freebsd-dev/sys/dev/bhnd/nvram/bhnd_nvram_common.h

/*-
 * Copyright (c) 2015-2016 Landon Fuller <landonf@FreeBSD.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
 *    redistribution must be conditioned upon including a substantially
 *    similar Disclaimer requirement for further binary redistribution.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGES.
 * 
 * $FreeBSD$
 */

#ifndef _BHND_NVRAM_BHND_NVRAM_COMMON_H_
#define _BHND_NVRAM_BHND_NVRAM_COMMON_H_

#include <sys/param.h>
#include <sys/malloc.h>

#include "bhnd_nvram.h"

struct bhnd_nvram_tuple;
struct bhnd_nvram_varmap;

struct bhnd_nvram_vardefn;

MALLOC_DECLARE(M_BHND_NVRAM);

extern const uint8_t bhnd_nvram_crc8_tab[];

#define	BHND_NVRAM_CRC8_INITIAL	0xFF		/**< Initial bhnd_nvram_crc8 value */
#define	BHND_NVRAM_CRC8_VALID	0x9F		/**< Valid CRC-8 checksum */
#define	BHND_SPROMREV_MAX	UINT8_MAX	/**< maximum supported SPROM revision */


/** NVRAM data type string representations */
typedef enum {
	BHND_NVRAM_SFMT_HEX	= 1,	/**< hex format */
	BHND_NVRAM_SFMT_DEC	= 2,	/**< decimal format */
	BHND_NVRAM_SFMT_MACADDR	= 3,	/**< mac address (canonical form, hex octets,
					     separated with ':') */
	BHND_NVRAM_SFMT_LEDDC	= 4,	/**< LED PWM duty-cycle (2 bytes -- on/off) */
	BHND_NVRAM_SFMT_CCODE	= 5	/**< count code format (2-3 ASCII chars, or hex string) */
} bhnd_nvram_sfmt;

size_t				 bhnd_nvram_type_width(bhnd_nvram_type type);
const char			*bhnd_nvram_type_fmt(bhnd_nvram_type type,
				     bhnd_nvram_sfmt sfmt, size_t elem_num);

const struct bhnd_nvram_vardefn	*bhnd_nvram_find_vardefn(const char *varname);

bool				 bhnd_nvram_validate_name(const char *name,
				     size_t name_len);
int				 bhnd_nvram_parse_octet_string(
				     const char *value, size_t value_len,
				     void *buf, size_t *len,
				     bhnd_nvram_type type);

int				 bhnd_nvram_varmap_init(
				     struct bhnd_nvram_varmap *map,
				     size_t nelements, int flags);
void				 bhnd_nvram_varmap_free(
				     struct bhnd_nvram_varmap *map);
int				 bhnd_nvram_varmap_add(
				     struct bhnd_nvram_varmap *map,
				     const char *name, const char *value,
				     size_t value_len);
int				 bhnd_nvram_varmap_remove(
				     struct bhnd_nvram_varmap *map,
				     const char *name);
struct bhnd_nvram_tuple		*bhnd_nvram_varmap_find(
				    struct bhnd_nvram_varmap *map,
				    const char *name, size_t name_len);
bool				 bhnd_nvram_varmap_contains(
				    struct bhnd_nvram_varmap *map,
				    const char *name, size_t name_len);

struct bhnd_nvram_tuple		*bhnd_nvram_tuple_alloc(const char *name,
				     const char *value);
void				 bhnd_nvram_tuple_free(
				     struct bhnd_nvram_tuple *tuple);

/** NVRAM variable flags */
enum {
	BHND_NVRAM_VF_ARRAY	= (1<<0),	/**< variable is an array */
	BHND_NVRAM_VF_MFGINT	= (1<<1),	/**< mfg-internal variable; should not be externally visible */
	BHND_NVRAM_VF_IGNALL1	= (1<<2)	/**< hide variable if its value has all bits set. */
};

/** SPROM revision compatibility declaration */
struct bhnd_sprom_compat {
	uint8_t		first;	/**< first compatible SPROM revision */
	uint8_t		last;	/**< last compatible SPROM revision, or BHND_SPROMREV_MAX */
};

/** SPROM value descriptor */
struct bhnd_sprom_offset {
	uint16_t	offset;	/**< byte offset within SPROM */
	bool		cont:1;	/**< value should be bitwise OR'd with the
				  *  previous offset descriptor */
	bhnd_nvram_type	type:7;	/**< data type */
	int8_t		shift;	/**< shift to be applied to the value */
	uint32_t	mask;	/**< mask to be applied to the value(s) */
};

/** SPROM-specific variable definition */
struct bhnd_sprom_vardefn {
	struct bhnd_sprom_compat	 compat;	/**< sprom compatibility declaration */
	const struct bhnd_sprom_offset	*offsets;	/**< offset descriptors */
	size_t				 num_offsets;	/**< number of offset descriptors */
};

/** NVRAM variable definition */
struct bhnd_nvram_vardefn {
	const char		*name;	  	/**< variable name */
	bhnd_nvram_type		 type;	 	/**< base data type */
	bhnd_nvram_sfmt		 sfmt;		/**< string format */
	uint32_t		 flags;		/**< BHND_NVRAM_VF_* flags */

	const struct bhnd_sprom_vardefn	*sp_defs;	/**< SPROM-specific variable definitions */
	size_t				 num_sp_defs;	/**< number of sprom definitions */
};

/**
 * NVRAM value tuple.
 */
struct bhnd_nvram_tuple {
	char	*name;		/**< variable name. */
	size_t	 name_len;	/**< variable length. */
	char	*value;		/**< value, or NULL if this tuple represents variable
				     deletion */
	size_t	 value_len;	/**< value length. */

	LIST_ENTRY(bhnd_nvram_tuple) t_link;
};

LIST_HEAD(bhnd_nvram_tuples, bhnd_nvram_tuple);

/** NVRAM tuple hash table */
struct bhnd_nvram_varmap {
	struct bhnd_nvram_tuples	*table;		/**< hash buckets */
	u_long				 mask;		/**< hash index mask */
};

/**
 * Calculate CRC-8 over @p buf.
 * 
 * @param buf input buffer
 * @param size buffer size
 * @param crc last computed crc, or BHND_NVRAM_CRC8_INITIAL
 */
static inline uint8_t
bhnd_nvram_crc8(const void *buf, size_t size, uint8_t crc)
{
	const uint8_t *p = (const uint8_t *)buf;
	while (size--)
		crc = bhnd_nvram_crc8_tab[(crc ^ *p++)];

	return (crc);
}

#endif /* _BHND_NVRAM_BHND_NVRAM_COMMON_H_ */