arch/powerpc/platforms/pseries/eeh_driver.c

   1 /*
   2  * PCI Error Recovery Driver for RPA-compliant PPC64 platform.
   3  * Copyright (C) 2004, 2005 Linas Vepstas <linas@linas.org>
   4  *
   5  * All rights reserved.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or (at
  10  * your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  15  * NON INFRINGEMENT.  See the GNU General Public License for more
  16  * details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21  *
  22  * Send feedback to <linas@us.ibm.com>
  23  *
  24  */
  25 #include <linux/delay.h>
  26 #include <linux/irq.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/notifier.h>
  29 #include <linux/pci.h>
  30 #include <asm/eeh.h>
  31 #include <asm/eeh_event.h>
  32 #include <asm/ppc-pci.h>
  33 #include <asm/pci-bridge.h>
  34 #include <asm/prom.h>
  35 #include <asm/rtas.h>
  36
  37
  38 static inline const char * pcid_name (struct pci_dev *pdev)
  39 {
  40         if (pdev->dev.driver)
  41                 return pdev->dev.driver->name;
  42         return "";
  43 }
  44
  45 #ifdef DEBUG
  46 static void print_device_node_tree (struct pci_dn *pdn, int dent)
  47 {
  48         int i;
  49         if (!pdn) return;
  50         for (i=0;i<dent; i++)
  51                 printk(" ");
  52         printk("dn=%s mode=%x \tcfg_addr=%x pe_addr=%x \tfull=%s\n",
  53                 pdn->node->name, pdn->eeh_mode, pdn->eeh_config_addr,
  54                 pdn->eeh_pe_config_addr, pdn->node->full_name);
  55         dent += 3;
  56         struct device_node *pc = pdn->node->child;
  57         while (pc) {
  58                 print_device_node_tree(PCI_DN(pc), dent);
  59                 pc = pc->sibling;
  60         }
  61 }
  62 #endif
  63
  64 /**
  65  * irq_in_use - return true if this irq is being used
  66  */
  67 static int irq_in_use(unsigned int irq)
  68 {
  69         int rc = 0;
  70         unsigned long flags;
  71    struct irq_desc *desc = irq_desc + irq;
  72
  73         spin_lock_irqsave(&desc->lock, flags);
  74         if (desc->action)
  75                 rc = 1;
  76         spin_unlock_irqrestore(&desc->lock, flags);
  77         return rc;
  78 }
  79
  80 /* ------------------------------------------------------- */
  81 /** eeh_report_error - report an EEH error to each device,
  82  *  collect up and merge the device responses.
  83  */
  84
  85 static void eeh_report_error(struct pci_dev *dev, void *userdata)
  86 {
  87         enum pci_ers_result rc, *res = userdata;
  88         struct pci_driver *driver = dev->driver;
  89
  90         dev->error_state = pci_channel_io_frozen;
  91
  92         if (!driver)
  93                 return;
  94
  95         if (irq_in_use (dev->irq)) {
  96                 struct device_node *dn = pci_device_to_OF_node(dev);
  97                 PCI_DN(dn)->eeh_mode |= EEH_MODE_IRQ_DISABLED;
  98                 disable_irq_nosync(dev->irq);
  99         }
 100         if (!driver->err_handler)
 101                 return;
 102         if (!driver->err_handler->error_detected)
 103                 return;
 104
 105         rc = driver->err_handler->error_detected (dev, pci_channel_io_frozen);
 106         if (*res == PCI_ERS_RESULT_NONE) *res = rc;
 107         if (*res == PCI_ERS_RESULT_NEED_RESET) return;
 108         if (*res == PCI_ERS_RESULT_DISCONNECT &&
 109              rc == PCI_ERS_RESULT_NEED_RESET) *res = rc;
 110 }
 111
 112 /** eeh_report_reset -- tell this device that the pci slot
 113  *  has been reset.
 114  */
 115
 116 static void eeh_report_reset(struct pci_dev *dev, void *userdata)
 117 {
 118         struct pci_driver *driver = dev->driver;
 119         struct device_node *dn = pci_device_to_OF_node(dev);
 120
 121         if (!driver)
 122                 return;
 123
 124         if ((PCI_DN(dn)->eeh_mode) & EEH_MODE_IRQ_DISABLED) {
 125                 PCI_DN(dn)->eeh_mode &= ~EEH_MODE_IRQ_DISABLED;
 126                 enable_irq(dev->irq);
 127         }
 128         if (!driver->err_handler)
 129                 return;
 130         if (!driver->err_handler->slot_reset)
 131                 return;
 132
 133         driver->err_handler->slot_reset(dev);
 134 }
 135
 136 static void eeh_report_resume(struct pci_dev *dev, void *userdata)
 137 {
 138         struct pci_driver *driver = dev->driver;
 139
 140         dev->error_state = pci_channel_io_normal;
 141
 142         if (!driver)
 143                 return;
 144         if (!driver->err_handler)
 145                 return;
 146         if (!driver->err_handler->resume)
 147                 return;
 148
 149         driver->err_handler->resume(dev);
 150 }
 151
 152 static void eeh_report_failure(struct pci_dev *dev, void *userdata)
 153 {
 154         struct pci_driver *driver = dev->driver;
 155
 156         dev->error_state = pci_channel_io_perm_failure;
 157
 158         if (!driver)
 159                 return;
 160
 161         if (irq_in_use (dev->irq)) {
 162                 struct device_node *dn = pci_device_to_OF_node(dev);
 163                 PCI_DN(dn)->eeh_mode |= EEH_MODE_IRQ_DISABLED;
 164                 disable_irq_nosync(dev->irq);
 165         }
 166         if (!driver->err_handler)
 167                 return;
 168         if (!driver->err_handler->error_detected)
 169                 return;
 170         driver->err_handler->error_detected(dev, pci_channel_io_perm_failure);
 171 }
 172
 173 /* ------------------------------------------------------- */
 174 /**
 175  * handle_eeh_events -- reset a PCI device after hard lockup.
 176  *
 177  * pSeries systems will isolate a PCI slot if the PCI-Host
 178  * bridge detects address or data parity errors, DMA's
 179  * occuring to wild addresses (which usually happen due to
 180  * bugs in device drivers or in PCI adapter firmware).
 181  * Slot isolations also occur if #SERR, #PERR or other misc
 182  * PCI-related errors are detected.
 183  *
 184  * Recovery process consists of unplugging the device driver
 185  * (which generated hotplug events to userspace), then issuing
 186  * a PCI #RST to the device, then reconfiguring the PCI config
 187  * space for all bridges & devices under this slot, and then
 188  * finally restarting the device drivers (which cause a second
 189  * set of hotplug events to go out to userspace).
 190  */
 191
 192 /**
 193  * eeh_reset_device() -- perform actual reset of a pci slot
 194  * Args: bus: pointer to the pci bus structure corresponding
 195  *            to the isolated slot. A non-null value will
 196  *            cause all devices under the bus to be removed
 197  *            and then re-added.
 198  *     pe_dn: pointer to a "Partionable Endpoint" device node.
 199  *            This is the top-level structure on which pci
 200  *            bus resets can be performed.
 201  */
 202
 203 static int eeh_reset_device (struct pci_dn *pe_dn, struct pci_bus *bus)
 204 {
 205         int rc;
 206         if (bus)
 207                 pcibios_remove_pci_devices(bus);
 208
 209         /* Reset the pci controller. (Asserts RST#; resets config space).
 210          * Reconfigure bridges and devices. Don't try to bring the system
 211          * up if the reset failed for some reason. */
 212         rc = rtas_set_slot_reset(pe_dn);
 213         if (rc)
 214                 return rc;
 215
 216         /* New-style config addrs might be shared across multiple devices,
 217          * Walk over all functions on this device */
 218         if (pe_dn->eeh_pe_config_addr) {
 219                 struct device_node *pe = pe_dn->node;
 220                 pe = pe->parent->child;
 221                 while (pe) {
 222                         struct pci_dn *ppe = PCI_DN(pe);
 223                         if (pe_dn->eeh_pe_config_addr == ppe->eeh_pe_config_addr) {
 224                                 rtas_configure_bridge(ppe);
 225                                 eeh_restore_bars(ppe);
 226                         }
 227                         pe = pe->sibling;
 228                 }
 229         } else {
 230                 rtas_configure_bridge(pe_dn);
 231                 eeh_restore_bars(pe_dn);
 232         }
 233
 234         /* Give the system 5 seconds to finish running the user-space
 235          * hotplug shutdown scripts, e.g. ifdown for ethernet.  Yes,
 236          * this is a hack, but if we don't do this, and try to bring
 237          * the device up before the scripts have taken it down,
 238          * potentially weird things happen.
 239          */
 240         if (bus) {
 241                 ssleep (5);
 242                 pcibios_add_pci_devices(bus);
 243         }
 244
 245         return 0;
 246 }
 247
 248 /* The longest amount of time to wait for a pci device
 249  * to come back on line, in seconds.
 250  */
 251 #define MAX_WAIT_FOR_RECOVERY 15
 252
 253 void handle_eeh_events (struct eeh_event *event)
 254 {
 255         struct device_node *frozen_dn;
 256         struct pci_dn *frozen_pdn;
 257         struct pci_bus *frozen_bus;
 258         int rc = 0;
 259         enum pci_ers_result result = PCI_ERS_RESULT_NONE;
 260
 261         frozen_dn = find_device_pe(event->dn);
 262         frozen_bus = pcibios_find_pci_bus(frozen_dn);
 263
 264         if (!frozen_dn) {
 265                 printk(KERN_ERR "EEH: Error: Cannot find partition endpoint for %s\n",
 266                         pci_name(event->dev));
 267                 return;
 268         }
 269
 270         /* There are two different styles for coming up with the PE.
 271          * In the old style, it was the highest EEH-capable device
 272          * which was always an EADS pci bridge.  In the new style,
 273          * there might not be any EADS bridges, and even when there are,
 274          * the firmware marks them as "EEH incapable". So another
 275          * two-step is needed to find the pci bus.. */
 276         if (!frozen_bus)
 277                 frozen_bus = pcibios_find_pci_bus (frozen_dn->parent);
 278
 279         if (!frozen_bus) {
 280                 printk(KERN_ERR "EEH: Cannot find PCI bus for %s\n",
 281                         frozen_dn->full_name);
 282                 return;
 283         }
 284
 285 #if 0
 286         /* We may get "permanent failure" messages on empty slots.
 287          * These are false alarms. Empty slots have no child dn. */
 288         if ((event->state == pci_channel_io_perm_failure) && (frozen_device == NULL))
 289                 return;
 290 #endif
 291
 292         frozen_pdn = PCI_DN(frozen_dn);
 293         frozen_pdn->eeh_freeze_count++;
 294
 295         if (frozen_pdn->eeh_freeze_count > EEH_MAX_ALLOWED_FREEZES)
 296                 goto hard_fail;
 297
 298         /* If the reset state is a '5' and the time to reset is 0 (infinity)
 299          * or is more then 15 seconds, then mark this as a permanent failure.
 300          */
 301         if ((event->state == pci_channel_io_perm_failure) &&
 302             ((event->time_unavail <= 0) ||
 303              (event->time_unavail > MAX_WAIT_FOR_RECOVERY*1000)))
 304                 goto hard_fail;
 305
 306         eeh_slot_error_detail(frozen_pdn, 1 /* Temporary Error */);
 307         printk(KERN_WARNING
 308            "EEH: This PCI device has failed %d times since last reboot: %s - %s\n",
 309                 frozen_pdn->eeh_freeze_count,
 310                 pci_name (frozen_pdn->pcidev),
 311                 pcid_name(frozen_pdn->pcidev));
 312
 313         /* Walk the various device drivers attached to this slot through
 314          * a reset sequence, giving each an opportunity to do what it needs
 315          * to accomplish the reset.  Each child gets a report of the
 316          * status ... if any child can't handle the reset, then the entire
 317          * slot is dlpar removed and added.
 318          */
 319         pci_walk_bus(frozen_bus, eeh_report_error, &result);
 320
 321         /* If all device drivers were EEH-unaware, then shut
 322          * down all of the device drivers, and hope they
 323          * go down willingly, without panicing the system.
 324          */
 325         if (result == PCI_ERS_RESULT_NONE) {
 326                 rc = eeh_reset_device(frozen_pdn, frozen_bus);
 327                 if (rc)
 328                         goto hard_fail;
 329         }
 330
 331         /* If any device called out for a reset, then reset the slot */
 332         if (result == PCI_ERS_RESULT_NEED_RESET) {
 333                 rc = eeh_reset_device(frozen_pdn, NULL);
 334                 if (rc)
 335                         goto hard_fail;
 336                 pci_walk_bus(frozen_bus, eeh_report_reset, 0);
 337         }
 338
 339         /* If all devices reported they can proceed, the re-enable PIO */
 340         if (result == PCI_ERS_RESULT_CAN_RECOVER) {
 341                 /* XXX Not supported; we brute-force reset the device */
 342                 rc = eeh_reset_device(frozen_pdn, NULL);
 343                 if (rc)
 344                         goto hard_fail;
 345                 pci_walk_bus(frozen_bus, eeh_report_reset, 0);
 346         }
 347
 348         /* Tell all device drivers that they can resume operations */
 349         pci_walk_bus(frozen_bus, eeh_report_resume, 0);
 350
 351         return;
 352
 353 hard_fail:
 354         /*
 355          * About 90% of all real-life EEH failures in the field
 356          * are due to poorly seated PCI cards. Only 10% or so are
 357          * due to actual, failed cards.
 358          */
 359         printk(KERN_ERR
 360            "EEH: PCI device %s - %s has failed %d times \n"
 361            "and has been permanently disabled.  Please try reseating\n"
 362            "this device or replacing it.\n",
 363                 pci_name (frozen_pdn->pcidev),
 364                 pcid_name(frozen_pdn->pcidev),
 365                 frozen_pdn->eeh_freeze_count);
 366
 367         eeh_slot_error_detail(frozen_pdn, 2 /* Permanent Error */);
 368
 369         /* Notify all devices that they're about to go down. */
 370         pci_walk_bus(frozen_bus, eeh_report_failure, 0);
 371
 372         /* Shut down the device drivers for good. */
 373         pcibios_remove_pci_devices(frozen_bus);
 374 }
 375
 376 /* ---------- end of file ---------- */