freebsd-nq/sys/cam/cam_xpt_periph.h

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/*-
* Data structures and definitions for dealing with the
* Common Access Method Transport (xpt) layer from peripheral
* drivers.
*
* 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.
*
1999-08-28 01:08:13 +00:00
* $FreeBSD$
*/
#ifndef _CAM_CAM_XPT_PERIPH_H
#define _CAM_CAM_XPT_PERIPH_H 1
Separate the parallel scsi knowledge out of the core of the XPT, and modularize it so that new transports can be created. Add a transport for SATA Add a periph+protocol layer for ATA Add a driver for AHCI-compliant hardware. Add a maxio field to CAM so that drivers can advertise their max I/O capability. Modify various drivers so that they are insulated from the value of MAXPHYS. The new ATA/SATA code supports AHCI-compliant hardware, and will override the classic ATA driver if it is loaded as a module at boot time or compiled into the kernel. The stack now support NCQ (tagged queueing) for increased performance on modern SATA drives. It also supports port multipliers. ATA drives are accessed via 'ada' device nodes. ATAPI drives are accessed via 'cd' device nodes. They can all be enumerated and manipulated via camcontrol, just like SCSI drives. SCSI commands are not translated to their ATA equivalents; ATA native commands are used throughout the entire stack, including camcontrol. See the camcontrol manpage for further details. Testing this code may require that you update your fstab, and possibly modify your BIOS to enable AHCI functionality, if available. This code is very experimental at the moment. The userland ABI/API has changed, so applications will need to be recompiled. It may change further in the near future. The 'ada' device name may also change as more infrastructure is completed in this project. The goal is to eventually put all CAM busses and devices until newbus, allowing for interesting topology and management options. Few functional changes will be seen with existing SCSI/SAS/FC drivers, though the userland ABI has still changed. In the future, transports specific modules for SAS and FC may appear in order to better support the topologies and capabilities of these technologies. The modularization of CAM and the addition of the ATA/SATA modules is meant to break CAM out of the mold of being specific to SCSI, letting it grow to be a framework for arbitrary transports and protocols. It also allows drivers to be written to support discrete hardware without jeopardizing the stability of non-related hardware. While only an AHCI driver is provided now, a Silicon Image driver is also in the works. Drivers for ICH1-4, ICH5-6, PIIX, classic IDE, and any other hardware is possible and encouraged. Help with new transports is also encouraged. Submitted by: scottl, mav Approved by: re
2009-07-10 08:18:08 +00:00
#include <cam/cam_queue.h>
#include <cam/cam_xpt.h>
/* Functions accessed by the peripheral drivers */
#ifdef _KERNEL
void xpt_polled_action(union ccb *ccb);
void xpt_release_ccb(union ccb *released_ccb);
void xpt_schedule(struct cam_periph *perph, u_int32_t new_priority);
int32_t xpt_add_periph(struct cam_periph *periph);
Fix several reference counting and object lifetime issues between the pass(4) and enc(4) drivers and devfs. The pass(4) driver uses the destroy_dev_sched() routine to schedule its device node for destruction in a separate thread context. It does this because the passcleanup() routine can get called indirectly from the passclose() routine, and that would cause a deadlock if the close routine tried to destroy its own device node. In any case, once a particular passthrough driver number, e.g. pass3, is destroyed, CAM considers that unit number (3 in this case) available for reuse. The problem is that devfs may not be done cleaning up the previous instance of pass3, and will panic if isn't done cleaning up the previous instance. The solution is to get a callback from devfs when the device node is removed, and make sure we hold a reference to the peripheral until that happens. Testing exposed some other cases where we have reference counting issues, and those were also fixed in the pass(4) driver. cam_periph.c: In camperiphfree(), reorder some of the operations. The peripheral destructor needs to be called before the peripheral is removed from the peripheral is removed from the list. This is because once we remove the peripheral from the list, and drop the topology lock, the peripheral number may be reused. But if the destructor hasn't been called yet, there may still be resources hanging around (like devfs nodes) that haven't been fully cleaned up. cam_xpt.c: Add an argument to xpt_remove_periph() to indicate whether the topology lock is already held. scsi_enc.c: Acquire an extra reference to the peripheral during registration, and release it once we get a callback from devfs indicating that the device node is gone. Call destroy_dev_sched_cb() in enc_oninvalidate() instead of calling destroy_dev() in the cleanup routine. scsi_pass.c: Add reference counting to handle peripheral and devfs object lifetime issues. Add a reference to the peripheral and the devfs node in the peripheral registration. Don't attempt to add a physical path alias if the peripheral has been marked invalid. Release the devfs reference once the initial physical path alias taskqueue run has completed. Schedule devfs node destruction in the passoninvalidate(), and release our peripheral reference in a new routine, passdevgonecb() once the devfs node is gone. This allows the peripheral to fully go away, and the peripheral destructor, passcleanup(), will get called. MFC after: 3 days Sponsored by: Spectra Logic
2012-06-20 17:08:00 +00:00
void xpt_remove_periph(struct cam_periph *periph,
int topology_lock_held);
void xpt_announce_periph(struct cam_periph *periph,
char *announce_string);
#endif
#endif /* _CAM_CAM_XPT_PERIPH_H */