aic79xx_osm.c

这个linux源代码是很全面的~基本完整了~使用c编译的~由于时间问题我没有亲自测试~但就算用来做参考资料也是非常好的

/*
 * Adaptec AIC79xx device driver for Linux.
 *
 * $Id: //depot/aic7xxx/linux/drivers/scsi/aic7xxx/aic79xx_osm.c#36 $
 *
 * --------------------------------------------------------------------------
 * Copyright (c) 1994-2000 Justin T. Gibbs.
 * Copyright (c) 1997-1999 Doug Ledford
 * Copyright (c) 2000-2002 Adaptec Inc.
 * 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.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * 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.
 */

/*
 * This is the only file where module.h should
 * embed module global version info.
 */
#define AHD_MODVERSION_FILE

#include "aic79xx_osm.h"
#include "aic79xx_inline.h"

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,3,0)
#include <linux/init.h>		/* __setup */
#endif

#include "../sd.h"		/* For geometry detection */

#include <linux/mm.h>		/* For fetching system memory size */

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,0)
/*
 * Lock protecting manipulation of the ahd softc list.
 */
spinlock_t ahd_list_spinlock;
#endif

#if LINUX_VERSION_CODE < KERNEL_VERSION(2,3,0)
struct proc_dir_entry proc_scsi_aic79xx = {
	PROC_SCSI_AIC79XX, 7, "aic79xx",
	S_IFDIR | S_IRUGO | S_IXUGO, 2,
	0, 0, 0, NULL, NULL, NULL, NULL, NULL, NULL, NULL
};
#endif

/*
 * Set this to the delay in seconds after SCSI bus reset.
 * Note, we honor this only for the initial bus reset.
 * The scsi error recovery code performs its own bus settle
 * delay handling for error recovery actions.
 */
#ifdef CONFIG_AIC79XX_RESET_DELAY_MS
#define AIC79XX_RESET_DELAY CONFIG_AIC79XX_RESET_DELAY_MS
#else
#define AIC79XX_RESET_DELAY 5000
#endif

/*
 * To change the default number of tagged transactions allowed per-device,
 * add a line to the lilo.conf file like:
 * append="aic79xx=verbose,tag_info:{{32,32,32,32},{32,32,32,32}}"
 * which will result in the first four devices on the first two
 * controllers being set to a tagged queue depth of 32.
 *
 * The tag_commands is an array of 16 to allow for wide and twin adapters.
 * Twin adapters will use indexes 0-7 for channel 0, and indexes 8-15
 * for channel 1.
 */
typedef struct {
	uint16_t tag_commands[16];	/* Allow for wide/twin adapters. */
} adapter_tag_info_t;

/*
 * Modify this as you see fit for your system.
 *
 * 0			tagged queuing disabled
 * 1 <= n <= 253	n == max tags ever dispatched.
 *
 * The driver will throttle the number of commands dispatched to a
 * device if it returns queue full.  For devices with a fixed maximum
 * queue depth, the driver will eventually determine this depth and
 * lock it in (a console message is printed to indicate that a lock
 * has occurred).  On some devices, queue full is returned for a temporary
 * resource shortage.  These devices will return queue full at varying
 * depths.  The driver will throttle back when the queue fulls occur and
 * attempt to slowly increase the depth over time as the device recovers
 * from the resource shortage.
 *
 * In this example, the first line will disable tagged queueing for all
 * the devices on the first probed aic79xx adapter.
 *
 * The second line enables tagged queueing with 4 commands/LUN for IDs
 * (0, 2-11, 13-15), disables tagged queueing for ID 12, and tells the
 * driver to attempt to use up to 64 tags for ID 1.
 *
 * The third line is the same as the first line.
 *
 * The fourth line disables tagged queueing for devices 0 and 3.  It
 * enables tagged queueing for the other IDs, with 16 commands/LUN
 * for IDs 1 and 4, 127 commands/LUN for ID 8, and 4 commands/LUN for
 * IDs 2, 5-7, and 9-15.
 */

/*
 * NOTE: The below structure is for reference only, the actual structure
 *       to modify in order to change things is just below this comment block.
adapter_tag_info_t aic79xx_tag_info[] =
{
	{{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}},
	{{4, 64, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 0, 4, 4, 4}},
	{{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}},
	{{0, 16, 4, 0, 16, 4, 4, 4, 127, 4, 4, 4, 4, 4, 4, 4}}
};
*/

#ifdef CONFIG_AIC79XX_CMDS_PER_DEVICE
#define AIC79XX_CMDS_PER_DEVICE CONFIG_AIC79XX_CMDS_PER_DEVICE
#else
#define AIC79XX_CMDS_PER_DEVICE AHD_MAX_QUEUE
#endif

#define AIC79XX_CONFIGED_TAG_COMMANDS {					\
	AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE,		\
	AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE,		\
	AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE,		\
	AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE,		\
	AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE,		\
	AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE,		\
	AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE,		\
	AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE		\
}

/*
 * By default, use the number of commands specified by
 * the users kernel configuration.
 */
static adapter_tag_info_t aic79xx_tag_info[] =
{
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS}
};

/*
 * By default, read streaming is disabled.  In theory,
 * read streaming should enhance performance, but early
 * U320 drive firmware actually performs slower with
 * read streaming enabled.
 */
#ifdef CONFIG_AIC79XX_ENABLE_RD_STRM
#define AIC79XX_CONFIGED_RD_STRM 0xFFFF
#else
#define AIC79XX_CONFIGED_RD_STRM 0
#endif

static uint16_t aic79xx_rd_strm_info[] =
{
	AIC79XX_CONFIGED_RD_STRM,
	AIC79XX_CONFIGED_RD_STRM,
	AIC79XX_CONFIGED_RD_STRM,
	AIC79XX_CONFIGED_RD_STRM,
	AIC79XX_CONFIGED_RD_STRM,
	AIC79XX_CONFIGED_RD_STRM,
	AIC79XX_CONFIGED_RD_STRM,
	AIC79XX_CONFIGED_RD_STRM,
	AIC79XX_CONFIGED_RD_STRM,
	AIC79XX_CONFIGED_RD_STRM,
	AIC79XX_CONFIGED_RD_STRM,
	AIC79XX_CONFIGED_RD_STRM,
	AIC79XX_CONFIGED_RD_STRM,
	AIC79XX_CONFIGED_RD_STRM,
	AIC79XX_CONFIGED_RD_STRM,
	AIC79XX_CONFIGED_RD_STRM
};

/*
 * There should be a specific return value for this in scsi.h, but
 * it seems that most drivers ignore it.
 */
#define DID_UNDERFLOW   DID_ERROR

void
ahd_print_path(struct ahd_softc *ahd, struct scb *scb)
{
	printk("(scsi%d:%c:%d:%d): ",
	       ahd->platform_data->host->host_no,
	       scb != NULL ? SCB_GET_CHANNEL(ahd, scb) : 'X',
	       scb != NULL ? SCB_GET_TARGET(ahd, scb) : -1,
	       scb != NULL ? SCB_GET_LUN(scb) : -1);
}

/*
 * XXX - these options apply unilaterally to _all_ adapters
 *       cards in the system.  This should be fixed.  Exceptions to this
 *       rule are noted in the comments.
 */

/*
 * Skip the scsi bus reset.  Non 0 make us skip the reset at startup.  This
 * has no effect on any later resets that might occur due to things like
 * SCSI bus timeouts.
 */
static uint32_t aic79xx_no_reset;

/*
 * Certain PCI motherboards will scan PCI devices from highest to lowest,
 * others scan from lowest to highest, and they tend to do all kinds of
 * strange things when they come into contact with PCI bridge chips.  The
 * net result of all this is that the PCI card that is actually used to boot
 * the machine is very hard to detect.  Most motherboards go from lowest
 * PCI slot number to highest, and the first SCSI controller found is the
 * one you boot from.  The only exceptions to this are when a controller
 * has its BIOS disabled.  So, we by default sort all of our SCSI controllers
 * from lowest PCI slot number to highest PCI slot number.  We also force
 * all controllers with their BIOS disabled to the end of the list.  This
 * works on *almost* all computers.  Where it doesn't work, we have this
 * option.  Setting this option to non-0 will reverse the order of the sort
 * to highest first, then lowest, but will still leave cards with their BIOS
 * disabled at the very end.  That should fix everyone up unless there are
 * really strange cirumstances.
 */
static int aic79xx_reverse_scan = 0;

/*
 * Should we force EXTENDED translation on a controller.
 *     0 == Use whatever is in the SEEPROM or default to off
 *     1 == Use whatever is in the SEEPROM or default to on
 */
static uint32_t aic79xx_extended = 0;

/*
 * PCI bus parity checking of the Adaptec controllers.  This is somewhat
 * dubious at best.  To my knowledge, this option has never actually
 * solved a PCI parity problem, but on certain machines with broken PCI
 * chipset configurations, it can generate tons of false error messages.
 * It's included in the driver for completeness.
 *   0 = Shut off PCI parity check
 *  -1 = Normal polarity pci parity checking
 *   1 = reverse polarity pci parity checking
 *
 * NOTE: you can't actually pass -1 on the lilo prompt.  So, to set this
 * variable to -1 you would actually want to simply pass the variable
 * name without a number.  That will invert the 0 which will result in
 * -1.
 */
static int aic79xx_pci_parity = 0;

/*
 * aic79xx_detect() has been run, so register all device arrivals
 * immediately with the system rather than deferring to the sorted
 * attachment performed by aic79xx_detect().
 */
int aic79xx_detect_complete;

/*
 * So that we can set how long each device is given as a selection timeout.
 * The table of values goes like this:
 *   0 - 256ms
 *   1 - 128ms
 *   2 - 64ms
 *   3 - 32ms
 * We default to 256ms because some older devices need a longer time
 * to respond to initial selection.
 */
static int aic79xx_seltime = 0x00;

/*
 * Certain devices do not perform any aging on commands.  Should the
 * device be saturated by commands in one portion of the disk, it is
 * possible for transactions on far away sectors to never be serviced.
 * To handle these devices, we can periodically send an ordered tag to
 * force all outstanding transactions to be serviced prior to a new
 * transaction.
 */
int aic79xx_periodic_otag;

/*
 * Module information and settable options.
 */
#ifdef MODULE
static char *aic79xx = NULL;
/*
 * Just in case someone uses commas to separate items on the insmod
 * command line, we define a dummy buffer here to avoid having insmod
 * write wild stuff into our code segment
 */
static char dummy_buffer[60] = "Please don't trounce on me insmod!!\n";

MODULE_AUTHOR("Maintainer: Justin T. Gibbs <[e-mail]>");
MODULE_DESCRIPTION("Adaptec Aic77XX/78XX SCSI Host Bus Adapter driver");
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,10)
MODULE_LICENSE("Dual BSD/GPL");
#endif
MODULE_PARM(aic79xx, "s");
MODULE_PARM_DESC(aic79xx, "period delimited, options string.
	verbose			Enable verbose/diagnostic logging
	debug			Bitmask of debug values to enable
	no_reset		Supress initial bus resets
	extended		Enable extended geometry on all controllers
	periodic_otag		Send an ordered tagged transaction periodically
				to prevent tag starvation.  This may be
				required by some older disk drives/RAID arrays. 
	reverse_scan		Sort PCI devices highest Bus/Slot to lowest
	tag_info:<tag_str>	Set per-target tag depth
	rd_strm:<rd_strm_masks> Set per-target read streaming setting.
	seltime:<int>		Selection Timeout(0/256ms,1/128ms,2/64ms,3/32ms)

	Sample /etc/modules.conf line:
		Enable verbose logging
		Set tag depth on Controller 2/Target 2 to 10 tags
		Shorten the selection timeout to 128ms from its default of 256

	options aic79xx='\"verbose.tag_info:{{}.{}.{..10}}.seltime:1\"'

	Sample /etc/modules.conf line:
		Change Read Streaming for Controller's 2 and 3

	options aic79xx='\"rd_strm:{..0xFFF0.0xC0F0}\"'
");
#endif

static void ahd_linux_handle_scsi_status(struct ahd_softc *,
					 struct ahd_linux_device *,
					 struct scb *);
static void ahd_linux_filter_command(struct ahd_softc*, Scsi_Cmnd*,
				     struct scb*);
static void ahd_linux_dev_timed_unfreeze(u_long arg);
#if NO_YET
static void ahd_linux_sem_timeout(u_long arg);
static int  ahd_linux_queue_recovery_cmd(Scsi_Cmnd *cmd, scb_flag flag);
#endif 
static void ahd_linux_initialize_scsi_bus(struct ahd_softc *ahd);
static void ahd_linux_select_queue_depth(struct Scsi_Host *host,
					 Scsi_Device *scsi_devs);
static u_int ahd_linux_user_tagdepth(struct ahd_softc *ahd,
				     struct ahd_devinfo *devinfo);
static void ahd_linux_device_queue_depth(struct ahd_softc *ahd,
					 Scsi_Device *device);
static struct ahd_linux_target*	ahd_linux_alloc_target(struct ahd_softc*,
						       u_int, u_int);
static void			ahd_linux_free_target(struct ahd_softc*,
						      struct ahd_linux_target*);
static struct ahd_linux_device*	ahd_linux_alloc_device(struct ahd_softc*,
						       struct ahd_linux_target*,
						       u_int);
static void			ahd_linux_free_device(struct ahd_softc*,
						      struct ahd_linux_device*);
static void ahd_linux_run_device_queue(struct ahd_softc*,
				       struct ahd_linux_device*);
static void ahd_linux_setup_tag_info(char *p, char *end);
static void ahd_linux_setup_rd_strm_info(char *p, char *end);
static int ahd_linux_next_unit(void);
static void ahd_runq_tasklet(unsigned long data);
static int ahd_linux_halt(struct notifier_block *nb, u_long event, void *buf);

static __inline struct ahd_linux_device*
		     ahd_linux_get_device(struct ahd_softc *ahd, u_int channel,
					  u_int target, u_int lun, int alloc);
static __inline void ahd_linux_queue_cmd_complete(struct ahd_softc *ahd,
						  Scsi_Cmnd *cmd);
static __inline void ahd_linux_run_complete_queue(struct ahd_softc *ahd,
						  struct ahd_cmd *acmd);
static __inline void ahd_linux_check_device_queue(struct ahd_softc *ahd,
						  struct ahd_linux_device *dev);
static __inline struct ahd_linux_device *
		     ahd_linux_next_device_to_run(struct ahd_softc *ahd);
static __inline void ahd_linux_run_device_queues(struct ahd_softc *ahd);
static __inline void ahd_linux_sniff_command(struct ahd_softc*, Scsi_Cmnd*,
					     struct scb*);
static __inline void ahd_linux_unmap_scb(struct ahd_softc*, struct scb*);

static __inline int ahd_linux_map_seg(struct ahd_softc *ahd, struct scb *scb,
		 		      struct ahd_dma_seg *sg,
				      bus_addr_t addr, bus_size_t len);

static __inline struct ahd_linux_device*
ahd_linux_get_device(struct ahd_softc *ahd, u_int channel, u_int target,
	       u_int lun, int alloc)
{
	struct ahd_linux_target *targ;
	struct ahd_linux_device *dev;
	u_int target_offset;

	target_offset = target;
	if (channel != 0)
		target_offset += 8;
	targ = ahd->platform_data->targets[target_offset];
	if (targ == NULL) {
		if (alloc != 0) {
			targ = ahd_linux_alloc_target(ahd, channel, target);
			if (targ == NULL)
				return (NULL);
		} else
			return (NULL);
	}
	dev = targ->devices[lun];
	if (dev == NULL && alloc != 0)
		dev = ahd_linux_alloc_device(ahd, targ, lun);
	return (dev);
}

static __inline void
ahd_linux_queue_cmd_complete(struct ahd_softc *ahd, Scsi_Cmnd *cmd)
{
	/*
	 * Typically, the complete queue has very few entries
	 * queued to it before the queue is emptied by
	 * ahd_linux_run_complete_queue, so sorting the entries
	 * by generation number should be inexpensive.
	 * We perform the sort so that commands that complete
	 * with an error are retuned in the order origionally
	 * queued to the controller so that any subsequent retries
	 * are performed in order.  The underlying ahd routines do
	 * not guarantee the order that aborted commands will be
	 * returned to us.
	 */
	struct ahd_completeq *completeq;
	struct ahd_cmd *list_cmd;
	struct ahd_cmd *acmd;

	/*
	 * If we want the request requeued, make sure there
	 * are sufficent retries.  In the old scsi error code,
	 * we used to be able to specify a result code that
	 * bypassed the retry count.  Now we must use this