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/errno.h>
  35 #include <linux/pci.h>
  36 #include <linux/delay.h>
  37 #include <linux/slab.h>
  38 #include <linux/jiffies.h>
  39
  40 #include "mlx4.h"
  41
  42 int mlx4_reset(struct mlx4_dev *dev)
  43 {
  44         void __iomem *reset;
  45         u32 *hca_header = NULL;
  46         int pcie_cap;
  47         u16 devctl;
  48         u16 linkctl;
  49         u16 vendor;
  50         unsigned long end;
  51         u32 sem;
  52         int i;
  53         int err = 0;
  54
  55 #define MLX4_RESET_BASE         0xf0000
  56 #define MLX4_RESET_SIZE           0x400
  57 #define MLX4_SEM_OFFSET           0x3fc
  58 #define MLX4_RESET_OFFSET          0x10
  59 #define MLX4_RESET_VALUE        swab32(1)
  60
  61 #define MLX4_SEM_TIMEOUT_JIFFIES        (10 * HZ)
  62 #define MLX4_RESET_TIMEOUT_JIFFIES      (2 * HZ)
  63
  64         /*
  65          * Reset the chip.  This is somewhat ugly because we have to
  66          * save off the PCI header before reset and then restore it
  67          * after the chip reboots.  We skip config space offsets 22
  68          * and 23 since those have a special meaning.
  69          */
  70
  71         /* Do we need to save off the full 4K PCI Express header?? */
  72         hca_header = kmalloc(256, GFP_KERNEL);
  73         if (!hca_header) {
  74                 err = -ENOMEM;
  75                 mlx4_err(dev, "Couldn't allocate memory to save HCA "
  76                           "PCI header, aborting.\n");
  77                 goto out;
  78         }
  79
  80         pcie_cap = pci_find_capability(dev->pdev, PCI_CAP_ID_EXP);
  81
  82         for (i = 0; i < 64; ++i) {
  83                 if (i == 22 || i == 23)
  84                         continue;
  85                 if (pci_read_config_dword(dev->pdev, i * 4, hca_header + i)) {
  86                         err = -ENODEV;
  87                         mlx4_err(dev, "Couldn't save HCA "
  88                                   "PCI header, aborting.\n");
  89                         goto out;
  90                 }
  91         }
  92
  93         reset = ioremap(pci_resource_start(dev->pdev, 0) + MLX4_RESET_BASE,
  94                         MLX4_RESET_SIZE);
  95         if (!reset) {
  96                 err = -ENOMEM;
  97                 mlx4_err(dev, "Couldn't map HCA reset register, aborting.\n");
  98                 goto out;
  99         }
 100
 101         /* grab HW semaphore to lock out flash updates */
 102         end = jiffies + MLX4_SEM_TIMEOUT_JIFFIES;
 103         do {
 104                 sem = readl(reset + MLX4_SEM_OFFSET);
 105                 if (!sem)
 106                         break;
 107
 108                 msleep(1);
 109         } while (time_before(jiffies, end));
 110
 111         if (sem) {
 112                 mlx4_err(dev, "Failed to obtain HW semaphore, aborting\n");
 113                 err = -EAGAIN;
 114                 iounmap(reset);
 115                 goto out;
 116         }
 117
 118         /* actually hit reset */
 119         writel(MLX4_RESET_VALUE, reset + MLX4_RESET_OFFSET);
 120         iounmap(reset);
 121
 122         /* Docs say to wait one second before accessing device */
 123         msleep(1000);
 124
 125         end = jiffies + MLX4_RESET_TIMEOUT_JIFFIES;
 126         do {
 127                 if (!pci_read_config_word(dev->pdev, PCI_VENDOR_ID, &vendor) &&
 128                     vendor != 0xffff)
 129                         break;
 130
 131                 msleep(1);
 132         } while (time_before(jiffies, end));
 133
 134         if (vendor == 0xffff) {
 135                 err = -ENODEV;
 136                 mlx4_err(dev, "PCI device did not come back after reset, "
 137                           "aborting.\n");
 138                 goto out;
 139         }
 140
 141         /* Now restore the PCI headers */
 142         if (pcie_cap) {
 143                 devctl = hca_header[(pcie_cap + PCI_EXP_DEVCTL) / 4];
 144                 if (pci_write_config_word(dev->pdev, pcie_cap + PCI_EXP_DEVCTL,
 145                                            devctl)) {
 146                         err = -ENODEV;
 147                         mlx4_err(dev, "Couldn't restore HCA PCI Express "
 148                                  "Device Control register, aborting.\n");
 149                         goto out;
 150                 }
 151                 linkctl = hca_header[(pcie_cap + PCI_EXP_LNKCTL) / 4];
 152                 if (pci_write_config_word(dev->pdev, pcie_cap + PCI_EXP_LNKCTL,
 153                                            linkctl)) {
 154                         err = -ENODEV;
 155                         mlx4_err(dev, "Couldn't restore HCA PCI Express "
 156                                  "Link control register, aborting.\n");
 157                         goto out;
 158                 }
 159         }
 160
 161         for (i = 0; i < 16; ++i) {
 162                 if (i * 4 == PCI_COMMAND)
 163                         continue;
 164
 165                 if (pci_write_config_dword(dev->pdev, i * 4, hca_header[i])) {
 166                         err = -ENODEV;
 167                         mlx4_err(dev, "Couldn't restore HCA reg %x, "
 168                                   "aborting.\n", i);
 169                         goto out;
 170                 }
 171         }
 172
 173         if (pci_write_config_dword(dev->pdev, PCI_COMMAND,
 174                                    hca_header[PCI_COMMAND / 4])) {
 175                 err = -ENODEV;
 176                 mlx4_err(dev, "Couldn't restore HCA COMMAND, "
 177                           "aborting.\n");
 178                 goto out;
 179         }
 180
 181 out:
 182         kfree(hca_header);
 183
 184         return err;
 185 }