drivers/edac/edac_pci.c

   1 /*
   2  * EDAC PCI component
   3  *
   4  * Author: Dave Jiang <djiang@mvista.com>
   5  *
   6  * 2007 (c) MontaVista Software, Inc. This file is licensed under
   7  * the terms of the GNU General Public License version 2. This program
   8  * is licensed "as is" without any warranty of any kind, whether express
   9  * or implied.
  10  *
  11  */
  12 #include <asm/page.h>
  13 #include <linux/uaccess.h>
  14 #include <linux/ctype.h>
  15 #include <linux/highmem.h>
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/slab.h>
  19 #include <linux/smp.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/sysctl.h>
  22 #include <linux/timer.h>
  23
  24 #include "edac_pci.h"
  25 #include "edac_module.h"
  26
  27 static DEFINE_MUTEX(edac_pci_ctls_mutex);
  28 static LIST_HEAD(edac_pci_list);
  29 static atomic_t pci_indexes = ATOMIC_INIT(0);
  30
  31 struct edac_pci_ctl_info *edac_pci_alloc_ctl_info(unsigned int sz_pvt,
  32                                                 const char *edac_pci_name)
  33 {
  34         struct edac_pci_ctl_info *pci;
  35         void *p = NULL, *pvt;
  36         unsigned int size;
  37
  38         edac_dbg(1, "\n");
  39
  40         pci = edac_align_ptr(&p, sizeof(*pci), 1);
  41         pvt = edac_align_ptr(&p, 1, sz_pvt);
  42         size = ((unsigned long)pvt) + sz_pvt;
  43
  44         /* Alloc the needed control struct memory */
  45         pci = kzalloc(size, GFP_KERNEL);
  46         if (pci  == NULL)
  47                 return NULL;
  48
  49         /* Now much private space */
  50         pvt = sz_pvt ? ((char *)pci) + ((unsigned long)pvt) : NULL;
  51
  52         pci->pvt_info = pvt;
  53         pci->op_state = OP_ALLOC;
  54
  55         snprintf(pci->name, strlen(edac_pci_name) + 1, "%s", edac_pci_name);
  56
  57         return pci;
  58 }
  59 EXPORT_SYMBOL_GPL(edac_pci_alloc_ctl_info);
  60
  61 void edac_pci_free_ctl_info(struct edac_pci_ctl_info *pci)
  62 {
  63         edac_dbg(1, "\n");
  64
  65         edac_pci_remove_sysfs(pci);
  66 }
  67 EXPORT_SYMBOL_GPL(edac_pci_free_ctl_info);
  68
  69 /*
  70  * find_edac_pci_by_dev()
  71  *      scans the edac_pci list for a specific 'struct device *'
  72  *
  73  *      return NULL if not found, or return control struct pointer
  74  */
  75 static struct edac_pci_ctl_info *find_edac_pci_by_dev(struct device *dev)
  76 {
  77         struct edac_pci_ctl_info *pci;
  78         struct list_head *item;
  79
  80         edac_dbg(1, "\n");
  81
  82         list_for_each(item, &edac_pci_list) {
  83                 pci = list_entry(item, struct edac_pci_ctl_info, link);
  84
  85                 if (pci->dev == dev)
  86                         return pci;
  87         }
  88
  89         return NULL;
  90 }
  91
  92 /*
  93  * add_edac_pci_to_global_list
  94  *      Before calling this function, caller must assign a unique value to
  95  *      edac_dev->pci_idx.
  96  *      Return:
  97  *              0 on success
  98  *              1 on failure
  99  */
 100 static int add_edac_pci_to_global_list(struct edac_pci_ctl_info *pci)
 101 {
 102         struct list_head *item, *insert_before;
 103         struct edac_pci_ctl_info *rover;
 104
 105         edac_dbg(1, "\n");
 106
 107         insert_before = &edac_pci_list;
 108
 109         /* Determine if already on the list */
 110         rover = find_edac_pci_by_dev(pci->dev);
 111         if (unlikely(rover != NULL))
 112                 goto fail0;
 113
 114         /* Insert in ascending order by 'pci_idx', so find position */
 115         list_for_each(item, &edac_pci_list) {
 116                 rover = list_entry(item, struct edac_pci_ctl_info, link);
 117
 118                 if (rover->pci_idx >= pci->pci_idx) {
 119                         if (unlikely(rover->pci_idx == pci->pci_idx))
 120                                 goto fail1;
 121
 122                         insert_before = item;
 123                         break;
 124                 }
 125         }
 126
 127         list_add_tail_rcu(&pci->link, insert_before);
 128         return 0;
 129
 130 fail0:
 131         edac_printk(KERN_WARNING, EDAC_PCI,
 132                 "%s (%s) %s %s already assigned %d\n",
 133                 dev_name(rover->dev), edac_dev_name(rover),
 134                 rover->mod_name, rover->ctl_name, rover->pci_idx);
 135         return 1;
 136
 137 fail1:
 138         edac_printk(KERN_WARNING, EDAC_PCI,
 139                 "but in low-level driver: attempt to assign\n"
 140                 "\tduplicate pci_idx %d in %s()\n", rover->pci_idx,
 141                 __func__);
 142         return 1;
 143 }
 144
 145 /*
 146  * del_edac_pci_from_global_list
 147  *
 148  *      remove the PCI control struct from the global list
 149  */
 150 static void del_edac_pci_from_global_list(struct edac_pci_ctl_info *pci)
 151 {
 152         list_del_rcu(&pci->link);
 153
 154         /* these are for safe removal of devices from global list while
 155          * NMI handlers may be traversing list
 156          */
 157         synchronize_rcu();
 158         INIT_LIST_HEAD(&pci->link);
 159 }
 160
 161 /*
 162  * edac_pci_workq_function()
 163  *
 164  *      periodic function that performs the operation
 165  *      scheduled by a workq request, for a given PCI control struct
 166  */
 167 static void edac_pci_workq_function(struct work_struct *work_req)
 168 {
 169         struct delayed_work *d_work = to_delayed_work(work_req);
 170         struct edac_pci_ctl_info *pci = to_edac_pci_ctl_work(d_work);
 171         int msec;
 172         unsigned long delay;
 173
 174         edac_dbg(3, "checking\n");
 175
 176         mutex_lock(&edac_pci_ctls_mutex);
 177
 178         if (pci->op_state != OP_RUNNING_POLL) {
 179                 mutex_unlock(&edac_pci_ctls_mutex);
 180                 return;
 181         }
 182
 183         if (edac_pci_get_check_errors())
 184                 pci->edac_check(pci);
 185
 186         /* if we are on a one second period, then use round */
 187         msec = edac_pci_get_poll_msec();
 188         if (msec == 1000)
 189                 delay = round_jiffies_relative(msecs_to_jiffies(msec));
 190         else
 191                 delay = msecs_to_jiffies(msec);
 192
 193         edac_queue_work(&pci->work, delay);
 194
 195         mutex_unlock(&edac_pci_ctls_mutex);
 196 }
 197
 198 int edac_pci_alloc_index(void)
 199 {
 200         return atomic_inc_return(&pci_indexes) - 1;
 201 }
 202 EXPORT_SYMBOL_GPL(edac_pci_alloc_index);
 203
 204 int edac_pci_add_device(struct edac_pci_ctl_info *pci, int edac_idx)
 205 {
 206         edac_dbg(0, "\n");
 207
 208         pci->pci_idx = edac_idx;
 209         pci->start_time = jiffies;
 210
 211         mutex_lock(&edac_pci_ctls_mutex);
 212
 213         if (add_edac_pci_to_global_list(pci))
 214                 goto fail0;
 215
 216         if (edac_pci_create_sysfs(pci)) {
 217                 edac_pci_printk(pci, KERN_WARNING,
 218                                 "failed to create sysfs pci\n");
 219                 goto fail1;
 220         }
 221
 222         if (pci->edac_check) {
 223                 pci->op_state = OP_RUNNING_POLL;
 224
 225                 INIT_DELAYED_WORK(&pci->work, edac_pci_workq_function);
 226                 edac_queue_work(&pci->work, msecs_to_jiffies(edac_pci_get_poll_msec()));
 227
 228         } else {
 229                 pci->op_state = OP_RUNNING_INTERRUPT;
 230         }
 231
 232         edac_pci_printk(pci, KERN_INFO,
 233                 "Giving out device to module %s controller %s: DEV %s (%s)\n",
 234                 pci->mod_name, pci->ctl_name, pci->dev_name,
 235                 edac_op_state_to_string(pci->op_state));
 236
 237         mutex_unlock(&edac_pci_ctls_mutex);
 238         return 0;
 239
 240         /* error unwind stack */
 241 fail1:
 242         del_edac_pci_from_global_list(pci);
 243 fail0:
 244         mutex_unlock(&edac_pci_ctls_mutex);
 245         return 1;
 246 }
 247 EXPORT_SYMBOL_GPL(edac_pci_add_device);
 248
 249 struct edac_pci_ctl_info *edac_pci_del_device(struct device *dev)
 250 {
 251         struct edac_pci_ctl_info *pci;
 252
 253         edac_dbg(0, "\n");
 254
 255         mutex_lock(&edac_pci_ctls_mutex);
 256
 257         /* ensure the control struct is on the global list
 258          * if not, then leave
 259          */
 260         pci = find_edac_pci_by_dev(dev);
 261         if (pci  == NULL) {
 262                 mutex_unlock(&edac_pci_ctls_mutex);
 263                 return NULL;
 264         }
 265
 266         pci->op_state = OP_OFFLINE;
 267
 268         del_edac_pci_from_global_list(pci);
 269
 270         mutex_unlock(&edac_pci_ctls_mutex);
 271
 272         if (pci->edac_check)
 273                 edac_stop_work(&pci->work);
 274
 275         edac_printk(KERN_INFO, EDAC_PCI,
 276                 "Removed device %d for %s %s: DEV %s\n",
 277                 pci->pci_idx, pci->mod_name, pci->ctl_name, edac_dev_name(pci));
 278
 279         return pci;
 280 }
 281 EXPORT_SYMBOL_GPL(edac_pci_del_device);
 282
 283 /*
 284  * edac_pci_generic_check
 285  *
 286  *      a Generic parity check API
 287  */
 288 static void edac_pci_generic_check(struct edac_pci_ctl_info *pci)
 289 {
 290         edac_dbg(4, "\n");
 291         edac_pci_do_parity_check();
 292 }
 293
 294 /* free running instance index counter */
 295 static int edac_pci_idx;
 296 #define EDAC_PCI_GENCTL_NAME    "EDAC PCI controller"
 297
 298 struct edac_pci_gen_data {
 299         int edac_idx;
 300 };
 301
 302 struct edac_pci_ctl_info *edac_pci_create_generic_ctl(struct device *dev,
 303                                                 const char *mod_name)
 304 {
 305         struct edac_pci_ctl_info *pci;
 306         struct edac_pci_gen_data *pdata;
 307
 308         pci = edac_pci_alloc_ctl_info(sizeof(*pdata), EDAC_PCI_GENCTL_NAME);
 309         if (!pci)
 310                 return NULL;
 311
 312         pdata = pci->pvt_info;
 313         pci->dev = dev;
 314         dev_set_drvdata(pci->dev, pci);
 315         pci->dev_name = pci_name(to_pci_dev(dev));
 316
 317         pci->mod_name = mod_name;
 318         pci->ctl_name = EDAC_PCI_GENCTL_NAME;
 319         if (edac_op_state == EDAC_OPSTATE_POLL)
 320                 pci->edac_check = edac_pci_generic_check;
 321
 322         pdata->edac_idx = edac_pci_idx++;
 323
 324         if (edac_pci_add_device(pci, pdata->edac_idx) > 0) {
 325                 edac_dbg(3, "failed edac_pci_add_device()\n");
 326                 edac_pci_free_ctl_info(pci);
 327                 return NULL;
 328         }
 329
 330         return pci;
 331 }
 332 EXPORT_SYMBOL_GPL(edac_pci_create_generic_ctl);
 333
 334 void edac_pci_release_generic_ctl(struct edac_pci_ctl_info *pci)
 335 {
 336         edac_dbg(0, "pci mod=%s\n", pci->mod_name);
 337
 338         edac_pci_del_device(pci->dev);
 339         edac_pci_free_ctl_info(pci);
 340 }
 341 EXPORT_SYMBOL_GPL(edac_pci_release_generic_ctl);