// SPDX-License-Identifier: GPL-2.0-only OR MIT
/* Copyright (c) 2024 Imagination Technologies Ltd. */

#include "pvr_device.h"
#include "pvr_fw.h"

#include <drm/drm_device.h>
#include <drm/drm_print.h>

#include <linux/elf.h>
#include <linux/string.h>
#include <linux/types.h>

/**
 * pvr_fw_process_elf_command_stream() - Process ELF firmware image and populate
 *                                       firmware sections
 * @pvr_dev: Device pointer.
 * @fw: Pointer to firmware image.
 * @fw_code_ptr: Pointer to FW code section.
 * @fw_data_ptr: Pointer to FW data section.
 * @fw_core_code_ptr: Pointer to FW coremem code section.
 * @fw_core_data_ptr: Pointer to FW coremem data section.
 *
 * Returns :
 *  * 0 on success, or
 *  * -EINVAL on any error in ELF command stream.
 */
int
pvr_fw_process_elf_command_stream(struct pvr_device *pvr_dev, const u8 *fw,
      u8 *fw_code_ptr, u8 *fw_data_ptr,
      u8 *fw_core_code_ptr, u8 *fw_core_data_ptr)
{
 struct elf32_hdr *header = (struct elf32_hdr *)fw;
 struct elf32_phdr *program_header = (struct elf32_phdr *)(fw + header->e_phoff);
 struct drm_device *drm_dev = from_pvr_device(pvr_dev);
 int err;

 for (u32 entry = 0; entry < header->e_phnum; entry++, program_header++) {
  void *write_addr;

  /* Only consider loadable entries in the ELF segment table */
  if (program_header->p_type != PT_LOAD)
   continue;

  err = pvr_fw_find_mmu_segment(pvr_dev, program_header->p_vaddr,
           program_header->p_memsz, fw_code_ptr, fw_data_ptr,
           fw_core_code_ptr, fw_core_data_ptr, &write_addr);
  if (err) {
   drm_err(drm_dev,
    "Addr 0x%x (size: %d) not found in any firmware segment",
    program_header->p_vaddr, program_header->p_memsz);
   return err;
  }

  /* Write to FW allocation only if available */
  if (write_addr) {
   memcpy(write_addr, fw + program_header->p_offset,
          program_header->p_filesz);

   memset((u8 *)write_addr + program_header->p_filesz, 0,
          program_header->p_memsz - program_header->p_filesz);
  }
 }

 return 0;
}