source: trunk/kernel/mm/mapper.c @ 183

Last change on this file since 183 was 183, checked in by max@…, 5 years ago

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1/*
2 * mapper.c - Map memory, file or device in process virtual address space.
3 *
4 * Authors   Mohamed Lamine Karaoui (2015)
5 *           Alain Greiner (2016)
6 *
7 * Copyright (c)  UPMC Sorbonne Universites
8 *
9 * This file is part of ALMOS-MKH.
10 *
11 * ALMOS-MKH is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; version 2.0 of the License.
14 *
15 * ALMOS-MKH is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
22 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
23 */
24
25#include <kernel_config.h>
26#include <hal_types.h>
27#include <hal_special.h>
28#include <hal_uspace.h>
29#include <grdxt.h>
30#include <rwlock.h>
31#include <printk.h>
32#include <thread.h>
33#include <core.h>
34#include <process.h>
35#include <kmem.h>
36#include <kcm.h>
37#include <page.h>
38#include <cluster.h>
39#include <vfs.h>
40#include <mapper.h>
41
42//////////////////////////
43mapper_t * mapper_create()
44{
45    mapper_t * mapper;
46    kmem_req_t req;
47    error_t    error;
48
49    // allocate memory for associated mapper
50    req.type  = KMEM_MAPPER;
51    req.size  = sizeof(mapper_t);
52    req.flags = AF_KERNEL | AF_ZERO;
53    mapper    = (mapper_t *)kmem_alloc( &req );
54
55    if( mapper == NULL )
56    {
57        printk("\n[ERROR] in %s : no memory for mapper descriptor\n", __FUNCTION__ );
58        return NULL;
59    }
60
61    // initialize refcount & inode
62    mapper->refcount = 0;
63    mapper->inode    = NULL;
64
65    // initialize radix tree
66    error = grdxt_init( &mapper->radix,
67                        CONFIG_VMM_GRDXT_W1,
68                        CONFIG_VMM_GRDXT_W2,
69                        CONFIG_VMM_GRDXT_W3 );
70
71    if( error )
72    {
73        printk("\n[ERROR] in %s : cannot initialize radix tree\n", __FUNCTION__ );
74        req.type  = KMEM_MAPPER;
75        req.ptr   = mapper;
76        kmem_free( &req );
77        return NULL;
78    }
79
80    // initialize mapper lock
81    rwlock_init(  &mapper->lock );
82
83    // initialize waiting threads xlist (empty)
84    xlist_root_init( XPTR( local_cxy , &mapper->wait_root ) );
85
86    // initialize vsegs xlist (empty)
87    xlist_root_init( XPTR( local_cxy , &mapper->vsegs_root ) );
88
89    return mapper;
90}
91
92///////////////////////////////////////////
93error_t mapper_destroy( mapper_t * mapper )
94{
95    page_t   * page;
96    uint32_t   found_index = 0;
97    uint32_t   start_index = 0;
98    kmem_req_t req;
99    error_t    error;
100
101    // scan radix three and release all registered pages to PPM
102    do
103    {
104        // get page from radix tree
105        page = (page_t *)grdxt_get_first( &mapper->radix , start_index , &found_index );
106
107        if( page != NULL )
108        {
109            // remove page from mapper and release to PPM
110            error = mapper_release_page( mapper , page );
111
112            if ( error ) return error;
113
114            // update start_key value for next page
115            start_index = found_index;
116        }
117    }
118    while( page != NULL );
119
120    // release the memory allocated to radix-tree itself
121    grdxt_destroy( &mapper->radix );
122
123    // release memory for mapper descriptor
124    req.type = KMEM_MAPPER;
125    req.ptr  = mapper;
126    kmem_free( &req );
127
128    return 0;
129}
130
131////////////////////////////////////////////
132page_t * mapper_get_page( mapper_t * mapper,
133                          uint32_t   index )
134{
135    kmem_req_t    req;
136    page_t      * page;
137    error_t       error;
138
139    thread_t * this = CURRENT_THREAD;
140
141    // take mapper lock in READ_MODE
142    rwlock_rd_lock( &mapper->lock );
143
144    // search page in radix tree
145    page = (page_t *)grdxt_lookup( &mapper->radix , index );
146
147    // test if page available in mapper
148    if( ( page == NULL) || page_is_flag( page , PG_INLOAD ) )  // page not available
149    {
150        // release the lock in READ_MODE and take it in WRITE_MODE
151        rwlock_rd_unlock( &mapper->lock );
152        rwlock_wr_lock( &mapper->lock );
153
154        // second test on missing page because the page status can have been modified
155        // by another thread, when passing from READ_MODE to WRITE_MODE.
156        // from this point there is no concurrent accesses to mapper.
157
158        page = grdxt_lookup( &mapper->radix , index );
159
160        if ( page == NULL )   // missing page => load it from file system
161        {
162            // allocate one page from PPM
163            req.type  = KMEM_PAGE;
164            req.size  = 0;
165            req.flags = AF_NONE;
166            page = kmem_alloc( &req );
167
168            if( page == NULL )
169            {
170                printk("\n[ERROR] in %s : thread %x cannot allocate a page in cluster %x\n",
171                       __FUNCTION__ , this->trdid , local_cxy );
172                rwlock_wr_unlock( &mapper->lock );
173                return NULL;
174            }
175
176            // initialize the page descriptor
177            page_init( page );
178            page_set_flag( page , PG_INIT );
179            page_set_flag( page , PG_INLOAD );
180            page_refcount_up( page );
181            page->mapper = mapper;
182            page->index  = index;
183
184            // insert page in mapper radix tree
185            error = grdxt_insert( &mapper->radix, index , page );
186
187            // release mapper lock from WRITE_MODE
188            rwlock_wr_unlock( &mapper->lock );
189
190            if( error )
191            {
192                printk("\n[ERROR] in %s : thread %x cannot insert page in mapper\n",
193                       __FUNCTION__ , this->trdid );
194                mapper_release_page( mapper , page );
195                page_clear_flag( page , PG_ALL );
196                req.ptr  = page;
197                req.type = KMEM_PAGE;
198                kmem_free(&req);
199                return NULL;
200            }
201
202            // launch I/O operation to load page from file system
203            error = vfs_move_page_to_mapper( page );
204
205            if( error )
206            {
207                printk("\n[ERROR] in %s : thread %x cannot load page from device\n",
208                       __FUNCTION__ , this->trdid );
209                mapper_release_page( mapper , page );
210                page_clear_flag( page , PG_ALL );
211                req.ptr  = page;
212                req.type = KMEM_PAGE;
213                kmem_free( &req );
214                return NULL;
215            }
216
217            // update the mapper and index fields in page descriptor
218            page->mapper = mapper;
219            page->index  = index;
220
221            // reset the page INLOAD flag to make the page available to all readers
222            page_clear_flag( page , PG_INLOAD );
223
224        }
225        else if( page_is_flag( page , PG_INLOAD ) )   // page is loaded by another thread
226        {
227            // release mapper lock from WRITE_MODE
228            rwlock_wr_unlock( &mapper->lock );
229
230            // deschedule to wait load completion
231            while( 1 )
232            {
233                // exit waiting loop when loaded
234                if(  page_is_flag( page , PG_INLOAD ) ) break;
235
236                // deschedule
237                sched_yield();
238            }
239
240        }
241
242        return page;
243    }
244    else
245    {
246         // release lock from READ_MODE
247         rwlock_rd_unlock( &mapper->lock );
248
249         return page;
250    }
251}
252
253///////////////////////////////////////////////
254error_t mapper_release_page( mapper_t * mapper,
255                             page_t   * page )
256{
257    error_t error;
258
259    // lauch IO operation to update page to file system
260    error = vfs_move_page_from_mapper( page );
261
262    if( error )
263    {
264        printk("\n[ERROR] in %s : cannot update file system\n", __FUNCTION__ );
265        return EIO;
266    }
267
268    // take mapper lock in WRITE_MODE
269    rwlock_wr_lock( &mapper->lock );
270
271    // remove physical page from radix tree
272    grdxt_remove( &mapper->radix , page->index );
273
274    // release mapper lock from WRITE_MODE
275    rwlock_wr_unlock( &mapper->lock );
276
277    // release page to PPM
278    kmem_req_t   req;
279    req.type  = KMEM_PAGE;
280    req.ptr   = page;
281    kmem_free( &req );
282
283    return 0;
284}
285
286/////////////////////////////////////////
287error_t mapper_move( mapper_t  *  mapper,
288                     bool_t       to_buffer,
289                     uint32_t     file_offset,
290                     void      *  buffer,
291                     uint32_t     size )
292{
293    uint32_t   page_offset;    // first byte to move to/from a mapper page
294    uint32_t   page_count;     // number of bytes to move to/from a mapper page
295    uint32_t   index;          // current mapper page index
296    uint32_t   done;           // number of moved bytes
297    page_t   * page;           // current mapper page descriptor
298    uint8_t  * map_ptr;        // current mapper  address
299    uint8_t  * buf_ptr;        // current buffer  address
300
301    // compute offsets of first and last bytes in file
302    uint32_t min_byte = file_offset;
303    uint32_t max_byte = file_offset + size -1;
304
305    // compute indexes of pages for first and last byte in mapper
306    uint32_t first = min_byte >> CONFIG_PPM_PAGE_SHIFT;
307    uint32_t last  = max_byte >> CONFIG_PPM_PAGE_SHIFT;
308
309    done = 0;
310
311    // loop on pages in mapper
312    for( index = first ; index <= last ; index++ )
313    {
314        // compute page_offset
315        if( index == first ) page_offset = min_byte & CONFIG_PPM_PAGE_MASK;
316        else                 page_offset = 0;
317
318        // compute page_count
319        if      ( first == last  ) page_count = size;
320        else if ( index == first ) page_count = CONFIG_PPM_PAGE_SIZE - page_offset;
321        else if ( index == last  ) page_count = (max_byte & CONFIG_PPM_PAGE_MASK) + 1;
322        else                       page_count = CONFIG_PPM_PAGE_SIZE;
323
324        // get page descriptor
325        page = mapper_get_page( mapper , index );
326
327        if ( page == NULL ) return EINVAL;
328
329        // compute pointer in mapper
330        map_ptr = (uint8_t *)ppm_page2vaddr( page ) + page_offset;
331
332        // compute pointer in buffer
333        buf_ptr = (uint8_t *)buffer + done;
334
335        // move fragment
336        if( to_buffer )
337        {
338            hal_copy_to_uspace( buf_ptr , map_ptr , page_count );
339        }
340        else
341        {
342            page_do_dirty( page );
343            hal_copy_from_uspace( map_ptr , buf_ptr , page_count );
344        }
345
346        done += page_count;
347    }
348
349    return 0;
350}
351
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