mthca_reset.c

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/*
 * Copyright (c) 2004 Topspin Communications.  All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/errno.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/slab.h>

#include "mthca_dev.h"
#include "mthca_cmd.h"

int mthca_reset(struct mthca_dev *mdev)
{
    int i;
    int err = 0;
    u32 *hca_header    = NULL;
    u32 *bridge_header = NULL;
    struct pci_dev *bridge = NULL;
    int bridge_pcix_cap = 0;
    int hca_pcie_cap = 0;
    int hca_pcix_cap = 0;

    u16 devctl;
    u16 linkctl;

#define MTHCA_RESET_OFFSET 0xf0010
#define MTHCA_RESET_VALUE  swab32(1)

    /*
     * Reset the chip.  This is somewhat ugly because we have to
     * save off the PCI header before reset and then restore it
     * after the chip reboots.  We skip config space offsets 22
     * and 23 since those have a special meaning.
     *
     * To make matters worse, for Tavor (PCI-X HCA) we have to
     * find the associated bridge device and save off its PCI
     * header as well.
     */

    if (!(mdev->mthca_flags & MTHCA_FLAG_PCIE)) {
        /* Look for the bridge -- its device ID will be 2 more
           than HCA's device ID. */
        while ((bridge = pci_get_device(mdev->pdev->vendor,
                        mdev->pdev->device + 2,
                        bridge)) != NULL) {
            if (bridge->hdr_type    == PCI_HEADER_TYPE_BRIDGE &&
                bridge->subordinate == mdev->pdev->bus) {
                mthca_dbg(mdev, "Found bridge: %s\n",
                      pci_name(bridge));
                break;
            }
        }

        if (!bridge) {
            /*
             * Didn't find a bridge for a Tavor device --
             * assume we're in no-bridge mode and hope for
             * the best.
             */
            mthca_warn(mdev, "No bridge found for %s\n",
                  pci_name(mdev->pdev));
        }

    }

    /* For Arbel do we need to save off the full 4K PCI Express header?? */
    hca_header = kmalloc(256, GFP_KERNEL);
    if (!hca_header) {
        err = -ENOMEM;
        mthca_err(mdev, "Couldn't allocate memory to save HCA "
              "PCI header, aborting.\n");
        goto out;
    }

    for (i = 0; i < 64; ++i) {
        if (i == 22 || i == 23)
            continue;
        if (pci_read_config_dword(mdev->pdev, i * 4, hca_header + i)) {
            err = -ENODEV;
            mthca_err(mdev, "Couldn't save HCA "
                  "PCI header, aborting.\n");
            goto out;
        }
    }

    hca_pcix_cap = pci_find_capability(mdev->pdev, PCI_CAP_ID_PCIX);
    hca_pcie_cap = pci_pcie_cap(mdev->pdev);

    if (bridge) {
        bridge_header = kmalloc(256, GFP_KERNEL);
        if (!bridge_header) {
            err = -ENOMEM;
            mthca_err(mdev, "Couldn't allocate memory to save HCA "
                  "bridge PCI header, aborting.\n");
            goto out;
        }

        for (i = 0; i < 64; ++i) {
            if (i == 22 || i == 23)
                continue;
            if (pci_read_config_dword(bridge, i * 4, bridge_header + i)) {
                err = -ENODEV;
                mthca_err(mdev, "Couldn't save HCA bridge "
                      "PCI header, aborting.\n");
                goto out;
            }
        }
        bridge_pcix_cap = pci_find_capability(bridge, PCI_CAP_ID_PCIX);
        if (!bridge_pcix_cap) {
                err = -ENODEV;
                mthca_err(mdev, "Couldn't locate HCA bridge "
                      "PCI-X capability, aborting.\n");
                goto out;
        }
    }

    /* actually hit reset */
    {
        void __iomem *reset = ioremap(pci_resource_start(mdev->pdev, 0) +
                          MTHCA_RESET_OFFSET, 4);

        if (!reset) {
            err = -ENOMEM;
            mthca_err(mdev, "Couldn't map HCA reset register, "
                  "aborting.\n");
            goto out;
        }

        writel(MTHCA_RESET_VALUE, reset);
        iounmap(reset);
    }

    /* Docs say to wait one second before accessing device */
    msleep(1000);

    /* Now wait for PCI device to start responding again */
    {
        u32 v;
        int c = 0;

        for (c = 0; c < 100; ++c) {
            if (pci_read_config_dword(bridge ? bridge : mdev->pdev, 0, &v)) {
                err = -ENODEV;
                mthca_err(mdev, "Couldn't access HCA after reset, "
                      "aborting.\n");
                goto out;
            }

            if (v != 0xffffffff)
                goto good;

            msleep(100);
        }

        err = -ENODEV;
        mthca_err(mdev, "PCI device did not come back after reset, "
              "aborting.\n");
        goto out;
    }

good:
    /* Now restore the PCI headers */
    if (bridge) {
        if (pci_write_config_dword(bridge, bridge_pcix_cap + 0x8,
                 bridge_header[(bridge_pcix_cap + 0x8) / 4])) {
            err = -ENODEV;
            mthca_err(mdev, "Couldn't restore HCA bridge Upstream "
                  "split transaction control, aborting.\n");
            goto out;
        }
        if (pci_write_config_dword(bridge, bridge_pcix_cap + 0xc,
                 bridge_header[(bridge_pcix_cap + 0xc) / 4])) {
            err = -ENODEV;
            mthca_err(mdev, "Couldn't restore HCA bridge Downstream "
                  "split transaction control, aborting.\n");
            goto out;
        }
        /*
         * Bridge control register is at 0x3e, so we'll
         * naturally restore it last in this loop.
         */
        for (i = 0; i < 16; ++i) {
            if (i * 4 == PCI_COMMAND)
                continue;

            if (pci_write_config_dword(bridge, i * 4, bridge_header[i])) {
                err = -ENODEV;
                mthca_err(mdev, "Couldn't restore HCA bridge reg %x, "
                      "aborting.\n", i);
                goto out;
            }
        }

        if (pci_write_config_dword(bridge, PCI_COMMAND,
                       bridge_header[PCI_COMMAND / 4])) {
            err = -ENODEV;
            mthca_err(mdev, "Couldn't restore HCA bridge COMMAND, "
                  "aborting.\n");
            goto out;
        }
    }

    if (hca_pcix_cap) {
        if (pci_write_config_dword(mdev->pdev, hca_pcix_cap,
                 hca_header[hca_pcix_cap / 4])) {
            err = -ENODEV;
            mthca_err(mdev, "Couldn't restore HCA PCI-X "
                  "command register, aborting.\n");
            goto out;
        }
    }

    if (hca_pcie_cap) {
        devctl = hca_header[(hca_pcie_cap + PCI_EXP_DEVCTL) / 4];
        if (pcie_capability_write_word(mdev->pdev, PCI_EXP_DEVCTL,
                           devctl)) {
            err = -ENODEV;
            mthca_err(mdev, "Couldn't restore HCA PCI Express "
                  "Device Control register, aborting.\n");
            goto out;
        }
        linkctl = hca_header[(hca_pcie_cap + PCI_EXP_LNKCTL) / 4];
        if (pcie_capability_write_word(mdev->pdev, PCI_EXP_LNKCTL,
                           linkctl)) {
            err = -ENODEV;
            mthca_err(mdev, "Couldn't restore HCA PCI Express "
                  "Link control register, aborting.\n");
            goto out;
        }
    }

    for (i = 0; i < 16; ++i) {
        if (i * 4 == PCI_COMMAND)
            continue;

        if (pci_write_config_dword(mdev->pdev, i * 4, hca_header[i])) {
            err = -ENODEV;
            mthca_err(mdev, "Couldn't restore HCA reg %x, "
                  "aborting.\n", i);
            goto out;
        }
    }

    if (pci_write_config_dword(mdev->pdev, PCI_COMMAND,
                   hca_header[PCI_COMMAND / 4])) {
        err = -ENODEV;
        mthca_err(mdev, "Couldn't restore HCA COMMAND, "
              "aborting.\n");
        goto out;
    }

out:
    if (bridge)
        pci_dev_put(bridge);
    kfree(bridge_header);
    kfree(hca_header);

    return err;
}