src/lib/dimm_info_util.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <device/dram/spd.h>
   4 #include <dimm_info_util.h>
   5 #include <smbios.h>
   6 #include <spd.h>
   7 #include <console/console.h>
   8
   9 uint8_t smbios_bus_width_to_spd_width(uint8_t ddr_type, uint16_t total_width,
  10                                       uint16_t data_width)
  11 {
  12         uint8_t out;
  13
  14         /* Lookup table as defined in the JEDEC Standard. */
  15         switch (data_width) {
  16         case 64:
  17                 out = MEMORY_BUS_WIDTH_64;
  18                 break;
  19         case 32:
  20                 out = MEMORY_BUS_WIDTH_32;
  21                 break;
  22         case 16:
  23                 out = MEMORY_BUS_WIDTH_16;
  24                 break;
  25         case 8:
  26                 out = MEMORY_BUS_WIDTH_8;
  27                 break;
  28         default:
  29                 printk(BIOS_NOTICE, "Unknown memory size %hu\n", data_width);
  30                 /*
  31                  * The SMBIOS spec says we should set 0xFFFF on an unknown
  32                  * value, but we don't have a way of passing that signal via SPD
  33                  * encoded values.
  34                  */
  35                 out = MEMORY_BUS_WIDTH_8;
  36                 break;
  37         }
  38
  39         uint16_t extension_bits = total_width - data_width;
  40
  41         switch (extension_bits) {
  42         case 8:
  43                 if (ddr_type == MEMORY_TYPE_DDR5 || ddr_type == MEMORY_TYPE_LPDDR5)
  44                         out |= SPD_ECC_8BIT_LP5_DDR5;
  45                 else
  46                         out |= SPD_ECC_8BIT;
  47                 break;
  48         case 0:
  49                 /* No extension bits */
  50                 break;
  51         default:
  52                 printk(BIOS_NOTICE, "Unknown number of extension bits %hu\n",
  53                        extension_bits);
  54                 break;
  55         }
  56
  57         return out;
  58 }
  59
  60 uint32_t smbios_memory_size_to_mib(uint16_t memory_size, uint32_t extended_size)
  61 {
  62         /* Memory size is unknown */
  63         if (memory_size == 0xFFFF)
  64                 return 0;
  65         /* (32 GiB - 1 MiB) or greater is expressed in the extended size. */
  66         else if (memory_size == 0x7FFF)
  67                 return extended_size;
  68         /* When the MSB is flipped, the value is specified in kilobytes */
  69         else if (memory_size & 0x8000)
  70                 return (memory_size ^ 0x8000) / KiB;
  71         /* Value contains MiB */
  72         else
  73                 return memory_size;
  74 }
  75
  76 uint8_t smbios_form_factor_to_spd_mod_type(smbios_memory_type memory_type,
  77                 smbios_memory_form_factor form_factor)
  78 {
  79         return convert_form_factor_to_module_type(memory_type, form_factor);
  80 }