2 * Copyright 2000, International Business Machines Corporation and others.
5 * This software has been released under the terms of the IBM Public
6 * License. For details, see the LICENSE file in the top-level source
7 * directory or online at http://www.openafs.org/dl/license10.html
11 * osi_alloc.c - Linux memory allocation routines.
14 #include <afsconfig.h>
15 #include "afs/param.h"
18 #include "afs/sysincludes.h"
19 #include "afsincludes.h"
23 #include "afs_atomlist.h"
24 #include "afs_lhash.h"
26 #define MAX_KMALLOC_SIZE PAGE_SIZE /* Max we should alloc with kmalloc */
29 #define KM_TYPE 1 /* kmalloc */
30 #define VM_TYPE 2 /* vmalloc */
32 struct osi_linux_mem {
36 /* These assume 32-bit pointers */
37 #define MEMTYPE(A) (((unsigned long)A) & 0x3)
38 #define MEMADDR(A) (void *)((unsigned long)(A) & (~0x3))
41 afs_atomlist *al_mem_pool; /* pool of osi_linux_mem structures */
42 afs_lhash *lh_mem_htab; /* mem hash table */
43 unsigned int allocator_init = 0; /* has the allocator been initialized? */
44 unsigned int afs_linux_cur_allocs = 0;
45 unsigned int afs_linux_total_allocs = 0;
46 unsigned int afs_linux_hash_verify_count = 0; /* used by hash_verify */
48 #if defined(AFS_LINUX24_ENV)
49 #include "h/vmalloc.h"
51 /* externs : can we do this in a better way. Including vmalloc.h causes other
53 extern void vfree(void *addr);
54 extern void *vmalloc(unsigned long size);
57 /* Allocator support functions (static) */
60 hash_equal(const void *a, const void *b)
62 return (MEMADDR(((struct osi_linux_mem *)a)->chunk) ==
63 MEMADDR(((struct osi_linux_mem *)b)->chunk));
67 /* linux_alloc : Allocates memory from the linux kernel. It uses
68 * kmalloc if possible. Otherwise, we use vmalloc.
70 * asize - size of memory required in bytes
72 * returns NULL if we failed to allocate memory.
73 * or pointer to memory if we succeeded.
76 linux_alloc(unsigned int asize, int drop_glock)
80 int haveGlock = ISAFS_GLOCK();
82 /* if we can use kmalloc use it to allocate the required memory. */
83 while (!new && max_retry) {
84 if (asize <= MAX_KMALLOC_SIZE) {
85 new = (void *)(unsigned long)kmalloc(asize,
92 if (new) /* piggy back alloc type */
93 new = (void *)(KM_TYPE | (unsigned long)new);
95 osi_Assert(drop_glock || !haveGlock);
96 if (drop_glock && haveGlock)
98 new = (void *)vmalloc(asize);
99 if (drop_glock && haveGlock)
101 if (new) /* piggy back alloc type */
102 new = (void *)(VM_TYPE | (unsigned long)new);
106 #ifdef set_current_state
107 set_current_state(TASK_INTERRUPTIBLE);
109 current->state = TASK_INTERRUPTIBLE;
111 if (drop_glock && haveGlock)
113 schedule_timeout(HZ);
114 if (drop_glock && haveGlock)
116 #ifdef set_current_state
117 set_current_state(TASK_RUNNING);
119 current->state = TASK_RUNNING;
125 memset(MEMADDR(new), 0, asize);
134 /* mask out the type information from the pointer and
135 * use the appropriate free routine to free the chunk.
137 switch (MEMTYPE(p)) {
145 printf("afs_osi_Free: Asked to free unknown type %d at 0x%lx\n",
146 (int)MEMTYPE(p), (unsigned long)MEMADDR(p));
152 /* hash_chunk() receives a pointer to a chunk and hashes it to produce a
153 * key that the hashtable can use. The key is obtained by
154 * right shifting out the 2 LSBs and then multiplying the
155 * result by a constant no. and dividing it with a large prime.
157 #define HASH_CONST 32786
158 #define HASH_PRIME 79367
164 key = (unsigned int)(long)p >> 2;
165 key = (key * HASH_CONST) % HASH_PRIME;
170 /* hash_free() : Invoked by osi_linux_free_afs_memory(), thru
171 * afs_lhash_iter(), this function is called by the lhash
172 * module for every entry in the hash table. hash_free
173 * frees the memory associated with the entry as well
174 * as returning the osi_linux_mem struct to its pool.
177 hash_free(size_t index, unsigned key, void *data)
179 linux_free(((struct osi_linux_mem *)data)->chunk);
180 afs_atomlist_put(al_mem_pool, data);
183 /* hash_verify() is invoked by osi_linux_verify_alloced_memory() thru
184 * afs_lhash_iter() and is called by the lhash module for every element
186 * hash_verify() verifies (within limits) that the memory passed to it is
190 hash_verify(size_t index, unsigned key, void *data)
192 struct osi_linux_mem *lmp = (struct osi_linux_mem *)data;
195 memtype = MEMTYPE(lmp->chunk);
196 if (memtype != KM_TYPE && memtype != VM_TYPE) {
198 ("osi_linux_verify_alloced_memory: unknown type %d at 0x%lx, index=%lu\n",
199 (int)memtype, (unsigned long)lmp->chunk, (unsigned long)index);
201 afs_linux_hash_verify_count++;
205 /* local_free() : wrapper for vfree(), to deal with incompatible protoypes */
207 local_free(void *p, size_t n)
212 /* linux_alloc_init(): Initializes the kernel memory allocator. As part
213 * of this process, it also initializes a pool of osi_linux_mem
214 * structures as well as the hash table itself.
220 linux_alloc_init(void)
222 /* initiate our pool of osi_linux_mem structs */
224 afs_atomlist_create(sizeof(struct osi_linux_mem), sizeof(long) * 1024,
225 (void *)vmalloc, local_free);
227 printf("afs_osi_Alloc: Error in initialization(atomlist_create)\n");
231 /* initialize the hash table to hold references to alloc'ed chunks */
232 lh_mem_htab = afs_lhash_create(hash_equal, (void *)vmalloc, local_free);
234 printf("afs_osi_Alloc: Error in initialization(lhash_create)\n");
242 /************** Linux memory allocator interface functions **********/
244 #if defined(AFS_LINUX24_ENV)
245 DECLARE_MUTEX(afs_linux_alloc_sem);
247 struct semaphore afs_linux_alloc_sem = MUTEX;
251 osi_linux_alloc(unsigned int asize, int drop_glock)
254 struct osi_linux_mem *lmem;
256 new = linux_alloc(asize, drop_glock); /* get a chunk of memory of size asize */
259 printf("afs_osi_Alloc: Can't vmalloc %d bytes.\n", asize);
263 down(&afs_linux_alloc_sem);
265 /* allocator hasn't been initialized yet */
266 if (allocator_init == 0) {
267 if (linux_alloc_init() == 0) {
270 allocator_init = 1; /* initialization complete */
273 /* get an atom to store the pointer to the chunk */
274 lmem = (struct osi_linux_mem *)afs_atomlist_get(al_mem_pool);
276 printf("afs_osi_Alloc: atomlist_get() failed.");
279 /* store the chunk reference */
282 /* hash in the chunk */
283 if (afs_lhash_enter(lh_mem_htab, hash_chunk(new), lmem) != 0) {
284 printf("afs_osi_Alloc: lhash_enter failed\n");
287 afs_linux_cur_allocs++; /* no. of current allocations */
288 afs_linux_total_allocs++; /* total no. of allocations done so far */
290 up(&afs_linux_alloc_sem);
303 /* osi_linux_free() - free chunk of memory passed to us.
306 osi_linux_free(void *addr)
308 struct osi_linux_mem lmem, *lmp;
310 down(&afs_linux_alloc_sem);
313 /* remove this chunk from our hash table */
315 (struct osi_linux_mem *)afs_lhash_remove(lh_mem_htab,
316 hash_chunk(addr), &lmem))) {
317 linux_free(lmp->chunk); /* this contains the piggybacked type info */
318 afs_atomlist_put(al_mem_pool, lmp); /* return osi_linux_mem struct to pool */
319 afs_linux_cur_allocs--;
321 printf("osi_linux_free: failed to remove chunk from hashtable\n");
325 up(&afs_linux_alloc_sem);
328 /* osi_linux_free_afs_memory() - free all chunks of memory allocated.
331 osi_linux_free_afs_memory(void)
333 down(&afs_linux_alloc_sem);
335 if (allocator_init) {
336 /* iterate through all elements in the hash table and free both
337 * the chunk and the atom associated with it.
339 afs_lhash_iter(lh_mem_htab, hash_free);
341 /* free the atomlist. */
342 afs_atomlist_destroy(al_mem_pool);
344 /* free the hashlist. */
345 afs_lhash_destroy(lh_mem_htab);
347 /* change the state so that the allocator is now uninitialized. */
350 up(&afs_linux_alloc_sem);
353 /* osi_linux_verify_alloced_memory(): verify all chunks of alloced memory in
357 osi_linux_verify_alloced_memory()
359 down(&afs_linux_alloc_sem);
361 /* count of times hash_verify was called. reset it to 0 before iteration */
362 afs_linux_hash_verify_count = 0;
364 /* iterate thru elements in the hash table */
365 afs_lhash_iter(lh_mem_htab, hash_verify);
367 if (afs_linux_hash_verify_count != afs_linux_cur_allocs) {
368 /* hmm, some pieces of memory are missing. */
370 ("osi_linux_verify_alloced_memory: %d chunks of memory are not accounted for during verify!\n",
371 afs_linux_hash_verify_count - afs_linux_cur_allocs);
374 up(&afs_linux_alloc_sem);