1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_BCM963XX_NVRAM_H__
3 #define __LINUX_BCM963XX_NVRAM_H__
4 
5 #include <linux/crc32.h>
6 #include <linux/if_ether.h>
7 #include <linux/sizes.h>
8 #include <linux/types.h>
9 
10 /*
11  * Broadcom BCM963xx SoC board nvram data structure.
12  *
13  * The nvram structure varies in size depending on the SoC board version. Use
14  * the appropriate minimum BCM963XX_NVRAM_*_SIZE define for the information
15  * you need instead of sizeof(struct bcm963xx_nvram) as this may change.
16  */
17 
18 #define BCM963XX_NVRAM_V4_SIZE		300
19 #define BCM963XX_NVRAM_V5_SIZE		(1 * SZ_1K)
20 
21 #define BCM963XX_DEFAULT_PSI_SIZE	64
22 
23 enum bcm963xx_nvram_nand_part {
24 	BCM963XX_NVRAM_NAND_PART_BOOT = 0,
25 	BCM963XX_NVRAM_NAND_PART_ROOTFS_1,
26 	BCM963XX_NVRAM_NAND_PART_ROOTFS_2,
27 	BCM963XX_NVRAM_NAND_PART_DATA,
28 	BCM963XX_NVRAM_NAND_PART_BBT,
29 
30 	__BCM963XX_NVRAM_NAND_NR_PARTS
31 };
32 
33 struct bcm963xx_nvram {
34 	u32	version;
35 	char	bootline[256];
36 	char	name[16];
37 	u32	main_tp_number;
38 	u32	psi_size;
39 	u32	mac_addr_count;
40 	u8	mac_addr_base[ETH_ALEN];
41 	u8	__reserved1[2];
42 	u32	checksum_v4;
43 
44 	u8	__reserved2[292];
45 	u32	nand_part_offset[__BCM963XX_NVRAM_NAND_NR_PARTS];
46 	u32	nand_part_size[__BCM963XX_NVRAM_NAND_NR_PARTS];
47 	u8	__reserved3[388];
48 	u32	checksum_v5;
49 };
50 
51 #define BCM963XX_NVRAM_NAND_PART_OFFSET(nvram, part) \
52 	bcm963xx_nvram_nand_part_offset(nvram, BCM963XX_NVRAM_NAND_PART_ ##part)
53 
54 static inline u64 __pure bcm963xx_nvram_nand_part_offset(
55 	const struct bcm963xx_nvram *nvram,
56 	enum bcm963xx_nvram_nand_part part)
57 {
58 	return nvram->nand_part_offset[part] * SZ_1K;
59 }
60 
61 #define BCM963XX_NVRAM_NAND_PART_SIZE(nvram, part) \
62 	bcm963xx_nvram_nand_part_size(nvram, BCM963XX_NVRAM_NAND_PART_ ##part)
63 
64 static inline u64 __pure bcm963xx_nvram_nand_part_size(
65 	const struct bcm963xx_nvram *nvram,
66 	enum bcm963xx_nvram_nand_part part)
67 {
68 	return nvram->nand_part_size[part] * SZ_1K;
69 }
70 
71 /*
72  * bcm963xx_nvram_checksum - Verify nvram checksum
73  *
74  * @nvram: pointer to full size nvram data structure
75  * @expected_out: optional pointer to store expected checksum value
76  * @actual_out: optional pointer to store actual checksum value
77  *
78  * Return: 0 if the checksum is valid, otherwise -EINVAL
79  */
80 static int __maybe_unused bcm963xx_nvram_checksum(
81 	const struct bcm963xx_nvram *nvram,
82 	u32 *expected_out, u32 *actual_out)
83 {
84 	u32 expected, actual;
85 	size_t len;
86 
87 	if (nvram->version <= 4) {
88 		expected = nvram->checksum_v4;
89 		len = BCM963XX_NVRAM_V4_SIZE - sizeof(u32);
90 	} else {
91 		expected = nvram->checksum_v5;
92 		len = BCM963XX_NVRAM_V5_SIZE - sizeof(u32);
93 	}
94 
95 	/*
96 	 * Calculate the CRC32 value for the nvram with a checksum value
97 	 * of 0 without modifying or copying the nvram by combining:
98 	 * - The CRC32 of the nvram without the checksum value
99 	 * - The CRC32 of a zero checksum value (which is also 0)
100 	 */
101 	actual = crc32_le_combine(
102 		crc32_le(~0, (u8 *)nvram, len), 0, sizeof(u32));
103 
104 	if (expected_out)
105 		*expected_out = expected;
106 
107 	if (actual_out)
108 		*actual_out = actual;
109 
110 	return expected == actual ? 0 : -EINVAL;
111 };
112 
113 #endif /* __LINUX_BCM963XX_NVRAM_H__ */
114