freebsd-skq/sys/cam/cam_xpt.h
scottl cd4455d638 MFC Alexander Motin's direct dispatch, multi-queue, and finer-grained
locking support for CAM

r256826:
Fix several target mode SIMs to not blindly clear ccb_h.flags field of
ATIO CCBs.  Not all CCB flags there belong to them.

r256836:
Remove hard limit on number of BIOs handled with one ATA TRIM request.

r256843:
Merge CAM locking changes from the projects/camlock branch to radically
reduce lock congestion and improve SMP scalability of the SCSI/ATA stack,
preparing the ground for the coming next GEOM direct dispatch support.

r256888:
Unconditionally acquire periph reference on CCB allocation failure.

r256895:
Fix memory and references leak due to unfreed path.

r256960:
Move CAM_UNQUEUED_INDEX setting to the last moment and under the periph lock.
This fixes race condition with cam_periph_ccbwait(), causing use-after-free.

r256975:
Minor (mostly cosmetical) addition to r256960.

r257054:
Some microoptimizations for da and ada drivers:
 - Replace ordered_tag_count counter with single flag;
 - From da remove outstanding_cmds counter, duplicating pending_ccbs list;
 - From da_softc remove unused links field.

r257482:
Fix lock recursion, triggered by `smartctl -a /dev/adaX`.

r257501:
Make getenv_*() functions and respectively TUNABLE_*_FETCH() macros not
allocate memory and so not require sleepable environment.  getenv() has
already used on-stack temporary storage, so just use it more rationally.
getenv_string() receives buffer as argument, so don't need another one.

r257914:
Some CAM locks polishing:
 - Fix LOR and possible lock recursion when handling high-power commands.
Introduce new lock to protect left power quota and list of frozen devices.
 - Correct locking around xpt periph creation.
 - Remove seems never used XPT_FLAG_OPEN xpt periph flag.

Again, Netflix assisted with testing the merge, but all of the credit goes
to Alexander and iX Systems.

Submitted by:	mav
Sponsored by:	iX Systems
2014-01-07 01:51:48 +00:00

138 lines
5.1 KiB
C

/*-
* Data structures and definitions for dealing with the
* Common Access Method Transport (xpt) layer.
*
* Copyright (c) 1997 Justin T. Gibbs.
* 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, immediately at the beginning of the file.
* 2. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, 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 DAMAGE.
*
* $FreeBSD$
*/
#ifndef _CAM_CAM_XPT_H
#define _CAM_CAM_XPT_H 1
/* Forward Declarations */
union ccb;
struct cam_periph;
struct cam_ed;
struct cam_sim;
/*
* Definition of a CAM path. Paths are created from bus, target, and lun ids
* via xpt_create_path and allow for reference to devices without recurring
* lookups in the edt.
*/
struct cam_path;
/* Path functions */
#ifdef _KERNEL
/*
* Definition of an async handler callback block. These are used to add
* SIMs and peripherals to the async callback lists.
*/
struct async_node {
SLIST_ENTRY(async_node) links;
u_int32_t event_enable; /* Async Event enables */
u_int32_t event_lock; /* Take SIM lock for handlers. */
void (*callback)(void *arg, u_int32_t code,
struct cam_path *path, void *args);
void *callback_arg;
};
SLIST_HEAD(async_list, async_node);
SLIST_HEAD(periph_list, cam_periph);
void xpt_action(union ccb *new_ccb);
void xpt_action_default(union ccb *new_ccb);
union ccb *xpt_alloc_ccb(void);
union ccb *xpt_alloc_ccb_nowait(void);
void xpt_free_ccb(union ccb *free_ccb);
void xpt_setup_ccb(struct ccb_hdr *ccb_h,
struct cam_path *path,
u_int32_t priority);
void xpt_merge_ccb(union ccb *master_ccb,
union ccb *slave_ccb);
cam_status xpt_create_path(struct cam_path **new_path_ptr,
struct cam_periph *perph,
path_id_t path_id,
target_id_t target_id, lun_id_t lun_id);
cam_status xpt_create_path_unlocked(struct cam_path **new_path_ptr,
struct cam_periph *perph,
path_id_t path_id,
target_id_t target_id, lun_id_t lun_id);
int xpt_getattr(char *buf, size_t len, const char *attr,
struct cam_path *path);
void xpt_free_path(struct cam_path *path);
void xpt_path_counts(struct cam_path *path, uint32_t *bus_ref,
uint32_t *periph_ref, uint32_t *target_ref,
uint32_t *device_ref);
int xpt_path_comp(struct cam_path *path1,
struct cam_path *path2);
int xpt_path_comp_dev(struct cam_path *path,
struct cam_ed *dev);
void xpt_print_path(struct cam_path *path);
void xpt_print_device(struct cam_ed *device);
void xpt_print(struct cam_path *path, const char *fmt, ...);
int xpt_path_string(struct cam_path *path, char *str,
size_t str_len);
path_id_t xpt_path_path_id(struct cam_path *path);
target_id_t xpt_path_target_id(struct cam_path *path);
lun_id_t xpt_path_lun_id(struct cam_path *path);
int xpt_path_legacy_ata_id(struct cam_path *path);
struct cam_sim *xpt_path_sim(struct cam_path *path);
struct cam_periph *xpt_path_periph(struct cam_path *path);
void xpt_async(u_int32_t async_code, struct cam_path *path,
void *async_arg);
void xpt_rescan(union ccb *ccb);
void xpt_hold_boot(void);
void xpt_release_boot(void);
void xpt_lock_buses(void);
void xpt_unlock_buses(void);
struct mtx * xpt_path_mtx(struct cam_path *path);
#define xpt_path_lock(path) mtx_lock(xpt_path_mtx(path))
#define xpt_path_unlock(path) mtx_unlock(xpt_path_mtx(path))
#define xpt_path_assert(path, what) mtx_assert(xpt_path_mtx(path), (what))
#define xpt_path_owned(path) mtx_owned(xpt_path_mtx(path))
#define xpt_path_sleep(path, chan, priority, wmesg, timo) \
msleep((chan), xpt_path_mtx(path), (priority), (wmesg), (timo))
cam_status xpt_register_async(int event, ac_callback_t *cbfunc,
void *cbarg, struct cam_path *path);
cam_status xpt_compile_path(struct cam_path *new_path,
struct cam_periph *perph,
path_id_t path_id,
target_id_t target_id,
lun_id_t lun_id);
cam_status xpt_clone_path(struct cam_path **new_path,
struct cam_path *path);
void xpt_copy_path(struct cam_path *new_path,
struct cam_path *path);
void xpt_release_path(struct cam_path *path);
#endif /* _KERNEL */
#endif /* _CAM_CAM_XPT_H */