drivers/edac/edac_pci.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * EDAC PCI component
0004  *
0005  * Author: Dave Jiang <djiang@mvista.com>
0006  *
0007  * 2007 (c) MontaVista Software, Inc.
0008  */
0009 #include <asm/page.h>
0010 #include <linux/uaccess.h>
0011 #include <linux/ctype.h>
0012 #include <linux/highmem.h>
0013 #include <linux/init.h>
0014 #include <linux/module.h>
0015 #include <linux/slab.h>
0016 #include <linux/smp.h>
0017 #include <linux/spinlock.h>
0018 #include <linux/sysctl.h>
0019 #include <linux/timer.h>
0020
0021 #include "edac_pci.h"
0022 #include "edac_module.h"
0023
0024 static DEFINE_MUTEX(edac_pci_ctls_mutex);
0025 static LIST_HEAD(edac_pci_list);
0026 static atomic_t pci_indexes = ATOMIC_INIT(0);
0027
0028 struct edac_pci_ctl_info *edac_pci_alloc_ctl_info(unsigned int sz_pvt,
0029                           const char *edac_pci_name)
0030 {
0031     struct edac_pci_ctl_info *pci;
0032
0033     edac_dbg(1, "\n");
0034
0035     pci = kzalloc(sizeof(struct edac_pci_ctl_info), GFP_KERNEL);
0036     if (!pci)
0037         return NULL;
0038
0039     if (sz_pvt) {
0040         pci->pvt_info = kzalloc(sz_pvt, GFP_KERNEL);
0041         if (!pci->pvt_info)
0042             goto free;
0043     }
0044
0045     pci->op_state = OP_ALLOC;
0046
0047     snprintf(pci->name, strlen(edac_pci_name) + 1, "%s", edac_pci_name);
0048
0049     return pci;
0050
0051 free:
0052     kfree(pci);
0053     return NULL;
0054 }
0055 EXPORT_SYMBOL_GPL(edac_pci_alloc_ctl_info);
0056
0057 void edac_pci_free_ctl_info(struct edac_pci_ctl_info *pci)
0058 {
0059     edac_dbg(1, "\n");
0060
0061     edac_pci_remove_sysfs(pci);
0062 }
0063 EXPORT_SYMBOL_GPL(edac_pci_free_ctl_info);
0064
0065 /*
0066  * find_edac_pci_by_dev()
0067  *  scans the edac_pci list for a specific 'struct device *'
0068  *
0069  *  return NULL if not found, or return control struct pointer
0070  */
0071 static struct edac_pci_ctl_info *find_edac_pci_by_dev(struct device *dev)
0072 {
0073     struct edac_pci_ctl_info *pci;
0074     struct list_head *item;
0075
0076     edac_dbg(1, "\n");
0077
0078     list_for_each(item, &edac_pci_list) {
0079         pci = list_entry(item, struct edac_pci_ctl_info, link);
0080
0081         if (pci->dev == dev)
0082             return pci;
0083     }
0084
0085     return NULL;
0086 }
0087
0088 /*
0089  * add_edac_pci_to_global_list
0090  *  Before calling this function, caller must assign a unique value to
0091  *  edac_dev->pci_idx.
0092  *  Return:
0093  *      0 on success
0094  *      1 on failure
0095  */
0096 static int add_edac_pci_to_global_list(struct edac_pci_ctl_info *pci)
0097 {
0098     struct list_head *item, *insert_before;
0099     struct edac_pci_ctl_info *rover;
0100
0101     edac_dbg(1, "\n");
0102
0103     insert_before = &edac_pci_list;
0104
0105     /* Determine if already on the list */
0106     rover = find_edac_pci_by_dev(pci->dev);
0107     if (unlikely(rover != NULL))
0108         goto fail0;
0109
0110     /* Insert in ascending order by 'pci_idx', so find position */
0111     list_for_each(item, &edac_pci_list) {
0112         rover = list_entry(item, struct edac_pci_ctl_info, link);
0113
0114         if (rover->pci_idx >= pci->pci_idx) {
0115             if (unlikely(rover->pci_idx == pci->pci_idx))
0116                 goto fail1;
0117
0118             insert_before = item;
0119             break;
0120         }
0121     }
0122
0123     list_add_tail_rcu(&pci->link, insert_before);
0124     return 0;
0125
0126 fail0:
0127     edac_printk(KERN_WARNING, EDAC_PCI,
0128         "%s (%s) %s %s already assigned %d\n",
0129         dev_name(rover->dev), edac_dev_name(rover),
0130         rover->mod_name, rover->ctl_name, rover->pci_idx);
0131     return 1;
0132
0133 fail1:
0134     edac_printk(KERN_WARNING, EDAC_PCI,
0135         "but in low-level driver: attempt to assign\n"
0136         "\tduplicate pci_idx %d in %s()\n", rover->pci_idx,
0137         __func__);
0138     return 1;
0139 }
0140
0141 /*
0142  * del_edac_pci_from_global_list
0143  *
0144  *  remove the PCI control struct from the global list
0145  */
0146 static void del_edac_pci_from_global_list(struct edac_pci_ctl_info *pci)
0147 {
0148     list_del_rcu(&pci->link);
0149
0150     /* these are for safe removal of devices from global list while
0151      * NMI handlers may be traversing list
0152      */
0153     synchronize_rcu();
0154     INIT_LIST_HEAD(&pci->link);
0155 }
0156
0157 /*
0158  * edac_pci_workq_function()
0159  *
0160  *  periodic function that performs the operation
0161  *  scheduled by a workq request, for a given PCI control struct
0162  */
0163 static void edac_pci_workq_function(struct work_struct *work_req)
0164 {
0165     struct delayed_work *d_work = to_delayed_work(work_req);
0166     struct edac_pci_ctl_info *pci = to_edac_pci_ctl_work(d_work);
0167     int msec;
0168     unsigned long delay;
0169
0170     edac_dbg(3, "checking\n");
0171
0172     mutex_lock(&edac_pci_ctls_mutex);
0173
0174     if (pci->op_state != OP_RUNNING_POLL) {
0175         mutex_unlock(&edac_pci_ctls_mutex);
0176         return;
0177     }
0178
0179     if (edac_pci_get_check_errors())
0180         pci->edac_check(pci);
0181
0182     /* if we are on a one second period, then use round */
0183     msec = edac_pci_get_poll_msec();
0184     if (msec == 1000)
0185         delay = round_jiffies_relative(msecs_to_jiffies(msec));
0186     else
0187         delay = msecs_to_jiffies(msec);
0188
0189     edac_queue_work(&pci->work, delay);
0190
0191     mutex_unlock(&edac_pci_ctls_mutex);
0192 }
0193
0194 int edac_pci_alloc_index(void)
0195 {
0196     return atomic_inc_return(&pci_indexes) - 1;
0197 }
0198 EXPORT_SYMBOL_GPL(edac_pci_alloc_index);
0199
0200 int edac_pci_add_device(struct edac_pci_ctl_info *pci, int edac_idx)
0201 {
0202     edac_dbg(0, "\n");
0203
0204     pci->pci_idx = edac_idx;
0205     pci->start_time = jiffies;
0206
0207     mutex_lock(&edac_pci_ctls_mutex);
0208
0209     if (add_edac_pci_to_global_list(pci))
0210         goto fail0;
0211
0212     if (edac_pci_create_sysfs(pci)) {
0213         edac_pci_printk(pci, KERN_WARNING,
0214                 "failed to create sysfs pci\n");
0215         goto fail1;
0216     }
0217
0218     if (pci->edac_check) {
0219         pci->op_state = OP_RUNNING_POLL;
0220
0221         INIT_DELAYED_WORK(&pci->work, edac_pci_workq_function);
0222         edac_queue_work(&pci->work, msecs_to_jiffies(edac_pci_get_poll_msec()));
0223
0224     } else {
0225         pci->op_state = OP_RUNNING_INTERRUPT;
0226     }
0227
0228     edac_pci_printk(pci, KERN_INFO,
0229         "Giving out device to module %s controller %s: DEV %s (%s)\n",
0230         pci->mod_name, pci->ctl_name, pci->dev_name,
0231         edac_op_state_to_string(pci->op_state));
0232
0233     mutex_unlock(&edac_pci_ctls_mutex);
0234     return 0;
0235
0236     /* error unwind stack */
0237 fail1:
0238     del_edac_pci_from_global_list(pci);
0239 fail0:
0240     mutex_unlock(&edac_pci_ctls_mutex);
0241     return 1;
0242 }
0243 EXPORT_SYMBOL_GPL(edac_pci_add_device);
0244
0245 struct edac_pci_ctl_info *edac_pci_del_device(struct device *dev)
0246 {
0247     struct edac_pci_ctl_info *pci;
0248
0249     edac_dbg(0, "\n");
0250
0251     mutex_lock(&edac_pci_ctls_mutex);
0252
0253     /* ensure the control struct is on the global list
0254      * if not, then leave
0255      */
0256     pci = find_edac_pci_by_dev(dev);
0257     if (pci  == NULL) {
0258         mutex_unlock(&edac_pci_ctls_mutex);
0259         return NULL;
0260     }
0261
0262     pci->op_state = OP_OFFLINE;
0263
0264     del_edac_pci_from_global_list(pci);
0265
0266     mutex_unlock(&edac_pci_ctls_mutex);
0267
0268     if (pci->edac_check)
0269         edac_stop_work(&pci->work);
0270
0271     edac_printk(KERN_INFO, EDAC_PCI,
0272         "Removed device %d for %s %s: DEV %s\n",
0273         pci->pci_idx, pci->mod_name, pci->ctl_name, edac_dev_name(pci));
0274
0275     return pci;
0276 }
0277 EXPORT_SYMBOL_GPL(edac_pci_del_device);
0278
0279 /*
0280  * edac_pci_generic_check
0281  *
0282  *  a Generic parity check API
0283  */
0284 static void edac_pci_generic_check(struct edac_pci_ctl_info *pci)
0285 {
0286     edac_dbg(4, "\n");
0287     edac_pci_do_parity_check();
0288 }
0289
0290 /* free running instance index counter */
0291 static int edac_pci_idx;
0292 #define EDAC_PCI_GENCTL_NAME    "EDAC PCI controller"
0293
0294 struct edac_pci_gen_data {
0295     int edac_idx;
0296 };
0297
0298 struct edac_pci_ctl_info *edac_pci_create_generic_ctl(struct device *dev,
0299                         const char *mod_name)
0300 {
0301     struct edac_pci_ctl_info *pci;
0302     struct edac_pci_gen_data *pdata;
0303
0304     pci = edac_pci_alloc_ctl_info(sizeof(*pdata), EDAC_PCI_GENCTL_NAME);
0305     if (!pci)
0306         return NULL;
0307
0308     pdata = pci->pvt_info;
0309     pci->dev = dev;
0310     dev_set_drvdata(pci->dev, pci);
0311     pci->dev_name = pci_name(to_pci_dev(dev));
0312
0313     pci->mod_name = mod_name;
0314     pci->ctl_name = EDAC_PCI_GENCTL_NAME;
0315     if (edac_op_state == EDAC_OPSTATE_POLL)
0316         pci->edac_check = edac_pci_generic_check;
0317
0318     pdata->edac_idx = edac_pci_idx++;
0319
0320     if (edac_pci_add_device(pci, pdata->edac_idx) > 0) {
0321         edac_dbg(3, "failed edac_pci_add_device()\n");
0322         edac_pci_free_ctl_info(pci);
0323         return NULL;
0324     }
0325
0326     return pci;
0327 }
0328 EXPORT_SYMBOL_GPL(edac_pci_create_generic_ctl);
0329
0330 void edac_pci_release_generic_ctl(struct edac_pci_ctl_info *pci)
0331 {
0332     edac_dbg(0, "pci mod=%s\n", pci->mod_name);
0333
0334     edac_pci_del_device(pci->dev);
0335     edac_pci_free_ctl_info(pci);
0336 }
0337 EXPORT_SYMBOL_GPL(edac_pci_release_generic_ctl);