src/soc/intel/alderlake/bootblock/update_descriptor.c

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2
   3 #include <cf9_reset.h>
   4 #include <commonlib/region.h>
   5 #include <console/console.h>
   6 #include <cpu/cpu.h>
   7 #include <cpu/intel/cpu_ids.h>
   8 #include <device/mmio.h>
   9 #include <fmap.h>
  10 #include <intelblocks/pmclib.h>
  11 #include <soc/bootblock.h>
  12 #include <types.h>
  13
  14 /* Flash Master 1 : HOST/BIOS */
  15 #define FLMSTR1                 0x80
  16
  17 /* Flash signature Offset */
  18 #define FLASH_SIGN_OFFSET       0x10
  19 #define FLMSTR_WR_SHIFT_V2      20
  20 #define FLASH_VAL_SIGN          0xFF0A55A
  21
  22 /* It checks whether host (Flash Master 1) has write access to the Descriptor Region or not */
  23 static bool is_descriptor_writeable(uint8_t *desc)
  24 {
  25         /* Check flash has valid signature */
  26         if (read32p(desc + FLASH_SIGN_OFFSET) != FLASH_VAL_SIGN) {
  27                 printk(BIOS_ERR, "Flash Descriptor is not valid\n");
  28                 return false;
  29         }
  30
  31         /* Check host has write access to the Descriptor Region */
  32         if (!((read32p(desc + FLMSTR1) >> FLMSTR_WR_SHIFT_V2) & BIT(0))) {
  33                 printk(BIOS_ERR, "Host doesn't have write access to Descriptor Region\n");
  34                 return false;
  35         }
  36
  37         return true;
  38 }
  39
  40 void configure_descriptor(struct descriptor_byte *bytes, size_t num)
  41 {
  42         uint8_t si_desc_buf[CONFIG_SI_DESC_REGION_SZ];
  43         struct region_device desc_rdev;
  44         bool update_required = false;
  45
  46         if (fmap_locate_area_as_rdev_rw(CONFIG_SI_DESC_REGION, &desc_rdev) < 0) {
  47                 printk(BIOS_ERR, "Failed to locate %s in the FMAP\n", CONFIG_SI_DESC_REGION);
  48                 return;
  49         }
  50
  51         if (rdev_readat(&desc_rdev, si_desc_buf, 0, CONFIG_SI_DESC_REGION_SZ) !=
  52                         CONFIG_SI_DESC_REGION_SZ) {
  53                 printk(BIOS_ERR, "Failed to read Descriptor Region from SPI Flash\n");
  54                 return;
  55         }
  56
  57         if (!is_descriptor_writeable(si_desc_buf))
  58                 return;
  59
  60         for (size_t i = 0; i < num; i++) {
  61                 size_t offset = bytes[i].offset;
  62                 uint8_t desired_value = bytes[i].desired_value;
  63                 printk(BIOS_DEBUG, "Current value of Descriptor byte 0x%zx: 0x%x\n",
  64                        offset, si_desc_buf[offset]);
  65                 if (si_desc_buf[offset] != desired_value) {
  66                         update_required = true;
  67                         si_desc_buf[offset] = desired_value;
  68                 }
  69         }
  70
  71         if (!update_required) {
  72                 printk(BIOS_DEBUG, "Update of Descriptor is not required!\n");
  73                 return;
  74         }
  75
  76         if (rdev_eraseat(&desc_rdev, 0, CONFIG_SI_DESC_REGION_SZ) != CONFIG_SI_DESC_REGION_SZ) {
  77                 printk(BIOS_ERR, "Failed to erase Descriptor Region area\n");
  78                 return;
  79         }
  80
  81         if (rdev_writeat(&desc_rdev, si_desc_buf, 0, CONFIG_SI_DESC_REGION_SZ)
  82                         != CONFIG_SI_DESC_REGION_SZ) {
  83                 printk(BIOS_ERR, "Failed to update Descriptor Region\n");
  84                 return;
  85         }
  86
  87         printk(BIOS_DEBUG, "Update of Descriptor successful, trigger GLOBAL RESET\n");
  88
  89         pmc_global_reset_enable(true);
  90         do_full_reset();
  91         die("Failed to trigger GLOBAL RESET\n");
  92 }