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/global_data.h>
  11 #include <asm/io.h>
  12
  13 DECLARE_GLOBAL_DATA_PTR;
  14
  15 const ulong patterns[]      = { 0x00000000,
  16                                 0xFFFFFFFF,
  17                                 0xFF00FF00,
  18                                 0x0F0F0F0F,
  19                                 0xF0F0F0F0};
  20 const ulong NBR_OF_PATTERNS = sizeof(patterns) / sizeof(*patterns);
  21 const ulong OFFS_PATTERN    = 3;
  22 const ulong REPEAT_PATTERN  = 1000;
  23
  24 void bootcount_store(ulong a)
  25 {
  26         ulong *save_addr;
  27         ulong size = 0;
  28         int i;
  29
  30         for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++)
  31                 size += gd->bd->bi_dram[i].size;
  32         save_addr = (ulong *)(size - BOOTCOUNT_ADDR);
  33         writel(a, save_addr);
  34         writel(CONFIG_SYS_BOOTCOUNT_MAGIC, &save_addr[1]);
  35
  36         for (i = 0; i < REPEAT_PATTERN; i++)
  37                 writel(patterns[i % NBR_OF_PATTERNS],
  38                         &save_addr[i + OFFS_PATTERN]);
  39
  40         /* Make sure the data is written to RAM */
  41         flush_dcache_range((ulong)&save_addr[0],
  42                            (((ulong)&save_addr[REPEAT_PATTERN + OFFS_PATTERN] &
  43                              ~(ARCH_DMA_MINALIGN - 1)) + ARCH_DMA_MINALIGN));
  44 }
  45
  46 ulong bootcount_load(void)
  47 {
  48         ulong *save_addr;
  49         ulong size = 0;
  50         ulong counter = 0;
  51         int i, tmp;
  52
  53         for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++)
  54                 size += gd->bd->bi_dram[i].size;
  55         save_addr = (ulong *)(size - BOOTCOUNT_ADDR);
  56
  57         counter = readl(&save_addr[0]);
  58
  59         /* Is the counter reliable, check in the big pattern for bit errors */
  60         for (i = 0; (i < REPEAT_PATTERN) && (counter != 0); i++) {
  61                 tmp = readl(&save_addr[i + OFFS_PATTERN]);
  62                 if (tmp != patterns[i % NBR_OF_PATTERNS])
  63                         counter = 0;
  64         }
  65         return counter;
  66 }