// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2015
 * Texas Instruments Incorporated - http://www.ti.com/
 */

#define LOG_CATEGORY UCLASS_REMOTEPROC

#define pr_fmt(fmt) "%s: " fmt, __func__
#include <common.h>
#include <elf.h>
#include <errno.h>
#include <log.h>
#include <malloc.h>
#include <virtio_ring.h>
#include <remoteproc.h>
#include <asm/io.h>
#include <dm/device-internal.h>
#include <dm.h>
#include <dm/uclass.h>
#include <dm/uclass-internal.h>
#include <linux/compat.h>

DECLARE_GLOBAL_DATA_PTR;

struct resource_table {
        u32 ver;
        u32 num;
        u32 reserved[2];
        u32 offset[0];
} __packed;

typedef int (*handle_resource_t) (struct udevice *, void *, int offset, int avail);

static struct resource_table *rsc_table;

/**
 * for_each_remoteproc_device() - iterate through the list of rproc devices
 * @fn: check function to call per match, if this function returns fail,
 *      iteration is aborted with the resultant error value
 * @skip_dev:   Device to skip calling the callback about.
 * @data:       Data to pass to the callback function
 *
 * Return: 0 if none of the callback returned a non 0 result, else returns the
 * result from the callback function
 */
static int for_each_remoteproc_device(int (*fn) (struct udevice *dev,
                                        struct dm_rproc_uclass_pdata *uc_pdata,
                                        const void *data),
                                      struct udevice *skip_dev,
                                      const void *data)
{
        struct udevice *dev;
        struct dm_rproc_uclass_pdata *uc_pdata;
        int ret;

        for (ret = uclass_find_first_device(UCLASS_REMOTEPROC, &dev); dev;
             ret = uclass_find_next_device(&dev)) {
                if (ret || dev == skip_dev)
                        continue;
                uc_pdata = dev_get_uclass_plat(dev);
                ret = fn(dev, uc_pdata, data);
                if (ret)
                        return ret;
        }

        return 0;
}

/**
 * _rproc_name_is_unique() - iteration helper to check if rproc name is unique
 * @dev:        device that we are checking name for
 * @uc_pdata:   uclass platform data
 * @data:       compare data (this is the name we want to ensure is unique)
 *
 * Return: 0 is there is no match(is unique); if there is a match(we dont
 * have a unique name), return -EINVAL.
 */
static int _rproc_name_is_unique(struct udevice *dev,
                                 struct dm_rproc_uclass_pdata *uc_pdata,
                                 const void *data)
{
        const char *check_name = data;

        /* devices not yet populated with data - so skip them */
        if (!uc_pdata->name || !check_name)
                return 0;

        /* Return 0 to search further if we dont match */
        if (strlen(uc_pdata->name) != strlen(check_name))
                return 0;

        if (!strcmp(uc_pdata->name, check_name))
                return -EINVAL;

        return 0;
}

/**
 * rproc_name_is_unique() - Check if the rproc name is unique
 * @check_dev:  Device we are attempting to ensure is unique
 * @check_name: Name we are trying to ensure is unique.
 *
 * Return: true if we have a unique name, false if name is not unique.
 */
static bool rproc_name_is_unique(struct udevice *check_dev,
                                 const char *check_name)
{
        int ret;

        ret = for_each_remoteproc_device(_rproc_name_is_unique,
                                         check_dev, check_name);
        return ret ? false : true;
}

/**
 * rproc_pre_probe() - Pre probe accessor for the uclass
 * @dev:        device for which we are preprobing
 *
 * Parses and fills up the uclass pdata for use as needed by core and
 * remote proc drivers.
 *
 * Return: 0 if all wernt ok, else appropriate error value.
 */
static int rproc_pre_probe(struct udevice *dev)
{
        struct dm_rproc_uclass_pdata *uc_pdata;
        const struct dm_rproc_ops *ops;

        uc_pdata = dev_get_uclass_plat(dev);

        /* See if we need to populate via fdt */

        if (!dev_get_plat(dev)) {
#if CONFIG_IS_ENABLED(OF_CONTROL)
                bool tmp;
                debug("'%s': using fdt\n", dev->name);
                uc_pdata->name = dev_read_string(dev, "remoteproc-name");

                /* Default is internal memory mapped */
                uc_pdata->mem_type = RPROC_INTERNAL_MEMORY_MAPPED;
                tmp = dev_read_bool(dev, "remoteproc-internal-memory-mapped");
                if (tmp)
                        uc_pdata->mem_type = RPROC_INTERNAL_MEMORY_MAPPED;
#else
                /* Nothing much we can do about this, can we? */
                return -EINVAL;
#endif

        } else {
                struct dm_rproc_uclass_pdata *pdata = dev_get_plat(dev);

                debug("'%s': using legacy data\n", dev->name);
                if (pdata->name)
                        uc_pdata->name = pdata->name;
                uc_pdata->mem_type = pdata->mem_type;
                uc_pdata->driver_plat_data = pdata->driver_plat_data;
        }

        /* Else try using device Name */
        if (!uc_pdata->name)
                uc_pdata->name = dev->name;
        if (!uc_pdata->name) {
                debug("Unnamed device!");
                return -EINVAL;
        }

        if (!rproc_name_is_unique(dev, uc_pdata->name)) {
                debug("%s duplicate name '%s'\n", dev->name, uc_pdata->name);
                return -EINVAL;
        }

        ops = rproc_get_ops(dev);
        if (!ops) {
                debug("%s driver has no ops?\n", dev->name);
                return -EINVAL;
        }

        if (!ops->load || !ops->start) {
                debug("%s driver has missing mandatory ops?\n", dev->name);
                return -EINVAL;
        }

        return 0;
}

/**
 * rproc_post_probe() - post probe accessor for the uclass
 * @dev:        deivce we finished probing
 *
 * initiate init function after the probe is completed. This allows
 * the remote processor drivers to split up the initializations between
 * probe and init as needed.
 *
 * Return: if the remote proc driver has a init routine, invokes it and
 * hands over the return value. overall, 0 if all went well, else appropriate
 * error value.
 */
static int rproc_post_probe(struct udevice *dev)
{
        const struct dm_rproc_ops *ops;

        ops = rproc_get_ops(dev);
        if (!ops) {
                debug("%s driver has no ops?\n", dev->name);
                return -EINVAL;
        }

        if (ops->init)
                return ops->init(dev);

        return 0;
}

/**
 * rproc_add_res() - After parsing the resource table add the mappings
 * @dev:        device we finished probing
 * @mapping: rproc_mem_entry for the resource
 *
 * Return: if the remote proc driver has a add_res routine, invokes it and
 * hands over the return value. overall, 0 if all went well, else appropriate
 * error value.
 */
static int rproc_add_res(struct udevice *dev, struct rproc_mem_entry *mapping)
{
        const struct dm_rproc_ops *ops = rproc_get_ops(dev);

        if (!ops->add_res)
                return -ENOSYS;

        return ops->add_res(dev, mapping);
}

/**
 * rproc_alloc_mem() - After parsing the resource table allocat mem
 * @dev:        device we finished probing
 * @len: rproc_mem_entry for the resource
 * @align: alignment for the resource
 *
 * Return: if the remote proc driver has a add_res routine, invokes it and
 * hands over the return value. overall, 0 if all went well, else appropriate
 * error value.
 */
static void *rproc_alloc_mem(struct udevice *dev, unsigned long len,
                             unsigned long align)
{
        const struct dm_rproc_ops *ops;

        ops = rproc_get_ops(dev);
        if (!ops) {
                debug("%s driver has no ops?\n", dev->name);
                return NULL;
        }

        if (ops->alloc_mem)
                return ops->alloc_mem(dev, len, align);

        return NULL;
}

/**
 * rproc_config_pagetable() - Configure page table for remote processor
 * @dev:        device we finished probing
 * @virt: Virtual address of the resource
 * @phys: Physical address the resource
 * @len: length the resource
 *
 * Return: if the remote proc driver has a add_res routine, invokes it and
 * hands over the return value. overall, 0 if all went well, else appropriate
 * error value.
 */
static int rproc_config_pagetable(struct udevice *dev, unsigned int virt,
                                  unsigned int phys, unsigned int len)
{
        const struct dm_rproc_ops *ops;

        ops = rproc_get_ops(dev);
        if (!ops) {
                debug("%s driver has no ops?\n", dev->name);
                return -EINVAL;
        }

        if (ops->config_pagetable)
                return ops->config_pagetable(dev, virt, phys, len);

        return 0;
}

UCLASS_DRIVER(rproc) = {
        .id = UCLASS_REMOTEPROC,
        .name = "remoteproc",
        .flags = DM_UC_FLAG_SEQ_ALIAS,
        .pre_probe = rproc_pre_probe,
        .post_probe = rproc_post_probe,
        .per_device_plat_auto   = sizeof(struct dm_rproc_uclass_pdata),
};

/* Remoteproc subsystem access functions */
/**
 * _rproc_probe_dev() - iteration helper to probe a rproc device
 * @dev:        device to probe
 * @uc_pdata:   uclass data allocated for the device
 * @data:       unused
 *
 * Return: 0 if all ok, else appropriate error value.
 */
static int _rproc_probe_dev(struct udevice *dev,
                            struct dm_rproc_uclass_pdata *uc_pdata,
                            const void *data)
{
        int ret;

        ret = device_probe(dev);

        if (ret)
                debug("%s: Failed to initialize - %d\n", dev->name, ret);
        return ret;
}

/**
 * _rproc_dev_is_probed() - check if the device has been probed
 * @dev:        device to check
 * @uc_pdata:   unused
 * @data:       unused
 *
 * Return: -EAGAIN if not probed else return 0
 */
static int _rproc_dev_is_probed(struct udevice *dev,
                            struct dm_rproc_uclass_pdata *uc_pdata,
                            const void *data)
{
        if (dev_get_flags(dev) & DM_FLAG_ACTIVATED)
                return 0;

        return -EAGAIN;
}

bool rproc_is_initialized(void)
{
        int ret = for_each_remoteproc_device(_rproc_dev_is_probed, NULL, NULL);
        return ret ? false : true;
}

int rproc_init(void)
{
        int ret;

        if (rproc_is_initialized()) {
                debug("Already initialized\n");
                return -EINVAL;
        }

        ret = for_each_remoteproc_device(_rproc_probe_dev, NULL, NULL);
        return ret;
}

int rproc_dev_init(int id)
{
        struct udevice *dev = NULL;
        int ret;

        ret = uclass_get_device_by_seq(UCLASS_REMOTEPROC, id, &dev);
        if (ret) {
                debug("Unknown remote processor id '%d' requested(%d)\n",
                      id, ret);
                return ret;
        }

        ret = device_probe(dev);
        if (ret)
                debug("%s: Failed to initialize - %d\n", dev->name, ret);

        return ret;
}

int rproc_load(int id, ulong addr, ulong size)
{
        struct udevice *dev = NULL;
        struct dm_rproc_uclass_pdata *uc_pdata;
        const struct dm_rproc_ops *ops;
        int ret;

        ret = uclass_get_device_by_seq(UCLASS_REMOTEPROC, id, &dev);
        if (ret) {
                debug("Unknown remote processor id '%d' requested(%d)\n",
                      id, ret);
                return ret;
        }

        uc_pdata = dev_get_uclass_plat(dev);

        ops = rproc_get_ops(dev);
        if (!ops) {
                debug("%s driver has no ops?\n", dev->name);
                return -EINVAL;
        }

        debug("Loading to '%s' from address 0x%08lX size of %lu bytes\n",
              uc_pdata->name, addr, size);
        if (ops->load)
                return ops->load(dev, addr, size);

        debug("%s: data corruption?? mandatory function is missing!\n",
              dev->name);

        return -EINVAL;
};

/*
 * Completely internal helper enums..
 * Keeping this isolated helps this code evolve independent of other
 * parts..
 */
enum rproc_ops {
        RPROC_START,
        RPROC_STOP,
        RPROC_RESET,
        RPROC_PING,
        RPROC_RUNNING,
};

/**
 * _rproc_ops_wrapper() - wrapper for invoking remote proc driver callback
 * @id:         id of the remote processor
 * @op:         one of rproc_ops that indicate what operation to invoke
 *
 * Most of the checks and verification for remoteproc operations are more
 * or less same for almost all operations. This allows us to put a wrapper
 * and use the common checks to allow the driver to function appropriately.
 *
 * Return: 0 if all ok, else appropriate error value.
 */
static int _rproc_ops_wrapper(int id, enum rproc_ops op)
{
        struct udevice *dev = NULL;
        struct dm_rproc_uclass_pdata *uc_pdata;
        const struct dm_rproc_ops *ops;
        int (*fn)(struct udevice *dev);
        bool mandatory = false;
        char *op_str;
        int ret;

        ret = uclass_get_device_by_seq(UCLASS_REMOTEPROC, id, &dev);
        if (ret) {
                debug("Unknown remote processor id '%d' requested(%d)\n",
                      id, ret);
                return ret;
        }

        uc_pdata = dev_get_uclass_plat(dev);

        ops = rproc_get_ops(dev);
        if (!ops) {
                debug("%s driver has no ops?\n", dev->name);
                return -EINVAL;
        }
        switch (op) {
        case RPROC_START:
                fn = ops->start;
                mandatory = true;
                op_str = "Starting";
                break;
        case RPROC_STOP:
                fn = ops->stop;
                op_str = "Stopping";
                break;
        case RPROC_RESET:
                fn = ops->reset;
                op_str = "Resetting";
                break;
        case RPROC_RUNNING:
                fn = ops->is_running;
                op_str = "Checking if running:";
                break;
        case RPROC_PING:
                fn = ops->ping;
                op_str = "Pinging";
                break;
        default:
                debug("what is '%d' operation??\n", op);
                return -EINVAL;
        }

        debug("%s %s...\n", op_str, uc_pdata->name);
        if (fn)
                return fn(dev);

        if (mandatory)
                debug("%s: data corruption?? mandatory function is missing!\n",
                      dev->name);

        return -ENOSYS;
}

int rproc_start(int id)
{
        return _rproc_ops_wrapper(id, RPROC_START);
};

int rproc_stop(int id)
{
        return _rproc_ops_wrapper(id, RPROC_STOP);
};

int rproc_reset(int id)
{
        return _rproc_ops_wrapper(id, RPROC_RESET);
};

int rproc_ping(int id)
{
        return _rproc_ops_wrapper(id, RPROC_PING);
};

int rproc_is_running(int id)
{
        return _rproc_ops_wrapper(id, RPROC_RUNNING);
};


static int handle_trace(struct udevice *dev, struct fw_rsc_trace *rsc,
                        int offset, int avail)
{
        if (sizeof(*rsc) > avail) {
                debug("trace rsc is truncated\n");
                return -EINVAL;
        }

        /*
         * make sure reserved bytes are zeroes
         */
        if (rsc->reserved) {
                debug("trace rsc has non zero reserved bytes\n");
                return -EINVAL;
        }

        debug("trace rsc: da 0x%x, len 0x%x\n", rsc->da, rsc->len);

        return 0;
}

static int handle_devmem(struct udevice *dev, struct fw_rsc_devmem *rsc,
                         int offset, int avail)
{
        struct rproc_mem_entry *mapping;

        if (sizeof(*rsc) > avail) {
                debug("devmem rsc is truncated\n");
                return -EINVAL;
        }

        /*
         * make sure reserved bytes are zeroes
         */
        if (rsc->reserved) {
                debug("devmem rsc has non zero reserved bytes\n");
                return -EINVAL;
        }

        debug("devmem rsc: pa 0x%x, da 0x%x, len 0x%x\n",
              rsc->pa, rsc->da, rsc->len);

        rproc_config_pagetable(dev, rsc->da, rsc->pa, rsc->len);

        mapping = kzalloc(sizeof(*mapping), GFP_KERNEL);
        if (!mapping)
                return -ENOMEM;

        /*
         * We'll need this info later when we'll want to unmap everything
         * (e.g. on shutdown).
         *
         * We can't trust the remote processor not to change the resource
         * table, so we must maintain this info independently.
         */
        mapping->dma = rsc->pa;
        mapping->da = rsc->da;
        mapping->len = rsc->len;
        rproc_add_res(dev, mapping);

        debug("mapped devmem pa 0x%x, da 0x%x, len 0x%x\n",
              rsc->pa, rsc->da, rsc->len);

        return 0;
}

static int handle_carveout(struct udevice *dev, struct fw_rsc_carveout *rsc,
                           int offset, int avail)
{
        struct rproc_mem_entry *mapping;

        if (sizeof(*rsc) > avail) {
                debug("carveout rsc is truncated\n");
                return -EINVAL;
        }

        /*
         * make sure reserved bytes are zeroes
         */
        if (rsc->reserved) {
                debug("carveout rsc has non zero reserved bytes\n");
                return -EINVAL;
        }

        debug("carveout rsc: da %x, pa %x, len %x, flags %x\n",
              rsc->da, rsc->pa, rsc->len, rsc->flags);

        rsc->pa = (uintptr_t)rproc_alloc_mem(dev, rsc->len, 8);
        if (!rsc->pa) {
                debug
                    ("failed to allocate carveout rsc: da %x, pa %x, len %x, flags %x\n",
                     rsc->da, rsc->pa, rsc->len, rsc->flags);
                return -ENOMEM;
        }
        rproc_config_pagetable(dev, rsc->da, rsc->pa, rsc->len);

        /*
         * Ok, this is non-standard.
         *
         * Sometimes we can't rely on the generic iommu-based DMA API
         * to dynamically allocate the device address and then set the IOMMU
         * tables accordingly, because some remote processors might
         * _require_ us to use hard coded device addresses that their
         * firmware was compiled with.
         *
         * In this case, we must use the IOMMU API directly and map
         * the memory to the device address as expected by the remote
         * processor.
         *
         * Obviously such remote processor devices should not be configured
         * to use the iommu-based DMA API: we expect 'dma' to contain the
         * physical address in this case.
         */
        mapping = kzalloc(sizeof(*mapping), GFP_KERNEL);
        if (!mapping)
                return -ENOMEM;

        /*
         * We'll need this info later when we'll want to unmap
         * everything (e.g. on shutdown).
         *
         * We can't trust the remote processor not to change the
         * resource table, so we must maintain this info independently.
         */
        mapping->dma = rsc->pa;
        mapping->da = rsc->da;
        mapping->len = rsc->len;
        rproc_add_res(dev, mapping);

        debug("carveout mapped 0x%x to 0x%x\n", rsc->da, rsc->pa);

        return 0;
}

#define RPROC_PAGE_SHIFT 12
#define RPROC_PAGE_SIZE  BIT(RPROC_PAGE_SHIFT)
#define RPROC_PAGE_ALIGN(x) (((x) + (RPROC_PAGE_SIZE - 1)) & ~(RPROC_PAGE_SIZE - 1))

static int alloc_vring(struct udevice *dev, struct fw_rsc_vdev *rsc, int i)
{
        struct fw_rsc_vdev_vring *vring = &rsc->vring[i];
        int size;
        int order;
        void *pa;

        debug("vdev rsc: vring%d: da %x, qsz %d, align %d\n",
              i, vring->da, vring->num, vring->align);

        /*
         * verify queue size and vring alignment are sane
         */
        if (!vring->num || !vring->align) {
                debug("invalid qsz (%d) or alignment (%d)\n", vring->num,
                      vring->align);
                return -EINVAL;
        }

        /*
         * actual size of vring (in bytes)
         */
        size = RPROC_PAGE_ALIGN(vring_size(vring->num, vring->align));
        order = vring->align >> RPROC_PAGE_SHIFT;

        pa = rproc_alloc_mem(dev, size, order);
        if (!pa) {
                debug("failed to allocate vring rsc\n");
                return -ENOMEM;
        }
        debug("alloc_mem(%#x, %d): %p\n", size, order, pa);
        vring->da = (uintptr_t)pa;

        return !pa;
}

static int handle_vdev(struct udevice *dev, struct fw_rsc_vdev *rsc,
                       int offset, int avail)
{
        int i, ret;
        void *pa;

        /*
         * make sure resource isn't truncated
         */
        if (sizeof(*rsc) + rsc->num_of_vrings * sizeof(struct fw_rsc_vdev_vring)
            + rsc->config_len > avail) {
                debug("vdev rsc is truncated\n");
                return -EINVAL;
        }

        /*
         * make sure reserved bytes are zeroes
         */
        if (rsc->reserved[0] || rsc->reserved[1]) {
                debug("vdev rsc has non zero reserved bytes\n");
                return -EINVAL;
        }

        debug("vdev rsc: id %d, dfeatures %x, cfg len %d, %d vrings\n",
              rsc->id, rsc->dfeatures, rsc->config_len, rsc->num_of_vrings);

        /*
         * we currently support only two vrings per rvdev
         */
        if (rsc->num_of_vrings > 2) {
                debug("too many vrings: %d\n", rsc->num_of_vrings);
                return -EINVAL;
        }

        /*
         * allocate the vrings
         */
        for (i = 0; i < rsc->num_of_vrings; i++) {
                ret = alloc_vring(dev, rsc, i);
                if (ret)
                        goto alloc_error;
        }

        pa = rproc_alloc_mem(dev, RPMSG_TOTAL_BUF_SPACE, 6);
        if (!pa) {
                debug("failed to allocate vdev rsc\n");
                return -ENOMEM;
        }
        debug("vring buffer alloc_mem(%#x, 6): %p\n", RPMSG_TOTAL_BUF_SPACE,
              pa);

        return 0;

 alloc_error:
        return ret;
}

/*
 * A lookup table for resource handlers. The indices are defined in
 * enum fw_resource_type.
 */
static handle_resource_t loading_handlers[RSC_LAST] = {
        [RSC_CARVEOUT] = (handle_resource_t)handle_carveout,
        [RSC_DEVMEM] = (handle_resource_t)handle_devmem,
        [RSC_TRACE] = (handle_resource_t)handle_trace,
        [RSC_VDEV] = (handle_resource_t)handle_vdev,
};

/*
 * handle firmware resource entries before booting the remote processor
 */
static int handle_resources(struct udevice *dev, int len,
                            handle_resource_t handlers[RSC_LAST])
{
        handle_resource_t handler;
        int ret = 0, i;

        for (i = 0; i < rsc_table->num; i++) {
                int offset = rsc_table->offset[i];
                struct fw_rsc_hdr *hdr = (void *)rsc_table + offset;
                int avail = len - offset - sizeof(*hdr);
                void *rsc = (void *)hdr + sizeof(*hdr);

                /*
                 * make sure table isn't truncated
                 */
                if (avail < 0) {
                        debug("rsc table is truncated\n");
                        return -EINVAL;
                }

                debug("rsc: type %d\n", hdr->type);

                if (hdr->type >= RSC_LAST) {
                        debug("unsupported resource %d\n", hdr->type);
                        continue;
                }

                handler = handlers[hdr->type];
                if (!handler)
                        continue;

                ret = handler(dev, rsc, offset + sizeof(*hdr), avail);
                if (ret)
                        break;
        }

        return ret;
}

static int
handle_intmem_to_l3_mapping(struct udevice *dev,
                            struct rproc_intmem_to_l3_mapping *l3_mapping)
{
        u32 i = 0;

        for (i = 0; i < l3_mapping->num_entries; i++) {
                struct l3_map *curr_map = &l3_mapping->mappings[i];
                struct rproc_mem_entry *mapping;

                mapping = kzalloc(sizeof(*mapping), GFP_KERNEL);
                if (!mapping)
                        return -ENOMEM;

                mapping->dma = curr_map->l3_addr;
                mapping->da = curr_map->priv_addr;
                mapping->len = curr_map->len;
                rproc_add_res(dev, mapping);
        }

        return 0;
}

static Elf32_Shdr *rproc_find_table(unsigned int addr)
{
        Elf32_Ehdr *ehdr;       /* Elf header structure pointer */
        Elf32_Shdr *shdr;       /* Section header structure pointer */
        Elf32_Shdr sectionheader;
        int i;
        u8 *elf_data;
        char *name_table;
        struct resource_table *ptable;

        ehdr = (Elf32_Ehdr *)(uintptr_t)addr;
        elf_data = (u8 *)ehdr;
        shdr = (Elf32_Shdr *)(elf_data + ehdr->e_shoff);
        memcpy(&sectionheader, &shdr[ehdr->e_shstrndx], sizeof(sectionheader));
        name_table = (char *)(elf_data + sectionheader.sh_offset);

        for (i = 0; i < ehdr->e_shnum; i++, shdr++) {
                memcpy(&sectionheader, shdr, sizeof(sectionheader));
                u32 size = sectionheader.sh_size;
                u32 offset = sectionheader.sh_offset;

                if (strcmp
                    (name_table + sectionheader.sh_name, ".resource_table"))
                        continue;

                ptable = (struct resource_table *)(elf_data + offset);

                /*
                 * make sure table has at least the header
                 */
                if (sizeof(struct resource_table) > size) {
                        debug("header-less resource table\n");
                        return NULL;
                }

                /*
                 * we don't support any version beyond the first
                 */
                if (ptable->ver != 1) {
                        debug("unsupported fw ver: %d\n", ptable->ver);
                        return NULL;
                }

                /*
                 * make sure reserved bytes are zeroes
                 */
                if (ptable->reserved[0] || ptable->reserved[1]) {
                        debug("non zero reserved bytes\n");
                        return NULL;
                }

                /*
                 * make sure the offsets array isn't truncated
                 */
                if (ptable->num * sizeof(ptable->offset[0]) +
                    sizeof(struct resource_table) > size) {
                        debug("resource table incomplete\n");
                        return NULL;
                }

                return shdr;
        }

        return NULL;
}

struct resource_table *rproc_find_resource_table(struct udevice *dev,
                                                 unsigned int addr,
                                                 int *tablesz)
{
        Elf32_Shdr *shdr;
        Elf32_Shdr sectionheader;
        struct resource_table *ptable;
        u8 *elf_data = (u8 *)(uintptr_t)addr;

        shdr = rproc_find_table(addr);
        if (!shdr) {
                debug("%s: failed to get resource section header\n", __func__);
                return NULL;
        }

        memcpy(&sectionheader, shdr, sizeof(sectionheader));
        ptable = (struct resource_table *)(elf_data + sectionheader.sh_offset);
        if (tablesz)
                *tablesz = sectionheader.sh_size;

        return ptable;
}

unsigned long rproc_parse_resource_table(struct udevice *dev, struct rproc *cfg)
{
        struct resource_table *ptable = NULL;
        int tablesz;
        int ret;
        unsigned long addr;

        addr = cfg->load_addr;

        ptable = rproc_find_resource_table(dev, addr, &tablesz);
        if (!ptable) {
                debug("%s : failed to find resource table\n", __func__);
                return 0;
        }

        debug("%s : found resource table\n", __func__);
        rsc_table = kzalloc(tablesz, GFP_KERNEL);
        if (!rsc_table) {
                debug("resource table alloc failed!\n");
                return 0;
        }

        /*
         * Copy the resource table into a local buffer before handling the
         * resource table.
         */
        memcpy(rsc_table, ptable, tablesz);
        if (cfg->intmem_to_l3_mapping)
                handle_intmem_to_l3_mapping(dev, cfg->intmem_to_l3_mapping);
        ret = handle_resources(dev, tablesz, loading_handlers);
        if (ret) {
                debug("handle_resources failed: %d\n", ret);
                return 0;
        }

        /*
         * Instead of trying to mimic the kernel flow of copying the
         * processed resource table into its post ELF load location in DDR
         * copying it into its original location.
         */
        memcpy(ptable, rsc_table, tablesz);
        free(rsc_table);
        rsc_table = NULL;

        return 1;
}