diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-30 20:05:21 -0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-30 20:05:21 -0400 |
| commit | 6de3d58dcfbab516dbe9aff36ea9542f40cd1bf2 (patch) | |
| tree | fc5b83ef3a34b40c71e397ee7b1e6c423628e786 /lib/klist.c | |
| parent | e0066c4ea9ffa420cb79814411ff74fdc7b7d98e (diff) | |
| parent | c3bb7fadaf52de3637b834002dac27f6250b4b49 (diff) | |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-2.6:
klist: fix coding style errors in klist.h and klist.c
driver core: remove no longer used "struct class_device"
pcmcia: remove pccard_sysfs_interface warnings
devres: support addresses greater than an unsigned long via dev_ioremap
kobject: do not copy vargs, just pass them around
sysfs: sysfs_update_group stub for CONFIG_SYSFS=n
DEBUGFS: Correct location of debugfs API documentation.
driver core: warn about duplicate driver names on the same bus
klist: implement klist_add_{after|before}()
klist: implement KLIST_INIT() and DEFINE_KLIST()
sysfs: Disallow truncation of files in sysfs
Diffstat (limited to 'lib/klist.c')
| -rw-r--r-- | lib/klist.c | 235 |
1 files changed, 116 insertions, 119 deletions
diff --git a/lib/klist.c b/lib/klist.c index 120bd175aa78..cca37f96faa2 100644 --- a/lib/klist.c +++ b/lib/klist.c | |||
| @@ -1,38 +1,37 @@ | |||
| 1 | /* | 1 | /* |
| 2 | * klist.c - Routines for manipulating klists. | 2 | * klist.c - Routines for manipulating klists. |
| 3 | * | 3 | * |
| 4 | * Copyright (C) 2005 Patrick Mochel | ||
| 4 | * | 5 | * |
| 5 | * This klist interface provides a couple of structures that wrap around | 6 | * This file is released under the GPL v2. |
| 6 | * struct list_head to provide explicit list "head" (struct klist) and | ||
| 7 | * list "node" (struct klist_node) objects. For struct klist, a spinlock | ||
| 8 | * is included that protects access to the actual list itself. struct | ||
| 9 | * klist_node provides a pointer to the klist that owns it and a kref | ||
| 10 | * reference count that indicates the number of current users of that node | ||
| 11 | * in the list. | ||
| 12 | * | 7 | * |
| 13 | * The entire point is to provide an interface for iterating over a list | 8 | * This klist interface provides a couple of structures that wrap around |
| 14 | * that is safe and allows for modification of the list during the | 9 | * struct list_head to provide explicit list "head" (struct klist) and list |
| 15 | * iteration (e.g. insertion and removal), including modification of the | 10 | * "node" (struct klist_node) objects. For struct klist, a spinlock is |
| 16 | * current node on the list. | 11 | * included that protects access to the actual list itself. struct |
| 12 | * klist_node provides a pointer to the klist that owns it and a kref | ||
| 13 | * reference count that indicates the number of current users of that node | ||
| 14 | * in the list. | ||
| 17 | * | 15 | * |
| 18 | * It works using a 3rd object type - struct klist_iter - that is declared | 16 | * The entire point is to provide an interface for iterating over a list |
| 19 | * and initialized before an iteration. klist_next() is used to acquire the | 17 | * that is safe and allows for modification of the list during the |
| 20 | * next element in the list. It returns NULL if there are no more items. | 18 | * iteration (e.g. insertion and removal), including modification of the |
| 21 | * Internally, that routine takes the klist's lock, decrements the reference | 19 | * current node on the list. |
| 22 | * count of the previous klist_node and increments the count of the next | ||
| 23 | * klist_node. It then drops the lock and returns. | ||
| 24 | * | 20 | * |
| 25 | * There are primitives for adding and removing nodes to/from a klist. | 21 | * It works using a 3rd object type - struct klist_iter - that is declared |
| 26 | * When deleting, klist_del() will simply decrement the reference count. | 22 | * and initialized before an iteration. klist_next() is used to acquire the |
| 27 | * Only when the count goes to 0 is the node removed from the list. | 23 | * next element in the list. It returns NULL if there are no more items. |
| 28 | * klist_remove() will try to delete the node from the list and block | 24 | * Internally, that routine takes the klist's lock, decrements the |
| 29 | * until it is actually removed. This is useful for objects (like devices) | 25 | * reference count of the previous klist_node and increments the count of |
| 30 | * that have been removed from the system and must be freed (but must wait | 26 | * the next klist_node. It then drops the lock and returns. |
| 31 | * until all accessors have finished). | ||
| 32 | * | 27 | * |
| 33 | * Copyright (C) 2005 Patrick Mochel | 28 | * There are primitives for adding and removing nodes to/from a klist. |
| 34 | * | 29 | * When deleting, klist_del() will simply decrement the reference count. |
| 35 | * This file is released under the GPL v2. | 30 | * Only when the count goes to 0 is the node removed from the list. |
| 31 | * klist_remove() will try to delete the node from the list and block until | ||
| 32 | * it is actually removed. This is useful for objects (like devices) that | ||
| 33 | * have been removed from the system and must be freed (but must wait until | ||
| 34 | * all accessors have finished). | ||
| 36 | */ | 35 | */ |
| 37 | 36 | ||
| 38 | #include <linux/klist.h> | 37 | #include <linux/klist.h> |
| @@ -40,10 +39,10 @@ | |||
| 40 | 39 | ||
| 41 | 40 | ||
| 42 | /** | 41 | /** |
| 43 | * klist_init - Initialize a klist structure. | 42 | * klist_init - Initialize a klist structure. |
| 44 | * @k: The klist we're initializing. | 43 | * @k: The klist we're initializing. |
| 45 | * @get: The get function for the embedding object (NULL if none) | 44 | * @get: The get function for the embedding object (NULL if none) |
| 46 | * @put: The put function for the embedding object (NULL if none) | 45 | * @put: The put function for the embedding object (NULL if none) |
| 47 | * | 46 | * |
| 48 | * Initialises the klist structure. If the klist_node structures are | 47 | * Initialises the klist structure. If the klist_node structures are |
| 49 | * going to be embedded in refcounted objects (necessary for safe | 48 | * going to be embedded in refcounted objects (necessary for safe |
| @@ -51,8 +50,7 @@ | |||
| 51 | * functions that take and release references on the embedding | 50 | * functions that take and release references on the embedding |
| 52 | * objects. | 51 | * objects. |
| 53 | */ | 52 | */ |
| 54 | 53 | void klist_init(struct klist *k, void (*get)(struct klist_node *), | |
| 55 | void klist_init(struct klist * k, void (*get)(struct klist_node *), | ||
| 56 | void (*put)(struct klist_node *)) | 54 | void (*put)(struct klist_node *)) |
| 57 | { | 55 | { |
| 58 | INIT_LIST_HEAD(&k->k_list); | 56 | INIT_LIST_HEAD(&k->k_list); |
| @@ -60,26 +58,23 @@ void klist_init(struct klist * k, void (*get)(struct klist_node *), | |||
| 60 | k->get = get; | 58 | k->get = get; |
| 61 | k->put = put; | 59 | k->put = put; |
| 62 | } | 60 | } |
| 63 | |||
| 64 | EXPORT_SYMBOL_GPL(klist_init); | 61 | EXPORT_SYMBOL_GPL(klist_init); |
| 65 | 62 | ||
| 66 | 63 | static void add_head(struct klist *k, struct klist_node *n) | |
| 67 | static void add_head(struct klist * k, struct klist_node * n) | ||
| 68 | { | 64 | { |
| 69 | spin_lock(&k->k_lock); | 65 | spin_lock(&k->k_lock); |
| 70 | list_add(&n->n_node, &k->k_list); | 66 | list_add(&n->n_node, &k->k_list); |
| 71 | spin_unlock(&k->k_lock); | 67 | spin_unlock(&k->k_lock); |
| 72 | } | 68 | } |
| 73 | 69 | ||
| 74 | static void add_tail(struct klist * k, struct klist_node * n) | 70 | static void add_tail(struct klist *k, struct klist_node *n) |
| 75 | { | 71 | { |
| 76 | spin_lock(&k->k_lock); | 72 | spin_lock(&k->k_lock); |
| 77 | list_add_tail(&n->n_node, &k->k_list); | 73 | list_add_tail(&n->n_node, &k->k_list); |
| 78 | spin_unlock(&k->k_lock); | 74 | spin_unlock(&k->k_lock); |
| 79 | } | 75 | } |
| 80 | 76 | ||
| 81 | 77 | static void klist_node_init(struct klist *k, struct klist_node *n) | |
| 82 | static void klist_node_init(struct klist * k, struct klist_node * n) | ||
| 83 | { | 78 | { |
| 84 | INIT_LIST_HEAD(&n->n_node); | 79 | INIT_LIST_HEAD(&n->n_node); |
| 85 | init_completion(&n->n_removed); | 80 | init_completion(&n->n_removed); |
| @@ -89,60 +84,83 @@ static void klist_node_init(struct klist * k, struct klist_node * n) | |||
| 89 | k->get(n); | 84 | k->get(n); |
| 90 | } | 85 | } |
| 91 | 86 | ||
| 92 | |||
| 93 | /** | 87 | /** |
| 94 | * klist_add_head - Initialize a klist_node and add it to front. | 88 | * klist_add_head - Initialize a klist_node and add it to front. |
| 95 | * @n: node we're adding. | 89 | * @n: node we're adding. |
| 96 | * @k: klist it's going on. | 90 | * @k: klist it's going on. |
| 97 | */ | 91 | */ |
| 98 | 92 | void klist_add_head(struct klist_node *n, struct klist *k) | |
| 99 | void klist_add_head(struct klist_node * n, struct klist * k) | ||
| 100 | { | 93 | { |
| 101 | klist_node_init(k, n); | 94 | klist_node_init(k, n); |
| 102 | add_head(k, n); | 95 | add_head(k, n); |
| 103 | } | 96 | } |
| 104 | |||
| 105 | EXPORT_SYMBOL_GPL(klist_add_head); | 97 | EXPORT_SYMBOL_GPL(klist_add_head); |
| 106 | 98 | ||
| 107 | |||
| 108 | /** | 99 | /** |
| 109 | * klist_add_tail - Initialize a klist_node and add it to back. | 100 | * klist_add_tail - Initialize a klist_node and add it to back. |
| 110 | * @n: node we're adding. | 101 | * @n: node we're adding. |
| 111 | * @k: klist it's going on. | 102 | * @k: klist it's going on. |
| 112 | */ | 103 | */ |
| 113 | 104 | void klist_add_tail(struct klist_node *n, struct klist *k) | |
| 114 | void klist_add_tail(struct klist_node * n, struct klist * k) | ||
| 115 | { | 105 | { |
| 116 | klist_node_init(k, n); | 106 | klist_node_init(k, n); |
| 117 | add_tail(k, n); | 107 | add_tail(k, n); |
| 118 | } | 108 | } |
| 119 | |||
| 120 | EXPORT_SYMBOL_GPL(klist_add_tail); | 109 | EXPORT_SYMBOL_GPL(klist_add_tail); |
| 121 | 110 | ||
| 111 | /** | ||
| 112 | * klist_add_after - Init a klist_node and add it after an existing node | ||
| 113 | * @n: node we're adding. | ||
| 114 | * @pos: node to put @n after | ||
| 115 | */ | ||
| 116 | void klist_add_after(struct klist_node *n, struct klist_node *pos) | ||
| 117 | { | ||
| 118 | struct klist *k = pos->n_klist; | ||
| 119 | |||
| 120 | klist_node_init(k, n); | ||
| 121 | spin_lock(&k->k_lock); | ||
| 122 | list_add(&n->n_node, &pos->n_node); | ||
| 123 | spin_unlock(&k->k_lock); | ||
| 124 | } | ||
| 125 | EXPORT_SYMBOL_GPL(klist_add_after); | ||
| 126 | |||
| 127 | /** | ||
| 128 | * klist_add_before - Init a klist_node and add it before an existing node | ||
| 129 | * @n: node we're adding. | ||
| 130 | * @pos: node to put @n after | ||
| 131 | */ | ||
| 132 | void klist_add_before(struct klist_node *n, struct klist_node *pos) | ||
| 133 | { | ||
| 134 | struct klist *k = pos->n_klist; | ||
| 135 | |||
| 136 | klist_node_init(k, n); | ||
| 137 | spin_lock(&k->k_lock); | ||
| 138 | list_add_tail(&n->n_node, &pos->n_node); | ||
| 139 | spin_unlock(&k->k_lock); | ||
| 140 | } | ||
| 141 | EXPORT_SYMBOL_GPL(klist_add_before); | ||
| 122 | 142 | ||
| 123 | static void klist_release(struct kref * kref) | 143 | static void klist_release(struct kref *kref) |
| 124 | { | 144 | { |
| 125 | struct klist_node * n = container_of(kref, struct klist_node, n_ref); | 145 | struct klist_node *n = container_of(kref, struct klist_node, n_ref); |
| 126 | 146 | ||
| 127 | list_del(&n->n_node); | 147 | list_del(&n->n_node); |
| 128 | complete(&n->n_removed); | 148 | complete(&n->n_removed); |
| 129 | n->n_klist = NULL; | 149 | n->n_klist = NULL; |
| 130 | } | 150 | } |
| 131 | 151 | ||
| 132 | static int klist_dec_and_del(struct klist_node * n) | 152 | static int klist_dec_and_del(struct klist_node *n) |
| 133 | { | 153 | { |
| 134 | return kref_put(&n->n_ref, klist_release); | 154 | return kref_put(&n->n_ref, klist_release); |
| 135 | } | 155 | } |
| 136 | 156 | ||
| 137 | |||
| 138 | /** | 157 | /** |
| 139 | * klist_del - Decrement the reference count of node and try to remove. | 158 | * klist_del - Decrement the reference count of node and try to remove. |
| 140 | * @n: node we're deleting. | 159 | * @n: node we're deleting. |
| 141 | */ | 160 | */ |
| 142 | 161 | void klist_del(struct klist_node *n) | |
| 143 | void klist_del(struct klist_node * n) | ||
| 144 | { | 162 | { |
| 145 | struct klist * k = n->n_klist; | 163 | struct klist *k = n->n_klist; |
| 146 | void (*put)(struct klist_node *) = k->put; | 164 | void (*put)(struct klist_node *) = k->put; |
| 147 | 165 | ||
| 148 | spin_lock(&k->k_lock); | 166 | spin_lock(&k->k_lock); |
| @@ -152,48 +170,40 @@ void klist_del(struct klist_node * n) | |||
| 152 | if (put) | 170 | if (put) |
| 153 | put(n); | 171 | put(n); |
| 154 | } | 172 | } |
| 155 | |||
| 156 | EXPORT_SYMBOL_GPL(klist_del); | 173 | EXPORT_SYMBOL_GPL(klist_del); |
| 157 | 174 | ||
| 158 | |||
| 159 | /** | 175 | /** |
| 160 | * klist_remove - Decrement the refcount of node and wait for it to go away. | 176 | * klist_remove - Decrement the refcount of node and wait for it to go away. |
| 161 | * @n: node we're removing. | 177 | * @n: node we're removing. |
| 162 | */ | 178 | */ |
| 163 | 179 | void klist_remove(struct klist_node *n) | |
| 164 | void klist_remove(struct klist_node * n) | ||
| 165 | { | 180 | { |
| 166 | klist_del(n); | 181 | klist_del(n); |
| 167 | wait_for_completion(&n->n_removed); | 182 | wait_for_completion(&n->n_removed); |
| 168 | } | 183 | } |
| 169 | |||
| 170 | EXPORT_SYMBOL_GPL(klist_remove); | 184 | EXPORT_SYMBOL_GPL(klist_remove); |
| 171 | 185 | ||
| 172 | |||
| 173 | /** | 186 | /** |
| 174 | * klist_node_attached - Say whether a node is bound to a list or not. | 187 | * klist_node_attached - Say whether a node is bound to a list or not. |
| 175 | * @n: Node that we're testing. | 188 | * @n: Node that we're testing. |
| 176 | */ | 189 | */ |
| 177 | 190 | int klist_node_attached(struct klist_node *n) | |
| 178 | int klist_node_attached(struct klist_node * n) | ||
| 179 | { | 191 | { |
| 180 | return (n->n_klist != NULL); | 192 | return (n->n_klist != NULL); |
| 181 | } | 193 | } |
| 182 | |||
| 183 | EXPORT_SYMBOL_GPL(klist_node_attached); | 194 | EXPORT_SYMBOL_GPL(klist_node_attached); |
| 184 | 195 | ||
| 185 | |||
| 186 | /** | 196 | /** |
| 187 | * klist_iter_init_node - Initialize a klist_iter structure. | 197 | * klist_iter_init_node - Initialize a klist_iter structure. |
| 188 | * @k: klist we're iterating. | 198 | * @k: klist we're iterating. |
| 189 | * @i: klist_iter we're filling. | 199 | * @i: klist_iter we're filling. |
| 190 | * @n: node to start with. | 200 | * @n: node to start with. |
| 191 | * | 201 | * |
| 192 | * Similar to klist_iter_init(), but starts the action off with @n, | 202 | * Similar to klist_iter_init(), but starts the action off with @n, |
| 193 | * instead of with the list head. | 203 | * instead of with the list head. |
| 194 | */ | 204 | */ |
| 195 | 205 | void klist_iter_init_node(struct klist *k, struct klist_iter *i, | |
| 196 | void klist_iter_init_node(struct klist * k, struct klist_iter * i, struct klist_node * n) | 206 | struct klist_node *n) |
| 197 | { | 207 | { |
| 198 | i->i_klist = k; | 208 | i->i_klist = k; |
| 199 | i->i_head = &k->k_list; | 209 | i->i_head = &k->k_list; |
| @@ -201,66 +211,56 @@ void klist_iter_init_node(struct klist * k, struct klist_iter * i, struct klist_ | |||
| 201 | if (n) | 211 | if (n) |
| 202 | kref_get(&n->n_ref); | 212 | kref_get(&n->n_ref); |
| 203 | } | 213 | } |
| 204 | |||
| 205 | EXPORT_SYMBOL_GPL(klist_iter_init_node); | 214 | EXPORT_SYMBOL_GPL(klist_iter_init_node); |
| 206 | 215 | ||
| 207 | |||
| 208 | /** | 216 | /** |
| 209 | * klist_iter_init - Iniitalize a klist_iter structure. | 217 | * klist_iter_init - Iniitalize a klist_iter structure. |
| 210 | * @k: klist we're iterating. | 218 | * @k: klist we're iterating. |
| 211 | * @i: klist_iter structure we're filling. | 219 | * @i: klist_iter structure we're filling. |
| 212 | * | 220 | * |
| 213 | * Similar to klist_iter_init_node(), but start with the list head. | 221 | * Similar to klist_iter_init_node(), but start with the list head. |
| 214 | */ | 222 | */ |
| 215 | 223 | void klist_iter_init(struct klist *k, struct klist_iter *i) | |
| 216 | void klist_iter_init(struct klist * k, struct klist_iter * i) | ||
| 217 | { | 224 | { |
| 218 | klist_iter_init_node(k, i, NULL); | 225 | klist_iter_init_node(k, i, NULL); |
| 219 | } | 226 | } |
| 220 | |||
| 221 | EXPORT_SYMBOL_GPL(klist_iter_init); | 227 | EXPORT_SYMBOL_GPL(klist_iter_init); |
| 222 | 228 | ||
| 223 | |||
| 224 | /** | 229 | /** |
| 225 | * klist_iter_exit - Finish a list iteration. | 230 | * klist_iter_exit - Finish a list iteration. |
| 226 | * @i: Iterator structure. | 231 | * @i: Iterator structure. |
| 227 | * | 232 | * |
| 228 | * Must be called when done iterating over list, as it decrements the | 233 | * Must be called when done iterating over list, as it decrements the |
| 229 | * refcount of the current node. Necessary in case iteration exited before | 234 | * refcount of the current node. Necessary in case iteration exited before |
| 230 | * the end of the list was reached, and always good form. | 235 | * the end of the list was reached, and always good form. |
| 231 | */ | 236 | */ |
| 232 | 237 | void klist_iter_exit(struct klist_iter *i) | |
| 233 | void klist_iter_exit(struct klist_iter * i) | ||
| 234 | { | 238 | { |
| 235 | if (i->i_cur) { | 239 | if (i->i_cur) { |
| 236 | klist_del(i->i_cur); | 240 | klist_del(i->i_cur); |
| 237 | i->i_cur = NULL; | 241 | i->i_cur = NULL; |
| 238 | } | 242 | } |
| 239 | } | 243 | } |
| 240 | |||
| 241 | EXPORT_SYMBOL_GPL(klist_iter_exit); | 244 | EXPORT_SYMBOL_GPL(klist_iter_exit); |
| 242 | 245 | ||
| 243 | 246 | static struct klist_node *to_klist_node(struct list_head *n) | |
| 244 | static struct klist_node * to_klist_node(struct list_head * n) | ||
| 245 | { | 247 | { |
| 246 | return container_of(n, struct klist_node, n_node); | 248 | return container_of(n, struct klist_node, n_node); |
| 247 | } | 249 | } |
| 248 | 250 | ||
| 249 | |||
| 250 | /** | 251 | /** |
| 251 | * klist_next - Ante up next node in list. | 252 | * klist_next - Ante up next node in list. |
| 252 | * @i: Iterator structure. | 253 | * @i: Iterator structure. |
| 253 | * | 254 | * |
| 254 | * First grab list lock. Decrement the reference count of the previous | 255 | * First grab list lock. Decrement the reference count of the previous |
| 255 | * node, if there was one. Grab the next node, increment its reference | 256 | * node, if there was one. Grab the next node, increment its reference |
| 256 | * count, drop the lock, and return that next node. | 257 | * count, drop the lock, and return that next node. |
| 257 | */ | 258 | */ |
| 258 | 259 | struct klist_node *klist_next(struct klist_iter *i) | |
| 259 | struct klist_node * klist_next(struct klist_iter * i) | ||
| 260 | { | 260 | { |
| 261 | struct list_head * next; | 261 | struct list_head *next; |
| 262 | struct klist_node * lnode = i->i_cur; | 262 | struct klist_node *lnode = i->i_cur; |
| 263 | struct klist_node * knode = NULL; | 263 | struct klist_node *knode = NULL; |
| 264 | void (*put)(struct klist_node *) = i->i_klist->put; | 264 | void (*put)(struct klist_node *) = i->i_klist->put; |
| 265 | 265 | ||
| 266 | spin_lock(&i->i_klist->k_lock); | 266 | spin_lock(&i->i_klist->k_lock); |
| @@ -281,7 +281,4 @@ struct klist_node * klist_next(struct klist_iter * i) | |||
| 281 | put(lnode); | 281 | put(lnode); |
| 282 | return knode; | 282 | return knode; |
| 283 | } | 283 | } |
| 284 | |||
| 285 | EXPORT_SYMBOL_GPL(klist_next); | 284 | EXPORT_SYMBOL_GPL(klist_next); |
| 286 | |||
| 287 | |||
