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 ]
  1 #include <linux/init.h>
  2 #include <linux/proc_fs.h>
  3 #include <linux/ctype.h>
  4 #include <linux/module.h>
  5 #include <linux/seq_file.h>
  6 #include <asm/uaccess.h>
  7 
  8 #define LINE_SIZE 80
  9 
 10 #include <asm/mtrr.h>
 11 #include "mtrr.h"
 12 
 13 /* RED-PEN: this is accessed without any locking */
 14 extern unsigned int *usage_table;
 15 
 16 
 17 #define FILE_FCOUNT(f) (((struct seq_file *)((f)->private_data))->private)
 18 
 19 static char *mtrr_strings[MTRR_NUM_TYPES] =
 20 {
 21     "uncachable",               /* 0 */
 22     "write-combining",          /* 1 */
 23     "?",                        /* 2 */
 24     "?",                        /* 3 */
 25     "write-through",            /* 4 */
 26     "write-protect",            /* 5 */
 27     "write-back",               /* 6 */
 28 };
 29 
 30 char *mtrr_attrib_to_str(int x)
 31 {
 32         return (x <= 6) ? mtrr_strings[x] : "?";
 33 }
 34 
 35 #ifdef CONFIG_PROC_FS
 36 
 37 static int
 38 mtrr_file_add(unsigned long base, unsigned long size,
 39               unsigned int type, char increment, struct file *file, int page)
 40 {
 41         int reg, max;
 42         unsigned int *fcount = FILE_FCOUNT(file); 
 43 
 44         max = num_var_ranges;
 45         if (fcount == NULL) {
 46                 fcount = kmalloc(max * sizeof *fcount, GFP_KERNEL);
 47                 if (!fcount)
 48                         return -ENOMEM;
 49                 memset(fcount, 0, max * sizeof *fcount);
 50                 FILE_FCOUNT(file) = fcount;
 51         }
 52         if (!page) {
 53                 if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
 54                         return -EINVAL;
 55                 base >>= PAGE_SHIFT;
 56                 size >>= PAGE_SHIFT;
 57         }
 58         reg = mtrr_add_page(base, size, type, 1);
 59         if (reg >= 0)
 60                 ++fcount[reg];
 61         return reg;
 62 }
 63 
 64 static int
 65 mtrr_file_del(unsigned long base, unsigned long size,
 66               struct file *file, int page)
 67 {
 68         int reg;
 69         unsigned int *fcount = FILE_FCOUNT(file);
 70 
 71         if (!page) {
 72                 if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
 73                         return -EINVAL;
 74                 base >>= PAGE_SHIFT;
 75                 size >>= PAGE_SHIFT;
 76         }
 77         reg = mtrr_del_page(-1, base, size);
 78         if (reg < 0)
 79                 return reg;
 80         if (fcount == NULL)
 81                 return reg;
 82         if (fcount[reg] < 1)
 83                 return -EINVAL;
 84         --fcount[reg];
 85         return reg;
 86 }
 87 
 88 /* RED-PEN: seq_file can seek now. this is ignored. */
 89 static ssize_t
 90 mtrr_write(struct file *file, const char __user *buf, size_t len, loff_t * ppos)
 91 /*  Format of control line:
 92     "base=%Lx size=%Lx type=%s"     OR:
 93     "disable=%d"
 94 */
 95 {
 96         int i, err;
 97         unsigned long reg;
 98         unsigned long long base, size;
 99         char *ptr;
100         char line[LINE_SIZE];
101 
102         if (!capable(CAP_SYS_ADMIN))
103                 return -EPERM;
104         memset(line, 0, LINE_SIZE);
105         if (len > LINE_SIZE)
106                 len = LINE_SIZE;
107         if (copy_from_user(line, buf, len - 1))
108                 return -EFAULT;
109         ptr = line + strlen(line) - 1;
110         if (*ptr == '\n')
111                 *ptr = '\0';
112         if (!strncmp(line, "disable=", 8)) {
113                 reg = simple_strtoul(line + 8, &ptr, 0);
114                 err = mtrr_del_page(reg, 0, 0);
115                 if (err < 0)
116                         return err;
117                 return len;
118         }
119         if (strncmp(line, "base=", 5))
120                 return -EINVAL;
121         base = simple_strtoull(line + 5, &ptr, 0);
122         for (; isspace(*ptr); ++ptr) ;
123         if (strncmp(ptr, "size=", 5))
124                 return -EINVAL;
125         size = simple_strtoull(ptr + 5, &ptr, 0);
126         if ((base & 0xfff) || (size & 0xfff))
127                 return -EINVAL;
128         for (; isspace(*ptr); ++ptr) ;
129         if (strncmp(ptr, "type=", 5))
130                 return -EINVAL;
131         ptr += 5;
132         for (; isspace(*ptr); ++ptr) ;
133         for (i = 0; i < MTRR_NUM_TYPES; ++i) {
134                 if (strcmp(ptr, mtrr_strings[i]))
135                         continue;
136                 base >>= PAGE_SHIFT;
137                 size >>= PAGE_SHIFT;
138                 err =
139                     mtrr_add_page((unsigned long) base, (unsigned long) size, i,
140                                   1);
141                 if (err < 0)
142                         return err;
143                 return len;
144         }
145         return -EINVAL;
146 }
147 
148 static int
149 mtrr_ioctl(struct inode *inode, struct file *file,
150            unsigned int cmd, unsigned long __arg)
151 {
152         int err;
153         mtrr_type type;
154         struct mtrr_sentry sentry;
155         struct mtrr_gentry gentry;
156         void __user *arg = (void __user *) __arg;
157 
158         switch (cmd) {
159         default:
160                 return -ENOTTY;
161         case MTRRIOC_ADD_ENTRY:
162                 if (!capable(CAP_SYS_ADMIN))
163                         return -EPERM;
164                 if (copy_from_user(&sentry, arg, sizeof sentry))
165                         return -EFAULT;
166                 err =
167                     mtrr_file_add(sentry.base, sentry.size, sentry.type, 1,
168                                   file, 0);
169                 if (err < 0)
170                         return err;
171                 break;
172         case MTRRIOC_SET_ENTRY:
173                 if (!capable(CAP_SYS_ADMIN))
174                         return -EPERM;
175                 if (copy_from_user(&sentry, arg, sizeof sentry))
176                         return -EFAULT;
177                 err = mtrr_add(sentry.base, sentry.size, sentry.type, 0);
178                 if (err < 0)
179                         return err;
180                 break;
181         case MTRRIOC_DEL_ENTRY:
182                 if (!capable(CAP_SYS_ADMIN))
183                         return -EPERM;
184                 if (copy_from_user(&sentry, arg, sizeof sentry))
185                         return -EFAULT;
186                 err = mtrr_file_del(sentry.base, sentry.size, file, 0);
187                 if (err < 0)
188                         return err;
189                 break;
190         case MTRRIOC_KILL_ENTRY:
191                 if (!capable(CAP_SYS_ADMIN))
192                         return -EPERM;
193                 if (copy_from_user(&sentry, arg, sizeof sentry))
194                         return -EFAULT;
195                 err = mtrr_del(-1, sentry.base, sentry.size);
196                 if (err < 0)
197                         return err;
198                 break;
199         case MTRRIOC_GET_ENTRY:
200                 if (copy_from_user(&gentry, arg, sizeof gentry))
201                         return -EFAULT;
202                 if (gentry.regnum >= num_var_ranges)
203                         return -EINVAL;
204                 mtrr_if->get(gentry.regnum, &gentry.base, &gentry.size, &type);
205 
206                 /* Hide entries that go above 4GB */
207                 if (gentry.base + gentry.size > 0x100000
208                     || gentry.size == 0x100000)
209                         gentry.base = gentry.size = gentry.type = 0;
210                 else {
211                         gentry.base <<= PAGE_SHIFT;
212                         gentry.size <<= PAGE_SHIFT;
213                         gentry.type = type;
214                 }
215 
216                 if (copy_to_user(arg, &gentry, sizeof gentry))
217                         return -EFAULT;
218                 break;
219         case MTRRIOC_ADD_PAGE_ENTRY:
220                 if (!capable(CAP_SYS_ADMIN))
221                         return -EPERM;
222                 if (copy_from_user(&sentry, arg, sizeof sentry))
223                         return -EFAULT;
224                 err =
225                     mtrr_file_add(sentry.base, sentry.size, sentry.type, 1,
226                                   file, 1);
227                 if (err < 0)
228                         return err;
229                 break;
230         case MTRRIOC_SET_PAGE_ENTRY:
231                 if (!capable(CAP_SYS_ADMIN))
232                         return -EPERM;
233                 if (copy_from_user(&sentry, arg, sizeof sentry))
234                         return -EFAULT;
235                 err = mtrr_add_page(sentry.base, sentry.size, sentry.type, 0);
236                 if (err < 0)
237                         return err;
238                 break;
239         case MTRRIOC_DEL_PAGE_ENTRY:
240                 if (!capable(CAP_SYS_ADMIN))
241                         return -EPERM;
242                 if (copy_from_user(&sentry, arg, sizeof sentry))
243                         return -EFAULT;
244                 err = mtrr_file_del(sentry.base, sentry.size, file, 1);
245                 if (err < 0)
246                         return err;
247                 break;
248         case MTRRIOC_KILL_PAGE_ENTRY:
249                 if (!capable(CAP_SYS_ADMIN))
250                         return -EPERM;
251                 if (copy_from_user(&sentry, arg, sizeof sentry))
252                         return -EFAULT;
253                 err = mtrr_del_page(-1, sentry.base, sentry.size);
254                 if (err < 0)
255                         return err;
256                 break;
257         case MTRRIOC_GET_PAGE_ENTRY:
258                 if (copy_from_user(&gentry, arg, sizeof gentry))
259                         return -EFAULT;
260                 if (gentry.regnum >= num_var_ranges)
261                         return -EINVAL;
262                 mtrr_if->get(gentry.regnum, &gentry.base, &gentry.size, &type);
263                 gentry.type = type;
264 
265                 if (copy_to_user(arg, &gentry, sizeof gentry))
266                         return -EFAULT;
267                 break;
268         }
269         return 0;
270 }
271 
272 static int
273 mtrr_close(struct inode *ino, struct file *file)
274 {
275         int i, max;
276         unsigned int *fcount = FILE_FCOUNT(file);
277 
278         if (fcount != NULL) {
279                 max = num_var_ranges;
280                 for (i = 0; i < max; ++i) {
281                         while (fcount[i] > 0) {
282                                 mtrr_del(i, 0, 0);
283                                 --fcount[i];
284                         }
285                 }
286                 kfree(fcount);
287                 FILE_FCOUNT(file) = NULL;
288         }
289         return single_release(ino, file);
290 }
291 
292 static int mtrr_seq_show(struct seq_file *seq, void *offset);
293 
294 static int mtrr_open(struct inode *inode, struct file *file)
295 {
296         if (!mtrr_if) 
297                 return -EIO;
298         if (!mtrr_if->get) 
299                 return -ENXIO; 
300         return single_open(file, mtrr_seq_show, NULL);
301 }
302 
303 static struct file_operations mtrr_fops = {
304         .owner   = THIS_MODULE,
305         .open    = mtrr_open, 
306         .read    = seq_read,
307         .llseek  = seq_lseek,
308         .write   = mtrr_write,
309         .ioctl   = mtrr_ioctl,
310         .release = mtrr_close,
311 };
312 
313 
314 static struct proc_dir_entry *proc_root_mtrr;
315 
316 
317 static int mtrr_seq_show(struct seq_file *seq, void *offset)
318 {
319         char factor;
320         int i, max, len;
321         mtrr_type type;
322         unsigned long base;
323         unsigned int size;
324 
325         len = 0;
326         max = num_var_ranges;
327         for (i = 0; i < max; i++) {
328                 mtrr_if->get(i, &base, &size, &type);
329                 if (size == 0)
330                         usage_table[i] = 0;
331                 else {
332                         if (size < (0x100000 >> PAGE_SHIFT)) {
333                                 /* less than 1MB */
334                                 factor = 'K';
335                                 size <<= PAGE_SHIFT - 10;
336                         } else {
337                                 factor = 'M';
338                                 size >>= 20 - PAGE_SHIFT;
339                         }
340                         /* RED-PEN: base can be > 32bit */ 
341                         len += seq_printf(seq, 
342                                    "reg%02i: base=0x%05lx000 (%4liMB), size=%4i%cB: %s, count=%d\n",
343                              i, base, base >> (20 - PAGE_SHIFT), size, factor,
344                              mtrr_attrib_to_str(type), usage_table[i]);
345                 }
346         }
347         return 0;
348 }
349 
350 static int __init mtrr_if_init(void)
351 {
352         struct cpuinfo_x86 *c = &boot_cpu_data;
353 
354         if ((!cpu_has(c, X86_FEATURE_MTRR)) &&
355             (!cpu_has(c, X86_FEATURE_K6_MTRR)) &&
356             (!cpu_has(c, X86_FEATURE_CYRIX_ARR)) &&
357             (!cpu_has(c, X86_FEATURE_CENTAUR_MCR)))
358                 return -ENODEV;
359 
360         proc_root_mtrr =
361             create_proc_entry("mtrr", S_IWUSR | S_IRUGO, &proc_root);
362         if (proc_root_mtrr) {
363                 proc_root_mtrr->owner = THIS_MODULE;
364                 proc_root_mtrr->proc_fops = &mtrr_fops;
365         }
366         return 0;
367 }
368 
369 arch_initcall(mtrr_if_init);
370 #endif                  /*  CONFIG_PROC_FS  */
371 
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