source: trunk/kernel/mm/mapper.c @ 296

Last change on this file since 296 was 296, checked in by alain, 4 years ago

Several modifs in the generic scheduler and in the hal_context to
fix the context switch mechanism.

File size: 11.7 KB
Line 
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 <memcpy.h>
33#include <thread.h>
34#include <core.h>
35#include <process.h>
36#include <kmem.h>
37#include <kcm.h>
38#include <page.h>
39#include <cluster.h>
40#include <vfs.h>
41#include <mapper.h>
42
43//////////////////////////////////////////////
44mapper_t * mapper_create( vfs_fs_type_t type )
45{
46    mapper_t * mapper;
47    kmem_req_t req;
48    error_t    error;
49
50    // allocate memory for associated mapper
51    req.type  = KMEM_MAPPER;
52    req.size  = sizeof(mapper_t);
53    req.flags = AF_KERNEL | AF_ZERO;
54    mapper    = (mapper_t *)kmem_alloc( &req );
55
56    if( mapper == NULL )
57    {
58        printk("\n[ERROR] in %s : no memory for mapper descriptor\n", __FUNCTION__ );
59        return NULL;
60    }
61
62    // initialize refcount & inode
63    mapper->refcount = 0;
64    mapper->inode    = NULL;
65
66    // initialize radix tree
67    error = grdxt_init( &mapper->radix,
68                        CONFIG_VMM_GRDXT_W1,
69                        CONFIG_VMM_GRDXT_W2,
70                        CONFIG_VMM_GRDXT_W3 );
71
72    if( error )
73    {
74        printk("\n[ERROR] in %s : cannot initialize radix tree\n", __FUNCTION__ );
75        req.type  = KMEM_MAPPER;
76        req.ptr   = mapper;
77        kmem_free( &req );
78        return NULL;
79    }
80
81    // initialize mapper type
82    mapper->type = type;
83
84    // initialize mapper lock
85    rwlock_init(  &mapper->lock );
86
87    // initialize waiting threads xlist (empty)
88    xlist_root_init( XPTR( local_cxy , &mapper->wait_root ) );
89
90    // initialize vsegs xlist (empty)
91    xlist_root_init( XPTR( local_cxy , &mapper->vsegs_root ) );
92
93    return mapper;
94
95}  // end mapper_create()
96
97///////////////////////////////////////////
98error_t mapper_destroy( mapper_t * mapper )
99{
100    page_t   * page;
101    uint32_t   found_index = 0;
102    uint32_t   start_index = 0;
103    kmem_req_t req;
104    error_t    error;
105
106    // scan radix three and release all registered pages to PPM
107    do
108    {
109        // get page from radix tree
110        page = (page_t *)grdxt_get_first( &mapper->radix , start_index , &found_index );
111
112        if( page != NULL )
113        {
114            // remove page from mapper and release to PPM
115            error = mapper_release_page( mapper , page );
116
117            if ( error ) return error;
118
119            // update start_key value for next page
120            start_index = found_index;
121        }
122    }
123    while( page != NULL );
124
125    // release the memory allocated to radix-tree itself
126    grdxt_destroy( &mapper->radix );
127
128    // release memory for mapper descriptor
129    req.type = KMEM_MAPPER;
130    req.ptr  = mapper;
131    kmem_free( &req );
132
133    return 0;
134
135}  // end mapper_destroy()
136
137////////////////////////////////////////////
138page_t * mapper_get_page( mapper_t * mapper,
139                          uint32_t   index )
140{
141    kmem_req_t    req;
142    page_t      * page;
143    error_t       error;
144
145    mapper_dmsg("\n[INFO] %s : enters for page %d in mapper %x\n",
146                __FUNCTION__ , index , mapper );
147
148    thread_t * this = CURRENT_THREAD;
149
150    // take mapper lock in READ_MODE
151    rwlock_rd_lock( &mapper->lock );
152
153    // search page in radix tree
154    page = (page_t *)grdxt_lookup( &mapper->radix , index );
155
156    // test if page available in mapper
157    if( ( page == NULL) || page_is_flag( page , PG_INLOAD ) )  // page not available
158    {
159
160        // release the lock in READ_MODE and take it in WRITE_MODE
161        rwlock_rd_unlock( &mapper->lock );
162        rwlock_wr_lock( &mapper->lock );
163
164        // second test on missing page because the page status can have been modified
165        // by another thread, when passing from READ_MODE to WRITE_MODE.
166        // from this point there is no concurrent accesses to mapper.
167
168        page = grdxt_lookup( &mapper->radix , index );
169
170        if ( page == NULL )   // missing page => create it and load it from file system
171        {
172            mapper_dmsg("\n[INFO] %s : missing page => load from device\n", __FUNCTION__ );
173
174            // allocate one page from PPM
175            req.type  = KMEM_PAGE;
176            req.size  = 0;
177            req.flags = AF_NONE;
178            page = kmem_alloc( &req );
179
180            if( page == NULL )
181            {
182                printk("\n[ERROR] in %s : thread %x cannot allocate a page in cluster %x\n",
183                       __FUNCTION__ , this->trdid , local_cxy );
184                rwlock_wr_unlock( &mapper->lock );
185                return NULL;
186            }
187
188            // initialize the page descriptor
189            page_init( page );
190            page_set_flag( page , PG_INIT );
191            page_set_flag( page , PG_INLOAD );
192            page_refcount_up( page );
193            page->mapper = mapper;
194            page->index  = index;
195
196            // insert page in mapper radix tree
197            error = grdxt_insert( &mapper->radix, index , page );
198
199            // release mapper lock from WRITE_MODE
200            rwlock_wr_unlock( &mapper->lock );
201
202            if( error )
203            {
204                printk("\n[ERROR] in %s : thread %x cannot insert page in mapper\n",
205                       __FUNCTION__ , this->trdid );
206                mapper_release_page( mapper , page );
207                page_clear_flag( page , PG_ALL );
208                req.ptr  = page;
209                req.type = KMEM_PAGE;
210                kmem_free(&req);
211                return NULL;
212            }
213
214            // update the mapper and index fields in page descriptor
215            // required by the vfs_move_page_to_mapper()
216            page->mapper = mapper;
217            page->index  = index;
218
219            // launch I/O operation to load page from file system
220            error = vfs_mapper_move_page( page , true );   // to mapper
221
222            if( error )
223            {
224                printk("\n[ERROR] in %s : thread %x cannot load page from device\n",
225                       __FUNCTION__ , this->trdid );
226                mapper_release_page( mapper , page );
227                page_clear_flag( page , PG_ALL );
228                req.ptr  = page;
229                req.type = KMEM_PAGE;
230                kmem_free( &req );
231                return NULL;
232            }
233
234            // reset the page INLOAD flag to make the page available to all readers
235            page_clear_flag( page , PG_INLOAD );
236
237        }
238        else if( page_is_flag( page , PG_INLOAD ) )   // page is loaded by another thread
239        {
240            // release mapper lock from WRITE_MODE
241            rwlock_wr_unlock( &mapper->lock );
242
243            // deschedule to wait load completion
244            while( 1 )
245            {
246                // exit waiting loop when loaded
247                if(  page_is_flag( page , PG_INLOAD ) ) break;
248
249                // deschedule
250                sched_yield( NULL );
251            }
252        }
253    }
254    else                          // page available in mapper
255    {
256
257        rwlock_rd_unlock( &mapper->lock );
258    }
259
260    mapper_dmsg("\n[INFO] %s : exit for page %d in mapper %x / page_desc = %x\n",
261                __FUNCTION__ , index , mapper , page );
262
263    return page;
264
265}  // end mapper_get_page()
266
267///////////////////////////////////////////////
268error_t mapper_release_page( mapper_t * mapper,
269                             page_t   * page )
270{
271    error_t error;
272
273    // lauch IO operation to update page to file system
274    error = vfs_mapper_move_page( page , false );    // from mapper
275
276    if( error )
277    {
278        printk("\n[ERROR] in %s : cannot update file system\n", __FUNCTION__ );
279        return EIO;
280    }
281
282    // take mapper lock in WRITE_MODE
283    rwlock_wr_lock( &mapper->lock );
284
285    // remove physical page from radix tree
286    grdxt_remove( &mapper->radix , page->index );
287
288    // release mapper lock from WRITE_MODE
289    rwlock_wr_unlock( &mapper->lock );
290
291    // release page to PPM
292    kmem_req_t   req;
293    req.type  = KMEM_PAGE;
294    req.ptr   = page;
295    kmem_free( &req );
296
297    return 0;
298
299}  // end mapper_release_page()
300
301////////////////////////////////////////////////
302error_t mapper_move_buffer( mapper_t  *  mapper,
303                            bool_t       to_buffer,
304                            bool_t       is_user,
305                            uint32_t     file_offset,
306                            void      *  buffer,
307                            uint32_t     size )
308{
309    uint32_t   page_offset;    // first byte to move to/from a mapper page
310    uint32_t   page_count;     // number of bytes to move to/from a mapper page
311    uint32_t   index;          // current mapper page index
312    uint32_t   done;           // number of moved bytes
313    page_t   * page;           // current mapper page descriptor
314    uint8_t  * map_ptr;        // current mapper  address
315    uint8_t  * buf_ptr;        // current buffer  address
316 
317    mapper_dmsg("\n[INFO] %s : enters / to_buf = %d / buffer = %x\n",
318                __FUNCTION__ , to_buffer , buffer );
319
320    // compute offsets of first and last bytes in file
321    uint32_t min_byte = file_offset;
322    uint32_t max_byte = file_offset + size -1;
323
324    // compute indexes of pages for first and last byte in mapper
325    uint32_t first = min_byte >> CONFIG_PPM_PAGE_SHIFT;
326    uint32_t last  = max_byte >> CONFIG_PPM_PAGE_SHIFT;
327
328    done = 0;
329
330    // loop on pages in mapper
331    for( index = first ; index <= last ; index++ )
332    {
333        // compute page_offset
334        if( index == first ) page_offset = min_byte & CONFIG_PPM_PAGE_MASK;
335        else                 page_offset = 0;
336
337        // compute page_count
338        if      ( first == last  ) page_count = size;
339        else if ( index == first ) page_count = CONFIG_PPM_PAGE_SIZE - page_offset;
340        else if ( index == last  ) page_count = (max_byte & CONFIG_PPM_PAGE_MASK) + 1;
341        else                       page_count = CONFIG_PPM_PAGE_SIZE;
342
343        mapper_dmsg("\n[INFO] %s : index = %d / offset = %d / count = %d\n",
344                    __FUNCTION__ , index , page_offset , page_count );
345
346        // get page descriptor
347        page = mapper_get_page( mapper , index );
348
349        if ( page == NULL ) return EINVAL;
350
351        // compute pointer in mapper
352        map_ptr = (uint8_t *)ppm_page2vaddr( page ) + page_offset;
353
354        // compute pointer in buffer
355        buf_ptr = (uint8_t *)buffer + done;
356
357        mapper_dmsg("\n[INFO] %s : index = %d / buf_ptr = %x / map_ptr = %x\n",
358                    __FUNCTION__ , index , buf_ptr , map_ptr );
359
360        // move fragment
361        if( to_buffer )
362        {
363            if( is_user ) hal_copy_to_uspace( buf_ptr , map_ptr , page_count );
364            else          memcpy( buf_ptr , map_ptr , page_count );
365        }
366        else                 
367        {
368            page_do_dirty( page );
369            if( is_user ) hal_copy_from_uspace( map_ptr , buf_ptr , page_count );
370            else          memcpy( map_ptr , buf_ptr , page_count );
371        }
372
373        done += page_count;
374    }
375
376    mapper_dmsg("\n[INFO] %s : exit for buffer %x\n",
377                __FUNCTION__, buffer );
378
379    return 0;
380
381}  // end mapper_move_buffer()
382
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