drivers/infiniband/hw/mthca/mthca_reset.c

   1 /*
   2  * Copyright (c) 2004 Topspin Communications.  All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the
   8  * OpenIB.org BSD license below:
   9  *
  10  *     Redistribution and use in source and binary forms, with or
  11  *     without modification, are permitted provided that the following
  12  *     conditions are met:
  13  *
  14  *      - Redistributions of source code must retain the above
  15  *        copyright notice, this list of conditions and the following
  16  *        disclaimer.
  17  *
  18  *      - Redistributions in binary form must reproduce the above
  19  *        copyright notice, this list of conditions and the following
  20  *        disclaimer in the documentation and/or other materials
  21  *        provided with the distribution.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30  * SOFTWARE.
  31  */
  32
  33 #include <linux/errno.h>
  34 #include <linux/pci.h>
  35 #include <linux/delay.h>
  36 #include <linux/slab.h>
  37
  38 #include "mthca_dev.h"
  39 #include "mthca_cmd.h"
  40
  41 int mthca_reset(struct mthca_dev *mdev)
  42 {
  43         int i;
  44         int err = 0;
  45         u32 *hca_header    = NULL;
  46         u32 *bridge_header = NULL;
  47         struct pci_dev *bridge = NULL;
  48         int bridge_pcix_cap = 0;
  49         int hca_pcie_cap = 0;
  50         int hca_pcix_cap = 0;
  51
  52         u16 devctl;
  53         u16 linkctl;
  54
  55 #define MTHCA_RESET_OFFSET 0xf0010
  56 #define MTHCA_RESET_VALUE  swab32(1)
  57
  58         /*
  59          * Reset the chip.  This is somewhat ugly because we have to
  60          * save off the PCI header before reset and then restore it
  61          * after the chip reboots.  We skip config space offsets 22
  62          * and 23 since those have a special meaning.
  63          *
  64          * To make matters worse, for Tavor (PCI-X HCA) we have to
  65          * find the associated bridge device and save off its PCI
  66          * header as well.
  67          */
  68
  69         if (!(mdev->mthca_flags & MTHCA_FLAG_PCIE)) {
  70                 /* Look for the bridge -- its device ID will be 2 more
  71                    than HCA's device ID. */
  72                 while ((bridge = pci_get_device(mdev->pdev->vendor,
  73                                                 mdev->pdev->device + 2,
  74                                                 bridge)) != NULL) {
  75                         if (bridge->hdr_type    == PCI_HEADER_TYPE_BRIDGE &&
  76                             bridge->subordinate == mdev->pdev->bus) {
  77                                 mthca_dbg(mdev, "Found bridge: %s\n",
  78                                           pci_name(bridge));
  79                                 break;
  80                         }
  81                 }
  82
  83                 if (!bridge) {
  84                         /*
  85                          * Didn't find a bridge for a Tavor device --
  86                          * assume we're in no-bridge mode and hope for
  87                          * the best.
  88                          */
  89                         mthca_warn(mdev, "No bridge found for %s\n",
  90                                   pci_name(mdev->pdev));
  91                 }
  92
  93         }
  94
  95         /* For Arbel do we need to save off the full 4K PCI Express header?? */
  96         hca_header = kmalloc(256, GFP_KERNEL);
  97         if (!hca_header) {
  98                 err = -ENOMEM;
  99                 mthca_err(mdev, "Couldn't allocate memory to save HCA "
 100                           "PCI header, aborting.\n");
 101                 goto out;
 102         }
 103
 104         for (i = 0; i < 64; ++i) {
 105                 if (i == 22 || i == 23)
 106                         continue;
 107                 if (pci_read_config_dword(mdev->pdev, i * 4, hca_header + i)) {
 108                         err = -ENODEV;
 109                         mthca_err(mdev, "Couldn't save HCA "
 110                                   "PCI header, aborting.\n");
 111                         goto out;
 112                 }
 113         }
 114
 115         hca_pcix_cap = pci_find_capability(mdev->pdev, PCI_CAP_ID_PCIX);
 116         hca_pcie_cap = pci_find_capability(mdev->pdev, PCI_CAP_ID_EXP);
 117
 118         if (bridge) {
 119                 bridge_header = kmalloc(256, GFP_KERNEL);
 120                 if (!bridge_header) {
 121                         err = -ENOMEM;
 122                         mthca_err(mdev, "Couldn't allocate memory to save HCA "
 123                                   "bridge PCI header, aborting.\n");
 124                         goto out;
 125                 }
 126
 127                 for (i = 0; i < 64; ++i) {
 128                         if (i == 22 || i == 23)
 129                                 continue;
 130                         if (pci_read_config_dword(bridge, i * 4, bridge_header + i)) {
 131                                 err = -ENODEV;
 132                                 mthca_err(mdev, "Couldn't save HCA bridge "
 133                                           "PCI header, aborting.\n");
 134                                 goto out;
 135                         }
 136                 }
 137                 bridge_pcix_cap = pci_find_capability(bridge, PCI_CAP_ID_PCIX);
 138                 if (!bridge_pcix_cap) {
 139                                 err = -ENODEV;
 140                                 mthca_err(mdev, "Couldn't locate HCA bridge "
 141                                           "PCI-X capability, aborting.\n");
 142                                 goto out;
 143                 }
 144         }
 145
 146         /* actually hit reset */
 147         {
 148                 void __iomem *reset = ioremap(pci_resource_start(mdev->pdev, 0) +
 149                                               MTHCA_RESET_OFFSET, 4);
 150
 151                 if (!reset) {
 152                         err = -ENOMEM;
 153                         mthca_err(mdev, "Couldn't map HCA reset register, "
 154                                   "aborting.\n");
 155                         goto out;
 156                 }
 157
 158                 writel(MTHCA_RESET_VALUE, reset);
 159                 iounmap(reset);
 160         }
 161
 162         /* Docs say to wait one second before accessing device */
 163         msleep(1000);
 164
 165         /* Now wait for PCI device to start responding again */
 166         {
 167                 u32 v;
 168                 int c = 0;
 169
 170                 for (c = 0; c < 100; ++c) {
 171                         if (pci_read_config_dword(bridge ? bridge : mdev->pdev, 0, &v)) {
 172                                 err = -ENODEV;
 173                                 mthca_err(mdev, "Couldn't access HCA after reset, "
 174                                           "aborting.\n");
 175                                 goto out;
 176                         }
 177
 178                         if (v != 0xffffffff)
 179                                 goto good;
 180
 181                         msleep(100);
 182                 }
 183
 184                 err = -ENODEV;
 185                 mthca_err(mdev, "PCI device did not come back after reset, "
 186                           "aborting.\n");
 187                 goto out;
 188         }
 189
 190 good:
 191         /* Now restore the PCI headers */
 192         if (bridge) {
 193                 if (pci_write_config_dword(bridge, bridge_pcix_cap + 0x8,
 194                                  bridge_header[(bridge_pcix_cap + 0x8) / 4])) {
 195                         err = -ENODEV;
 196                         mthca_err(mdev, "Couldn't restore HCA bridge Upstream "
 197                                   "split transaction control, aborting.\n");
 198                         goto out;
 199                 }
 200                 if (pci_write_config_dword(bridge, bridge_pcix_cap + 0xc,
 201                                  bridge_header[(bridge_pcix_cap + 0xc) / 4])) {
 202                         err = -ENODEV;
 203                         mthca_err(mdev, "Couldn't restore HCA bridge Downstream "
 204                                   "split transaction control, aborting.\n");
 205                         goto out;
 206                 }
 207                 /*
 208                  * Bridge control register is at 0x3e, so we'll
 209                  * naturally restore it last in this loop.
 210                  */
 211                 for (i = 0; i < 16; ++i) {
 212                         if (i * 4 == PCI_COMMAND)
 213                                 continue;
 214
 215                         if (pci_write_config_dword(bridge, i * 4, bridge_header[i])) {
 216                                 err = -ENODEV;
 217                                 mthca_err(mdev, "Couldn't restore HCA bridge reg %x, "
 218                                           "aborting.\n", i);
 219                                 goto out;
 220                         }
 221                 }
 222
 223                 if (pci_write_config_dword(bridge, PCI_COMMAND,
 224                                            bridge_header[PCI_COMMAND / 4])) {
 225                         err = -ENODEV;
 226                         mthca_err(mdev, "Couldn't restore HCA bridge COMMAND, "
 227                                   "aborting.\n");
 228                         goto out;
 229                 }
 230         }
 231
 232         if (hca_pcix_cap) {
 233                 if (pci_write_config_dword(mdev->pdev, hca_pcix_cap,
 234                                  hca_header[hca_pcix_cap / 4])) {
 235                         err = -ENODEV;
 236                         mthca_err(mdev, "Couldn't restore HCA PCI-X "
 237                                   "command register, aborting.\n");
 238                         goto out;
 239                 }
 240         }
 241
 242         if (hca_pcie_cap) {
 243                 devctl = hca_header[(hca_pcie_cap + PCI_EXP_DEVCTL) / 4];
 244                 if (pci_write_config_word(mdev->pdev, hca_pcie_cap + PCI_EXP_DEVCTL,
 245                                            devctl)) {
 246                         err = -ENODEV;
 247                         mthca_err(mdev, "Couldn't restore HCA PCI Express "
 248                                   "Device Control register, aborting.\n");
 249                         goto out;
 250                 }
 251                 linkctl = hca_header[(hca_pcie_cap + PCI_EXP_LNKCTL) / 4];
 252                 if (pci_write_config_word(mdev->pdev, hca_pcie_cap + PCI_EXP_LNKCTL,
 253                                            linkctl)) {
 254                         err = -ENODEV;
 255                         mthca_err(mdev, "Couldn't restore HCA PCI Express "
 256                                   "Link control register, aborting.\n");
 257                         goto out;
 258                 }
 259         }
 260
 261         for (i = 0; i < 16; ++i) {
 262                 if (i * 4 == PCI_COMMAND)
 263                         continue;
 264
 265                 if (pci_write_config_dword(mdev->pdev, i * 4, hca_header[i])) {
 266                         err = -ENODEV;
 267                         mthca_err(mdev, "Couldn't restore HCA reg %x, "
 268                                   "aborting.\n", i);
 269                         goto out;
 270                 }
 271         }
 272
 273         if (pci_write_config_dword(mdev->pdev, PCI_COMMAND,
 274                                    hca_header[PCI_COMMAND / 4])) {
 275                 err = -ENODEV;
 276                 mthca_err(mdev, "Couldn't restore HCA COMMAND, "
 277                           "aborting.\n");
 278                 goto out;
 279         }
 280
 281 out:
 282         if (bridge)
 283                 pci_dev_put(bridge);
 284         kfree(bridge_header);
 285         kfree(hca_header);
 286
 287         return err;
 288 }