Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]

Diff markup

Differences between /linux/fs/proc/proc_devtree.c (Version 2.6.25) and /linux/fs/proc/proc_devtree.c (Version 2.6.25.8)


  1 /*                                                  1 /*
  2  * proc_devtree.c - handles /proc/device-tree       2  * proc_devtree.c - handles /proc/device-tree
  3  *                                                  3  *
  4  * Copyright 1997 Paul Mackerras                    4  * Copyright 1997 Paul Mackerras
  5  */                                                 5  */
  6 #include <linux/errno.h>                            6 #include <linux/errno.h>
  7 #include <linux/time.h>                             7 #include <linux/time.h>
  8 #include <linux/proc_fs.h>                          8 #include <linux/proc_fs.h>
  9 #include <linux/stat.h>                             9 #include <linux/stat.h>
 10 #include <linux/string.h>                          10 #include <linux/string.h>
 11 #include <asm/prom.h>                              11 #include <asm/prom.h>
 12 #include <asm/uaccess.h>                           12 #include <asm/uaccess.h>
 13                                                    13 
 14 #ifndef HAVE_ARCH_DEVTREE_FIXUPS                   14 #ifndef HAVE_ARCH_DEVTREE_FIXUPS
 15 static inline void set_node_proc_entry(struct      15 static inline void set_node_proc_entry(struct device_node *np,
 16                                        struct      16                                        struct proc_dir_entry *de)
 17 {                                                  17 {
 18 }                                                  18 }
 19 #endif                                             19 #endif
 20                                                    20 
 21 static struct proc_dir_entry *proc_device_tree     21 static struct proc_dir_entry *proc_device_tree;
 22                                                    22 
 23 /*                                                 23 /*
 24  * Supply data on a read from /proc/device-tre     24  * Supply data on a read from /proc/device-tree/node/property.
 25  */                                                25  */
 26 static int property_read_proc(char *page, char     26 static int property_read_proc(char *page, char **start, off_t off,
 27                               int count, int *     27                               int count, int *eof, void *data)
 28 {                                                  28 {
 29         struct property *pp = data;                29         struct property *pp = data;
 30         int n;                                     30         int n;
 31                                                    31 
 32         if (off >= pp->length) {                   32         if (off >= pp->length) {
 33                 *eof = 1;                          33                 *eof = 1;
 34                 return 0;                          34                 return 0;
 35         }                                          35         }
 36         n = pp->length - off;                      36         n = pp->length - off;
 37         if (n > count)                             37         if (n > count)
 38                 n = count;                         38                 n = count;
 39         else                                       39         else
 40                 *eof = 1;                          40                 *eof = 1;
 41         memcpy(page, (char *)pp->value + off,      41         memcpy(page, (char *)pp->value + off, n);
 42         *start = page;                             42         *start = page;
 43         return n;                                  43         return n;
 44 }                                                  44 }
 45                                                    45 
 46 /*                                                 46 /*
 47  * For a node with a name like "gc@10", we mak     47  * For a node with a name like "gc@10", we make symlinks called "gc"
 48  * and "@10" to it.                                48  * and "@10" to it.
 49  */                                                49  */
 50                                                    50 
 51 /*                                                 51 /*
 52  * Add a property to a node                        52  * Add a property to a node
 53  */                                                53  */
 54 static struct proc_dir_entry *                     54 static struct proc_dir_entry *
 55 __proc_device_tree_add_prop(struct proc_dir_en     55 __proc_device_tree_add_prop(struct proc_dir_entry *de, struct property *pp,
 56                 const char *name)                  56                 const char *name)
 57 {                                                  57 {
 58         struct proc_dir_entry *ent;                58         struct proc_dir_entry *ent;
 59                                                    59 
 60         /*                                         60         /*
 61          * Unfortunately proc_register puts ea     61          * Unfortunately proc_register puts each new entry
 62          * at the beginning of the list.  So w     62          * at the beginning of the list.  So we rearrange them.
 63          */                                        63          */
 64         ent = create_proc_read_entry(name,         64         ent = create_proc_read_entry(name,
 65                                      strncmp(n     65                                      strncmp(name, "security-", 9)
 66                                      ? S_IRUGO     66                                      ? S_IRUGO : S_IRUSR, de,
 67                                      property_     67                                      property_read_proc, pp);
 68         if (ent == NULL)                           68         if (ent == NULL)
 69                 return NULL;                       69                 return NULL;
 70                                                    70 
 71         if (!strncmp(name, "security-", 9))        71         if (!strncmp(name, "security-", 9))
 72                 ent->size = 0; /* don't leak n     72                 ent->size = 0; /* don't leak number of password chars */
 73         else                                       73         else
 74                 ent->size = pp->length;            74                 ent->size = pp->length;
 75                                                    75 
 76         return ent;                                76         return ent;
 77 }                                                  77 }
 78                                                    78 
 79                                                    79 
 80 void proc_device_tree_add_prop(struct proc_dir     80 void proc_device_tree_add_prop(struct proc_dir_entry *pde, struct property *prop)
 81 {                                                  81 {
 82         __proc_device_tree_add_prop(pde, prop,     82         __proc_device_tree_add_prop(pde, prop, prop->name);
 83 }                                                  83 }
 84                                                    84 
 85 void proc_device_tree_remove_prop(struct proc_     85 void proc_device_tree_remove_prop(struct proc_dir_entry *pde,
 86                                   struct prope     86                                   struct property *prop)
 87 {                                                  87 {
 88         remove_proc_entry(prop->name, pde);        88         remove_proc_entry(prop->name, pde);
 89 }                                                  89 }
 90                                                    90 
 91 void proc_device_tree_update_prop(struct proc_     91 void proc_device_tree_update_prop(struct proc_dir_entry *pde,
 92                                   struct prope     92                                   struct property *newprop,
 93                                   struct prope     93                                   struct property *oldprop)
 94 {                                                  94 {
 95         struct proc_dir_entry *ent;                95         struct proc_dir_entry *ent;
 96                                                    96 
 97         for (ent = pde->subdir; ent != NULL; e     97         for (ent = pde->subdir; ent != NULL; ent = ent->next)
 98                 if (ent->data == oldprop)          98                 if (ent->data == oldprop)
 99                         break;                     99                         break;
100         if (ent == NULL) {                        100         if (ent == NULL) {
101                 printk(KERN_WARNING "device-tr    101                 printk(KERN_WARNING "device-tree: property \"%s\" "
102                        " does not exist\n", ol    102                        " does not exist\n", oldprop->name);
103         } else {                                  103         } else {
104                 ent->data = newprop;              104                 ent->data = newprop;
105                 ent->size = newprop->length;      105                 ent->size = newprop->length;
106         }                                         106         }
107 }                                                 107 }
108                                                   108 
109 /*                                                109 /*
110  * Various dodgy firmware might give us nodes     110  * Various dodgy firmware might give us nodes and/or properties with
111  * conflicting names. That's generally ok, exc    111  * conflicting names. That's generally ok, except for exporting via /proc,
112  * so munge names here to ensure they're uniqu    112  * so munge names here to ensure they're unique.
113  */                                               113  */
114                                                   114 
115 static int duplicate_name(struct proc_dir_entr    115 static int duplicate_name(struct proc_dir_entry *de, const char *name)
116 {                                                 116 {
117         struct proc_dir_entry *ent;               117         struct proc_dir_entry *ent;
118         int found = 0;                            118         int found = 0;
119                                                   119 
120         spin_lock(&proc_subdir_lock);             120         spin_lock(&proc_subdir_lock);
121                                                   121 
122         for (ent = de->subdir; ent != NULL; en    122         for (ent = de->subdir; ent != NULL; ent = ent->next) {
123                 if (strcmp(ent->name, name) ==    123                 if (strcmp(ent->name, name) == 0) {
124                         found = 1;                124                         found = 1;
125                         break;                    125                         break;
126                 }                                 126                 }
127         }                                         127         }
128                                                   128 
129         spin_unlock(&proc_subdir_lock);           129         spin_unlock(&proc_subdir_lock);
130                                                   130 
131         return found;                             131         return found;
132 }                                                 132 }
133                                                   133 
134 static const char *fixup_name(struct device_no    134 static const char *fixup_name(struct device_node *np, struct proc_dir_entry *de,
135                 const char *name)                 135                 const char *name)
136 {                                                 136 {
137         char *fixed_name;                         137         char *fixed_name;
138         int fixup_len = strlen(name) + 2 + 1;     138         int fixup_len = strlen(name) + 2 + 1; /* name + #x + \0 */
139         int i = 1, size;                          139         int i = 1, size;
140                                                   140 
141 realloc:                                          141 realloc:
142         fixed_name = kmalloc(fixup_len, GFP_KE    142         fixed_name = kmalloc(fixup_len, GFP_KERNEL);
143         if (fixed_name == NULL) {                 143         if (fixed_name == NULL) {
144                 printk(KERN_ERR "device-tree:     144                 printk(KERN_ERR "device-tree: Out of memory trying to fixup "
145                                 "name \"%s\"\n    145                                 "name \"%s\"\n", name);
146                 return name;                      146                 return name;
147         }                                         147         }
148                                                   148 
149 retry:                                            149 retry:
150         size = snprintf(fixed_name, fixup_len,    150         size = snprintf(fixed_name, fixup_len, "%s#%d", name, i);
151         size++; /* account for NULL */            151         size++; /* account for NULL */
152                                                   152 
153         if (size > fixup_len) {                   153         if (size > fixup_len) {
154                 /* We ran out of space, free a    154                 /* We ran out of space, free and reallocate. */
155                 kfree(fixed_name);                155                 kfree(fixed_name);
156                 fixup_len = size;                 156                 fixup_len = size;
157                 goto realloc;                     157                 goto realloc;
158         }                                         158         }
159                                                   159 
160         if (duplicate_name(de, fixed_name)) {     160         if (duplicate_name(de, fixed_name)) {
161                 /* Multiple duplicates. Retry     161                 /* Multiple duplicates. Retry with a different offset. */
162                 i++;                              162                 i++;
163                 goto retry;                       163                 goto retry;
164         }                                         164         }
165                                                   165 
166         printk(KERN_WARNING "device-tree: Dupl    166         printk(KERN_WARNING "device-tree: Duplicate name in %s, "
167                         "renamed to \"%s\"\n",    167                         "renamed to \"%s\"\n", np->full_name, fixed_name);
168                                                   168 
169         return fixed_name;                        169         return fixed_name;
170 }                                                 170 }
171                                                   171 
172 /*                                                172 /*
173  * Process a node, adding entries for its chil    173  * Process a node, adding entries for its children and its properties.
174  */                                               174  */
175 void proc_device_tree_add_node(struct device_n    175 void proc_device_tree_add_node(struct device_node *np,
176                                struct proc_dir    176                                struct proc_dir_entry *de)
177 {                                                 177 {
178         struct property *pp;                      178         struct property *pp;
179         struct proc_dir_entry *ent;               179         struct proc_dir_entry *ent;
180         struct device_node *child;                180         struct device_node *child;
181         const char *p;                            181         const char *p;
182                                                   182 
183         set_node_proc_entry(np, de);              183         set_node_proc_entry(np, de);
184         for (child = NULL; (child = of_get_nex    184         for (child = NULL; (child = of_get_next_child(np, child));) {
185                 /* Use everything after the la    185                 /* Use everything after the last slash, or the full name */
186                 p = strrchr(child->full_name,     186                 p = strrchr(child->full_name, '/');
187                 if (!p)                           187                 if (!p)
188                         p = child->full_name;     188                         p = child->full_name;
189                 else                              189                 else
190                         ++p;                      190                         ++p;
191                                                   191 
192                 if (duplicate_name(de, p))        192                 if (duplicate_name(de, p))
193                         p = fixup_name(np, de,    193                         p = fixup_name(np, de, p);
194                                                   194 
195                 ent = proc_mkdir(p, de);          195                 ent = proc_mkdir(p, de);
196                 if (ent == 0)                     196                 if (ent == 0)
197                         break;                    197                         break;
198                 proc_device_tree_add_node(chil    198                 proc_device_tree_add_node(child, ent);
199         }                                         199         }
200         of_node_put(child);                       200         of_node_put(child);
201                                                   201 
202         for (pp = np->properties; pp != 0; pp     202         for (pp = np->properties; pp != 0; pp = pp->next) {
203                 p = pp->name;                     203                 p = pp->name;
204                                                   204 
205                 if (duplicate_name(de, p))        205                 if (duplicate_name(de, p))
206                         p = fixup_name(np, de,    206                         p = fixup_name(np, de, p);
207                                                   207 
208                 ent = __proc_device_tree_add_p    208                 ent = __proc_device_tree_add_prop(de, pp, p);
209                 if (ent == 0)                     209                 if (ent == 0)
210                         break;                    210                         break;
211         }                                         211         }
212 }                                                 212 }
213                                                   213 
214 /*                                                214 /*
215  * Called on initialization to set up the /pro    215  * Called on initialization to set up the /proc/device-tree subtree
216  */                                               216  */
217 void proc_device_tree_init(void)                  217 void proc_device_tree_init(void)
218 {                                                 218 {
219         struct device_node *root;                 219         struct device_node *root;
220         if ( !have_of )                           220         if ( !have_of )
221                 return;                           221                 return;
222         proc_device_tree = proc_mkdir("device-    222         proc_device_tree = proc_mkdir("device-tree", NULL);
223         if (proc_device_tree == 0)                223         if (proc_device_tree == 0)
224                 return;                           224                 return;
225         root = of_find_node_by_path("/");         225         root = of_find_node_by_path("/");
226         if (root == 0) {                          226         if (root == 0) {
227                 printk(KERN_ERR "/proc/device-    227                 printk(KERN_ERR "/proc/device-tree: can't find root\n");
228                 return;                           228                 return;
229         }                                         229         }
230         proc_device_tree_add_node(root, proc_d    230         proc_device_tree_add_node(root, proc_device_tree);
231         of_node_put(root);                        231         of_node_put(root);
232 }                                                 232 }
233                                                   233 
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