/*
 * Copyright(c) 2015, 2016 Intel Corporation.
 *
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * BSD LICENSE
 *
 * 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.
 *  - Neither the name of Intel Corporation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include <linux/firmware.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/crc32.h>

#include "hfi.h"
#include "trace.h"

/*
 * Make it easy to toggle firmware file name and if it gets loaded by
 * editing the following. This may be something we do while in development
 * but not necessarily something a user would ever need to use.
 */
#define DEFAULT_FW_8051_NAME_FPGA "hfi_dc8051.bin"
#define DEFAULT_FW_8051_NAME_ASIC "hfi1_dc8051.fw"
#define DEFAULT_FW_FABRIC_NAME "hfi1_fabric.fw"
#define DEFAULT_FW_SBUS_NAME "hfi1_sbus.fw"
#define DEFAULT_FW_PCIE_NAME "hfi1_pcie.fw"
#define DEFAULT_PLATFORM_CONFIG_NAME "hfi1_platform.dat"
#define ALT_FW_8051_NAME_ASIC "hfi1_dc8051_d.fw"
#define ALT_FW_FABRIC_NAME "hfi1_fabric_d.fw"
#define ALT_FW_SBUS_NAME "hfi1_sbus_d.fw"
#define ALT_FW_PCIE_NAME "hfi1_pcie_d.fw"

static uint fw_8051_load = 1;
static uint fw_fabric_serdes_load = 1;
static uint fw_pcie_serdes_load = 1;
static uint fw_sbus_load = 1;

/*
 * Access required in platform.c
 * Maintains state of whether the platform config was fetched via the
 * fallback option
 */
uint platform_config_load;

/* Firmware file names get set in hfi1_firmware_init() based on the above */
static char *fw_8051_name;
static char *fw_fabric_serdes_name;
static char *fw_sbus_name;
static char *fw_pcie_serdes_name;
static char *platform_config_name;

#define SBUS_MAX_POLL_COUNT 100
#define SBUS_COUNTER(reg, name) \
        (((reg) >> ASIC_STS_SBUS_COUNTERS_##name##_CNT_SHIFT) & \
         ASIC_STS_SBUS_COUNTERS_##name##_CNT_MASK)

/*
 * Firmware security header.
 */
struct css_header {
        u32 module_type;
        u32 header_len;
        u32 header_version;
        u32 module_id;
        u32 module_vendor;
        u32 date;               /* BCD yyyymmdd */
        u32 size;               /* in DWORDs */
        u32 key_size;           /* in DWORDs */
        u32 modulus_size;       /* in DWORDs */
        u32 exponent_size;      /* in DWORDs */
        u32 reserved[22];
};

/* expected field values */
#define CSS_MODULE_TYPE    0x00000006
#define CSS_HEADER_LEN     0x000000a1
#define CSS_HEADER_VERSION 0x00010000
#define CSS_MODULE_VENDOR  0x00008086

#define KEY_SIZE      256
#define MU_SIZE         8
#define EXPONENT_SIZE   4

/* the file itself */
struct firmware_file {
        struct css_header css_header;
        u8 modulus[KEY_SIZE];
        u8 exponent[EXPONENT_SIZE];
        u8 signature[KEY_SIZE];
        u8 firmware[];
};

struct augmented_firmware_file {
        struct css_header css_header;
        u8 modulus[KEY_SIZE];
        u8 exponent[EXPONENT_SIZE];
        u8 signature[KEY_SIZE];
        u8 r2[KEY_SIZE];
        u8 mu[MU_SIZE];
        u8 firmware[];
};

/* augmented file size difference */
#define AUGMENT_SIZE (sizeof(struct augmented_firmware_file) - \
                                                sizeof(struct firmware_file))

struct firmware_details {
        /* Linux core piece */
        const struct firmware *fw;

        struct css_header *css_header;
        u8 *firmware_ptr;               /* pointer to binary data */
        u32 firmware_len;               /* length in bytes */
        u8 *modulus;                    /* pointer to the modulus */
        u8 *exponent;                   /* pointer to the exponent */
        u8 *signature;                  /* pointer to the signature */
        u8 *r2;                         /* pointer to r2 */
        u8 *mu;                         /* pointer to mu */
        struct augmented_firmware_file dummy_header;
};

/*
 * The mutex protects fw_state, fw_err, and all of the firmware_details
 * variables.
 */
static DEFINE_MUTEX(fw_mutex);
enum fw_state {
        FW_EMPTY,
        FW_TRY,
        FW_FINAL,
        FW_ERR
};

static enum fw_state fw_state = FW_EMPTY;
static int fw_err;
static struct firmware_details fw_8051;
static struct firmware_details fw_fabric;
static struct firmware_details fw_pcie;
static struct firmware_details fw_sbus;
static const struct firmware *platform_config;

/* flags for turn_off_spicos() */
#define SPICO_SBUS   0x1
#define SPICO_FABRIC 0x2
#define ENABLE_SPICO_SMASK 0x1

/* security block commands */
#define RSA_CMD_INIT  0x1
#define RSA_CMD_START 0x2

/* security block status */
#define RSA_STATUS_IDLE   0x0
#define RSA_STATUS_ACTIVE 0x1
#define RSA_STATUS_DONE   0x2
#define RSA_STATUS_FAILED 0x3

/* RSA engine timeout, in ms */
#define RSA_ENGINE_TIMEOUT 100 /* ms */

/* hardware mutex timeout, in ms */
#define HM_TIMEOUT 10 /* ms */

/* 8051 memory access timeout, in us */
#define DC8051_ACCESS_TIMEOUT 100 /* us */

/* the number of fabric SerDes on the SBus */
#define NUM_FABRIC_SERDES 4

/* SBus fabric SerDes addresses, one set per HFI */
static const u8 fabric_serdes_addrs[2][NUM_FABRIC_SERDES] = {
        { 0x01, 0x02, 0x03, 0x04 },
        { 0x28, 0x29, 0x2a, 0x2b }
};

/* SBus PCIe SerDes addresses, one set per HFI */
static const u8 pcie_serdes_addrs[2][NUM_PCIE_SERDES] = {
        { 0x08, 0x0a, 0x0c, 0x0e, 0x10, 0x12, 0x14, 0x16,
          0x18, 0x1a, 0x1c, 0x1e, 0x20, 0x22, 0x24, 0x26 },
        { 0x2f, 0x31, 0x33, 0x35, 0x37, 0x39, 0x3b, 0x3d,
          0x3f, 0x41, 0x43, 0x45, 0x47, 0x49, 0x4b, 0x4d }
};

/* SBus PCIe PCS addresses, one set per HFI */
const u8 pcie_pcs_addrs[2][NUM_PCIE_SERDES] = {
        { 0x09, 0x0b, 0x0d, 0x0f, 0x11, 0x13, 0x15, 0x17,
          0x19, 0x1b, 0x1d, 0x1f, 0x21, 0x23, 0x25, 0x27 },
        { 0x30, 0x32, 0x34, 0x36, 0x38, 0x3a, 0x3c, 0x3e,
          0x40, 0x42, 0x44, 0x46, 0x48, 0x4a, 0x4c, 0x4e }
};

/* SBus fabric SerDes broadcast addresses, one per HFI */
static const u8 fabric_serdes_broadcast[2] = { 0xe4, 0xe5 };
static const u8 all_fabric_serdes_broadcast = 0xe1;

/* SBus PCIe SerDes broadcast addresses, one per HFI */
const u8 pcie_serdes_broadcast[2] = { 0xe2, 0xe3 };
static const u8 all_pcie_serdes_broadcast = 0xe0;

/* forwards */
static void dispose_one_firmware(struct firmware_details *fdet);
static int load_fabric_serdes_firmware(struct hfi1_devdata *dd,
                                       struct firmware_details *fdet);

/*
 * Read a single 64-bit value from 8051 data memory.
 *
 * Expects:
 * o caller to have already set up data read, no auto increment
 * o caller to turn off read enable when finished
 *
 * The address argument is a byte offset.  Bits 0:2 in the address are
 * ignored - i.e. the hardware will always do aligned 8-byte reads as if
 * the lower bits are zero.
 *
 * Return 0 on success, -ENXIO on a read error (timeout).
 */
static int __read_8051_data(struct hfi1_devdata *dd, u32 addr, u64 *result)
{
        u64 reg;
        int count;

        /* start the read at the given address */
        reg = ((addr & DC_DC8051_CFG_RAM_ACCESS_CTRL_ADDRESS_MASK)
                        << DC_DC8051_CFG_RAM_ACCESS_CTRL_ADDRESS_SHIFT)
                | DC_DC8051_CFG_RAM_ACCESS_CTRL_READ_ENA_SMASK;
        write_csr(dd, DC_DC8051_CFG_RAM_ACCESS_CTRL, reg);

        /* wait until ACCESS_COMPLETED is set */
        count = 0;
        while ((read_csr(dd, DC_DC8051_CFG_RAM_ACCESS_STATUS)
                    & DC_DC8051_CFG_RAM_ACCESS_STATUS_ACCESS_COMPLETED_SMASK)
                    == 0) {
                count++;
                if (count > DC8051_ACCESS_TIMEOUT) {
                        dd_dev_err(dd, "timeout reading 8051 data\n");
                        return -ENXIO;
                }
                ndelay(10);
        }

        /* gather the data */
        *result = read_csr(dd, DC_DC8051_CFG_RAM_ACCESS_RD_DATA);

        return 0;
}

/*
 * Read 8051 data starting at addr, for len bytes.  Will read in 8-byte chunks.
 * Return 0 on success, -errno on error.
 */
int read_8051_data(struct hfi1_devdata *dd, u32 addr, u32 len, u64 *result)
{
        unsigned long flags;
        u32 done;
        int ret = 0;

        spin_lock_irqsave(&dd->dc8051_memlock, flags);

        /* data read set-up, no auto-increment */
        write_csr(dd, DC_DC8051_CFG_RAM_ACCESS_SETUP, 0);

        for (done = 0; done < len; addr += 8, done += 8, result++) {
                ret = __read_8051_data(dd, addr, result);
                if (ret)
                        break;
        }

        /* turn off read enable */
        write_csr(dd, DC_DC8051_CFG_RAM_ACCESS_CTRL, 0);

        spin_unlock_irqrestore(&dd->dc8051_memlock, flags);

        return ret;
}

/*
 * Write data or code to the 8051 code or data RAM.
 */
static int write_8051(struct hfi1_devdata *dd, int code, u32 start,
                      const u8 *data, u32 len)
{
        u64 reg;
        u32 offset;
        int aligned, count;

        /* check alignment */
        aligned = ((unsigned long)data & 0x7) == 0;

        /* write set-up */
        reg = (code ? DC_DC8051_CFG_RAM_ACCESS_SETUP_RAM_SEL_SMASK : 0ull)
                | DC_DC8051_CFG_RAM_ACCESS_SETUP_AUTO_INCR_ADDR_SMASK;
        write_csr(dd, DC_DC8051_CFG_RAM_ACCESS_SETUP, reg);

        reg = ((start & DC_DC8051_CFG_RAM_ACCESS_CTRL_ADDRESS_MASK)
                        << DC_DC8051_CFG_RAM_ACCESS_CTRL_ADDRESS_SHIFT)
                | DC_DC8051_CFG_RAM_ACCESS_CTRL_WRITE_ENA_SMASK;
        write_csr(dd, DC_DC8051_CFG_RAM_ACCESS_CTRL, reg);

        /* write */
        for (offset = 0; offset < len; offset += 8) {
                int bytes = len - offset;

                if (bytes < 8) {
                        reg = 0;
                        memcpy(&reg, &data[offset], bytes);
                } else if (aligned) {
                        reg = *(u64 *)&data[offset];
                } else {
                        memcpy(&reg, &data[offset], 8);
                }
                write_csr(dd, DC_DC8051_CFG_RAM_ACCESS_WR_DATA, reg);

                /* wait until ACCESS_COMPLETED is set */
                count = 0;
                while ((read_csr(dd, DC_DC8051_CFG_RAM_ACCESS_STATUS)
                    & DC_DC8051_CFG_RAM_ACCESS_STATUS_ACCESS_COMPLETED_SMASK)
                    == 0) {
                        count++;
                        if (count > DC8051_ACCESS_TIMEOUT) {
                                dd_dev_err(dd, "timeout writing 8051 data\n");
                                return -ENXIO;
                        }
                        udelay(1);
                }
        }

        /* turn off write access, auto increment (also sets to data access) */
        write_csr(dd, DC_DC8051_CFG_RAM_ACCESS_CTRL, 0);
        write_csr(dd, DC_DC8051_CFG_RAM_ACCESS_SETUP, 0);

        return 0;
}

/* return 0 if values match, non-zero and complain otherwise */
static int invalid_header(struct hfi1_devdata *dd, const char *what,
                          u32 actual, u32 expected)
{
        if (actual == expected)
                return 0;

        dd_dev_err(dd,
                   "invalid firmware header field %s: expected 0x%x, actual 0x%x\n",
                   what, expected, actual);
        return 1;
}

/*
 * Verify that the static fields in the CSS header match.
 */
static int verify_css_header(struct hfi1_devdata *dd, struct css_header *css)
{
        /* verify CSS header fields (most sizes are in DW, so add /4) */
        if (invalid_header(dd, "module_type", css->module_type,
                           CSS_MODULE_TYPE) ||
            invalid_header(dd, "header_len", css->header_len,
                           (sizeof(struct firmware_file) / 4)) ||
            invalid_header(dd, "header_version", css->header_version,
                           CSS_HEADER_VERSION) ||
            invalid_header(dd, "module_vendor", css->module_vendor,
                           CSS_MODULE_VENDOR) ||
            invalid_header(dd, "key_size", css->key_size, KEY_SIZE / 4) ||
            invalid_header(dd, "modulus_size", css->modulus_size,
                           KEY_SIZE / 4) ||
            invalid_header(dd, "exponent_size", css->exponent_size,
                           EXPONENT_SIZE / 4)) {
                return -EINVAL;
        }
        return 0;
}

/*
 * Make sure there are at least some bytes after the prefix.
 */
static int payload_check(struct hfi1_devdata *dd, const char *name,
                         long file_size, long prefix_size)
{
        /* make sure we have some payload */
        if (prefix_size >= file_size) {
                dd_dev_err(dd,
                           "firmware \"%s\", size %ld, must be larger than %ld bytes\n",
                           name, file_size, prefix_size);
                return -EINVAL;
        }

        return 0;
}

/*
 * Request the firmware from the system.  Extract the pieces and fill in
 * fdet.  If successful, the caller will need to call dispose_one_firmware().
 * Returns 0 on success, -ERRNO on error.
 */
static int obtain_one_firmware(struct hfi1_devdata *dd, const char *name,
                               struct firmware_details *fdet)
{
        struct css_header *css;
        int ret;

        memset(fdet, 0, sizeof(*fdet));

        ret = request_firmware(&fdet->fw, name, &dd->pcidev->dev);
        if (ret) {
                dd_dev_warn(dd, "cannot find firmware \"%s\", err %d\n",
                            name, ret);
                return ret;
        }

        /* verify the firmware */
        if (fdet->fw->size < sizeof(struct css_header)) {
                dd_dev_err(dd, "firmware \"%s\" is too small\n", name);
                ret = -EINVAL;
                goto done;
        }
        css = (struct css_header *)fdet->fw->data;

        hfi1_cdbg(FIRMWARE, "Firmware %s details:", name);
        hfi1_cdbg(FIRMWARE, "file size: 0x%lx bytes", fdet->fw->size);
        hfi1_cdbg(FIRMWARE, "CSS structure:");
        hfi1_cdbg(FIRMWARE, "  module_type    0x%x", css->module_type);
        hfi1_cdbg(FIRMWARE, "  header_len     0x%03x (0x%03x bytes)",
                  css->header_len, 4 * css->header_len);
        hfi1_cdbg(FIRMWARE, "  header_version 0x%x", css->header_version);
        hfi1_cdbg(FIRMWARE, "  module_id      0x%x", css->module_id);
        hfi1_cdbg(FIRMWARE, "  module_vendor  0x%x", css->module_vendor);
        hfi1_cdbg(FIRMWARE, "  date           0x%x", css->date);
        hfi1_cdbg(FIRMWARE, "  size           0x%03x (0x%03x bytes)",
                  css->size, 4 * css->size);
        hfi1_cdbg(FIRMWARE, "  key_size       0x%03x (0x%03x bytes)",
                  css->key_size, 4 * css->key_size);
        hfi1_cdbg(FIRMWARE, "  modulus_size   0x%03x (0x%03x bytes)",
                  css->modulus_size, 4 * css->modulus_size);
        hfi1_cdbg(FIRMWARE, "  exponent_size  0x%03x (0x%03x bytes)",
                  css->exponent_size, 4 * css->exponent_size);
        hfi1_cdbg(FIRMWARE, "firmware size: 0x%lx bytes",
                  fdet->fw->size - sizeof(struct firmware_file));

        /*
         * If the file does not have a valid CSS header, fail.
         * Otherwise, check the CSS size field for an expected size.
         * The augmented file has r2 and mu inserted after the header
         * was generated, so there will be a known difference between
         * the CSS header size and the actual file size.  Use this
         * difference to identify an augmented file.
         *
         * Note: css->size is in DWORDs, multiply by 4 to get bytes.
         */
        ret = verify_css_header(dd, css);
        if (ret) {
                dd_dev_info(dd, "Invalid CSS header for \"%s\"\n", name);
        } else if ((css->size * 4) == fdet->fw->size) {
                /* non-augmented firmware file */
                struct firmware_file *ff = (struct firmware_file *)
                                                        fdet->fw->data;

                /* make sure there are bytes in the payload */
                ret = payload_check(dd, name, fdet->fw->size,
                                    sizeof(struct firmware_file));
                if (ret == 0) {
                        fdet->css_header = css;
                        fdet->modulus = ff->modulus;
                        fdet->exponent = ff->exponent;
                        fdet->signature = ff->signature;
                        fdet->r2 = fdet->dummy_header.r2; /* use dummy space */
                        fdet->mu = fdet->dummy_header.mu; /* use dummy space */
                        fdet->firmware_ptr = ff->firmware;
                        fdet->firmware_len = fdet->fw->size -
                                                sizeof(struct firmware_file);
                        /*
                         * Header does not include r2 and mu - generate here.
                         * For now, fail.
                         */
                        dd_dev_err(dd, "driver is unable to validate firmware without r2 and mu (not in firmware file)\n");
                        ret = -EINVAL;
                }
        } else if ((css->size * 4) + AUGMENT_SIZE == fdet->fw->size) {
                /* augmented firmware file */
                struct augmented_firmware_file *aff =
                        (struct augmented_firmware_file *)fdet->fw->data;

                /* make sure there are bytes in the payload */
                ret = payload_check(dd, name, fdet->fw->size,
                                    sizeof(struct augmented_firmware_file));
                if (ret == 0) {
                        fdet->css_header = css;
                        fdet->modulus = aff->modulus;
                        fdet->exponent = aff->exponent;
                        fdet->signature = aff->signature;
                        fdet->r2 = aff->r2;
                        fdet->mu = aff->mu;
                        fdet->firmware_ptr = aff->firmware;
                        fdet->firmware_len = fdet->fw->size -
                                        sizeof(struct augmented_firmware_file);
                }
        } else {
                /* css->size check failed */
                dd_dev_err(dd,
                           "invalid firmware header field size: expected 0x%lx or 0x%lx, actual 0x%x\n",
                           fdet->fw->size / 4,
                           (fdet->fw->size - AUGMENT_SIZE) / 4,
                           css->size);

                ret = -EINVAL;
        }

done:
        /* if returning an error, clean up after ourselves */
        if (ret)
                dispose_one_firmware(fdet);
        return ret;
}

static void dispose_one_firmware(struct firmware_details *fdet)
{
        release_firmware(fdet->fw);
        /* erase all previous information */
        memset(fdet, 0, sizeof(*fdet));
}

/*
 * Obtain the 4 firmwares from the OS.  All must be obtained at once or not
 * at all.  If called with the firmware state in FW_TRY, use alternate names.
 * On exit, this routine will have set the firmware state to one of FW_TRY,
 * FW_FINAL, or FW_ERR.
 *
 * Must be holding fw_mutex.
 */
static void __obtain_firmware(struct hfi1_devdata *dd)
{
        int err = 0;

        if (fw_state == FW_FINAL)       /* nothing more to obtain */
                return;
        if (fw_state == FW_ERR)         /* already in error */
                return;

        /* fw_state is FW_EMPTY or FW_TRY */
retry:
        if (fw_state == FW_TRY) {
                /*
                 * We tried the original and it failed.  Move to the
                 * alternate.
                 */
                dd_dev_warn(dd, "using alternate firmware names\n");
                /*
                 * Let others run.  Some systems, when missing firmware, does
                 * something that holds for 30 seconds.  If we do that twice
                 * in a row it triggers task blocked warning.
                 */
                cond_resched();
                if (fw_8051_load)
                        dispose_one_firmware(&fw_8051);
                if (fw_fabric_serdes_load)
                        dispose_one_firmware(&fw_fabric);
                if (fw_sbus_load)
                        dispose_one_firmware(&fw_sbus);
                if (fw_pcie_serdes_load)
                        dispose_one_firmware(&fw_pcie);
                fw_8051_name = ALT_FW_8051_NAME_ASIC;
                fw_fabric_serdes_name = ALT_FW_FABRIC_NAME;
                fw_sbus_name = ALT_FW_SBUS_NAME;
                fw_pcie_serdes_name = ALT_FW_PCIE_NAME;
        }

        if (fw_sbus_load) {
                err = obtain_one_firmware(dd, fw_sbus_name, &fw_sbus);
                if (err)
                        goto done;
        }

        if (fw_pcie_serdes_load) {
                err = obtain_one_firmware(dd, fw_pcie_serdes_name, &fw_pcie);
                if (err)
                        goto done;
        }

        if (fw_fabric_serdes_load) {
                err = obtain_one_firmware(dd, fw_fabric_serdes_name,
                                          &fw_fabric);
                if (err)
                        goto done;
        }

        if (fw_8051_load) {
                err = obtain_one_firmware(dd, fw_8051_name, &fw_8051);
                if (err)
                        goto done;
        }

done:
        if (err) {
                /* oops, had problems obtaining a firmware */
                if (fw_state == FW_EMPTY && dd->icode == ICODE_RTL_SILICON) {
                        /* retry with alternate (RTL only) */
                        fw_state = FW_TRY;
                        goto retry;
                }
                dd_dev_err(dd, "unable to obtain working firmware\n");
                fw_state = FW_ERR;
                fw_err = -ENOENT;
        } else {
                /* success */
                if (fw_state == FW_EMPTY &&
                    dd->icode != ICODE_FUNCTIONAL_SIMULATOR)
                        fw_state = FW_TRY;      /* may retry later */
                else
                        fw_state = FW_FINAL;    /* cannot try again */
        }
}

/*
 * Called by all HFIs when loading their firmware - i.e. device probe time.
 * The first one will do the actual firmware load.  Use a mutex to resolve
 * any possible race condition.
 *
 * The call to this routine cannot be moved to driver load because the kernel
 * call request_firmware() requires a device which is only available after
 * the first device probe.
 */
static int obtain_firmware(struct hfi1_devdata *dd)
{
        unsigned long timeout;
        int err = 0;

        mutex_lock(&fw_mutex);

        /* 40s delay due to long delay on missing firmware on some systems */
        timeout = jiffies + msecs_to_jiffies(40000);
        while (fw_state == FW_TRY) {
                /*
                 * Another device is trying the firmware.  Wait until it
                 * decides what works (or not).
                 */
                if (time_after(jiffies, timeout)) {
                        /* waited too long */
                        dd_dev_err(dd, "Timeout waiting for firmware try");
                        fw_state = FW_ERR;
                        fw_err = -ETIMEDOUT;
                        break;
                }
                mutex_unlock(&fw_mutex);
                msleep(20);     /* arbitrary delay */
                mutex_lock(&fw_mutex);
        }
        /* not in FW_TRY state */

        if (fw_state == FW_FINAL) {
                if (platform_config) {
                        dd->platform_config.data = platform_config->data;
                        dd->platform_config.size = platform_config->size;
                }
                goto done;      /* already acquired */
        } else if (fw_state == FW_ERR) {
                goto done;      /* already tried and failed */
        }
        /* fw_state is FW_EMPTY */

        /* set fw_state to FW_TRY, FW_FINAL, or FW_ERR, and fw_err */
        __obtain_firmware(dd);

        if (platform_config_load) {
                platform_config = NULL;
                err = request_firmware(&platform_config, platform_config_name,
                                       &dd->pcidev->dev);
                if (err) {
                        platform_config = NULL;
                        goto done;
                }
                dd->platform_config.data = platform_config->data;
                dd->platform_config.size = platform_config->size;
        }

done:
        mutex_unlock(&fw_mutex);

        return fw_err;
}

/*
 * Called when the driver unloads.  The timing is asymmetric with its
 * counterpart, obtain_firmware().  If called at device remove time,
 * then it is conceivable that another device could probe while the
 * firmware is being disposed.  The mutexes can be moved to do that
 * safely, but then the firmware would be requested from the OS multiple
 * times.
 *
 * No mutex is needed as the driver is unloading and there cannot be any
 * other callers.
 */
void dispose_firmware(void)
{
        dispose_one_firmware(&fw_8051);
        dispose_one_firmware(&fw_fabric);
        dispose_one_firmware(&fw_pcie);
        dispose_one_firmware(&fw_sbus);

        release_firmware(platform_config);
        platform_config = NULL;

        /* retain the error state, otherwise revert to empty */
        if (fw_state != FW_ERR)
                fw_state = FW_EMPTY;
}

/*
 * Called with the result of a firmware download.
 *
 * Return 1 to retry loading the firmware, 0 to stop.
 */
static int retry_firmware(struct hfi1_devdata *dd, int load_result)
{
        int retry;

        mutex_lock(&fw_mutex);

        if (load_result == 0) {
                /*
                 * The load succeeded, so expect all others to do the same.
                 * Do not retry again.
                 */
                if (fw_state == FW_TRY)
                        fw_state = FW_FINAL;
                retry = 0;      /* do NOT retry */
        } else if (fw_state == FW_TRY) {
                /* load failed, obtain alternate firmware */
                __obtain_firmware(dd);
                retry = (fw_state == FW_FINAL);
        } else {
                /* else in FW_FINAL or FW_ERR, no retry in either case */
                retry = 0;
        }

        mutex_unlock(&fw_mutex);
        return retry;
}

/*
 * Write a block of data to a given array CSR.  All calls will be in
 * multiples of 8 bytes.
 */
static void write_rsa_data(struct hfi1_devdata *dd, int what,
                           const u8 *data, int nbytes)
{
        int qw_size = nbytes / 8;
        int i;

        if (((unsigned long)data & 0x7) == 0) {
                /* aligned */
                u64 *ptr = (u64 *)data;

                for (i = 0; i < qw_size; i++, ptr++)
                        write_csr(dd, what + (8 * i), *ptr);
        } else {
                /* not aligned */
                for (i = 0; i < qw_size; i++, data += 8) {
                        u64 value;

                        memcpy(&value, data, 8);
                        write_csr(dd, what + (8 * i), value);
                }
        }
}

/*
 * Write a block of data to a given CSR as a stream of writes.  All calls will
 * be in multiples of 8 bytes.
 */
static void write_streamed_rsa_data(struct hfi1_devdata *dd, int what,
                                    const u8 *data, int nbytes)
{
        u64 *ptr = (u64 *)data;
        int qw_size = nbytes / 8;

        for (; qw_size > 0; qw_size--, ptr++)
                write_csr(dd, what, *ptr);
}

/*
 * Download the signature and start the RSA mechanism.  Wait for
 * RSA_ENGINE_TIMEOUT before giving up.
 */
static int run_rsa(struct hfi1_devdata *dd, const char *who,
                   const u8 *signature)
{
        unsigned long timeout;
        u64 reg;
        u32 status;
        int ret = 0;

        /* write the signature */
        write_rsa_data(dd, MISC_CFG_RSA_SIGNATURE, signature, KEY_SIZE);

        /* initialize RSA */
        write_csr(dd, MISC_CFG_RSA_CMD, RSA_CMD_INIT);

        /*
         * Make sure the engine is idle and insert a delay between the two
         * writes to MISC_CFG_RSA_CMD.
         */
        status = (read_csr(dd, MISC_CFG_FW_CTRL)
                           & MISC_CFG_FW_CTRL_RSA_STATUS_SMASK)
                             >> MISC_CFG_FW_CTRL_RSA_STATUS_SHIFT;
        if (status != RSA_STATUS_IDLE) {
                dd_dev_err(dd, "%s security engine not idle - giving up\n",
                           who);
                return -EBUSY;
        }

        /* start RSA */
        write_csr(dd, MISC_CFG_RSA_CMD, RSA_CMD_START);

        /*
         * Look for the result.
         *
         * The RSA engine is hooked up to two MISC errors.  The driver
         * masks these errors as they do not respond to the standard
         * error "clear down" mechanism.  Look for these errors here and
         * clear them when possible.  This routine will exit with the
         * errors of the current run still set.
         *
         * MISC_FW_AUTH_FAILED_ERR
         *      Firmware authorization failed.  This can be cleared by
         *      re-initializing the RSA engine, then clearing the status bit.
         *      Do not re-init the RSA angine immediately after a successful
         *      run - this will reset the current authorization.
         *
         * MISC_KEY_MISMATCH_ERR
         *      Key does not match.  The only way to clear this is to load
         *      a matching key then clear the status bit.  If this error
         *      is raised, it will persist outside of this routine until a
         *      matching key is loaded.
         */
        timeout = msecs_to_jiffies(RSA_ENGINE_TIMEOUT) + jiffies;
        while (1) {
                status = (read_csr(dd, MISC_CFG_FW_CTRL)
                           & MISC_CFG_FW_CTRL_RSA_STATUS_SMASK)
                             >> MISC_CFG_FW_CTRL_RSA_STATUS_SHIFT;

                if (status == RSA_STATUS_IDLE) {
                        /* should not happen */
                        dd_dev_err(dd, "%s firmware security bad idle state\n",
                                   who);
                        ret = -EINVAL;
                        break;
                } else if (status == RSA_STATUS_DONE) {
                        /* finished successfully */
                        break;
                } else if (status == RSA_STATUS_FAILED) {
                        /* finished unsuccessfully */
                        ret = -EINVAL;
                        break;
                }
                /* else still active */

                if (time_after(jiffies, timeout)) {
                        /*
                         * Timed out while active.  We can't reset the engine
                         * if it is stuck active, but run through the
                         * error code to see what error bits are set.
                         */
                        dd_dev_err(dd, "%s firmware security time out\n", who);
                        ret = -ETIMEDOUT;
                        break;
                }

                msleep(20);
        }

        /*
         * Arrive here on success or failure.  Clear all RSA engine
         * errors.  All current errors will stick - the RSA logic is keeping
         * error high.  All previous errors will clear - the RSA logic
         * is not keeping the error high.
         */
        write_csr(dd, MISC_ERR_CLEAR,
                  MISC_ERR_STATUS_MISC_FW_AUTH_FAILED_ERR_SMASK |
                  MISC_ERR_STATUS_MISC_KEY_MISMATCH_ERR_SMASK);
        /*
         * All that is left are the current errors.  Print warnings on
         * authorization failure details, if any.  Firmware authorization
         * can be retried, so these are only warnings.
         */
        reg = read_csr(dd, MISC_ERR_STATUS);
        if (ret) {
                if (reg & MISC_ERR_STATUS_MISC_FW_AUTH_FAILED_ERR_SMASK)
                        dd_dev_warn(dd, "%s firmware authorization failed\n",
                                    who);
                if (reg & MISC_ERR_STATUS_MISC_KEY_MISMATCH_ERR_SMASK)
                        dd_dev_warn(dd, "%s firmware key mismatch\n", who);
        }

        return ret;
}

static void load_security_variables(struct hfi1_devdata *dd,
                                    struct firmware_details *fdet)
{
        /* Security variables a.  Write the modulus */
        write_rsa_data(dd, MISC_CFG_RSA_MODULUS, fdet->modulus, KEY_SIZE);
        /* Security variables b.  Write the r2 */
        write_rsa_data(dd, MISC_CFG_RSA_R2, fdet->r2, KEY_SIZE);
        /* Security variables c.  Write the mu */
        write_rsa_data(dd, MISC_CFG_RSA_MU, fdet->mu, MU_SIZE);
        /* Security variables d.  Write the header */
        write_streamed_rsa_data(dd, MISC_CFG_SHA_PRELOAD,
                                (u8 *)fdet->css_header,
                                sizeof(struct css_header));
}

/* return the 8051 firmware state */
static inline u32 get_firmware_state(struct hfi1_devdata *dd)
{
        u64 reg = read_csr(dd, DC_DC8051_STS_CUR_STATE);

        return (reg >> DC_DC8051_STS_CUR_STATE_FIRMWARE_SHIFT)
                                & DC_DC8051_STS_CUR_STATE_FIRMWARE_MASK;
}

/*
 * Wait until the firmware is up and ready to take host requests.
 * Return 0 on success, -ETIMEDOUT on timeout.
 */
int wait_fm_ready(struct hfi1_devdata *dd, u32 mstimeout)
{
        unsigned long timeout;

        /* in the simulator, the fake 8051 is always ready */
        if (dd->icode == ICODE_FUNCTIONAL_SIMULATOR)
                return 0;

        timeout = msecs_to_jiffies(mstimeout) + jiffies;
        while (1) {
                if (get_firmware_state(dd) == 0xa0)     /* ready */
                        return 0;
                if (time_after(jiffies, timeout))       /* timed out */
                        return -ETIMEDOUT;
                usleep_range(1950, 2050); /* sleep 2ms-ish */
        }
}

/*
 * Load the 8051 firmware.
 */
static int load_8051_firmware(struct hfi1_devdata *dd,
                              struct firmware_details *fdet)
{
        u64 reg;
        int ret;
        u8 ver_a, ver_b;

        /*
         * DC Reset sequence
         * Load DC 8051 firmware
         */
        /*
         * DC reset step 1: Reset DC8051
         */
        reg = DC_DC8051_CFG_RST_M8051W_SMASK
                | DC_DC8051_CFG_RST_CRAM_SMASK
                | DC_DC8051_CFG_RST_DRAM_SMASK
                | DC_DC8051_CFG_RST_IRAM_SMASK

                | DC_DC8051_CFG_RST_SFR_SMASK;
        write_csr(dd, DC_DC8051_CFG_RST, reg);

        /*
         * DC reset step 2 (optional): Load 8051 data memory with link
         * configuration
         */

        /*
         * DC reset step 3: Load DC8051 firmware
         */
        /* release all but the core reset */
        reg = DC_DC8051_CFG_RST_M8051W_SMASK;
        write_csr(dd, DC_DC8051_CFG_RST, reg);

        /* Firmware load step 1 */
        load_security_variables(dd, fdet);

        /*
         * Firmware load step 2.  Clear MISC_CFG_FW_CTRL.FW_8051_LOADED
         */
        write_csr(dd, MISC_CFG_FW_CTRL, 0);

        /* Firmware load steps 3-5 */
        ret = write_8051(dd, 1/*code*/, 0, fdet->firmware_ptr,
                         fdet->firmware_len);
        if (ret)
                return ret;

        /*
         * DC reset step 4. Host starts the DC8051 firmware
         */
        /*
         * Firmware load step 6.  Set MISC_CFG_FW_CTRL.FW_8051_LOADED
         */
        write_csr(dd, MISC_CFG_FW_CTRL, MISC_CFG_FW_CTRL_FW_8051_LOADED_SMASK);

        /* Firmware load steps 7-10 */
        ret = run_rsa(dd, "8051", fdet->signature);
        if (ret)
                return ret;

        /* clear all reset bits, releasing the 8051 */
        write_csr(dd, DC_DC8051_CFG_RST, 0ull);

        /*
         * DC reset step 5. Wait for firmware to be ready to accept host
         * requests.
         */
        ret = wait_fm_ready(dd, TIMEOUT_8051_START);
        if (ret) { /* timed out */
                dd_dev_err(dd, "8051 start timeout, current state 0x%x\n",
                           get_firmware_state(dd));
                return -ETIMEDOUT;
        }

        read_misc_status(dd, &ver_a, &ver_b);
        dd_dev_info(dd, "8051 firmware version %d.%d\n",
                    (int)ver_b, (int)ver_a);
        dd->dc8051_ver = dc8051_ver(ver_b, ver_a);

        return 0;
}

/*
 * Write the SBus request register
 *
 * No need for masking - the arguments are sized exactly.
 */
void sbus_request(struct hfi1_devdata *dd,
                  u8 receiver_addr, u8 data_addr, u8 command, u32 data_in)
{
        write_csr(dd, ASIC_CFG_SBUS_REQUEST,
                  ((u64)data_in << ASIC_CFG_SBUS_REQUEST_DATA_IN_SHIFT) |
                  ((u64)command << ASIC_CFG_SBUS_REQUEST_COMMAND_SHIFT) |
                  ((u64)data_addr << ASIC_CFG_SBUS_REQUEST_DATA_ADDR_SHIFT) |
                  ((u64)receiver_addr <<
                   ASIC_CFG_SBUS_REQUEST_RECEIVER_ADDR_SHIFT));
}

/*
 * Turn off the SBus and fabric serdes spicos.
 *
 * + Must be called with Sbus fast mode turned on.
 * + Must be called after fabric serdes broadcast is set up.
 * + Must be called before the 8051 is loaded - assumes 8051 is not loaded
 *   when using MISC_CFG_FW_CTRL.
 */
static void turn_off_spicos(struct hfi1_devdata *dd, int flags)
{
        /* only needed on A0 */
        if (!is_ax(dd))
                return;

        dd_dev_info(dd, "Turning off spicos:%s%s\n",
                    flags & SPICO_SBUS ? " SBus" : "",
                    flags & SPICO_FABRIC ? " fabric" : "");

        write_csr(dd, MISC_CFG_FW_CTRL, ENABLE_SPICO_SMASK);
        /* disable SBus spico */
        if (flags & SPICO_SBUS)
                sbus_request(dd, SBUS_MASTER_BROADCAST, 0x01,
                             WRITE_SBUS_RECEIVER, 0x00000040);

        /* disable the fabric serdes spicos */
        if (flags & SPICO_FABRIC)
                sbus_request(dd, fabric_serdes_broadcast[dd->hfi1_id],
                             0x07, WRITE_SBUS_RECEIVER, 0x00000000);
        write_csr(dd, MISC_CFG_FW_CTRL, 0);
}

/*
 * Reset all of the fabric serdes for this HFI in preparation to take the
 * link to Polling.
 *
 * To do a reset, we need to write to to the serdes registers.  Unfortunately,
 * the fabric serdes download to the other HFI on the ASIC will have turned
 * off the firmware validation on this HFI.  This means we can't write to the
 * registers to reset the serdes.  Work around this by performing a complete
 * re-download and validation of the fabric serdes firmware.  This, as a
 * by-product, will reset the serdes.  NOTE: the re-download requires that
 * the 8051 be in the Offline state.  I.e. not actively trying to use the
 * serdes.  This routine is called at the point where the link is Offline and
 * is getting ready to go to Polling.
 */
void fabric_serdes_reset(struct hfi1_devdata *dd)
{
        int ret;

        if (!fw_fabric_serdes_load)
                return;

        ret = acquire_chip_resource(dd, CR_SBUS, SBUS_TIMEOUT);
        if (ret) {
                dd_dev_err(dd,
                           "Cannot acquire SBus resource to reset fabric SerDes - perhaps you should reboot\n");
                return;
        }
        set_sbus_fast_mode(dd);

        if (is_ax(dd)) {
                /* A0 serdes do not work with a re-download */
                u8 ra = fabric_serdes_broadcast[dd->hfi1_id];

                /* place SerDes in reset and disable SPICO */
                sbus_request(dd, ra, 0x07, WRITE_SBUS_RECEIVER, 0x00000011);
                /* wait 100 refclk cycles @ 156.25MHz => 640ns */
                udelay(1);
                /* remove SerDes reset */
                sbus_request(dd, ra, 0x07, WRITE_SBUS_RECEIVER, 0x00000010);
                /* turn SPICO enable on */
                sbus_request(dd, ra, 0x07, WRITE_SBUS_RECEIVER, 0x00000002);
        } else {
                turn_off_spicos(dd, SPICO_FABRIC);
                /*
                 * No need for firmware retry - what to download has already
                 * been decided.
                 * No need to pay attention to the load return - the only
                 * failure is a validation failure, which has already been
                 * checked by the initial download.
                 */
                (void)load_fabric_serdes_firmware(dd, &fw_fabric);
        }

        clear_sbus_fast_mode(dd);
        release_chip_resource(dd, CR_SBUS);
}

/* Access to the SBus in this routine should probably be serialized */
int sbus_request_slow(struct hfi1_devdata *dd,
                      u8 receiver_addr, u8 data_addr, u8 command, u32 data_in)
{
        u64 reg, count = 0;

        /* make sure fast mode is clear */
        clear_sbus_fast_mode(dd);

        sbus_request(dd, receiver_addr, data_addr, command, data_in);
        write_csr(dd, ASIC_CFG_SBUS_EXECUTE,
                  ASIC_CFG_SBUS_EXECUTE_EXECUTE_SMASK);
        /* Wait for both DONE and RCV_DATA_VALID to go high */
        reg = read_csr(dd, ASIC_STS_SBUS_RESULT);
        while (!((reg & ASIC_STS_SBUS_RESULT_DONE_SMASK) &&
                 (reg & ASIC_STS_SBUS_RESULT_RCV_DATA_VALID_SMASK))) {
                if (count++ >= SBUS_MAX_POLL_COUNT) {
                        u64 counts = read_csr(dd, ASIC_STS_SBUS_COUNTERS);
                        /*
                         * If the loop has timed out, we are OK if DONE bit
                         * is set and RCV_DATA_VALID and EXECUTE counters
                         * are the same. If not, we cannot proceed.
                         */
                        if ((reg & ASIC_STS_SBUS_RESULT_DONE_SMASK) &&
                            (SBUS_COUNTER(counts, RCV_DATA_VALID) ==
                             SBUS_COUNTER(counts, EXECUTE)))
                                break;
                        return -ETIMEDOUT;
                }
                udelay(1);
                reg = read_csr(dd, ASIC_STS_SBUS_RESULT);
        }
        count = 0;
        write_csr(dd, ASIC_CFG_SBUS_EXECUTE, 0);
        /* Wait for DONE to clear after EXECUTE is cleared */
        reg = read_csr(dd, ASIC_STS_SBUS_RESULT);
        while (reg & ASIC_STS_SBUS_RESULT_DONE_SMASK) {
                if (count++ >= SBUS_MAX_POLL_COUNT)
                        return -ETIME;
                udelay(1);
                reg = read_csr(dd, ASIC_STS_SBUS_RESULT);
        }
        return 0;
}

static int load_fabric_serdes_firmware(struct hfi1_devdata *dd,
                                       struct firmware_details *fdet)
{
        int i, err;
        const u8 ra = fabric_serdes_broadcast[dd->hfi1_id]; /* receiver addr */

        dd_dev_info(dd, "Downloading fabric firmware\n");

        /* step 1: load security variables */
        load_security_variables(dd, fdet);
        /* step 2: place SerDes in reset and disable SPICO */
        sbus_request(dd, ra, 0x07, WRITE_SBUS_RECEIVER, 0x00000011);
        /* wait 100 refclk cycles @ 156.25MHz => 640ns */
        udelay(1);
        /* step 3:  remove SerDes reset */
        sbus_request(dd, ra, 0x07, WRITE_SBUS_RECEIVER, 0x00000010);
        /* step 4: assert IMEM override */
        sbus_request(dd, ra, 0x00, WRITE_SBUS_RECEIVER, 0x40000000);
        /* step 5: download SerDes machine code */
        for (i = 0; i < fdet->firmware_len; i += 4) {
                sbus_request(dd, ra, 0x0a, WRITE_SBUS_RECEIVER,
                             *(u32 *)&fdet->firmware_ptr[i]);
        }
        /* step 6: IMEM override off */
        sbus_request(dd, ra, 0x00, WRITE_SBUS_RECEIVER, 0x00000000);
        /* step 7: turn ECC on */
        sbus_request(dd, ra, 0x0b, WRITE_SBUS_RECEIVER, 0x000c0000);

        /* steps 8-11: run the RSA engine */
        err = run_rsa(dd, "fabric serdes", fdet->signature);
        if (err)
                return err;

        /* step 12: turn SPICO enable on */
        sbus_request(dd, ra, 0x07, WRITE_SBUS_RECEIVER, 0x00000002);
        /* step 13: enable core hardware interrupts */
        sbus_request(dd, ra, 0x08, WRITE_SBUS_RECEIVER, 0x00000000);

        return 0;
}

static int load_sbus_firmware(struct hfi1_devdata *dd,
                              struct firmware_details *fdet)
{
        int i, err;
        const u8 ra = SBUS_MASTER_BROADCAST; /* receiver address */

        dd_dev_info(dd, "Downloading SBus firmware\n");

        /* step 1: load security variables */
        load_security_variables(dd, fdet);
        /* step 2: place SPICO into reset and enable off */
        sbus_request(dd, ra, 0x01, WRITE_SBUS_RECEIVER, 0x000000c0);
        /* step 3: remove reset, enable off, IMEM_CNTRL_EN on */
        sbus_request(dd, ra, 0x01, WRITE_SBUS_RECEIVER, 0x00000240);
        /* step 4: set starting IMEM address for burst download */
        sbus_request(dd, ra, 0x03, WRITE_SBUS_RECEIVER, 0x80000000);
        /* step 5: download the SBus Master machine code */
        for (i = 0; i < fdet->firmware_len; i += 4) {
                sbus_request(dd, ra, 0x14, WRITE_SBUS_RECEIVER,
                             *(u32 *)&fdet->firmware_ptr[i]);
        }
        /* step 6: set IMEM_CNTL_EN off */
        sbus_request(dd, ra, 0x01, WRITE_SBUS_RECEIVER, 0x00000040);
        /* step 7: turn ECC on */
        sbus_request(dd, ra, 0x16, WRITE_SBUS_RECEIVER, 0x000c0000);

        /* steps 8-11: run the RSA engine */
        err = run_rsa(dd, "SBus", fdet->signature);
        if (err)
                return err;

        /* step 12: set SPICO_ENABLE on */
        sbus_request(dd, ra, 0x01, WRITE_SBUS_RECEIVER, 0x00000140);

        return 0;
}

static int load_pcie_serdes_firmware(struct hfi1_devdata *dd,
                                     struct firmware_details *fdet)
{
        int i;
        const u8 ra = SBUS_MASTER_BROADCAST; /* receiver address */

        dd_dev_info(dd, "Downloading PCIe firmware\n");

        /* step 1: load security variables */
        load_security_variables(dd, fdet);
        /* step 2: assert single step (halts the SBus Master spico) */
        sbus_request(dd, ra, 0x05, WRITE_SBUS_RECEIVER, 0x00000001);
        /* step 3: enable XDMEM access */
        sbus_request(dd, ra, 0x01, WRITE_SBUS_RECEIVER, 0x00000d40);
        /* step 4: load firmware into SBus Master XDMEM */
        /*
         * NOTE: the dmem address, write_en, and wdata are all pre-packed,
         * we only need to pick up the bytes and write them
         */
        for (i = 0; i < fdet->firmware_len; i += 4) {
                sbus_request(dd, ra, 0x04, WRITE_SBUS_RECEIVER,
                             *(u32 *)&fdet->firmware_ptr[i]);
        }
        /* step 5: disable XDMEM access */
        sbus_request(dd, ra, 0x01, WRITE_SBUS_RECEIVER, 0x00000140);
        /* step 6: allow SBus Spico to run */
        sbus_request(dd, ra, 0x05, WRITE_SBUS_RECEIVER, 0x00000000);

        /*
         * steps 7-11: run RSA, if it succeeds, firmware is available to
         * be swapped
         */
        return run_rsa(dd, "PCIe serdes", fdet->signature);
}

/*
 * Set the given broadcast values on the given list of devices.
 */
static void set_serdes_broadcast(struct hfi1_devdata *dd, u8 bg1, u8 bg2,
                                 const u8 *addrs, int count)
{
        while (--count >= 0) {
                /*
                 * Set BROADCAST_GROUP_1 and BROADCAST_GROUP_2, leave
                 * defaults for everything else.  Do not read-modify-write,
                 * per instruction from the manufacturer.
                 *
                 * Register 0xfd:
                 *      bits    what
                 *      -----   ---------------------------------
                 *        0     IGNORE_BROADCAST  (default 0)
                 *      11:4    BROADCAST_GROUP_1 (default 0xff)
                 *      23:16   BROADCAST_GROUP_2 (default 0xff)
                 */
                sbus_request(dd, addrs[count], 0xfd, WRITE_SBUS_RECEIVER,
                             (u32)bg1 << 4 | (u32)bg2 << 16);
        }
}

int acquire_hw_mutex(struct hfi1_devdata *dd)
{
        unsigned long timeout;
        int try = 0;
        u8 mask = 1 << dd->hfi1_id;
        u8 user;

retry:
        timeout = msecs_to_jiffies(HM_TIMEOUT) + jiffies;
        while (1) {
                write_csr(dd, ASIC_CFG_MUTEX, mask);
                user = (u8)read_csr(dd, ASIC_CFG_MUTEX);
                if (user == mask)
                        return 0; /* success */
                if (time_after(jiffies, timeout))
                        break; /* timed out */
                msleep(20);
        }

        /* timed out */
        dd_dev_err(dd,
                   "Unable to acquire hardware mutex, mutex mask %u, my mask %u (%s)\n",
                   (u32)user, (u32)mask, (try == 0) ? "retrying" : "giving up");

        if (try == 0) {
                /* break mutex and retry */
                write_csr(dd, ASIC_CFG_MUTEX, 0);
                try++;
                goto retry;
        }

        return -EBUSY;
}

void release_hw_mutex(struct hfi1_devdata *dd)
{
        write_csr(dd, ASIC_CFG_MUTEX, 0);
}

/* return the given resource bit(s) as a mask for the given HFI */
static inline u64 resource_mask(u32 hfi1_id, u32 resource)
{
        return ((u64)resource) << (hfi1_id ? CR_DYN_SHIFT : 0);
}

static void fail_mutex_acquire_message(struct hfi1_devdata *dd,
                                       const char *func)
{
        dd_dev_err(dd,
                   "%s: hardware mutex stuck - suggest rebooting the machine\n",
                   func);
}

/*
 * Acquire access to a chip resource.
 *
 * Return 0 on success, -EBUSY if resource busy, -EIO if mutex acquire failed.
 */
static int __acquire_chip_resource(struct hfi1_devdata *dd, u32 resource)
{
        u64 scratch0, all_bits, my_bit;
        int ret;

        if (resource & CR_DYN_MASK) {
                /* a dynamic resource is in use if either HFI has set the bit */
                all_bits = resource_mask(0, resource) |
                                                resource_mask(1, resource);
                my_bit = resource_mask(dd->hfi1_id, resource);
        } else {
                /* non-dynamic resources are not split between HFIs */
                all_bits = resource;
                my_bit = resource;
        }

        /* lock against other callers within the driver wanting a resource */
        mutex_lock(&dd->asic_data->asic_resource_mutex);

        ret = acquire_hw_mutex(dd);
        if (ret) {
                fail_mutex_acquire_message(dd, __func__);
                ret = -EIO;
                goto done;
        }

        scratch0 = read_csr(dd, ASIC_CFG_SCRATCH);
        if (scratch0 & all_bits) {
                ret = -EBUSY;
        } else {
                write_csr(dd, ASIC_CFG_SCRATCH, scratch0 | my_bit);
                /* force write to be visible to other HFI on another OS */
                (void)read_csr(dd, ASIC_CFG_SCRATCH);
        }

        release_hw_mutex(dd);

done:
        mutex_unlock(&dd->asic_data->asic_resource_mutex);
        return ret;
}

/*
 * Acquire access to a chip resource, wait up to mswait milliseconds for
 * the resource to become available.
 *
 * Return 0 on success, -EBUSY if busy (even after wait), -EIO if mutex
 * acquire failed.
 */
int acquire_chip_resource(struct hfi1_devdata *dd, u32 resource, u32 mswait)
{
        unsigned long timeout;
        int ret;

        timeout = jiffies + msecs_to_jiffies(mswait);
        while (1) {
                ret = __acquire_chip_resource(dd, resource);
                if (ret != -EBUSY)
                        return ret;
                /* resource is busy, check our timeout */
                if (time_after_eq(jiffies, timeout))
                        return -EBUSY;
                usleep_range(80, 120);  /* arbitrary delay */
        }
}

/*
 * Release access to a chip resource
 */
void release_chip_resource(struct hfi1_devdata *dd, u32 resource)
{
        u64 scratch0, bit;

        /* only dynamic resources should ever be cleared */
        if (!(resource & CR_DYN_MASK)) {
                dd_dev_err(dd, "%s: invalid resource 0x%x\n", __func__,
                           resource);
                return;
        }
        bit = resource_mask(dd->hfi1_id, resource);

        /* lock against other callers within the driver wanting a resource */
        mutex_lock(&dd->asic_data->asic_resource_mutex);

        if (acquire_hw_mutex(dd)) {
                fail_mutex_acquire_message(dd, __func__);
                goto done;
        }

        scratch0 = read_csr(dd, ASIC_CFG_SCRATCH);
        if ((scratch0 & bit) != 0) {
                scratch0 &= ~bit;
                write_csr(dd, ASIC_CFG_SCRATCH, scratch0);
                /* force write to be visible to other HFI on another OS */
                (void)read_csr(dd, ASIC_CFG_SCRATCH);
        } else {
                dd_dev_warn(dd, "%s: id %d, resource 0x%x: bit not set\n",
                            __func__, dd->hfi1_id, resource);
        }

        release_hw_mutex(dd);

done:
        mutex_unlock(&dd->asic_data->asic_resource_mutex);
}

/*
 * Return true if resource is set, false otherwise.  Print a warning
 * if not set and a function is supplied.
 */
bool check_chip_resource(struct hfi1_devdata *dd, u32 resource,
                         const char *func)
{
        u64 scratch0, bit;

        if (resource & CR_DYN_MASK)
                bit = resource_mask(dd->hfi1_id, resource);
        else
                bit = resource;

        scratch0 = read_csr(dd, ASIC_CFG_SCRATCH);
        if ((scratch0 & bit) == 0) {
                if (func)
                        dd_dev_warn(dd,
                                    "%s: id %d, resource 0x%x, not acquired!\n",
                                    func, dd->hfi1_id, resource);
                return false;
        }
        return true;
}

static void clear_chip_resources(struct hfi1_devdata *dd, const char *func)
{
        u64 scratch0;

        /* lock against other callers within the driver wanting a resource */
        mutex_lock(&dd->asic_data->asic_resource_mutex);

        if (acquire_hw_mutex(dd)) {
                fail_mutex_acquire_message(dd, func);
                goto done;
        }

        /* clear all dynamic access bits for this HFI */
        scratch0 = read_csr(dd, ASIC_CFG_SCRATCH);
        scratch0 &= ~resource_mask(dd->hfi1_id, CR_DYN_MASK);
        write_csr(dd, ASIC_CFG_SCRATCH, scratch0);
        /* force write to be visible to other HFI on another OS */
        (void)read_csr(dd, ASIC_CFG_SCRATCH);

        release_hw_mutex(dd);

done:
        mutex_unlock(&dd->asic_data->asic_resource_mutex);
}

void init_chip_resources(struct hfi1_devdata *dd)
{
        /* clear any holds left by us */
        clear_chip_resources(dd, __func__);
}

void finish_chip_resources(struct hfi1_devdata *dd)
{
        /* clear any holds left by us */
        clear_chip_resources(dd, __func__);
}

void set_sbus_fast_mode(struct hfi1_devdata *dd)
{
        write_csr(dd, ASIC_CFG_SBUS_EXECUTE,
                  ASIC_CFG_SBUS_EXECUTE_FAST_MODE_SMASK);
}

void clear_sbus_fast_mode(struct hfi1_devdata *dd)
{
        u64 reg, count = 0;

        reg = read_csr(dd, ASIC_STS_SBUS_COUNTERS);
        while (SBUS_COUNTER(reg, EXECUTE) !=
               SBUS_COUNTER(reg, RCV_DATA_VALID)) {
                if (count++ >= SBUS_MAX_POLL_COUNT)
                        break;
                udelay(1);
                reg = read_csr(dd, ASIC_STS_SBUS_COUNTERS);
        }
        write_csr(dd, ASIC_CFG_SBUS_EXECUTE, 0);
}

int load_firmware(struct hfi1_devdata *dd)
{
        int ret;

        if (fw_fabric_serdes_load) {
                ret = acquire_chip_resource(dd, CR_SBUS, SBUS_TIMEOUT);
                if (ret)
                        return ret;

                set_sbus_fast_mode(dd);

                set_serdes_broadcast(dd, all_fabric_serdes_broadcast,
                                     fabric_serdes_broadcast[dd->hfi1_id],
                                     fabric_serdes_addrs[dd->hfi1_id],
                                     NUM_FABRIC_SERDES);
                turn_off_spicos(dd, SPICO_FABRIC);
                do {
                        ret = load_fabric_serdes_firmware(dd, &fw_fabric);
                } while (retry_firmware(dd, ret));

                clear_sbus_fast_mode(dd);
                release_chip_resource(dd, CR_SBUS);
                if (ret)
                        return ret;
        }

        if (fw_8051_load) {
                do {
                        ret = load_8051_firmware(dd, &fw_8051);
                } while (retry_firmware(dd, ret));
                if (ret)
                        return ret;
        }

        return 0;
}

int hfi1_firmware_init(struct hfi1_devdata *dd)
{
        /* only RTL can use these */
        if (dd->icode != ICODE_RTL_SILICON) {
                fw_fabric_serdes_load = 0;
                fw_pcie_serdes_load = 0;
                fw_sbus_load = 0;
        }

        /* no 8051 or QSFP on simulator */
        if (dd->icode == ICODE_FUNCTIONAL_SIMULATOR) {
                fw_8051_load = 0;
                platform_config_load = 0;
        }

        if (!fw_8051_name) {
                if (dd->icode == ICODE_RTL_SILICON)
                        fw_8051_name = DEFAULT_FW_8051_NAME_ASIC;
                else
                        fw_8051_name = DEFAULT_FW_8051_NAME_FPGA;
        }
        if (!fw_fabric_serdes_name)
                fw_fabric_serdes_name = DEFAULT_FW_FABRIC_NAME;
        if (!fw_sbus_name)
                fw_sbus_name = DEFAULT_FW_SBUS_NAME;
        if (!fw_pcie_serdes_name)
                fw_pcie_serdes_name = DEFAULT_FW_PCIE_NAME;
        if (!platform_config_name)
                platform_config_name = DEFAULT_PLATFORM_CONFIG_NAME;

        return obtain_firmware(dd);
}

/*
 * This function is a helper function for parse_platform_config(...) and
 * does not check for validity of the platform configuration cache
 * (because we know it is invalid as we are building up the cache).
 * As such, this should not be called from anywhere other than
 * parse_platform_config
 */
static int check_meta_version(struct hfi1_devdata *dd, u32 *system_table)
{
        u32 meta_ver, meta_ver_meta, ver_start, ver_len, mask;
        struct platform_config_cache *pcfgcache = &dd->pcfg_cache;

        if (!system_table)
                return -EINVAL;

        meta_ver_meta =
        *(pcfgcache->config_tables[PLATFORM_CONFIG_SYSTEM_TABLE].table_metadata
        + SYSTEM_TABLE_META_VERSION);

        mask = ((1 << METADATA_TABLE_FIELD_START_LEN_BITS) - 1);
        ver_start = meta_ver_meta & mask;

        meta_ver_meta >>= METADATA_TABLE_FIELD_LEN_SHIFT;

        mask = ((1 << METADATA_TABLE_FIELD_LEN_LEN_BITS) - 1);
        ver_len = meta_ver_meta & mask;

        ver_start /= 8;
        meta_ver = *((u8 *)system_table + ver_start) & ((1 << ver_len) - 1);

        if (meta_ver < 5) {
                dd_dev_info(
                        dd, "%s:Please update platform config\n", __func__);
                return -EINVAL;
        }
        return 0;
}

int parse_platform_config(struct hfi1_devdata *dd)
{
        struct platform_config_cache *pcfgcache = &dd->pcfg_cache;
        u32 *ptr = NULL;
        u32 header1 = 0, header2 = 0, magic_num = 0, crc = 0, file_length = 0;
        u32 record_idx = 0, table_type = 0, table_length_dwords = 0;
        int ret = -EINVAL; /* assume failure */

        if (!dd->platform_config.data) {
                dd_dev_info(dd, "%s: Missing config file\n", __func__);
                goto bail;
        }
        ptr = (u32 *)dd->platform_config.data;

        magic_num = *ptr;
        ptr++;
        if (magic_num != PLATFORM_CONFIG_MAGIC_NUM) {
                dd_dev_info(dd, "%s: Bad config file\n", __func__);
                goto bail;
        }

        /* Field is file size in DWORDs */
        file_length = (*ptr) * 4;
        ptr++;

        if (file_length > dd->platform_config.size) {
                dd_dev_info(dd, "%s:File claims to be larger than read size\n",
                            __func__);
                goto bail;
        } else if (file_length < dd->platform_config.size) {
                dd_dev_info(dd,
                            "%s:File claims to be smaller than read size, continuing\n",
                            __func__);
        }
        /* exactly equal, perfection */

        /*
         * In both cases where we proceed, using the self-reported file length
         * is the safer option
         */
        while (ptr < (u32 *)(dd->platform_config.data + file_length)) {
                header1 = *ptr;
                header2 = *(ptr + 1);
                if (header1 != ~header2) {
                        dd_dev_info(dd, "%s: Failed validation at offset %ld\n",
                                    __func__, (ptr - (u32 *)
                                               dd->platform_config.data));
                        goto bail;
                }

                record_idx = *ptr &
                        ((1 << PLATFORM_CONFIG_HEADER_RECORD_IDX_LEN_BITS) - 1);

                table_length_dwords = (*ptr >>
                                PLATFORM_CONFIG_HEADER_TABLE_LENGTH_SHIFT) &
                      ((1 << PLATFORM_CONFIG_HEADER_TABLE_LENGTH_LEN_BITS) - 1);

                table_type = (*ptr >> PLATFORM_CONFIG_HEADER_TABLE_TYPE_SHIFT) &
                        ((1 << PLATFORM_CONFIG_HEADER_TABLE_TYPE_LEN_BITS) - 1);

                /* Done with this set of headers */
                ptr += 2;

                if (record_idx) {
                        /* data table */
                        switch (table_type) {
                        case PLATFORM_CONFIG_SYSTEM_TABLE:
                                pcfgcache->config_tables[table_type].num_table =
                                                                        1;
                                ret = check_meta_version(dd, ptr);
                                if (ret)
                                        goto bail;
                                break;
                        case PLATFORM_CONFIG_PORT_TABLE:
                                pcfgcache->config_tables[table_type].num_table =
                                                                        2;
                                break;
                        case PLATFORM_CONFIG_RX_PRESET_TABLE:
                                /* fall through */
                        case PLATFORM_CONFIG_TX_PRESET_TABLE:
                                /* fall through */
                        case PLATFORM_CONFIG_QSFP_ATTEN_TABLE:
                                /* fall through */
                        case PLATFORM_CONFIG_VARIABLE_SETTINGS_TABLE:
                                pcfgcache->config_tables[table_type].num_table =
                                                        table_length_dwords;
                                break;
                        default:
                                dd_dev_info(dd,
                                            "%s: Unknown data table %d, offset %ld\n",
                                            __func__, table_type,
                                            (ptr - (u32 *)
                                             dd->platform_config.data));
                                goto bail; /* We don't trust this file now */
                        }
                        pcfgcache->config_tables[table_type].table = ptr;
                } else {
                        /* metadata table */
                        switch (table_type) {
                        case PLATFORM_CONFIG_SYSTEM_TABLE:
                                /* fall through */
                        case PLATFORM_CONFIG_PORT_TABLE:
                                /* fall through */
                        case PLATFORM_CONFIG_RX_PRESET_TABLE:
                                /* fall through */
                        case PLATFORM_CONFIG_TX_PRESET_TABLE:
                                /* fall through */
                        case PLATFORM_CONFIG_QSFP_ATTEN_TABLE:
                                /* fall through */
                        case PLATFORM_CONFIG_VARIABLE_SETTINGS_TABLE:
                                break;
                        default:
                                dd_dev_info(dd,
                                            "%s: Unknown meta table %d, offset %ld\n",
                                            __func__, table_type,
                                            (ptr -
                                             (u32 *)dd->platform_config.data));
                                goto bail; /* We don't trust this file now */
                        }
                        pcfgcache->config_tables[table_type].table_metadata =
                                                                        ptr;
                }

                /* Calculate and check table crc */
                crc = crc32_le(~(u32)0, (unsigned char const *)ptr,
                               (table_length_dwords * 4));
                crc ^= ~(u32)0;

                /* Jump the table */
                ptr += table_length_dwords;
                if (crc != *ptr) {
                        dd_dev_info(dd, "%s: Failed CRC check at offset %ld\n",
                                    __func__, (ptr -
                                               (u32 *)
                                               dd->platform_config.data));
                        goto bail;
                }
                /* Jump the CRC DWORD */
                ptr++;
        }

        pcfgcache->cache_valid = 1;
        return 0;
bail:
        memset(pcfgcache, 0, sizeof(struct platform_config_cache));
        return ret;
}

static int get_platform_fw_field_metadata(struct hfi1_devdata *dd, int table,
                                          int field, u32 *field_len_bits,
                                          u32 *field_start_bits)
{
        struct platform_config_cache *pcfgcache = &dd->pcfg_cache;
        u32 *src_ptr = NULL;

        if (!pcfgcache->cache_valid)
                return -EINVAL;

        switch (table) {
        case PLATFORM_CONFIG_SYSTEM_TABLE:
                /* fall through */
        case PLATFORM_CONFIG_PORT_TABLE:
                /* fall through */
        case PLATFORM_CONFIG_RX_PRESET_TABLE:
                /* fall through */
        case PLATFORM_CONFIG_TX_PRESET_TABLE:
                /* fall through */
        case PLATFORM_CONFIG_QSFP_ATTEN_TABLE:
                /* fall through */
        case PLATFORM_CONFIG_VARIABLE_SETTINGS_TABLE:
                if (field && field < platform_config_table_limits[table])
                        src_ptr =
                        pcfgcache->config_tables[table].table_metadata + field;
                break;
        default:
                dd_dev_info(dd, "%s: Unknown table\n", __func__);
                break;
        }

        if (!src_ptr)
                return -EINVAL;

        if (field_start_bits)
                *field_start_bits = *src_ptr &
                      ((1 << METADATA_TABLE_FIELD_START_LEN_BITS) - 1);

        if (field_len_bits)
                *field_len_bits = (*src_ptr >> METADATA_TABLE_FIELD_LEN_SHIFT)
                       & ((1 << METADATA_TABLE_FIELD_LEN_LEN_BITS) - 1);

        return 0;
}

/* This is the central interface to getting data out of the platform config
 * file. It depends on parse_platform_config() having populated the
 * platform_config_cache in hfi1_devdata, and checks the cache_valid member to
 * validate the sanity of the cache.
 *
 * The non-obvious parameters:
 * @table_index: Acts as a look up key into which instance of the tables the
 * relevant field is fetched from.
 *
 * This applies to the data tables that have multiple instances. The port table
 * is an exception to this rule as each HFI only has one port and thus the
 * relevant table can be distinguished by hfi_id.
 *
 * @data: pointer to memory that will be populated with the field requested.
 * @len: length of memory pointed by @data in bytes.
 */
int get_platform_config_field(struct hfi1_devdata *dd,
                              enum platform_config_table_type_encoding
                              table_type, int table_index, int field_index,
                              u32 *data, u32 len)
{
        int ret = 0, wlen = 0, seek = 0;
        u32 field_len_bits = 0, field_start_bits = 0, *src_ptr = NULL;
        struct platform_config_cache *pcfgcache = &dd->pcfg_cache;

        if (data)
                memset(data, 0, len);
        else
                return -EINVAL;

        ret = get_platform_fw_field_metadata(dd, table_type, field_index,
                                             &field_len_bits,
                                             &field_start_bits);
        if (ret)
                return -EINVAL;

        /* Convert length to bits */
        len *= 8;

        /* Our metadata function checked cache_valid and field_index for us */
        switch (table_type) {
        case PLATFORM_CONFIG_SYSTEM_TABLE:
                src_ptr = pcfgcache->config_tables[table_type].table;

                if (field_index != SYSTEM_TABLE_QSFP_POWER_CLASS_MAX) {
                        if (len < field_len_bits)
                                return -EINVAL;

                        seek = field_start_bits / 8;
                        wlen = field_len_bits / 8;

                        src_ptr = (u32 *)((u8 *)src_ptr + seek);

                        /*
                         * We expect the field to be byte aligned and whole byte
                         * lengths if we are here
                         */
                        memcpy(data, src_ptr, wlen);
                        return 0;
                }
                break;
        case PLATFORM_CONFIG_PORT_TABLE:
                /* Port table is 4 DWORDS */
                src_ptr = dd->hfi1_id ?
                        pcfgcache->config_tables[table_type].table + 4 :
                        pcfgcache->config_tables[table_type].table;
                break;
        case PLATFORM_CONFIG_RX_PRESET_TABLE:
                /* fall through */
        case PLATFORM_CONFIG_TX_PRESET_TABLE:
                /* fall through */
        case PLATFORM_CONFIG_QSFP_ATTEN_TABLE:
                /* fall through */
        case PLATFORM_CONFIG_VARIABLE_SETTINGS_TABLE:
                src_ptr = pcfgcache->config_tables[table_type].table;

                if (table_index <
                        pcfgcache->config_tables[table_type].num_table)
                        src_ptr += table_index;
                else
                        src_ptr = NULL;
                break;
        default:
                dd_dev_info(dd, "%s: Unknown table\n", __func__);
                break;
        }

        if (!src_ptr || len < field_len_bits)
                return -EINVAL;

        src_ptr += (field_start_bits / 32);
        *data = (*src_ptr >> (field_start_bits % 32)) &
                        ((1 << field_len_bits) - 1);

        return 0;
}

/*
 * Download the firmware needed for the Gen3 PCIe SerDes.  An update
 * to the SBus firmware is needed before updating the PCIe firmware.
 *
 * Note: caller must be holding the SBus resource.

 */
int load_pcie_firmware(struct hfi1_devdata *dd)
{
        int ret = 0;

        /* both firmware loads below use the SBus */
        set_sbus_fast_mode(dd);

        if (fw_sbus_load) {
                turn_off_spicos(dd, SPICO_SBUS);
                do {
                        ret = load_sbus_firmware(dd, &fw_sbus);
                } while (retry_firmware(dd, ret));
                if (ret)
                        goto done;
        }

        if (fw_pcie_serdes_load) {
                dd_dev_info(dd, "Setting PCIe SerDes broadcast\n");
                set_serdes_broadcast(dd, all_pcie_serdes_broadcast,
                                     pcie_serdes_broadcast[dd->hfi1_id],
                                     pcie_serdes_addrs[dd->hfi1_id],
                                     NUM_PCIE_SERDES);
                do {
                        ret = load_pcie_serdes_firmware(dd, &fw_pcie);
                } while (retry_firmware(dd, ret));
                if (ret)
                        goto done;
        }

done:
        clear_sbus_fast_mode(dd);

        return ret;
}

/*
 * Read the GUID from the hardware, store it in dd.
 */
void read_guid(struct hfi1_devdata *dd)
{
        /* Take the DC out of reset to get a valid GUID value */
        write_csr(dd, CCE_DC_CTRL, 0);
        (void)read_csr(dd, CCE_DC_CTRL);

        dd->base_guid = read_csr(dd, DC_DC8051_CFG_LOCAL_GUID);
        dd_dev_info(dd, "GUID %llx",
                    (unsigned long long)dd->base_guid);
}