sanboot.h

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#ifndef _IPXE_SANBOOT_H
#define _IPXE_SANBOOT_H

/** @file
 *
 * iPXE sanboot API
 *
 * The sanboot API provides methods for hooking, unhooking,
 * describing, and booting from SAN devices.
 */

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );

#include <ipxe/api.h>
#include <ipxe/refcnt.h>
#include <ipxe/list.h>
#include <ipxe/uri.h>
#include <ipxe/retry.h>
#include <ipxe/process.h>
#include <ipxe/blockdev.h>
#include <ipxe/acpi.h>
#include <ipxe/uuid.h>
#include <config/sanboot.h>

/**
 * Default SAN drive number
 *
 * The drive number is an externally defined concept only in a BIOS
 * environment, where it represents the INT13 drive number (0x80 for
 * the first hard disk).  We retain it in other environments to allow
 * for a simple way for iPXE commands to refer to SAN drives.
 */
#define SAN_DEFAULT_DRIVE 0x80

/** A SAN path */
struct san_path {
        /** Containing SAN device */
        struct san_device *sandev;
        /** Path index */
        unsigned int index;
        /** SAN device URI */
        struct uri *uri;
        /** List of open/closed paths */
        struct list_head list;

        /** Underlying block device interface */
        struct interface block;
        /** Process */
        struct process process;
        /** Path status */
        int path_rc;

        /** ACPI descriptor (if applicable) */
        struct acpi_descriptor *desc;
};

/** A SAN device */
struct san_device {
        /** Reference count */
        struct refcnt refcnt;
        /** List of SAN devices */
        struct list_head list;

        /** Drive number */
        unsigned int drive;
        /** Flags */
        unsigned int flags;

        /** Command interface */
        struct interface command;
        /** Command timeout timer */
        struct retry_timer timer;
        /** Command status */
        int command_rc;

        /** Raw block device capacity */
        struct block_device_capacity capacity;
        /** Block size shift
         *
         * To allow for emulation of CD-ROM access, this represents
         * the left-shift required to translate from exposed logical
         * I/O blocks to underlying blocks.
         */
        unsigned int blksize_shift;
        /** Drive is a CD-ROM */
        int is_cdrom;

        /** Driver private data */
        void *priv;

        /** Number of paths */
        unsigned int paths;
        /** Current active path */
        struct san_path *active;
        /** List of opened SAN paths */
        struct list_head opened;
        /** List of closed SAN paths */
        struct list_head closed;
        /** SAN paths */
        struct san_path path[0];
};

/** SAN device flags */
enum san_device_flags {
        /** Device should not be included in description tables */
        SAN_NO_DESCRIBE = 0x0001,
};

/** SAN boot configuration parameters */
struct san_boot_config {
        /** Boot filename (or NULL to use default) */
        const char *filename;
        /** Required extra filename (or NULL to ignore) */
        const char *extra;
        /** Filesystem label (or NULL to ignore volume label) */
        const char *label;
        /** UUID (or NULL to ignore UUID) */
        union uuid *uuid;
};

/**
 * Calculate static inline sanboot API function name
 *
 * @v _prefix           Subsystem prefix
 * @v _api_func         API function
 * @ret _subsys_func    Subsystem API function
 */
#define SANBOOT_INLINE( _subsys, _api_func ) \
        SINGLE_API_INLINE ( SANBOOT_PREFIX_ ## _subsys, _api_func )

/**
 * Provide a sanboot API implementation
 *
 * @v _prefix           Subsystem prefix
 * @v _api_func         API function
 * @v _func             Implementing function
 */
#define PROVIDE_SANBOOT( _subsys, _api_func, _func ) \
        PROVIDE_SINGLE_API ( SANBOOT_PREFIX_ ## _subsys, _api_func, _func )

/**
 * Provide a static inline sanboot API implementation
 *
 * @v _prefix           Subsystem prefix
 * @v _api_func         API function
 */
#define PROVIDE_SANBOOT_INLINE( _subsys, _api_func ) \
        PROVIDE_SINGLE_API_INLINE ( SANBOOT_PREFIX_ ## _subsys, _api_func )

/* Include all architecture-independent sanboot API headers */
#include <ipxe/null_sanboot.h>
#include <ipxe/dummy_sanboot.h>
#include <ipxe/efi/efi_block.h>

/* Include all architecture-dependent sanboot API headers */
#include <bits/sanboot.h>

/**
 * Hook SAN device
 *
 * @v drive             Drive number
 * @v uris              List of URIs
 * @v count             Number of URIs
 * @v flags             Flags
 * @ret drive           Drive number, or negative error
 */
int san_hook ( unsigned int drive, struct uri **uris, unsigned int count,
               unsigned int flags );

/**
 * Unhook SAN device
 *
 * @v drive             Drive number
 */
void san_unhook ( unsigned int drive );

/**
 * Attempt to boot from a SAN device
 *
 * @v drive             Drive number
 * @v config            Boot configuration parameters
 * @ret rc              Return status code
 */
int san_boot ( unsigned int drive, struct san_boot_config *config );

/**
 * Describe SAN devices for SAN-booted operating system
 *
 * @ret rc              Return status code
 */
int san_describe ( void );

extern struct list_head san_devices;

/** Iterate over all SAN devices */
#define for_each_sandev( sandev ) \
        list_for_each_entry ( (sandev), &san_devices, list )

/** There exist some SAN devices
 *
 * @ret existence       Existence of SAN devices
 */
static inline int have_sandevs ( void ) {
        return ( ! list_empty ( &san_devices ) );
}

/**
 * Get reference to SAN device
 *
 * @v sandev            SAN device
 * @ret sandev          SAN device
 */
static inline __attribute__ (( always_inline )) struct san_device *
sandev_get ( struct san_device *sandev ) {
        ref_get ( &sandev->refcnt );
        return sandev;
}

/**
 * Drop reference to SAN device
 *
 * @v sandev            SAN device
 */
static inline __attribute__ (( always_inline )) void
sandev_put ( struct san_device *sandev ) {
        ref_put ( &sandev->refcnt );
}

/**
 * Calculate SAN device block size
 *
 * @v sandev            SAN device
 * @ret blksize         Sector size
 */
static inline size_t sandev_blksize ( struct san_device *sandev ) {
        return ( sandev->capacity.blksize << sandev->blksize_shift );
}

/**
 * Calculate SAN device capacity
 *
 * @v sandev            SAN device
 * @ret blocks          Number of blocks
 */
static inline uint64_t sandev_capacity ( struct san_device *sandev ) {
        return ( sandev->capacity.blocks >> sandev->blksize_shift );
}

/**
 * Check if SAN device needs to be reopened
 *
 * @v sandev            SAN device
 * @ret needs_reopen    SAN device needs to be reopened
 */
static inline int sandev_needs_reopen ( struct san_device *sandev ) {
        return ( sandev->active == NULL );
}

extern struct san_device * sandev_find ( unsigned int drive );
extern struct san_device * sandev_next ( unsigned int drive );
extern int sandev_reopen ( struct san_device *sandev );
extern int sandev_reset ( struct san_device *sandev );
extern int sandev_read ( struct san_device *sandev, uint64_t lba,
                         unsigned int count, userptr_t buffer );
extern int sandev_write ( struct san_device *sandev, uint64_t lba,
                          unsigned int count, userptr_t buffer );
extern struct san_device * alloc_sandev ( struct uri **uris, unsigned int count,
                                          size_t priv_size );
extern int register_sandev ( struct san_device *sandev, unsigned int drive,
                             unsigned int flags );
extern void unregister_sandev ( struct san_device *sandev );
extern unsigned int san_default_drive ( void );

#endif /* _IPXE_SANBOOT_H */