 jermar 80
            as->asid = ASID_KERNEL;
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        else
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            as->asid = ASID_INVALID;
703 jermar 83
 
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        as->ptl0 = ptl0;
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        if (!as->ptl0) {
86
            pte_t *src_ptl0, *dst_ptl0;
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88
            src_ptl0 = (pte_t *) PA2KA((__address) GET_PTL0_ADDRESS());
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            dst_ptl0 = (pte_t *) frame_alloc(FRAME_KA | FRAME_PANIC, ONE_FRAME, NULL);
90
 
91
//          memsetb((__address) dst_ptl0, PAGE_SIZE, 0);
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//          memcpy((void *) &dst_ptl0[KAS_START_INDEX], (void *) &src_ptl0[KAS_START_INDEX], KAS_INDICES);
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            memcpy((void *) dst_ptl0,(void *) src_ptl0, PAGE_SIZE);
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            as->ptl0 = (pte_t *) KA2PA((__address) dst_ptl0);
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        }
98
    }
99
 
100
    return as;
101
}
102
 
103
/** 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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 *
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 * @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.
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 */
114
as_area_t *as_area_create(as_t *as, as_area_type_t type, size_t size, __address base)
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{
116
    ipl_t ipl;
117
    as_area_t *a;
118
 
119
    if (base % PAGE_SIZE)
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        panic("addr not aligned to a page boundary");
121
 
122
    ipl = interrupts_disable();
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    spinlock_lock(&as->lock);
124
 
125
    /*
126
     * TODO: test as_area which is to be created doesn't overlap with an existing one.
127
     */
128
 
129
    a = (as_area_t *) malloc(sizeof(as_area_t));
754 jermar 130
    if (a) {   
703 jermar 131
        spinlock_initialize(&a->lock, "as_area_lock");
132
 
133
        link_initialize(&a->link);         
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        a->type = type;
135
        a->size = size;
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        a->base = base;
137
 
138
        list_append(&a->link, &as->as_area_head);
139
    }
140
 
141
    spinlock_unlock(&as->lock);
142
    interrupts_restore(ipl);
704 jermar 143
 
703 jermar 144
    return a;
145
}
146
 
754 jermar 147
/** Initialize mapping for one page of address space.
703 jermar 148
 *
754 jermar 149
 * This functions maps 'page' to 'frame' according
150
 * to attributes of the address space area to
151
 * wich 'page' belongs.
703 jermar 152
 *
754 jermar 153
 * @param a Target address space.
154
 * @param page Virtual page within the area.
155
 * @param frame Physical frame to which page will be mapped.
703 jermar 156
 */
754 jermar 157
void as_set_mapping(as_t *as, __address page, __address frame)
703 jermar 158
{
754 jermar 159
    as_area_t *a, *area = NULL;
160
    link_t *cur;
703 jermar 161
    ipl_t ipl;
162
 
163
    ipl = interrupts_disable();
754 jermar 164
    spinlock_lock(&as->lock);
703 jermar 165
 
754 jermar 166
    /*
167
     * First, try locate an area.
168
     */
169
    for (cur = as->as_area_head.next; cur != &as->as_area_head; cur = cur->next) {
170
        a = list_get_instance(cur, as_area_t, link);
171
        spinlock_lock(&a->lock);
172
 
173
        if ((page >= a->base) && (page < a->base + a->size * PAGE_SIZE)) {
174
            area = a;
175
            break;
176
        }
177
 
178
        spinlock_unlock(&a->lock);
179
    }
718 decky 180
 
754 jermar 181
    if (!area) {
182
        panic("page not part of any as_area\n");
183
    }
184
 
185
    /*
186
     * Note: area->lock is held.
187
     */
188
 
755 jermar 189
    page_mapping_insert(as, page, frame, get_area_flags(area), (__address) as->ptl0);
754 jermar 190
 
191
    spinlock_unlock(&area->lock);
192
    spinlock_unlock(&as->lock);
703 jermar 193
    interrupts_restore(ipl);
194
}
195
 
196
/** Handle page fault within the current address space.
197
 *
198
 * This is the high-level page fault handler.
199
 * Interrupts are assumed disabled.
200
 *
201
 * @param page Faulting page.
202
 *
704 jermar 203
 * @return 0 on page fault, 1 on success.
703 jermar 204
 */
205
int as_page_fault(__address page)
206
{
207
    link_t *cur;
208
    as_area_t *a, *area = NULL;
209
    __address frame;
210
 
211
    ASSERT(AS);
212
    spinlock_lock(&AS->lock);
213
 
214
    /*
215
     * Search this areas of this address space for presence of 'page'.
216
     */
217
    for (cur = AS->as_area_head.next; cur != &AS->as_area_head; cur = cur->next) {
218
        a = list_get_instance(cur, as_area_t, link);
219
        spinlock_lock(&a->lock);
220
 
221
        if ((page >= a->base) && (page < a->base + a->size * PAGE_SIZE)) {
222
 
223
            /*
224
             * We found the area containing 'page'.
225
             * TODO: access checking
226
             */
227
            area = a;
228
            break;
229
        }
230
 
231
        spinlock_unlock(&a->lock);
232
    }
233
 
234
    if (!area) {
235
        /*
236
         * No area contained mapping for 'page'.
237
         * Signal page fault to low-level handler.
238
         */
239
        spinlock_unlock(&AS->lock);
240
        return 0;
241
    }
242
 
243
    /*
244
     * Note: area->lock is held.
245
     */
246
 
247
    /*
754 jermar 248
     * In general, there can be several reasons that
249
     * can have caused this fault.
250
     *
251
     * - non-existent mapping: the area is a scratch
252
     *   area (e.g. stack) and so far has not been
253
     *   allocated a frame for the faulting page
254
     *
255
     * - non-present mapping: another possibility,
256
     *   currently not implemented, would be frame
257
     *   reuse; when this becomes a possibility,
258
     *   do not forget to distinguish between
259
     *   the different causes
703 jermar 260
     */
754 jermar 261
    frame = frame_alloc(0, ONE_FRAME, NULL);
262
    memsetb(PA2KA(frame), FRAME_SIZE, 0);
703 jermar 263
 
264
    /*
265
     * Map 'page' to 'frame'.
266
     * Note that TLB shootdown is not attempted as only new information is being
267
     * inserted into page tables.
268
     */
755 jermar 269
    page_mapping_insert(AS, page, frame, get_area_flags(area), (__address) AS->ptl0);
703 jermar 270
 
271
    spinlock_unlock(&area->lock);
272
    spinlock_unlock(&AS->lock);
273
 
274
    return 1;
275
}
276
 
277
/** Install address space on CPU.
278
 *
279
 * @param as Address space.
280
 */
281
void as_install(as_t *as)
282
{
283
    ipl_t ipl;
284
 
727 jermar 285
    asid_install(as);
286
 
703 jermar 287
    ipl = interrupts_disable();
288
    spinlock_lock(&as->lock);
289
    ASSERT(as->ptl0);
290
    SET_PTL0_ADDRESS(as->ptl0);
291
    spinlock_unlock(&as->lock);
292
    interrupts_restore(ipl);
293
 
294
    /*
295
     * Perform architecture-specific steps.
727 jermar 296
     * (e.g. write ASID to hardware register etc.)
703 jermar 297
     */
298
    as_install_arch(as);
299
 
300
    AS = as;
301
}
754 jermar 302
 
303
/** Compute flags for virtual address translation subsytem.
304
 *
305
 * The address space area must be locked.
306
 * Interrupts must be disabled.
307
 *
308
 * @param a Address space area.
309
 *
310
 * @return Flags to be used in page_mapping_insert().
311
 */
312
int get_area_flags(as_area_t *a)
313
{
314
    int flags;
315
 
316
    switch (a->type) {
317
        case AS_AREA_TEXT:
318
            flags = PAGE_EXEC | PAGE_READ | PAGE_USER | PAGE_PRESENT | PAGE_CACHEABLE;
319
            break;
320
        case AS_AREA_DATA:
321
        case AS_AREA_STACK:
322
            flags = PAGE_READ | PAGE_WRITE | PAGE_USER | PAGE_PRESENT | PAGE_CACHEABLE;
323
            break;
324
        default:
325
            panic("unexpected as_area_type_t %d", a->type);
326
    }
327
 
328
    return flags;
329
}