1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
  2/******************************************************************************
  3 *
  4 * Module Name: utcache - local cache allocation routines
  5 *
  6 * Copyright (C) 2000 - 2020, Intel Corp.
  7 *
  8 *****************************************************************************/
  9
 10#include <acpi/acpi.h>
 11#include "accommon.h"
 12
 13#define _COMPONENT          ACPI_UTILITIES
 14ACPI_MODULE_NAME("utcache")
 15
 16#ifdef ACPI_USE_LOCAL_CACHE
 17/*******************************************************************************
 18 *
 19 * FUNCTION:    acpi_os_create_cache
 20 *
 21 * PARAMETERS:  cache_name      - Ascii name for the cache
 22 *              object_size     - Size of each cached object
 23 *              max_depth       - Maximum depth of the cache (in objects)
 24 *              return_cache    - Where the new cache object is returned
 25 *
 26 * RETURN:      Status
 27 *
 28 * DESCRIPTION: Create a cache object
 29 *
 30 ******************************************************************************/
 31acpi_status
 32acpi_os_create_cache(char *cache_name,
 33		     u16 object_size,
 34		     u16 max_depth, struct acpi_memory_list **return_cache)
 35{
 36	struct acpi_memory_list *cache;
 37
 38	ACPI_FUNCTION_ENTRY();
 39
 40	if (!cache_name || !return_cache || !object_size) {
 41		return (AE_BAD_PARAMETER);
 42	}
 43
 44	/* Create the cache object */
 45
 46	cache = acpi_os_allocate(sizeof(struct acpi_memory_list));
 47	if (!cache) {
 48		return (AE_NO_MEMORY);
 49	}
 50
 51	/* Populate the cache object and return it */
 52
 53	memset(cache, 0, sizeof(struct acpi_memory_list));
 54	cache->list_name = cache_name;
 55	cache->object_size = object_size;
 56	cache->max_depth = max_depth;
 57
 58	*return_cache = cache;
 59	return (AE_OK);
 60}
 61
 62/*******************************************************************************
 63 *
 64 * FUNCTION:    acpi_os_purge_cache
 65 *
 66 * PARAMETERS:  cache           - Handle to cache object
 67 *
 68 * RETURN:      Status
 69 *
 70 * DESCRIPTION: Free all objects within the requested cache.
 71 *
 72 ******************************************************************************/
 73
 74acpi_status acpi_os_purge_cache(struct acpi_memory_list *cache)
 75{
 76	void *next;
 77	acpi_status status;
 78
 79	ACPI_FUNCTION_ENTRY();
 80
 81	if (!cache) {
 82		return (AE_BAD_PARAMETER);
 83	}
 84
 85	status = acpi_ut_acquire_mutex(ACPI_MTX_CACHES);
 86	if (ACPI_FAILURE(status)) {
 87		return (status);
 88	}
 89
 90	/* Walk the list of objects in this cache */
 91
 92	while (cache->list_head) {
 93
 94		/* Delete and unlink one cached state object */
 95
 96		next = ACPI_GET_DESCRIPTOR_PTR(cache->list_head);
 97		ACPI_FREE(cache->list_head);
 98
 99		cache->list_head = next;
100		cache->current_depth--;
101	}
102
103	(void)acpi_ut_release_mutex(ACPI_MTX_CACHES);
104	return (AE_OK);
105}
106
107/*******************************************************************************
108 *
109 * FUNCTION:    acpi_os_delete_cache
110 *
111 * PARAMETERS:  cache           - Handle to cache object
112 *
113 * RETURN:      Status
114 *
115 * DESCRIPTION: Free all objects within the requested cache and delete the
116 *              cache object.
117 *
118 ******************************************************************************/
119
120acpi_status acpi_os_delete_cache(struct acpi_memory_list *cache)
121{
122	acpi_status status;
123
124	ACPI_FUNCTION_ENTRY();
125
126	/* Purge all objects in the cache */
127
128	status = acpi_os_purge_cache(cache);
129	if (ACPI_FAILURE(status)) {
130		return (status);
131	}
132
133	/* Now we can delete the cache object */
134
135	acpi_os_free(cache);
136	return (AE_OK);
137}
138
139/*******************************************************************************
140 *
141 * FUNCTION:    acpi_os_release_object
142 *
143 * PARAMETERS:  cache       - Handle to cache object
144 *              object      - The object to be released
145 *
146 * RETURN:      None
147 *
148 * DESCRIPTION: Release an object to the specified cache. If cache is full,
149 *              the object is deleted.
150 *
151 ******************************************************************************/
152
153acpi_status acpi_os_release_object(struct acpi_memory_list *cache, void *object)
154{
155	acpi_status status;
156
157	ACPI_FUNCTION_ENTRY();
158
159	if (!cache || !object) {
160		return (AE_BAD_PARAMETER);
161	}
162
163	/* If cache is full, just free this object */
164
165	if (cache->current_depth >= cache->max_depth) {
166		ACPI_FREE(object);
167		ACPI_MEM_TRACKING(cache->total_freed++);
168	}
169
170	/* Otherwise put this object back into the cache */
171
172	else {
173		status = acpi_ut_acquire_mutex(ACPI_MTX_CACHES);
174		if (ACPI_FAILURE(status)) {
175			return (status);
176		}
177
178		/* Mark the object as cached */
179
180		memset(object, 0xCA, cache->object_size);
181		ACPI_SET_DESCRIPTOR_TYPE(object, ACPI_DESC_TYPE_CACHED);
182
183		/* Put the object at the head of the cache list */
184
185		ACPI_SET_DESCRIPTOR_PTR(object, cache->list_head);
186		cache->list_head = object;
187		cache->current_depth++;
188
189		(void)acpi_ut_release_mutex(ACPI_MTX_CACHES);
190	}
191
192	return (AE_OK);
193}
194
195/*******************************************************************************
196 *
197 * FUNCTION:    acpi_os_acquire_object
198 *
199 * PARAMETERS:  cache           - Handle to cache object
200 *
201 * RETURN:      the acquired object. NULL on error
202 *
203 * DESCRIPTION: Get an object from the specified cache. If cache is empty,
204 *              the object is allocated.
205 *
206 ******************************************************************************/
207
208void *acpi_os_acquire_object(struct acpi_memory_list *cache)
209{
210	acpi_status status;
211	void *object;
212
213	ACPI_FUNCTION_TRACE(os_acquire_object);
214
215	if (!cache) {
216		return_PTR(NULL);
217	}
218
219	status = acpi_ut_acquire_mutex(ACPI_MTX_CACHES);
220	if (ACPI_FAILURE(status)) {
221		return_PTR(NULL);
222	}
223
224	ACPI_MEM_TRACKING(cache->requests++);
225
226	/* Check the cache first */
227
228	if (cache->list_head) {
229
230		/* There is an object available, use it */
231
232		object = cache->list_head;
233		cache->list_head = ACPI_GET_DESCRIPTOR_PTR(object);
234
235		cache->current_depth--;
236
237		ACPI_MEM_TRACKING(cache->hits++);
238		ACPI_DEBUG_PRINT_RAW((ACPI_DB_EXEC,
239				      "%s: Object %p from %s cache\n",
240				      ACPI_GET_FUNCTION_NAME, object,
241				      cache->list_name));
242
243		status = acpi_ut_release_mutex(ACPI_MTX_CACHES);
244		if (ACPI_FAILURE(status)) {
245			return_PTR(NULL);
246		}
247
248		/* Clear (zero) the previously used Object */
249
250		memset(object, 0, cache->object_size);
251	} else {
252		/* The cache is empty, create a new object */
253
254		ACPI_MEM_TRACKING(cache->total_allocated++);
255
256#ifdef ACPI_DBG_TRACK_ALLOCATIONS
257		if ((cache->total_allocated - cache->total_freed) >
258		    cache->max_occupied) {
259			cache->max_occupied =
260			    cache->total_allocated - cache->total_freed;
261		}
262#endif
263
264		/* Avoid deadlock with ACPI_ALLOCATE_ZEROED */
265
266		status = acpi_ut_release_mutex(ACPI_MTX_CACHES);
267		if (ACPI_FAILURE(status)) {
268			return_PTR(NULL);
269		}
270
271		object = ACPI_ALLOCATE_ZEROED(cache->object_size);
272		if (!object) {
273			return_PTR(NULL);
274		}
275	}
276
277	return_PTR(object);
278}
279#endif				/* ACPI_USE_LOCAL_CACHE */