blkman.h

newos is new operation system

#ifndef __BLKMAN_H__
#define __BLKMAN_H__

#include <kernel/fs/devfs.h>

// shamelessly pinched from BeOS
// some of them seem to be kind of useless;
// especially I don't like one error having multiple names
// like TIMEOUT or NO_MEMORY
#define ERR_DEV_GENERAL					-5120

#define ERR_DEV_INVALID_IOCTL			ERR_DEV_GENERAL - 1
#define ERR_DEV_NO_MEMORY				ERR_DEV_GENERAL - 2
#define ERR_DEV_BAD_DRIVE_NUM			ERR_DEV_GENERAL - 3
#define ERR_DEV_NO_MEDIA				ERR_DEV_GENERAL - 4
#define ERR_DEV_UNREADABLE				ERR_DEV_GENERAL - 5
#define ERR_DEV_FORMAT_ERROR			ERR_DEV_GENERAL - 6
#define ERR_DEV_TIMEOUT					ERR_DEV_GENERAL - 7
#define ERR_DEV_RECALIBRATE_ERROR		ERR_DEV_GENERAL - 8
#define ERR_DEV_SEEK_ERROR				ERR_DEV_GENERAL - 9
#define ERR_DEV_ID_ERROR				ERR_DEV_GENERAL - 10
#define ERR_DEV_READ_ERROR				ERR_DEV_GENERAL - 11
#define ERR_DEV_WRITE_ERROR				ERR_DEV_GENERAL - 12
#define ERR_DEV_NOT_READY				ERR_DEV_GENERAL - 13
#define ERR_DEV_MEDIA_CHANGED			ERR_DEV_GENERAL - 14
#define ERR_DEV_MEDIA_CHANGE_REQUESTED	ERR_DEV_GENERAL - 15
#define ERR_DEV_RESOURCE_CONFLICT		ERR_DEV_GENERAL - 16
#define ERR_DEV_CONFIGURATION_ERROR		ERR_DEV_GENERAL - 17
#define ERR_DEV_DISABLED_BY_USER		ERR_DEV_GENERAL - 18
#define ERR_DEV_DOOR_OPEN				ERR_DEV_GENERAL - 19

typedef struct blkdev_info *blkdev_cookie;
typedef struct blkdev_handle_info *blkdev_handle_cookie;
typedef struct blkman_device_info *blkman_dev_cookie;



typedef struct blkdev_params {
	// these properties can be changed
	uint block_size;
	uint64 capacity;

	// these entries cannot be changed later on
	size_t alignment;				// this must 2^i-1 for some i
	size_t max_blocks;
	size_t dma_boundary;
	bool dma_boundary_solid;
	int max_sg_num;
} blkdev_params;

typedef struct phys_vec {
	addr_t start;					// physical address
	size_t len;
} phys_vec;

// two reason why to use array of size 1:
// 1. zero-sized arrays aren't standard C
// 2. it's handy if you need a temporary global variable with num=1
typedef struct phys_vecs {
	size_t num;
	size_t total_len;
	phys_vec vec[1];
} phys_vecs;

#define PHYS_VECS(name, size) \
	uint8 name[sizeof(phys_vecs) + (size - 1)*sizeof(phys_vec)]; \
	phys_vecs *name = (phys_vecs *)name

enum {
	// if the media got changed, all read/write accesses must be rejected
	// until get_media_status gets called
	IOCTL_GET_MEDIA_STATUS	= 0x8000
};


#define BLKMAN_MODULE_NAME "generic/blkman/v1"

typedef struct blkdev_interface {
	// iovecs are physical address here
	// pos and num_blocks are in blocks; bytes_transferred in bytes
	// vecs are guaranteed to be sufficient
	int (*open)( blkdev_cookie cookie, blkdev_handle_cookie *handle );
	int (*close)( blkdev_handle_cookie handle );

	int (*read) ( blkdev_handle_cookie handle, const phys_vecs *vecs,
		off_t pos, size_t num_blocks, size_t *bytes_transferred );
	int (*write) ( blkdev_handle_cookie handle, const phys_vecs *vecs,
		off_t pos, size_t num_blocks, size_t *bytes_transferred );

	int (*ioctl)( blkdev_handle_cookie handle, int op, void *buf, size_t len );
} blkdev_interface;

typedef struct blkman_interface {
	int (*register_blkdev)( blkdev_interface *interface, blkdev_cookie cookie,
		const char *name, blkman_dev_cookie *blkman_cookie,
		blkdev_params *params );
	int (*unregister_blkdev)( blkman_dev_cookie blkman_cookie );

	int (*set_capacity)( blkman_dev_cookie blkman_cookie, uint64 capacity, size_t block_size );
} blkman_interface;

#endif