/*
 * Copyright (C) 2016 Google, Inc
 * Written by Simon Glass <sjg@chromium.org>
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#include <common.h>
#include <errno.h>
#include <image.h>
#include <libfdt.h>
#include <spl.h>

/**
 * spl_fit_get_image_node(): By using the matching configuration subnode,
 * retrieve the name of an image, specified by a property name and an index
 * into that.
 * @fit:        Pointer to the FDT blob.
 * @images:     Offset of the /images subnode.
 * @type:       Name of the property within the configuration subnode.
 * @index:      Index into the list of strings in this property.
 *
 * Return:      the node offset of the respective image node or a negative
 *              error number.
 */
static int spl_fit_get_image_node(const void *fit, int images,
                                  const char *type, int index)
{
        const char *name, *str;
        int node, conf_node;
        int len, i;

        conf_node = fit_find_config_node(fit);
        if (conf_node < 0) {
#ifdef CONFIG_SPL_LIBCOMMON_SUPPORT
                printf("No matching DT out of these options:\n");
                for (node = fdt_first_subnode(fit, conf_node);
                     node >= 0;
                     node = fdt_next_subnode(fit, node)) {
                        name = fdt_getprop(fit, node, "description", &len);
                        printf("   %s\n", name);
                }
#endif
                return conf_node;
        }

        name = fdt_getprop(fit, conf_node, type, &len);
        if (!name) {
                debug("cannot find property '%s': %d\n", type, len);
                return -EINVAL;
        }

        str = name;
        for (i = 0; i < index; i++) {
                str = strchr(str, '\0') + 1;
                if (!str || (str - name >= len)) {
                        debug("no string for index %d\n", index);
                        return -E2BIG;
                }
        }

        debug("%s: '%s'\n", type, str);
        node = fdt_subnode_offset(fit, images, str);
        if (node < 0) {
                debug("cannot find image node '%s': %d\n", str, node);
                return -EINVAL;
        }

        return node;
}

static int get_aligned_image_offset(struct spl_load_info *info, int offset)
{
        /*
         * If it is a FS read, get the first address before offset which is
         * aligned to ARCH_DMA_MINALIGN. If it is raw read return the
         * block number to which offset belongs.
         */
        if (info->filename)
                return offset & ~(ARCH_DMA_MINALIGN - 1);

        return offset / info->bl_len;
}

static int get_aligned_image_overhead(struct spl_load_info *info, int offset)
{
        /*
         * If it is a FS read, get the difference between the offset and
         * the first address before offset which is aligned to
         * ARCH_DMA_MINALIGN. If it is raw read return the offset within the
         * block.
         */
        if (info->filename)
                return offset & (ARCH_DMA_MINALIGN - 1);

        return offset % info->bl_len;
}

static int get_aligned_image_size(struct spl_load_info *info, int data_size,
                                  int offset)
{
        data_size = data_size + get_aligned_image_overhead(info, offset);

        if (info->filename)
                return data_size;

        return (data_size + info->bl_len - 1) / info->bl_len;
}

/**
 * spl_load_fit_image(): load the image described in a certain FIT node
 * @info:       points to information about the device to load data from
 * @sector:     the start sector of the FIT image on the device
 * @fit:        points to the flattened device tree blob describing the FIT
 *              image
 * @base_offset: the beginning of the data area containing the actual
 *              image data, relative to the beginning of the FIT
 * @node:       offset of the DT node describing the image to load (relative
 *              to @fit)
 * @image_info: will be filled with information about the loaded image
 *              If the FIT node does not contain a "load" (address) property,
 *              the image gets loaded to the address pointed to by the
 *              load_addr member in this struct.
 *
 * Return:      0 on success or a negative error number.
 */
static int spl_load_fit_image(struct spl_load_info *info, ulong sector,
                              void *fit, ulong base_offset, int node,
                              struct spl_image_info *image_info)
{
        ulong offset;
        size_t length;
        ulong load_addr, load_ptr;
        void *src;
        ulong overhead;
        int nr_sectors;
        int align_len = ARCH_DMA_MINALIGN - 1;

        offset = fdt_getprop_u32(fit, node, "data-offset");
        if (offset == FDT_ERROR)
                return -ENOENT;
        offset += base_offset;
        length = fdt_getprop_u32(fit, node, "data-size");
        if (length == FDT_ERROR)
                return -ENOENT;
        load_addr = fdt_getprop_u32(fit, node, "load");
        if (load_addr == FDT_ERROR && image_info)
                load_addr = image_info->load_addr;
        load_ptr = (load_addr + align_len) & ~align_len;

        overhead = get_aligned_image_overhead(info, offset);
        nr_sectors = get_aligned_image_size(info, length, offset);

        if (info->read(info, sector + get_aligned_image_offset(info, offset),
                       nr_sectors, (void*)load_ptr) != nr_sectors)
                return -EIO;
        debug("image: dst=%lx, offset=%lx, size=%lx\n", load_ptr, offset,
              (unsigned long)length);

        src = (void *)load_ptr + overhead;
#ifdef CONFIG_SPL_FIT_IMAGE_POST_PROCESS
        board_fit_image_post_process(&src, &length);
#endif

        memcpy((void*)load_addr, src, length);

        if (image_info) {
                image_info->load_addr = load_addr;
                image_info->size = length;
                image_info->entry_point = fdt_getprop_u32(fit, node, "entry");
        }

        return 0;
}

int spl_load_simple_fit(struct spl_image_info *spl_image,
                        struct spl_load_info *info, ulong sector, void *fit)
{
        int sectors;
        ulong size;
        unsigned long count;
        struct spl_image_info image_info;
        int node, images, ret;
        int base_offset, align_len = ARCH_DMA_MINALIGN - 1;
        int index = 0;

        /*
         * Figure out where the external images start. This is the base for the
         * data-offset properties in each image.
         */
        size = fdt_totalsize(fit);
        size = (size + 3) & ~3;
        base_offset = (size + 3) & ~3;

        /*
         * So far we only have one block of data from the FIT. Read the entire
         * thing, including that first block, placing it so it finishes before
         * where we will load the image.
         *
         * Note that we will load the image such that its first byte will be
         * at the load address. Since that byte may be part-way through a
         * block, we may load the image up to one block before the load
         * address. So take account of that here by subtracting an addition
         * block length from the FIT start position.
         *
         * In fact the FIT has its own load address, but we assume it cannot
         * be before CONFIG_SYS_TEXT_BASE.
         */
        fit = (void *)((CONFIG_SYS_TEXT_BASE - size - info->bl_len -
                        align_len) & ~align_len);
        sectors = get_aligned_image_size(info, size, 0);
        count = info->read(info, sector, sectors, fit);
        debug("fit read sector %lx, sectors=%d, dst=%p, count=%lu\n",
              sector, sectors, fit, count);
        if (count == 0)
                return -EIO;

        /* find the node holding the images information */
        images = fdt_path_offset(fit, FIT_IMAGES_PATH);
        if (images < 0) {
                debug("%s: Cannot find /images node: %d\n", __func__, images);
                return -1;
        }

        /* find the U-Boot image */
        node = spl_fit_get_image_node(fit, images, "firmware", 0);
        if (node < 0) {
                debug("could not find firmware image, trying loadables...\n");
                node = spl_fit_get_image_node(fit, images, "loadables", 0);
                /*
                 * If we pick the U-Boot image from "loadables", start at
                 * the second image when later loading additional images.
                 */
                index = 1;
        }
        if (node < 0) {
                debug("%s: Cannot find u-boot image node: %d\n",
                      __func__, node);
                return -1;
        }

        /* Load the image and set up the spl_image structure */
        ret = spl_load_fit_image(info, sector, fit, base_offset, node,
                                 spl_image);
        if (ret)
                return ret;

        spl_image->os = IH_OS_U_BOOT;

        /* Figure out which device tree the board wants to use */
        node = spl_fit_get_image_node(fit, images, FIT_FDT_PROP, 0);
        if (node < 0) {
                debug("%s: cannot find FDT node\n", __func__);
                return node;
        }

        /*
         * Read the device tree and place it after the image.
         * Align the destination address to ARCH_DMA_MINALIGN.
         */
        image_info.load_addr = spl_image->load_addr + spl_image->size;
        ret = spl_load_fit_image(info, sector, fit, base_offset, node,
                                 &image_info);
        if (ret < 0)
                return ret;

        /* Now check if there are more images for us to load */
        for (; ; index++) {
                node = spl_fit_get_image_node(fit, images, "loadables", index);
                if (node < 0)
                        break;

                ret = spl_load_fit_image(info, sector, fit, base_offset, node,
                                         &image_info);
                if (ret < 0)
                        continue;

                /*
                 * If the "firmware" image did not provide an entry point,
                 * use the first valid entry point from the loadables.
                 */
                if (spl_image->entry_point == FDT_ERROR &&
                    image_info.entry_point != FDT_ERROR)
                        spl_image->entry_point = image_info.entry_point;
        }

        /*
         * If a platform does not provide CONFIG_SYS_UBOOT_START, U-Boot's
         * Makefile will set it to 0 and it will end up as the entry point
         * here. What it actually means is: use the load address.
         */
        if (spl_image->entry_point == FDT_ERROR || spl_image->entry_point == 0)
                spl_image->entry_point = spl_image->load_addr;

        return 0;
}