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 <cpu_func.h>
8 #include <asm/cache.h>
9 #include <asm/global_data.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 
bootcount_store(ulong a)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 
bootcount_load(void)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 }
66