/*
 * Copyright(c) 2011-2016 Intel Corporation. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * 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.
 *
 * Authors:
 *    Zhi Wang <zhi.a.wang@intel.com>
 *
 * Contributors:
 *    Changbin Du <changbin.du@intel.com>
 *
 */

#include <linux/firmware.h>
#include <linux/crc32.h>

#include "i915_drv.h"
#include "gvt.h"
#include "i915_pvinfo.h"

#define FIRMWARE_VERSION (0x0)

struct gvt_firmware_header {
        u64 magic;
        u32 crc32;              /* protect the data after this field */
        u32 version;
        u64 cfg_space_size;
        u64 cfg_space_offset;   /* offset in the file */
        u64 mmio_size;
        u64 mmio_offset;        /* offset in the file */
        unsigned char data[1];
};

#define dev_to_drm_minor(d) dev_get_drvdata((d))

static ssize_t
gvt_firmware_read(struct file *filp, struct kobject *kobj,
             struct bin_attribute *attr, char *buf,
             loff_t offset, size_t count)
{
        memcpy(buf, attr->private + offset, count);
        return count;
}

static struct bin_attribute firmware_attr = {
        .attr = {.name = "gvt_firmware", .mode = (S_IRUSR)},
        .read = gvt_firmware_read,
        .write = NULL,
        .mmap = NULL,
};

static int mmio_snapshot_handler(struct intel_gvt *gvt, u32 offset, void *data)
{
        *(u32 *)(data + offset) = intel_uncore_read_notrace(gvt->gt->uncore,
                                                            _MMIO(offset));
        return 0;
}

static int expose_firmware_sysfs(struct intel_gvt *gvt)
{
        struct intel_gvt_device_info *info = &gvt->device_info;
        struct pci_dev *pdev = to_pci_dev(gvt->gt->i915->drm.dev);
        struct gvt_firmware_header *h;
        void *firmware;
        void *p;
        unsigned long size, crc32_start;
        int i, ret;

        size = sizeof(*h) + info->mmio_size + info->cfg_space_size;
        firmware = vzalloc(size);
        if (!firmware)
                return -ENOMEM;

        h = firmware;

        h->magic = VGT_MAGIC;
        h->version = FIRMWARE_VERSION;
        h->cfg_space_size = info->cfg_space_size;
        h->cfg_space_offset = offsetof(struct gvt_firmware_header, data);
        h->mmio_size = info->mmio_size;
        h->mmio_offset = h->cfg_space_offset + h->cfg_space_size;

        p = firmware + h->cfg_space_offset;

        for (i = 0; i < h->cfg_space_size; i += 4)
                pci_read_config_dword(pdev, i, p + i);

        memcpy(gvt->firmware.cfg_space, p, info->cfg_space_size);

        p = firmware + h->mmio_offset;

        /* Take a snapshot of hw mmio registers. */
        intel_gvt_for_each_tracked_mmio(gvt, mmio_snapshot_handler, p);

        memcpy(gvt->firmware.mmio, p, info->mmio_size);

        crc32_start = offsetof(struct gvt_firmware_header, crc32) + 4;
        h->crc32 = crc32_le(0, firmware + crc32_start, size - crc32_start);

        firmware_attr.size = size;
        firmware_attr.private = firmware;

        ret = device_create_bin_file(&pdev->dev, &firmware_attr);
        if (ret) {
                vfree(firmware);
                return ret;
        }
        return 0;
}

static void clean_firmware_sysfs(struct intel_gvt *gvt)
{
        struct pci_dev *pdev = to_pci_dev(gvt->gt->i915->drm.dev);

        device_remove_bin_file(&pdev->dev, &firmware_attr);
        vfree(firmware_attr.private);
}

/**
 * intel_gvt_free_firmware - free GVT firmware
 * @gvt: intel gvt device
 *
 */
void intel_gvt_free_firmware(struct intel_gvt *gvt)
{
        if (!gvt->firmware.firmware_loaded)
                clean_firmware_sysfs(gvt);

        kfree(gvt->firmware.cfg_space);
        vfree(gvt->firmware.mmio);
}

static int verify_firmware(struct intel_gvt *gvt,
                           const struct firmware *fw)
{
        struct intel_gvt_device_info *info = &gvt->device_info;
        struct pci_dev *pdev = to_pci_dev(gvt->gt->i915->drm.dev);
        struct gvt_firmware_header *h;
        unsigned long id, crc32_start;
        const void *mem;
        const char *item;
        u64 file, request;

        h = (struct gvt_firmware_header *)fw->data;

        crc32_start = offsetofend(struct gvt_firmware_header, crc32);
        mem = fw->data + crc32_start;

#define VERIFY(s, a, b) do { \
        item = (s); file = (u64)(a); request = (u64)(b); \
        if ((a) != (b)) \
                goto invalid_firmware; \
} while (0)

        VERIFY("magic number", h->magic, VGT_MAGIC);
        VERIFY("version", h->version, FIRMWARE_VERSION);
        VERIFY("crc32", h->crc32, crc32_le(0, mem, fw->size - crc32_start));
        VERIFY("cfg space size", h->cfg_space_size, info->cfg_space_size);
        VERIFY("mmio size", h->mmio_size, info->mmio_size);

        mem = (fw->data + h->cfg_space_offset);

        id = *(u16 *)(mem + PCI_VENDOR_ID);
        VERIFY("vender id", id, pdev->vendor);

        id = *(u16 *)(mem + PCI_DEVICE_ID);
        VERIFY("device id", id, pdev->device);

        id = *(u8 *)(mem + PCI_REVISION_ID);
        VERIFY("revision id", id, pdev->revision);

#undef VERIFY
        return 0;

invalid_firmware:
        gvt_dbg_core("Invalid firmware: %s [file] 0x%llx [request] 0x%llx\n",
                     item, file, request);
        return -EINVAL;
}

#define GVT_FIRMWARE_PATH "i915/gvt"

/**
 * intel_gvt_load_firmware - load GVT firmware
 * @gvt: intel gvt device
 *
 */
int intel_gvt_load_firmware(struct intel_gvt *gvt)
{
        struct intel_gvt_device_info *info = &gvt->device_info;
        struct pci_dev *pdev = to_pci_dev(gvt->gt->i915->drm.dev);
        struct intel_gvt_firmware *firmware = &gvt->firmware;
        struct gvt_firmware_header *h;
        const struct firmware *fw;
        char *path;
        void *mem;
        int ret;

        path = kmalloc(PATH_MAX, GFP_KERNEL);
        if (!path)
                return -ENOMEM;

        mem = kmalloc(info->cfg_space_size, GFP_KERNEL);
        if (!mem) {
                kfree(path);
                return -ENOMEM;
        }

        firmware->cfg_space = mem;

        mem = vmalloc(info->mmio_size);
        if (!mem) {
                kfree(path);
                kfree(firmware->cfg_space);
                return -ENOMEM;
        }

        firmware->mmio = mem;

        sprintf(path, "%s/vid_0x%04x_did_0x%04x_rid_0x%02x.golden_hw_state",
                 GVT_FIRMWARE_PATH, pdev->vendor, pdev->device,
                 pdev->revision);

        gvt_dbg_core("request hw state firmware %s...\n", path);

        ret = request_firmware(&fw, path, gvt->gt->i915->drm.dev);
        kfree(path);

        if (ret)
                goto expose_firmware;

        gvt_dbg_core("success.\n");

        ret = verify_firmware(gvt, fw);
        if (ret)
                goto out_free_fw;

        gvt_dbg_core("verified.\n");

        h = (struct gvt_firmware_header *)fw->data;

        memcpy(firmware->cfg_space, fw->data + h->cfg_space_offset,
               h->cfg_space_size);
        memcpy(firmware->mmio, fw->data + h->mmio_offset,
               h->mmio_size);

        release_firmware(fw);
        firmware->firmware_loaded = true;
        return 0;

out_free_fw:
        release_firmware(fw);
expose_firmware:
        expose_firmware_sysfs(gvt);
        return 0;
}