bcm963xx_nvram.h

  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
 23enum 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
 33struct 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
 54static 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
 64static 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 */
 80static int __maybe_unused bcm963xx_nvram_checksum(
 81	const struct bcm963xx_nvram *nvram,
 82	u32 *expected_out, u32 *actual_out)
 83{
 84	const u32 zero = 0;
 85	u32 expected, actual;
 86	size_t len;
 87
 88	if (nvram->version <= 4) {
 89		expected = nvram->checksum_v4;
 90		len = BCM963XX_NVRAM_V4_SIZE;
 91	} else {
 92		expected = nvram->checksum_v5;
 93		len = BCM963XX_NVRAM_V5_SIZE;
 94	}
 95
 96	/* Calculate the CRC32 of the nvram with the checksum field set to 0. */
 97	actual = crc32_le(~0, nvram, len - sizeof(u32));
 98	actual = crc32_le(actual, &zero, sizeof(u32));
 99
100	if (expected_out)
101		*expected_out = expected;
102
103	if (actual_out)
104		*actual_out = actual;
105
106	return expected == actual ? 0 : -EINVAL;
107};
108
109#endif /* __LINUX_BCM963XX_NVRAM_H__ */