drivers/net/mlx4/reset.c

   1 /*
   2  * Copyright (c) 2006, 2007 Cisco Systems, Inc.  All rights reserved.
   3  * Copyright (c) 2007, 2008 Mellanox Technologies. All rights reserved.
   4  *
   5  * This software is available to you under a choice of one of two
   6  * licenses.  You may choose to be licensed under the terms of the GNU
   7  * General Public License (GPL) Version 2, available from the file
   8  * COPYING in the main directory of this source tree, or the
   9  * OpenIB.org BSD license below:
  10  *
  11  *     Redistribution and use in source and binary forms, with or
  12  *     without modification, are permitted provided that the following
  13  *     conditions are met:
  14  *
  15  *      - Redistributions of source code must retain the above
  16  *        copyright notice, this list of conditions and the following
  17  *        disclaimer.
  18  *
  19  *      - Redistributions in binary form must reproduce the above
  20  *        copyright notice, this list of conditions and the following
  21  *        disclaimer in the documentation and/or other materials
  22  *        provided with the distribution.
  23  *
  24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  31  * SOFTWARE.
  32  */
  33
  34 #include <linux/init.h>
  35 #include <linux/errno.h>
  36 #include <linux/pci.h>
  37 #include <linux/delay.h>
  38 #include <linux/slab.h>
  39 #include <linux/jiffies.h>
  40
  41 #include "mlx4.h"
  42
  43 int mlx4_reset(struct mlx4_dev *dev)
  44 {
  45         void __iomem *reset;
  46         u32 *hca_header = NULL;
  47         int pcie_cap;
  48         u16 devctl;
  49         u16 linkctl;
  50         u16 vendor;
  51         unsigned long end;
  52         u32 sem;
  53         int i;
  54         int err = 0;
  55
  56 #define MLX4_RESET_BASE         0xf0000
  57 #define MLX4_RESET_SIZE           0x400
  58 #define MLX4_SEM_OFFSET           0x3fc
  59 #define MLX4_RESET_OFFSET          0x10
  60 #define MLX4_RESET_VALUE        swab32(1)
  61
  62 #define MLX4_SEM_TIMEOUT_JIFFIES        (10 * HZ)
  63 #define MLX4_RESET_TIMEOUT_JIFFIES      (2 * HZ)
  64
  65         /*
  66          * Reset the chip.  This is somewhat ugly because we have to
  67          * save off the PCI header before reset and then restore it
  68          * after the chip reboots.  We skip config space offsets 22
  69          * and 23 since those have a special meaning.
  70          */
  71
  72         /* Do we need to save off the full 4K PCI Express header?? */
  73         hca_header = kmalloc(256, GFP_KERNEL);
  74         if (!hca_header) {
  75                 err = -ENOMEM;
  76                 mlx4_err(dev, "Couldn't allocate memory to save HCA "
  77                           "PCI header, aborting.\n");
  78                 goto out;
  79         }
  80
  81         pcie_cap = pci_find_capability(dev->pdev, PCI_CAP_ID_EXP);
  82
  83         for (i = 0; i < 64; ++i) {
  84                 if (i == 22 || i == 23)
  85                         continue;
  86                 if (pci_read_config_dword(dev->pdev, i * 4, hca_header + i)) {
  87                         err = -ENODEV;
  88                         mlx4_err(dev, "Couldn't save HCA "
  89                                   "PCI header, aborting.\n");
  90                         goto out;
  91                 }
  92         }
  93
  94         reset = ioremap(pci_resource_start(dev->pdev, 0) + MLX4_RESET_BASE,
  95                         MLX4_RESET_SIZE);
  96         if (!reset) {
  97                 err = -ENOMEM;
  98                 mlx4_err(dev, "Couldn't map HCA reset register, aborting.\n");
  99                 goto out;
 100         }
 101
 102         /* grab HW semaphore to lock out flash updates */
 103         end = jiffies + MLX4_SEM_TIMEOUT_JIFFIES;
 104         do {
 105                 sem = readl(reset + MLX4_SEM_OFFSET);
 106                 if (!sem)
 107                         break;
 108
 109                 msleep(1);
 110         } while (time_before(jiffies, end));
 111
 112         if (sem) {
 113                 mlx4_err(dev, "Failed to obtain HW semaphore, aborting\n");
 114                 err = -EAGAIN;
 115                 iounmap(reset);
 116                 goto out;
 117         }
 118
 119         /* actually hit reset */
 120         writel(MLX4_RESET_VALUE, reset + MLX4_RESET_OFFSET);
 121         iounmap(reset);
 122
 123         /* Docs say to wait one second before accessing device */
 124         msleep(1000);
 125
 126         end = jiffies + MLX4_RESET_TIMEOUT_JIFFIES;
 127         do {
 128                 if (!pci_read_config_word(dev->pdev, PCI_VENDOR_ID, &vendor) &&
 129                     vendor != 0xffff)
 130                         break;
 131
 132                 msleep(1);
 133         } while (time_before(jiffies, end));
 134
 135         if (vendor == 0xffff) {
 136                 err = -ENODEV;
 137                 mlx4_err(dev, "PCI device did not come back after reset, "
 138                           "aborting.\n");
 139                 goto out;
 140         }
 141
 142         /* Now restore the PCI headers */
 143         if (pcie_cap) {
 144                 devctl = hca_header[(pcie_cap + PCI_EXP_DEVCTL) / 4];
 145                 if (pci_write_config_word(dev->pdev, pcie_cap + PCI_EXP_DEVCTL,
 146                                            devctl)) {
 147                         err = -ENODEV;
 148                         mlx4_err(dev, "Couldn't restore HCA PCI Express "
 149                                  "Device Control register, aborting.\n");
 150                         goto out;
 151                 }
 152                 linkctl = hca_header[(pcie_cap + PCI_EXP_LNKCTL) / 4];
 153                 if (pci_write_config_word(dev->pdev, pcie_cap + PCI_EXP_LNKCTL,
 154                                            linkctl)) {
 155                         err = -ENODEV;
 156                         mlx4_err(dev, "Couldn't restore HCA PCI Express "
 157                                  "Link control register, aborting.\n");
 158                         goto out;
 159                 }
 160         }
 161
 162         for (i = 0; i < 16; ++i) {
 163                 if (i * 4 == PCI_COMMAND)
 164                         continue;
 165
 166                 if (pci_write_config_dword(dev->pdev, i * 4, hca_header[i])) {
 167                         err = -ENODEV;
 168                         mlx4_err(dev, "Couldn't restore HCA reg %x, "
 169                                   "aborting.\n", i);
 170                         goto out;
 171                 }
 172         }
 173
 174         if (pci_write_config_dword(dev->pdev, PCI_COMMAND,
 175                                    hca_header[PCI_COMMAND / 4])) {
 176                 err = -ENODEV;
 177                 mlx4_err(dev, "Couldn't restore HCA COMMAND, "
 178                           "aborting.\n");
 179                 goto out;
 180         }
 181
 182 out:
 183         kfree(hca_header);
 184
 185         return err;
 186 }