drivers/bootcount/bootcount_ram.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * (C) Copyright 2010
   4  * Heiko Schocher, DENX Software Engineering, hs@denx.de.
   5  */
   6
   7 #include <common.h>
   8 #include <cpu_func.h>
   9 #include <asm/cache.h>
  10 #include <asm/io.h>
  11
  12 DECLARE_GLOBAL_DATA_PTR;
  13
  14 const ulong patterns[]      = { 0x00000000,
  15                                 0xFFFFFFFF,
  16                                 0xFF00FF00,
  17                                 0x0F0F0F0F,
  18                                 0xF0F0F0F0};
  19 const ulong NBR_OF_PATTERNS = sizeof(patterns) / sizeof(*patterns);
  20 const ulong OFFS_PATTERN    = 3;
  21 const ulong REPEAT_PATTERN  = 1000;
  22
  23 void bootcount_store(ulong a)
  24 {
  25         ulong *save_addr;
  26         ulong size = 0;
  27         int i;
  28
  29         for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++)
  30                 size += gd->bd->bi_dram[i].size;
  31         save_addr = (ulong *)(size - BOOTCOUNT_ADDR);
  32         writel(a, save_addr);
  33         writel(CONFIG_SYS_BOOTCOUNT_MAGIC, &save_addr[1]);
  34
  35         for (i = 0; i < REPEAT_PATTERN; i++)
  36                 writel(patterns[i % NBR_OF_PATTERNS],
  37                         &save_addr[i + OFFS_PATTERN]);
  38
  39         /* Make sure the data is written to RAM */
  40         flush_dcache_range((ulong)&save_addr[0],
  41                            (((ulong)&save_addr[REPEAT_PATTERN + OFFS_PATTERN] &
  42                              ~(ARCH_DMA_MINALIGN - 1)) + ARCH_DMA_MINALIGN));
  43 }
  44
  45 ulong bootcount_load(void)
  46 {
  47         ulong *save_addr;
  48         ulong size = 0;
  49         ulong counter = 0;
  50         int i, tmp;
  51
  52         for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++)
  53                 size += gd->bd->bi_dram[i].size;
  54         save_addr = (ulong *)(size - BOOTCOUNT_ADDR);
  55
  56         counter = readl(&save_addr[0]);
  57
  58         /* Is the counter reliable, check in the big pattern for bit errors */
  59         for (i = 0; (i < REPEAT_PATTERN) && (counter != 0); i++) {
  60                 tmp = readl(&save_addr[i + OFFS_PATTERN]);
  61                 if (tmp != patterns[i % NBR_OF_PATTERNS])
  62                         counter = 0;
  63         }
  64         return counter;
  65 }