1 #ifndef __LINUX_BCM963XX_NVRAM_H__
2 #define __LINUX_BCM963XX_NVRAM_H__
3 
4 #include <linux/crc32.h>
5 #include <linux/if_ether.h>
6 #include <linux/sizes.h>
7 #include <linux/types.h>
8 
9 /*
10  * Broadcom BCM963xx SoC board nvram data structure.
11  *
12  * The nvram structure varies in size depending on the SoC board version. Use
13  * the appropriate minimum BCM963XX_NVRAM_*_SIZE define for the information
14  * you need instead of sizeof(struct bcm963xx_nvram) as this may change.
15  */
16 
17 #define BCM963XX_NVRAM_V4_SIZE		300
18 #define BCM963XX_NVRAM_V5_SIZE		(1 * SZ_1K)
19 
20 #define BCM963XX_DEFAULT_PSI_SIZE	64
21 
22 enum bcm963xx_nvram_nand_part {
23 	BCM963XX_NVRAM_NAND_PART_BOOT = 0,
24 	BCM963XX_NVRAM_NAND_PART_ROOTFS_1,
25 	BCM963XX_NVRAM_NAND_PART_ROOTFS_2,
26 	BCM963XX_NVRAM_NAND_PART_DATA,
27 	BCM963XX_NVRAM_NAND_PART_BBT,
28 
29 	__BCM963XX_NVRAM_NAND_NR_PARTS
30 };
31 
32 struct bcm963xx_nvram {
33 	u32	version;
34 	char	bootline[256];
35 	char	name[16];
36 	u32	main_tp_number;
37 	u32	psi_size;
38 	u32	mac_addr_count;
39 	u8	mac_addr_base[ETH_ALEN];
40 	u8	__reserved1[2];
41 	u32	checksum_v4;
42 
43 	u8	__reserved2[292];
44 	u32	nand_part_offset[__BCM963XX_NVRAM_NAND_NR_PARTS];
45 	u32	nand_part_size[__BCM963XX_NVRAM_NAND_NR_PARTS];
46 	u8	__reserved3[388];
47 	u32	checksum_v5;
48 };
49 
50 #define BCM963XX_NVRAM_NAND_PART_OFFSET(nvram, part) \
51 	bcm963xx_nvram_nand_part_offset(nvram, BCM963XX_NVRAM_NAND_PART_ ##part)
52 
53 static inline u64 __pure bcm963xx_nvram_nand_part_offset(
54 	const struct bcm963xx_nvram *nvram,
55 	enum bcm963xx_nvram_nand_part part)
56 {
57 	return nvram->nand_part_offset[part] * SZ_1K;
58 }
59 
60 #define BCM963XX_NVRAM_NAND_PART_SIZE(nvram, part) \
61 	bcm963xx_nvram_nand_part_size(nvram, BCM963XX_NVRAM_NAND_PART_ ##part)
62 
63 static inline u64 __pure bcm963xx_nvram_nand_part_size(
64 	const struct bcm963xx_nvram *nvram,
65 	enum bcm963xx_nvram_nand_part part)
66 {
67 	return nvram->nand_part_size[part] * SZ_1K;
68 }
69 
70 /*
71  * bcm963xx_nvram_checksum - Verify nvram checksum
72  *
73  * @nvram: pointer to full size nvram data structure
74  * @expected_out: optional pointer to store expected checksum value
75  * @actual_out: optional pointer to store actual checksum value
76  *
77  * Return: 0 if the checksum is valid, otherwise -EINVAL
78  */
79 static int __maybe_unused bcm963xx_nvram_checksum(
80 	const struct bcm963xx_nvram *nvram,
81 	u32 *expected_out, u32 *actual_out)
82 {
83 	u32 expected, actual;
84 	size_t len;
85 
86 	if (nvram->version <= 4) {
87 		expected = nvram->checksum_v4;
88 		len = BCM963XX_NVRAM_V4_SIZE - sizeof(u32);
89 	} else {
90 		expected = nvram->checksum_v5;
91 		len = BCM963XX_NVRAM_V5_SIZE - sizeof(u32);
92 	}
93 
94 	/*
95 	 * Calculate the CRC32 value for the nvram with a checksum value
96 	 * of 0 without modifying or copying the nvram by combining:
97 	 * - The CRC32 of the nvram without the checksum value
98 	 * - The CRC32 of a zero checksum value (which is also 0)
99 	 */
100 	actual = crc32_le_combine(
101 		crc32_le(~0, (u8 *)nvram, len), 0, sizeof(u32));
102 
103 	if (expected_out)
104 		*expected_out = expected;
105 
106 	if (actual_out)
107 		*actual_out = actual;
108 
109 	return expected == actual ? 0 : -EINVAL;
110 };
111 
112 #endif /* __LINUX_BCM963XX_NVRAM_H__ */
113