source: trunk/kernel/mm/kcm.c @ 168

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1/*
2 * kcm.c - Per cluster & per type Kernel Cache Manager access functions
3 *
4 * Author  Ghassan Almaless (2008,2009,2010,2011,2012)
5 *         Alain Greiner    (2016,2017)
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 <list.h>
29#include <printk.h>
30#include <bits.h>
31#include <ppm.h>
32#include <thread.h>
33#include <page.h>
34#include <cluster.h>
35#include <kmem.h>
36#include <kcm.h>
37
38//////////////////////////////////////////////////////////////////////////////////////
39// This static function returns pointer on an allocated block from an active page.
40// It returns NULL if no block available in selected page.
41// It changes the page status if required.
42//////////////////////////////////////////////////////////////////////////////////////
43// @ kcm      : pointer on kcm allocator.
44// @ kcm_page : pointer on active kcm page to use.
45/////////////////////////////////////////////////////////////////////////////////////
46static void * kcm_get_block( kcm_t      * kcm,
47                             kcm_page_t * kcm_page )
48{
49        kcm_dmsg("\n[INFO] %s : enters for %s / page %x / count = %d / active = %d\n",
50                 __FUNCTION__ , kmem_type_str( kcm->type ) ,
51                 (intptr_t)kcm_page , kcm_page->count , kcm_page->active );
52
53        assert( kcm_page->active , __FUNCTION__ , "kcm_page should be active" );
54
55        // get first block available
56        int32_t index = bitmap_ffs( kcm_page->bitmap , kcm->blocks_nr );
57
58        assert( (index != -1) , __FUNCTION__ , "kcm_page should not be full" );
59
60        // allocate block
61        bitmap_clear( kcm_page->bitmap , index );
62
63        // increase kcm_page count
64        kcm_page->count ++;
65
66        // change the kcm_page to busy if no more free block in page
67        if( kcm_page->count >= kcm->blocks_nr )
68        {
69                kcm_page->active = 0;
70                list_unlink( &kcm_page->list);
71                kcm->active_pages_nr --;
72
73                list_add_first( &kcm->busy_root , &kcm_page->list);
74                kcm->busy_pages_nr ++;
75                kcm_page->busy = 1;
76        }
77
78        // compute return pointer
79        void * ptr = (void *)((intptr_t)kcm_page + CONFIG_KCM_SLOT_SIZE
80                     + (index * kcm->block_size) );
81
82        kcm_dmsg("\n[INFO] %s : allocated one block  %s / ptr = %p / page = %x / count = %d\n",
83                 __FUNCTION__ , kmem_type_str( kcm->type ) , ptr ,
84                 (intptr_t)kcm_page , kcm_page->count );
85
86        return ptr;
87}
88
89/////////////////////////////////////////////////////////////////////////////////////
90// This static function releases a previously allocated block.
91// It changes the kcm_page status if required.
92/////////////////////////////////////////////////////////////////////////////////////
93// @ kcm   : pointer on kcm allocator.
94// @ ptr   : pointer on block to be released.
95/////////////////////////////////////////////////////////////////////////////////////
96static void kcm_put_block ( kcm_t * kcm,
97                            void  * ptr )
98{
99        kcm_page_t * kcm_page;
100        uint32_t     index;
101
102        // compute pointer on kcm_page from block pointer
103        kcm_page = (kcm_page_t*)((intptr_t)ptr & ~CONFIG_PPM_PAGE_MASK);
104
105        // compute block index from block pointer
106        index = ((uint8_t *)ptr - (uint8_t *)kcm_page - CONFIG_KCM_SLOT_SIZE) / kcm->block_size;
107
108        bitmap_set( kcm_page->bitmap , index );
109        kcm_page->count --;
110
111        // change the page to active if it was busy
112        if( kcm_page->busy )
113        {
114                kcm_page->busy = 0;
115                list_unlink( &kcm_page->list );
116                kcm->busy_pages_nr --;
117
118                list_add_last( &kcm->active_root, &kcm_page->list );
119                kcm->active_pages_nr ++;
120                kcm_page->active = 1;
121        }
122
123        // change the kcm_page to free if last block in active page
124        if( (kcm_page->active) && (kcm_page->count == 0) )
125        {
126                kcm_page->active = 0;
127                list_unlink( &kcm_page->list);
128                kcm->active_pages_nr --;
129
130                list_add_first( &kcm->free_root , &kcm_page->list);
131                kcm->free_pages_nr ++;
132        }
133}
134
135/////////////////////////////////////////////////////////////////////////////////////
136// This static function allocates one page from PPM. It initializes
137// the kcm_page descriptor, and introduces the new kcm_page into freelist.
138/////////////////////////////////////////////////////////////////////////////////////
139static error_t freelist_populate( kcm_t * kcm )
140{
141        page_t     * page;
142        kcm_page_t * kcm_page;
143        kmem_req_t   req;
144
145        // get one page from local PPM
146        req.type  = KMEM_PAGE;
147        req.size  = 0;
148        req.flags = AF_KERNEL;
149        page = kmem_alloc( &req );
150
151        if( page == NULL )
152        {
153                printk("\n[ERROR] in %s : failed to allocate page in cluster %d\n",
154                       __FUNCTION__ , local_cxy );
155                return ENOMEM;
156        }
157
158        // get page base address
159        kcm_page = (kcm_page_t *)ppm_page2vaddr( page );
160
161        // initialize KCM-page descriptor
162        bitmap_set_range( kcm_page->bitmap , 0 , kcm->blocks_nr );
163
164        kcm_page->busy          = 0;
165        kcm_page->active        = 0;
166        kcm_page->count      = 0;
167        kcm_page->kcm           = kcm;
168        kcm_page->page          = page;
169
170        // introduce new page in free-list
171        list_add_first( &kcm->free_root , &kcm_page->list );
172        kcm->free_pages_nr ++;
173
174        return 0;
175}
176
177/////////////////////////////////////////////////////////////////////////////////////
178// This private function gets one KCM page from the KCM freelist.
179// It populates the freelist if required.
180/////////////////////////////////////////////////////////////////////////////////////
181static kcm_page_t * freelist_get( kcm_t * kcm )
182{
183        error_t      error;
184        kcm_page_t * kcm_page;
185
186        // get a new page from PPM if freelist empty
187        if( kcm->free_pages_nr == 0 )
188        {
189                error = freelist_populate( kcm );
190                if( error ) return NULL;
191        }
192
193        // get first KCM page from freelist and unlink it
194        kcm_page = LIST_FIRST( &kcm->free_root, kcm_page_t , list );
195        list_unlink( &kcm_page->list );
196        kcm->free_pages_nr --;
197
198        return kcm_page;
199}
200
201//////////////////////////////
202void kcm_init( kcm_t    * kcm,
203                   uint32_t   type )
204{
205        // the kcm_page descriptor mut fit in the KCM slot
206        assert( (sizeof(kcm_page_t) <= CONFIG_KCM_SLOT_SIZE) ,
207                 __FUNCTION__ , "KCM slot too small\n" );
208
209        // initialize lock
210        spinlock_init( &kcm->lock );
211
212        // initialize KCM type
213        kcm->type = type;
214
215        // initialize KCM page lists
216        kcm->free_pages_nr   = 0;
217        kcm->busy_pages_nr   = 0;
218        kcm->active_pages_nr = 0;
219        list_root_init( &kcm->free_root );
220        list_root_init( &kcm->busy_root );
221        list_root_init( &kcm->active_root );
222
223        // initialize block size
224        uint32_t block_size = ARROUND_UP( kmem_type_size( type ) , CONFIG_KCM_SLOT_SIZE );
225        kcm->block_size = block_size;
226
227        // initialize number of blocks per page
228        uint32_t  blocks_nr = (CONFIG_PPM_PAGE_SIZE - CONFIG_KCM_SLOT_SIZE) / block_size;
229        kcm->blocks_nr = blocks_nr;
230
231        kcm_dmsg("\n[INFO] %s : KCM %s initialised / block_size = %d / blocks_nr = %d\n",
232                 __FUNCTION__ , kmem_type_str( type ) , kcm->block_size , kcm->blocks_nr );
233}
234
235///////////////////////////////
236void kcm_destroy( kcm_t * kcm )
237{
238        kcm_page_t   * kcm_page;
239        list_entry_t * iter;
240
241        // get KCM lock
242        spinlock_lock( &kcm->lock );
243
244        // release all free pages
245        LIST_FOREACH( &kcm->free_root , iter )
246        {
247                kcm_page = (kcm_page_t *)LIST_ELEMENT( iter , kcm_page_t , list );
248                list_unlink( iter );
249                kcm->free_pages_nr --;
250                ppm_free_pages( kcm_page->page );
251        }
252
253        // release all active pages
254        LIST_FOREACH( &kcm->active_root , iter )
255        {
256                kcm_page = (kcm_page_t *)LIST_ELEMENT( iter , kcm_page_t , list );
257                list_unlink( iter );
258                kcm->free_pages_nr --;
259                ppm_free_pages( kcm_page->page );
260        }
261
262        // release all busy pages
263        LIST_FOREACH( &kcm->busy_root , iter )
264        {
265                kcm_page = (kcm_page_t *)LIST_ELEMENT( iter , kcm_page_t , list );
266                list_unlink( iter );
267                kcm->free_pages_nr --;
268                ppm_free_pages( kcm_page->page );
269        }
270
271        // release KCM lock
272        spinlock_unlock( &kcm->lock );
273}
274
275///////////////////////////////
276void * kcm_alloc( kcm_t * kcm )
277{
278        kcm_page_t * kcm_page;
279        void       * ptr = NULL;   // pointer on block
280
281        // get lock
282        spinlock_lock( &kcm->lock );
283
284        // get an active page
285        if( list_is_empty( &kcm->active_root ) )  // no active page => get one
286        {
287                // get a page from free list
288                kcm_page = freelist_get( kcm );
289
290                if( kcm_page == NULL ) return NULL;
291
292                // insert page in active list
293                list_add_first( &kcm->active_root , &kcm_page->list );
294                kcm->active_pages_nr ++;
295                kcm_page->active = 1;
296
297                kcm_dmsg("\n[INFO] %s : enters for type %s at cycle %d / new page = %x / count = %d\n",
298                         __FUNCTION__ , kmem_type_str( kcm->type ) , hal_get_cycles() ,
299                         (intptr_t)kcm_page , kcm_page->count );
300
301        }
302        else                                    // get first page from active list
303        {
304                // get page pointer from active list
305                kcm_page = (kcm_page_t *)LIST_FIRST( &kcm->active_root , kcm_page_t , list );
306
307                kcm_dmsg("\n[INFO] %s : enters for type %s at cycle %d / page = %x / count = %d\n",
308                         __FUNCTION__ , kmem_type_str( kcm->type ) , hal_get_cycles() ,
309                         (intptr_t)kcm_page , kcm_page->count );
310        }
311
312        // get a block from selected active page
313        // cannot fail, as an active page cannot be full...
314        ptr  = kcm_get_block( kcm , kcm_page );
315
316        // release lock
317        spinlock_unlock( &kcm->lock );
318
319        return ptr;
320}
321
322///////////////////////////
323void kcm_free( void * ptr )
324{
325        kcm_page_t * kcm_page;
326        kcm_t      * kcm;
327
328        assert( (ptr != NULL) , __FUNCTION__ , "pointer cannot be NULL" );
329
330        kcm_page = (kcm_page_t *)((intptr_t)ptr & ~CONFIG_PPM_PAGE_MASK);
331        kcm      = kcm_page->kcm;
332
333        // get lock
334        spinlock_lock( &kcm->lock );
335
336        // release block
337        kcm_put_block( kcm , ptr );
338
339        // release lock
340        spinlock_unlock( &kcm->lock );
341}
342
343////////////////////////////
344void kcm_print (kcm_t * kcm)
345{
346        printk("*** KCM type = %s / free_pages = %d / busy_pages = %d / active_pages = %d\n",
347               kmem_type_str( kcm->type ) ,
348               kcm->free_pages_nr ,
349               kcm->busy_pages_nr ,
350               kcm->active_pages_nr );
351}
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