arch/x86/lib/ramtest.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2014 Google, Inc
   4  *
   5  * From Coreboot src/lib/ramtest.c
   6  */
   7
   8 #include <common.h>
   9 #include <asm/io.h>
  10 #include <asm/post.h>
  11
  12 static void write_phys(unsigned long addr, u32 value)
  13 {
  14 #if CONFIG_SSE2
  15         asm volatile(
  16                 "movnti %1, (%0)"
  17                 : /* outputs */
  18                 : "r" (addr), "r" (value) /* inputs */
  19                 : /* clobbers */
  20                 );
  21 #else
  22         writel(value, addr);
  23 #endif
  24 }
  25
  26 static u32 read_phys(unsigned long addr)
  27 {
  28         return readl(addr);
  29 }
  30
  31 static void phys_memory_barrier(void)
  32 {
  33 #if CONFIG_SSE2
  34         /* Needed for movnti */
  35         asm volatile(
  36                 "sfence"
  37                 :
  38                 :
  39                 : "memory"
  40         );
  41 #else
  42         asm volatile(""
  43                 :
  44                 :
  45                 : "memory");
  46 #endif
  47 }
  48
  49 void quick_ram_check(void)
  50 {
  51         int fail = 0;
  52         u32 backup;
  53
  54         backup = read_phys(CONFIG_RAMBASE);
  55         write_phys(CONFIG_RAMBASE, 0x55555555);
  56         phys_memory_barrier();
  57         if (read_phys(CONFIG_RAMBASE) != 0x55555555)
  58                 fail = 1;
  59         write_phys(CONFIG_RAMBASE, 0xaaaaaaaa);
  60         phys_memory_barrier();
  61         if (read_phys(CONFIG_RAMBASE) != 0xaaaaaaaa)
  62                 fail = 1;
  63         write_phys(CONFIG_RAMBASE, 0x00000000);
  64         phys_memory_barrier();
  65         if (read_phys(CONFIG_RAMBASE) != 0x00000000)
  66                 fail = 1;
  67         write_phys(CONFIG_RAMBASE, 0xffffffff);
  68         phys_memory_barrier();
  69         if (read_phys(CONFIG_RAMBASE) != 0xffffffff)
  70                 fail = 1;
  71
  72         write_phys(CONFIG_RAMBASE, backup);
  73         if (fail) {
  74                 post_code(POST_RAM_FAILURE);
  75                 panic("RAM INIT FAILURE!\n");
  76         }
  77         phys_memory_barrier();
  78 }