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