freebsd-dev/sys/cam/cam_queue.h
Alexander Motin 83c5d981ac MFp4: Large set of CAM inprovements.
- Unify bus reset/probe sequence. Whenever bus attached at boot or later,
CAM will automatically reset and scan it. It allows to remove duplicate
code from many drivers.
- Any bus, attached before CAM completed it's boot-time initialization,
will equally join to the process, delaying boot if needed.
- New kern.cam.boot_delay loader tunable should help controllers that
are still unable to register their buses in time (such as slow USB/
PCCard/ CardBus devices), by adding one more event to wait on boot.
- To allow synchronization between different CAM levels, concept of
requests priorities was extended. Priorities now split between several
"run levels". Device can be freezed at specified level, allowing higher
priority requests to pass. For example, no payload requests allowed,
until PMP driver enable port. ATA XPT negotiate transfer parameters,
periph driver configure caching and so on.
- Frozen requests are no more counted by request allocation scheduler.
It fixes deadlocks, when frozen low priority payload requests occupying
slots, required by higher levels to manage theit execution.
- Two last changes were holding proper ATA reinitialization and error
recovery implementation. Now it is done: SATA controllers and Port
Multipliers now implement automatic hot-plug and should correctly
recover from timeouts and bus resets.
- Improve SCSI error recovery for devices on buses without automatic sense
reporting, such as ATAPI or USB. For example, it allows CAM to wait, while
CD drive loads disk, instead of immediately return error status.
- Decapitalize diagnostic messages and make them more readable and sensible.
- Teach PMP driver to limit maximum speed on fan-out ports.
- Make boot wait for PMP scan completes, and make rescan more reliable.
- Fix pass driver, to return CCB to user level in case of error.
- Increase number of retries in cd driver, as device may return several UAs.
2010-01-28 08:41:30 +00:00

329 lines
8.1 KiB
C

/*-
* CAM request queue management definitions.
*
* 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_QUEUE_H
#define _CAM_CAM_QUEUE_H 1
#ifdef _KERNEL
#include <sys/queue.h>
#include <cam/cam.h>
/*
* This structure implements a heap based priority queue. The queue
* assumes that the objects stored in it begin with a cam_qentry
* structure holding the priority information used to sort the objects.
* This structure is opaque to clients (outside of the XPT layer) to allow
* the implementation to change without affecting them.
*/
struct camq {
cam_pinfo **queue_array;
int array_size;
int entries;
u_int32_t generation;
u_int32_t qfrozen_cnt[CAM_RL_VALUES];
};
TAILQ_HEAD(ccb_hdr_tailq, ccb_hdr);
LIST_HEAD(ccb_hdr_list, ccb_hdr);
SLIST_HEAD(ccb_hdr_slist, ccb_hdr);
struct cam_ccbq {
struct camq queue;
int devq_openings;
int dev_openings;
int dev_active;
int held;
};
struct cam_ed;
struct cam_devq {
struct camq alloc_queue;
struct camq send_queue;
struct cam_ed *active_dev;
int alloc_openings;
int alloc_active;
int send_openings;
int send_active;
};
struct cam_devq *cam_devq_alloc(int devices, int openings);
int cam_devq_init(struct cam_devq *devq, int devices,
int openings);
void cam_devq_free(struct cam_devq *devq);
u_int32_t cam_devq_resize(struct cam_devq *camq, int openings);
/*
* Allocate a cam_ccb_queue structure and initialize it.
*/
struct cam_ccbq *cam_ccbq_alloc(int openings);
u_int32_t cam_ccbq_resize(struct cam_ccbq *ccbq, int devices);
int cam_ccbq_init(struct cam_ccbq *ccbq, int openings);
void cam_ccbq_free(struct cam_ccbq *ccbq);
void cam_ccbq_fini(struct cam_ccbq *ccbq);
/*
* Allocate and initialize a cam_queue structure.
*/
struct camq *camq_alloc(int size);
/*
* Resize a cam queue
*/
u_int32_t camq_resize(struct camq *queue, int new_size);
/*
* Initialize a camq structure. Return 0 on success, 1 on failure.
*/
int camq_init(struct camq *camq, int size);
/*
* Free a cam_queue structure. This should only be called if a controller
* driver failes somehow during its attach routine or is unloaded and has
* obtained a cam_queue structure.
*/
void camq_free(struct camq *queue);
/*
* Finialize any internal storage or state of a cam_queue.
*/
void camq_fini(struct camq *queue);
/*
* cam_queue_insert: Given a CAM queue with at least one open spot,
* insert the new entry maintaining order.
*/
void camq_insert(struct camq *queue, cam_pinfo *new_entry);
/*
* camq_remove: Remove and arbitrary entry from the queue maintaining
* queue order.
*/
cam_pinfo *camq_remove(struct camq *queue, int index);
#define CAMQ_HEAD 1 /* Head of queue index */
/* Index the first element in the heap */
#define CAMQ_GET_HEAD(camq) ((camq)->queue_array[CAMQ_HEAD])
/* Get the first element priority. */
#define CAMQ_GET_PRIO(camq) (((camq)->entries > 0) ? \
((camq)->queue_array[CAMQ_HEAD]->priority) : 0)
/*
* camq_change_priority: Raise or lower the priority of an entry
* maintaining queue order.
*/
void camq_change_priority(struct camq *queue, int index,
u_int32_t new_priority);
static __inline int
cam_ccbq_pending_ccb_count(struct cam_ccbq *ccbq);
static __inline void
cam_ccbq_take_opening(struct cam_ccbq *ccbq);
static __inline int
cam_ccbq_insert_ccb(struct cam_ccbq *ccbq, union ccb *new_ccb);
static __inline int
cam_ccbq_remove_ccb(struct cam_ccbq *ccbq, union ccb *ccb);
static __inline union ccb *
cam_ccbq_peek_ccb(struct cam_ccbq *ccbq, int index);
static __inline void
cam_ccbq_send_ccb(struct cam_ccbq *queue, union ccb *send_ccb);
static __inline void
cam_ccbq_ccb_done(struct cam_ccbq *ccbq, union ccb *done_ccb);
static __inline void
cam_ccbq_release_opening(struct cam_ccbq *ccbq);
static __inline int
cam_ccbq_pending_ccb_count(struct cam_ccbq *ccbq)
{
return (ccbq->queue.entries);
}
static __inline void
cam_ccbq_take_opening(struct cam_ccbq *ccbq)
{
ccbq->devq_openings--;
ccbq->held++;
}
static __inline int
cam_ccbq_insert_ccb(struct cam_ccbq *ccbq, union ccb *new_ccb)
{
ccbq->held--;
camq_insert(&ccbq->queue, &new_ccb->ccb_h.pinfo);
if (ccbq->queue.qfrozen_cnt[CAM_PRIORITY_TO_RL(
new_ccb->ccb_h.pinfo.priority)] > 0) {
ccbq->devq_openings++;
ccbq->held++;
return (1);
} else
return (0);
}
static __inline int
cam_ccbq_remove_ccb(struct cam_ccbq *ccbq, union ccb *ccb)
{
camq_remove(&ccbq->queue, ccb->ccb_h.pinfo.index);
if (ccbq->queue.qfrozen_cnt[CAM_PRIORITY_TO_RL(
ccb->ccb_h.pinfo.priority)] > 0) {
ccbq->devq_openings--;
ccbq->held--;
return (1);
} else
return (0);
}
static __inline union ccb *
cam_ccbq_peek_ccb(struct cam_ccbq *ccbq, int index)
{
return((union ccb *)ccbq->queue.queue_array[index]);
}
static __inline void
cam_ccbq_send_ccb(struct cam_ccbq *ccbq, union ccb *send_ccb)
{
send_ccb->ccb_h.pinfo.index = CAM_ACTIVE_INDEX;
ccbq->dev_active++;
ccbq->dev_openings--;
}
static __inline void
cam_ccbq_ccb_done(struct cam_ccbq *ccbq, union ccb *done_ccb)
{
ccbq->dev_active--;
ccbq->dev_openings++;
ccbq->held++;
}
static __inline void
cam_ccbq_release_opening(struct cam_ccbq *ccbq)
{
ccbq->held--;
ccbq->devq_openings++;
}
static __inline int
cam_ccbq_freeze(struct cam_ccbq *ccbq, cam_rl rl, u_int32_t cnt)
{
int i, frozen = 0;
cam_rl p, n;
/* Find pevious run level. */
for (p = 0; p < CAM_RL_VALUES && ccbq->queue.qfrozen_cnt[p] == 0; p++);
/* Find new run level. */
n = min(rl, p);
/* Apply new run level. */
for (i = rl; i < CAM_RL_VALUES; i++)
ccbq->queue.qfrozen_cnt[i] += cnt;
/* Update ccbq statistics. */
if (n == p)
return (0);
for (i = CAMQ_HEAD; i <= ccbq->queue.entries; i++) {
cam_rl rrl =
CAM_PRIORITY_TO_RL(ccbq->queue.queue_array[i]->priority);
if (rrl < n)
continue;
if (rrl >= p)
break;
ccbq->devq_openings++;
ccbq->held++;
frozen++;
}
return (frozen);
}
static __inline int
cam_ccbq_release(struct cam_ccbq *ccbq, cam_rl rl, u_int32_t cnt)
{
int i, released = 0;
cam_rl p, n;
/* Apply new run level. */
for (i = rl; i < CAM_RL_VALUES; i++)
ccbq->queue.qfrozen_cnt[i] -= cnt;
/* Find new run level. */
for (n = 0; n < CAM_RL_VALUES && ccbq->queue.qfrozen_cnt[n] == 0; n++);
/* Find previous run level. */
p = min(rl, n);
/* Update ccbq statistics. */
if (n == p)
return (0);
for (i = CAMQ_HEAD; i <= ccbq->queue.entries; i++) {
cam_rl rrl =
CAM_PRIORITY_TO_RL(ccbq->queue.queue_array[i]->priority);
if (rrl < p)
continue;
if (rrl >= n)
break;
ccbq->devq_openings--;
ccbq->held--;
released++;
}
return (released);
}
static __inline u_int32_t
cam_ccbq_frozen(struct cam_ccbq *ccbq, cam_rl rl)
{
return (ccbq->queue.qfrozen_cnt[rl]);
}
static __inline u_int32_t
cam_ccbq_frozen_top(struct cam_ccbq *ccbq)
{
cam_rl rl;
rl = CAM_PRIORITY_TO_RL(CAMQ_GET_PRIO(&ccbq->queue));
return (ccbq->queue.qfrozen_cnt[rl]);
}
#endif /* _KERNEL */
#endif /* _CAM_CAM_QUEUE_H */