arch/x86/lib/ramtest.c

   1 /*
   2  * Copyright (c) 2014 Google, Inc
   3  *
   4  * From Coreboot src/lib/ramtest.c
   5  *
   6  * SPDX-License-Identifier:     GPL-2.0
   7  */
   8
   9 #include <common.h>
  10 #include <asm/io.h>
  11 #include <asm/post.h>
  12
  13 static void write_phys(unsigned long addr, u32 value)
  14 {
  15 #if CONFIG_SSE2
  16         asm volatile(
  17                 "movnti %1, (%0)"
  18                 : /* outputs */
  19                 : "r" (addr), "r" (value) /* inputs */
  20                 : /* clobbers */
  21                 );
  22 #else
  23         writel(value, addr);
  24 #endif
  25 }
  26
  27 static u32 read_phys(unsigned long addr)
  28 {
  29         return readl(addr);
  30 }
  31
  32 static void phys_memory_barrier(void)
  33 {
  34 #if CONFIG_SSE2
  35         /* Needed for movnti */
  36         asm volatile(
  37                 "sfence"
  38                 :
  39                 :
  40                 : "memory"
  41         );
  42 #else
  43         asm volatile(""
  44                 :
  45                 :
  46                 : "memory");
  47 #endif
  48 }
  49
  50 void quick_ram_check(void)
  51 {
  52         int fail = 0;
  53         u32 backup;
  54
  55         backup = read_phys(CONFIG_RAMBASE);
  56         write_phys(CONFIG_RAMBASE, 0x55555555);
  57         phys_memory_barrier();
  58         if (read_phys(CONFIG_RAMBASE) != 0x55555555)
  59                 fail = 1;
  60         write_phys(CONFIG_RAMBASE, 0xaaaaaaaa);
  61         phys_memory_barrier();
  62         if (read_phys(CONFIG_RAMBASE) != 0xaaaaaaaa)
  63                 fail = 1;
  64         write_phys(CONFIG_RAMBASE, 0x00000000);
  65         phys_memory_barrier();
  66         if (read_phys(CONFIG_RAMBASE) != 0x00000000)
  67                 fail = 1;
  68         write_phys(CONFIG_RAMBASE, 0xffffffff);
  69         phys_memory_barrier();
  70         if (read_phys(CONFIG_RAMBASE) != 0xffffffff)
  71                 fail = 1;
  72
  73         write_phys(CONFIG_RAMBASE, backup);
  74         if (fail) {
  75                 post_code(POST_RAM_FAILURE);
  76                 panic("RAM INIT FAILURE!\n");
  77         }
  78         phys_memory_barrier();
  79 }