// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
 */

#include <common.h>
#include <cbfs.h>
#include <log.h>
#include <malloc.h>
#include <asm/byteorder.h>

/* Offset of master header from the start of a coreboot ROM */
#define MASTER_HDR_OFFSET       0x38

static const u32 good_magic = 0x4f524243;
static const u8 good_file_magic[] = "LARCHIVE";

/**
 * struct cbfs_priv - Private data for this driver
 *
 * @initialised: true if this CBFS has been inited
 * @start: Start position of CBFS in memory, typically memory-mapped SPI flash
 * @header: Header read from the CBFS, byte-swapped so U-Boot can access it
 * @file_cache: List of file headers read from CBFS
 * @result: Success/error result
 */
struct cbfs_priv {
        bool initialized;
        void *start;
        struct cbfs_header header;
        struct cbfs_cachenode *file_cache;
        enum cbfs_result result;
};

static struct cbfs_priv cbfs_s;

const char *file_cbfs_error(void)
{
        switch (cbfs_s.result) {
        case CBFS_SUCCESS:
                return "Success";
        case CBFS_NOT_INITIALIZED:
                return "CBFS not initialized";
        case CBFS_BAD_HEADER:
                return "Bad CBFS header";
        case CBFS_BAD_FILE:
                return "Bad CBFS file";
        case CBFS_FILE_NOT_FOUND:
                return "File not found";
        default:
                return "Unknown";
        }
}

enum cbfs_result cbfs_get_result(void)
{
        return cbfs_s.result;
}

/* Do endian conversion on the CBFS header structure. */
static void swap_header(struct cbfs_header *dest, struct cbfs_header *src)
{
        dest->magic = be32_to_cpu(src->magic);
        dest->version = be32_to_cpu(src->version);
        dest->rom_size = be32_to_cpu(src->rom_size);
        dest->boot_block_size = be32_to_cpu(src->boot_block_size);
        dest->align = be32_to_cpu(src->align);
        dest->offset = be32_to_cpu(src->offset);
}

/* Do endian conversion on a CBFS file header. */
static void swap_file_header(struct cbfs_fileheader *dest,
                             const struct cbfs_fileheader *src)
{
        memcpy(&dest->magic, &src->magic, sizeof(dest->magic));
        dest->len = be32_to_cpu(src->len);
        dest->type = be32_to_cpu(src->type);
        dest->attributes_offset = be32_to_cpu(src->attributes_offset);
        dest->offset = be32_to_cpu(src->offset);
}

/**
 * fill_node() - Fill a node struct with information from the CBFS
 *
 * @node: Node to fill
 * @start: Pointer to the start of the CBFS file in memory
 * @header: Pointer to the header information (in our enddianess)
 * @return 0 if OK, -EBADF if the header is too small
 */
static int fill_node(struct cbfs_cachenode *node, void *start,
                     struct cbfs_fileheader *header)
{
        uint name_len;
        uint offset;

        /* Check the header is large enough */
        if (header->offset < sizeof(struct cbfs_fileheader))
                return -EBADF;

        node->next = NULL;
        node->type = header->type;
        node->data = start + header->offset;
        node->data_length = header->len;
        name_len = header->offset - sizeof(struct cbfs_fileheader);
        node->name = start + sizeof(struct cbfs_fileheader);
        node->name_length = name_len;
        node->attr_offset = header->attributes_offset;
        node->comp_algo = CBFS_COMPRESS_NONE;
        node->decomp_size = 0;

        for (offset = node->attr_offset; offset < header->offset;) {
                const struct cbfs_file_attribute *attr;
                uint tag, len;

                attr = start + offset;
                tag = be32_to_cpu(attr->tag);
                len = be32_to_cpu(attr->len);
                if (tag == CBFS_FILE_ATTR_TAG_COMPRESSION) {
                        struct cbfs_file_attr_compression *comp;

                        comp = start + offset;
                        node->comp_algo = be32_to_cpu(comp->compression);
                        node->decomp_size =
                                be32_to_cpu(comp->decompressed_size);
                }

                offset += len;
        }

        return 0;
}

/*
 * Given a starting position in memory, scan forward, bounded by a size, and
 * find the next valid CBFS file. No memory is allocated by this function. The
 * caller is responsible for allocating space for the new file structure.
 *
 * @param start         The location in memory to start from.
 * @param size          The size of the memory region to search.
 * @param align         The alignment boundaries to check on.
 * @param node  A pointer to the file structure to load.
 * @param used          A pointer to the count of of bytes scanned through,
 *                      including the file if one is found.
 *
 * @return 0 if a file is found, -ENOENT if one isn't, -EBADF if a bad header
 *      is found.
 */
static int file_cbfs_next_file(struct cbfs_priv *priv, void *start, int size,
                               int align, struct cbfs_cachenode *node,
                               int *used)
{
        struct cbfs_fileheader header;

        *used = 0;

        while (size >= align) {
                const struct cbfs_fileheader *file_header = start;
                int ret;

                /* Check if there's a file here. */
                if (memcmp(good_file_magic, &file_header->magic,
                           sizeof(file_header->magic))) {
                        *used += align;
                        size -= align;
                        start += align;
                        continue;
                }

                swap_file_header(&header, file_header);
                if (header.offset >= size)
                        return log_msg_ret("range", -E2BIG);
                ret = fill_node(node, start, &header);
                if (ret) {
                        priv->result = CBFS_BAD_FILE;
                        return log_msg_ret("fill", ret);
                }

                *used += ALIGN(header.len, align);
                return 0;
        }

        return -ENOENT;
}

/* Look through a CBFS instance and copy file metadata into regular memory. */
static int file_cbfs_fill_cache(struct cbfs_priv *priv, int size, int align)
{
        struct cbfs_cachenode *cache_node;
        struct cbfs_cachenode *node;
        struct cbfs_cachenode **cache_tail = &priv->file_cache;
        void *start;

        /* Clear out old information. */
        cache_node = priv->file_cache;
        while (cache_node) {
                struct cbfs_cachenode *old_node = cache_node;
                cache_node = cache_node->next;
                free(old_node);
        }
        priv->file_cache = NULL;

        start = priv->start;
        while (size >= align) {
                int used;
                int ret;

                node = malloc(sizeof(struct cbfs_cachenode));
                if (!node)
                        return -ENOMEM;
                ret = file_cbfs_next_file(priv, start, size, align, node,
                                          &used);

                if (ret < 0) {
                        free(node);
                        if (ret == -ENOENT)
                                break;
                        return ret;
                }
                *cache_tail = node;
                cache_tail = &node->next;

                size -= used;
                start += used;
        }
        priv->result = CBFS_SUCCESS;

        return 0;
}

/**
 * load_header() - Load the CBFS header
 *
 * Get the CBFS header out of the ROM and do endian conversion.
 *
 * @priv: Private data, which is inited by this function
 * @addr: Address of CBFS header in memory-mapped SPI flash
 * @return 0 if OK, -ENXIO if the header is bad
 */
static int load_header(struct cbfs_priv *priv, ulong addr)
{
        struct cbfs_header *header = &priv->header;
        struct cbfs_header *header_in_rom;

        memset(priv, '\0', sizeof(*priv));
        header_in_rom = (struct cbfs_header *)addr;
        swap_header(header, header_in_rom);

        if (header->magic != good_magic || header->offset >
                        header->rom_size - header->boot_block_size) {
                priv->result = CBFS_BAD_HEADER;
                return -ENXIO;
        }

        return 0;
}

/**
 * file_cbfs_load_header() - Get the CBFS header out of the ROM, given the end
 *
 * @priv: Private data, which is inited by this function
 * @end_of_rom: Address of the last byte of the ROM (typically 0xffffffff)
 * @return 0 if OK, -ENXIO if the header is bad
 */
static int file_cbfs_load_header(struct cbfs_priv *priv, ulong end_of_rom)
{
        int offset = *(u32 *)(end_of_rom - 3);
        int ret;

        ret = load_header(priv, end_of_rom + offset + 1);
        if (ret)
                return ret;
        priv->start = (void *)(end_of_rom + 1 - priv->header.rom_size);

        return 0;
}

/**
 * cbfs_load_header_ptr() - Get the CBFS header out of the ROM, given the base
 *
 * @priv: Private data, which is inited by this function
 * @base: Address of the first byte of the ROM (e.g. 0xff000000)
 * @return 0 if OK, -ENXIO if the header is bad
 */
static int cbfs_load_header_ptr(struct cbfs_priv *priv, ulong base)
{
        int ret;

        ret = load_header(priv, base + MASTER_HDR_OFFSET);
        if (ret)
                return ret;
        priv->start = (void *)base;

        return 0;
}

static int cbfs_init(struct cbfs_priv *priv, ulong end_of_rom)
{
        int ret;

        ret = file_cbfs_load_header(priv, end_of_rom);
        if (ret)
                return ret;

        ret = file_cbfs_fill_cache(priv, priv->header.rom_size,
                                   priv->header.align);
        if (ret)
                return ret;
        priv->initialized = true;

        return 0;
}

int file_cbfs_init(ulong end_of_rom)
{
        return cbfs_init(&cbfs_s, end_of_rom);
}

int cbfs_init_mem(ulong base, ulong size, bool require_hdr,
                  struct cbfs_priv **privp)
{
        struct cbfs_priv priv_s, *priv = &priv_s;
        int ret;

        /*
         * Use a local variable to start with until we know that the * CBFS is
         * valid. Note that size is detected from the header, if present,
         * meaning the parameter is ignored.
         */
        ret = cbfs_load_header_ptr(priv, base);
        if (ret) {
                if (require_hdr || size == CBFS_SIZE_UNKNOWN)
                        return ret;
                memset(priv, '\0', sizeof(struct cbfs_priv));
                priv->header.rom_size = size;
                priv->header.align = CBFS_ALIGN_SIZE;
                priv->start = (void *)base;
        }

        ret = file_cbfs_fill_cache(priv, priv->header.rom_size,
                                   priv->header.align);
        if (ret)
                return log_msg_ret("fill", ret);

        priv->initialized = true;
        priv = malloc(sizeof(priv_s));
        if (!priv)
                return -ENOMEM;
        memcpy(priv, &priv_s, sizeof(priv_s));
        *privp = priv;

        return 0;
}

const struct cbfs_header *file_cbfs_get_header(void)
{
        struct cbfs_priv *priv = &cbfs_s;

        if (priv->initialized) {
                priv->result = CBFS_SUCCESS;
                return &priv->header;
        } else {
                priv->result = CBFS_NOT_INITIALIZED;
                return NULL;
        }
}

const struct cbfs_cachenode *cbfs_get_first(const struct cbfs_priv *priv)
{
        return priv->file_cache;
}

void cbfs_get_next(const struct cbfs_cachenode **filep)
{
        if (*filep)
                *filep = (*filep)->next;
}

const struct cbfs_cachenode *file_cbfs_get_first(void)
{
        struct cbfs_priv *priv = &cbfs_s;

        if (!priv->initialized) {
                priv->result = CBFS_NOT_INITIALIZED;
                return NULL;
        } else {
                priv->result = CBFS_SUCCESS;
                return priv->file_cache;
        }
}

void file_cbfs_get_next(const struct cbfs_cachenode **file)
{
        struct cbfs_priv *priv = &cbfs_s;

        if (!priv->initialized) {
                priv->result = CBFS_NOT_INITIALIZED;
                *file = NULL;
                return;
        }

        if (*file)
                *file = (*file)->next;
        priv->result = CBFS_SUCCESS;
}

const struct cbfs_cachenode *cbfs_find_file(struct cbfs_priv *priv,
                                            const char *name)
{
        struct cbfs_cachenode *cache_node = priv->file_cache;

        if (!priv->initialized) {
                priv->result = CBFS_NOT_INITIALIZED;
                return NULL;
        }

        while (cache_node) {
                if (!strcmp(name, cache_node->name))
                        break;
                cache_node = cache_node->next;
        }
        if (!cache_node)
                priv->result = CBFS_FILE_NOT_FOUND;
        else
                priv->result = CBFS_SUCCESS;

        return cache_node;
}

const struct cbfs_cachenode *file_cbfs_find(const char *name)
{
        return cbfs_find_file(&cbfs_s, name);
}

static int find_uncached(struct cbfs_priv *priv, const char *name, void *start,
                         struct cbfs_cachenode *node)
{
        int size = priv->header.rom_size;
        int align = priv->header.align;

        while (size >= align) {
                int used;
                int ret;

                ret = file_cbfs_next_file(priv, start, size, align, node,
                                          &used);
                if (ret == -ENOENT)
                        break;
                else if (ret)
                        return ret;
                if (!strcmp(name, node->name))
                        return 0;

                size -= used;
                start += used;
        }
        priv->result = CBFS_FILE_NOT_FOUND;

        return -ENOENT;
}

int file_cbfs_find_uncached(ulong end_of_rom, const char *name,
                            struct cbfs_cachenode *node)
{
        struct cbfs_priv priv;
        void *start;
        int ret;

        ret = file_cbfs_load_header(&priv, end_of_rom);
        if (ret)
                return ret;
        start = priv.start;

        return find_uncached(&priv, name, start, node);
}

int file_cbfs_find_uncached_base(ulong base, const char *name,
                                 struct cbfs_cachenode *node)
{
        struct cbfs_priv priv;
        int ret;

        ret = cbfs_load_header_ptr(&priv, base);
        if (ret)
                return ret;

        return find_uncached(&priv, name, (void *)base, node);
}

const char *file_cbfs_name(const struct cbfs_cachenode *file)
{
        cbfs_s.result = CBFS_SUCCESS;

        return file->name;
}

u32 file_cbfs_size(const struct cbfs_cachenode *file)
{
        cbfs_s.result = CBFS_SUCCESS;

        return file->data_length;
}

u32 file_cbfs_type(const struct cbfs_cachenode *file)
{
        cbfs_s.result = CBFS_SUCCESS;

        return file->type;
}

long file_cbfs_read(const struct cbfs_cachenode *file, void *buffer,
                    unsigned long maxsize)
{
        u32 size;

        size = file->data_length;
        if (maxsize && size > maxsize)
                size = maxsize;

        memcpy(buffer, file->data, size);
        cbfs_s.result = CBFS_SUCCESS;

        return size;
}