freebsd-dev/sys/cam/ctl/ctl_backend.h
Alexander Motin 767300e87a Make struct ctl_be_lun first element of struct ctl_be_*_lun.
It allows to remove some extra pointer dereferences and slightly tightens
up the code by unification.

MFC after:	2 weeks
Sponsored by:	iXsystems, Inc.
2020-05-28 21:30:29 +00:00

253 lines
8.9 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2003 Silicon Graphics International Corp.
* Copyright (c) 2014-2017 Alexander Motin <mav@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
* substantially 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 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.
*
* $Id: //depot/users/kenm/FreeBSD-test2/sys/cam/ctl/ctl_backend.h#2 $
* $FreeBSD$
*/
/*
* CTL backend driver definitions
*
* Author: Ken Merry <ken@FreeBSD.org>
*/
#ifndef _CTL_BACKEND_H_
#define _CTL_BACKEND_H_
#include <cam/ctl/ctl_ioctl.h>
#include <sys/nv.h>
typedef enum {
CTL_LUN_SERSEQ_OFF,
CTL_LUN_SERSEQ_READ,
CTL_LUN_SERSEQ_ON
} ctl_lun_serseq;
#ifdef _KERNEL
#define CTL_BACKEND_DECLARE(name, driver) \
static int name ## _modevent(module_t mod, int type, void *data) \
{ \
switch (type) { \
case MOD_LOAD: \
return (ctl_backend_register( \
(struct ctl_backend_driver *)data)); \
break; \
case MOD_UNLOAD: \
return (ctl_backend_deregister( \
(struct ctl_backend_driver *)data)); \
break; \
default: \
return EOPNOTSUPP; \
} \
return 0; \
} \
static moduledata_t name ## _mod = { \
#name, \
name ## _modevent, \
(void *)&driver \
}; \
DECLARE_MODULE(name, name ## _mod, SI_SUB_CONFIGURE, SI_ORDER_FOURTH); \
MODULE_DEPEND(name, ctl, 1, 1, 1); \
MODULE_DEPEND(name, cam, 1, 1, 1)
struct ctl_be_lun;
typedef void (*be_callback_t)(struct ctl_be_lun *be_lun);
/*
* The lun_type field is the SCSI device type of this particular LUN. In
* general, this should be T_DIRECT, although backends will want to create
* a processor LUN, typically at LUN 0. See scsi_all.h for the defines for
* the various SCSI device types.
*
* The flags are described above.
*
* The be_lun field is the backend driver's own context that will get
* passsed back so that it can tell which LUN CTL is referencing.
*
* maxlba is the maximum accessible LBA on the LUN. Note that this is
* different from the capacity of the array. capacity = maxlba + 1
*
* blocksize is the size, in bytes, of each LBA on the LUN. In general
* this should be 512. In theory CTL should be able to handle other block
* sizes. Host application software may not deal with it very well, though.
*
* pblockexp is the log2() of number of LBAs on the LUN per physical sector.
*
* pblockoff is the lowest LBA on the LUN aligned to physical sector.
*
* ublockexp is the log2() of number of LBAs on the LUN per UNMAP block.
*
* ublockoff is the lowest LBA on the LUN aligned to UNMAP block.
*
* atomicblock is the number of blocks that can be written atomically.
*
* opttxferlen is the number of blocks that can be written in one operation.
*
* req_lun_id is the requested LUN ID. CTL only pays attention to this
* field if the CTL_LUN_FLAG_ID_REQ flag is set. If the requested LUN ID is
* not available, the LUN addition will fail. If a particular LUN ID isn't
* requested, the first available LUN ID will be allocated.
*
* serial_num is the device serial number returned in the SCSI INQUIRY VPD
* page 0x80. This should be a unique, per-shelf value. The data inside
* this field should be ASCII only, left aligned, and any unused space
* should be padded out with ASCII spaces. This field should NOT be NULL
* terminated.
*
* device_id is the T10 device identifier returned in the SCSI INQUIRY VPD
* page 0x83. This should be a unique, per-LUN value. The data inside
* this field should be ASCII only, left aligned, and any unused space
* should be padded with ASCII spaces. This field should NOT be NULL
* terminated.
*
* The lun_shutdown() method is the callback for the ctl_remove_lun()
* call. It is called when all outstanding I/O for that LUN has been
* completed and CTL has deleted the resources for that LUN. When the CTL
* backend gets this call, it can safely free its per-LUN resources.
*
* The be field is a pointer to the ctl_backend_driver structure, which
* contains the backend methods to be called by CTL.
*
* The ctl_lun field is for CTL internal use only, and should not be used
* by the backend.
*
* The links field is for CTL internal use only, and should not be used by
* the backend.
*/
struct ctl_be_lun {
uint8_t lun_type; /* passed to CTL */
ctl_backend_lun_flags flags; /* passed to CTL */
ctl_lun_serseq serseq; /* passed to CTL */
uint64_t maxlba; /* passed to CTL */
uint32_t blocksize; /* passed to CTL */
uint16_t pblockexp; /* passed to CTL */
uint16_t pblockoff; /* passed to CTL */
uint16_t ublockexp; /* passed to CTL */
uint16_t ublockoff; /* passed to CTL */
uint32_t atomicblock; /* passed to CTL */
uint32_t opttxferlen; /* passed to CTL */
uint32_t req_lun_id; /* passed to CTL */
uint32_t lun_id; /* returned from CTL */
uint8_t serial_num[CTL_SN_LEN]; /* passed to CTL */
uint8_t device_id[CTL_DEVID_LEN];/* passed to CTL */
be_callback_t lun_shutdown; /* passed to CTL */
struct ctl_backend_driver *be; /* passed to CTL */
void *ctl_lun; /* used by CTL */
nvlist_t *options; /* passed to CTL */
STAILQ_ENTRY(ctl_be_lun) links; /* used by CTL */
};
typedef enum {
CTL_BE_FLAG_NONE = 0x00, /* no flags */
CTL_BE_FLAG_HAS_CONFIG = 0x01, /* can do config reads, writes */
} ctl_backend_flags;
typedef int (*be_init_t)(void);
typedef int (*be_shutdown_t)(void);
typedef int (*be_func_t)(union ctl_io *io);
typedef void (*be_vfunc_t)(union ctl_io *io);
typedef int (*be_ioctl_t)(struct cdev *dev, u_long cmd, caddr_t addr, int flag,
struct thread *td);
typedef int (*be_luninfo_t)(struct ctl_be_lun *be_lun, struct sbuf *sb);
typedef uint64_t (*be_lunattr_t)(struct ctl_be_lun *be_lun, const char *attrname);
struct ctl_backend_driver {
char name[CTL_BE_NAME_LEN]; /* passed to CTL */
ctl_backend_flags flags; /* passed to CTL */
be_init_t init; /* passed to CTL */
be_shutdown_t shutdown; /* passed to CTL */
be_func_t data_submit; /* passed to CTL */
be_func_t data_move_done; /* passed to CTL */
be_func_t config_read; /* passed to CTL */
be_func_t config_write; /* passed to CTL */
be_ioctl_t ioctl; /* passed to CTL */
be_luninfo_t lun_info; /* passed to CTL */
be_lunattr_t lun_attr; /* passed to CTL */
#ifdef CS_BE_CONFIG_MOVE_DONE_IS_NOT_USED
be_func_t config_move_done; /* passed to backend */
#endif
#if 0
be_vfunc_t config_write_done; /* passed to backend */
#endif
STAILQ_ENTRY(ctl_backend_driver) links; /* used by CTL */
};
int ctl_backend_register(struct ctl_backend_driver *be);
int ctl_backend_deregister(struct ctl_backend_driver *be);
struct ctl_backend_driver *ctl_backend_find(char *backend_name);
/*
* To add a LUN, call ctl_add_lun().
*/
int ctl_add_lun(struct ctl_be_lun *be_lun);
/*
* To remove a LUN, first call ctl_remove_lun().
* You will get the lun_shutdown() callback when all
* I/O to the LUN has completed and the LUN has been deleted.
*/
int ctl_remove_lun(struct ctl_be_lun *be_lun);
/*
* To start a LUN (transition from powered off to powered on state) call
* ctl_start_lun(). To stop a LUN (transition from powered on to powered
* off state) call ctl_stop_lun().
*/
int ctl_start_lun(struct ctl_be_lun *be_lun);
int ctl_stop_lun(struct ctl_be_lun *be_lun);
/*
* Methods to notify about media and tray status changes.
*/
int ctl_lun_no_media(struct ctl_be_lun *be_lun);
int ctl_lun_has_media(struct ctl_be_lun *be_lun);
int ctl_lun_ejected(struct ctl_be_lun *be_lun);
/*
* Called on LUN HA role change.
*/
int ctl_lun_primary(struct ctl_be_lun *be_lun);
int ctl_lun_secondary(struct ctl_be_lun *be_lun);
/*
* Let the backend notify the initiators about changes.
*/
void ctl_lun_capacity_changed(struct ctl_be_lun *be_lun);
#endif /* _KERNEL */
#endif /* _CTL_BACKEND_H_ */
/*
* vim: ts=8
*/