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-rw-r--r--include/scsi/scsi_host.h405
1 files changed, 336 insertions, 69 deletions
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index ecd53d7872d..94844fc77b9 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -5,15 +5,22 @@
#include <linux/list.h>
#include <linux/types.h>
#include <linux/workqueue.h>
+#include <linux/mutex.h>
+#include <linux/seq_file.h>
+#include <scsi/scsi.h>
+struct request_queue;
struct block_device;
+struct completion;
struct module;
struct scsi_cmnd;
struct scsi_device;
+struct scsi_host_cmd_pool;
struct scsi_target;
struct Scsi_Host;
struct scsi_host_cmd_pool;
struct scsi_transport_template;
+struct blk_queue_tags;
/*
@@ -21,24 +28,29 @@ struct scsi_transport_template;
* NONE: Self evident. Host adapter is not capable of scatter-gather.
* ALL: Means that the host adapter module can do scatter-gather,
* and that there is no limit to the size of the table to which
- * we scatter/gather data.
+ * we scatter/gather data. The value we set here is the maximum
+ * single element sglist. To use chained sglists, the adapter
+ * has to set a value beyond ALL (and correctly use the chain
+ * handling API.
* Anything else: Indicates the maximum number of chains that can be
* used in one scatter-gather request.
*/
#define SG_NONE 0
-#define SG_ALL 0xff
+#define SG_ALL SCSI_MAX_SG_SEGMENTS
+#define MODE_UNKNOWN 0x00
+#define MODE_INITIATOR 0x01
+#define MODE_TARGET 0x02
#define DISABLE_CLUSTERING 0
#define ENABLE_CLUSTERING 1
-enum scsi_eh_timer_return {
- EH_NOT_HANDLED,
- EH_HANDLED,
- EH_RESET_TIMER,
+enum {
+ SCSI_QDEPTH_DEFAULT, /* default requested change, e.g. from sysfs */
+ SCSI_QDEPTH_QFULL, /* scsi-ml requested due to queue full */
+ SCSI_QDEPTH_RAMP_UP, /* scsi-ml requested due to threshold event */
};
-
struct scsi_host_template {
struct module *module;
const char *name;
@@ -117,8 +129,28 @@ struct scsi_host_template {
*
* STATUS: REQUIRED
*/
- int (* queuecommand)(struct scsi_cmnd *,
- void (*done)(struct scsi_cmnd *));
+ int (* queuecommand)(struct Scsi_Host *, struct scsi_cmnd *);
+
+ /*
+ * The transfer functions are used to queue a scsi command to
+ * the LLD. When the driver is finished processing the command
+ * the done callback is invoked.
+ *
+ * This is called to inform the LLD to transfer
+ * scsi_bufflen(cmd) bytes. scsi_sg_count(cmd) speciefies the
+ * number of scatterlist entried in the command and
+ * scsi_sglist(cmd) returns the scatterlist.
+ *
+ * return values: see queuecommand
+ *
+ * If the LLD accepts the cmd, it should set the result to an
+ * appropriate value when completed before calling the done function.
+ *
+ * STATUS: REQUIRED FOR TARGET DRIVERS
+ */
+ /* TODO: rename */
+ int (* transfer_response)(struct scsi_cmnd *,
+ void (*done)(struct scsi_cmnd *));
/*
* This is an error handling strategy routine. You don't need to
@@ -138,27 +170,13 @@ struct scsi_host_template {
*
* Status: REQUIRED (at least one of them)
*/
- int (* eh_strategy_handler)(struct Scsi_Host *);
int (* eh_abort_handler)(struct scsi_cmnd *);
int (* eh_device_reset_handler)(struct scsi_cmnd *);
+ int (* eh_target_reset_handler)(struct scsi_cmnd *);
int (* eh_bus_reset_handler)(struct scsi_cmnd *);
int (* eh_host_reset_handler)(struct scsi_cmnd *);
/*
- * This is an optional routine to notify the host that the scsi
- * timer just fired. The returns tell the timer routine what to
- * do about this:
- *
- * EH_HANDLED: I fixed the error, please complete the command
- * EH_RESET_TIMER: I need more time, reset the timer and
- * begin counting again
- * EH_NOT_HANDLED Begin normal error recovery
- *
- * Status: OPTIONAL
- */
- enum scsi_eh_timer_return (* eh_timed_out)(struct scsi_cmnd *);
-
- /*
* Before the mid layer attempts to scan for a new device where none
* currently exists, it will call this entry in your driver. Should
* your driver need to allocate any structs or perform any other init
@@ -253,61 +271,120 @@ struct scsi_host_template {
void (* target_destroy)(struct scsi_target *);
/*
- * fill in this function to allow the queue depth of this host
- * to be changeable (on a per device basis). returns either
+ * If a host has the ability to discover targets on its own instead
+ * of scanning the entire bus, it can fill in this function and
+ * call scsi_scan_host(). This function will be called periodically
+ * until it returns 1 with the scsi_host and the elapsed time of
+ * the scan in jiffies.
+ *
+ * Status: OPTIONAL
+ */
+ int (* scan_finished)(struct Scsi_Host *, unsigned long);
+
+ /*
+ * If the host wants to be called before the scan starts, but
+ * after the midlayer has set up ready for the scan, it can fill
+ * in this function.
+ *
+ * Status: OPTIONAL
+ */
+ void (* scan_start)(struct Scsi_Host *);
+
+ /*
+ * Fill in this function to allow the queue depth of this host
+ * to be changeable (on a per device basis). Returns either
* the current queue depth setting (may be different from what
* was passed in) or an error. An error should only be
* returned if the requested depth is legal but the driver was
* unable to set it. If the requested depth is illegal, the
* driver should set and return the closest legal queue depth.
*
+ * Status: OPTIONAL
*/
- int (* change_queue_depth)(struct scsi_device *, int);
+ int (* change_queue_depth)(struct scsi_device *, int, int);
/*
- * fill in this function to allow the changing of tag types
+ * Fill in this function to allow the changing of tag types
* (this also allows the enabling/disabling of tag command
* queueing). An error should only be returned if something
* went wrong in the driver while trying to set the tag type.
* If the driver doesn't support the requested tag type, then
* it should set the closest type it does support without
* returning an error. Returns the actual tag type set.
+ *
+ * Status: OPTIONAL
*/
int (* change_queue_type)(struct scsi_device *, int);
/*
- * This function determines the bios parameters for a given
+ * This function determines the BIOS parameters for a given
* harddisk. These tend to be numbers that are made up by
* the host adapter. Parameters:
* size, device, list (heads, sectors, cylinders)
*
- * Status: OPTIONAL */
+ * Status: OPTIONAL
+ */
int (* bios_param)(struct scsi_device *, struct block_device *,
sector_t, int []);
/*
+ * This function is called when one or more partitions on the
+ * device reach beyond the end of the device.
+ *
+ * Status: OPTIONAL
+ */
+ void (*unlock_native_capacity)(struct scsi_device *);
+
+ /*
* Can be used to export driver statistics and other infos to the
* world outside the kernel ie. userspace and it also provides an
* interface to feed the driver with information.
*
* Status: OBSOLETE
*/
- int (*proc_info)(struct Scsi_Host *, char *, char **, off_t, int, int);
+ int (*show_info)(struct seq_file *, struct Scsi_Host *);
+ int (*write_info)(struct Scsi_Host *, char *, int);
+
+ /*
+ * This is an optional routine that allows the transport to become
+ * involved when a scsi io timer fires. The return value tells the
+ * timer routine how to finish the io timeout handling:
+ * EH_HANDLED: I fixed the error, please complete the command
+ * EH_RESET_TIMER: I need more time, reset the timer and
+ * begin counting again
+ * EH_NOT_HANDLED Begin normal error recovery
+ *
+ * Status: OPTIONAL
+ */
+ enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
+
+ /* This is an optional routine that allows transport to initiate
+ * LLD adapter or firmware reset using sysfs attribute.
+ *
+ * Return values: 0 on success, -ve value on failure.
+ *
+ * Status: OPTIONAL
+ */
+
+ int (*host_reset)(struct Scsi_Host *shost, int reset_type);
+#define SCSI_ADAPTER_RESET 1
+#define SCSI_FIRMWARE_RESET 2
+
/*
* Name of proc directory
*/
- char *proc_name;
+ const char *proc_name;
/*
* Used to store the procfs directory if a driver implements the
- * proc_info method.
+ * show_info method.
*/
struct proc_dir_entry *proc_dir;
/*
* This determines if we will use a non-interrupt driven
- * or an interrupt driven scheme, It is set to the maximum number
+ * or an interrupt driven scheme. It is set to the maximum number
* of simultaneous commands a given host adapter will accept.
*/
int can_queue;
@@ -326,14 +403,15 @@ struct scsi_host_template {
* of scatter-gather.
*/
unsigned short sg_tablesize;
+ unsigned short sg_prot_tablesize;
/*
- * If the host adapter has limitations beside segment count
+ * Set this if the host adapter has limitations beside segment count.
*/
unsigned short max_sectors;
/*
- * dma scatter gather segment boundary limit. a segment crossing this
+ * DMA scatter gather segment boundary limit. A segment crossing this
* boundary will be split in two.
*/
unsigned long dma_boundary;
@@ -342,7 +420,7 @@ struct scsi_host_template {
* This specifies "machine infinity" for host templates which don't
* limit the transfer size. Note this limit represents an absolute
* maximum, and may be over the transfer limits allowed for
- * individual devices (e.g. 256 for SCSI-1)
+ * individual devices (e.g. 256 for SCSI-1).
*/
#define SCSI_DEFAULT_MAX_SECTORS 1024
@@ -364,12 +442,17 @@ struct scsi_host_template {
unsigned char present;
/*
- * true if this host adapter uses unchecked DMA onto an ISA bus.
+ * This specifies the mode that a LLD supports.
+ */
+ unsigned supported_mode:2;
+
+ /*
+ * True if this host adapter uses unchecked DMA onto an ISA bus.
*/
unsigned unchecked_isa_dma:1;
/*
- * true if this host adapter can make good use of clustering.
+ * True if this host adapter can make good use of clustering.
* I originally thought that if the tablesize was large that it
* was a waste of CPU cycles to prepare a cluster list, but
* it works out that the Buslogic is faster if you use a smaller
@@ -379,7 +462,7 @@ struct scsi_host_template {
unsigned use_clustering:1;
/*
- * True for emulated SCSI host adapters (e.g. ATAPI)
+ * True for emulated SCSI host adapters (e.g. ATAPI).
*/
unsigned emulated:1;
@@ -389,13 +472,20 @@ struct scsi_host_template {
unsigned skip_settle_delay:1;
/*
- * ordered write support
+ * True if we are using ordered write support.
*/
- unsigned ordered_flush:1;
unsigned ordered_tag:1;
+ /* True if the controller does not support WRITE SAME */
+ unsigned no_write_same:1;
+
/*
- * Countdown for host blocking with no commands outstanding
+ * True if asynchronous aborts are not supported
+ */
+ unsigned no_async_abort:1;
+
+ /*
+ * Countdown for host blocking with no commands outstanding.
*/
unsigned int max_host_blocked;
@@ -411,7 +501,7 @@ struct scsi_host_template {
/*
* Pointer to the sysfs class properties for this host, NULL terminated.
*/
- struct class_device_attribute **shost_attrs;
+ struct device_attribute **shost_attrs;
/*
* Pointer to the SCSI device properties for this host, NULL terminated.
@@ -426,9 +516,43 @@ struct scsi_host_template {
* module_init/module_exit.
*/
struct list_head legacy_hosts;
+
+ /*
+ * Vendor Identifier associated with the host
+ *
+ * Note: When specifying vendor_id, be sure to read the
+ * Vendor Type and ID formatting requirements specified in
+ * scsi_netlink.h
+ */
+ u64 vendor_id;
+
+ /*
+ * Additional per-command data allocated for the driver.
+ */
+ unsigned int cmd_size;
+ struct scsi_host_cmd_pool *cmd_pool;
};
/*
+ * Temporary #define for host lock push down. Can be removed when all
+ * drivers have been updated to take advantage of unlocked
+ * queuecommand.
+ *
+ */
+#define DEF_SCSI_QCMD(func_name) \
+ int func_name(struct Scsi_Host *shost, struct scsi_cmnd *cmd) \
+ { \
+ unsigned long irq_flags; \
+ int rc; \
+ spin_lock_irqsave(shost->host_lock, irq_flags); \
+ scsi_cmd_get_serial(shost, cmd); \
+ rc = func_name##_lck (cmd, cmd->scsi_done); \
+ spin_unlock_irqrestore(shost->host_lock, irq_flags); \
+ return rc; \
+ }
+
+
+/*
* shost state: If you alter this, you also need to alter scsi_sysfs.c
* (for the ascii descriptions) and the state model enforcer:
* scsi_host_set_state()
@@ -463,30 +587,38 @@ struct Scsi_Host {
spinlock_t default_lock;
spinlock_t *host_lock;
- struct semaphore scan_mutex;/* serialize scanning activity */
+ struct mutex scan_mutex;/* serialize scanning activity */
struct list_head eh_cmd_q;
struct task_struct * ehandler; /* Error recovery thread. */
- struct semaphore * eh_action; /* Wait for specific actions on the
- host. */
- unsigned int eh_active:1; /* Indicates the eh thread is awake and active if
- this is true. */
+ struct completion * eh_action; /* Wait for specific actions on the
+ host. */
wait_queue_head_t host_wait;
struct scsi_host_template *hostt;
struct scsi_transport_template *transportt;
/*
+ * Area to keep a shared tag map (if needed, will be
+ * NULL if not).
+ */
+ struct blk_queue_tag *bqt;
+
+ /*
* The following two fields are protected with host_lock;
* however, eh routines can safely access during eh processing
* without acquiring the lock.
*/
unsigned int host_busy; /* commands actually active on low-level */
unsigned int host_failed; /* commands that failed. */
+ unsigned int host_eh_scheduled; /* EH scheduled without command */
- unsigned short host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
- int resetting; /* if set, it means that last_reset is a valid value */
+ unsigned int host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
+
+ /* next two fields are used to bound the time spent in error handling */
+ int eh_deadline;
unsigned long last_reset;
+
/*
* These three parameters can be used to allow for wide scsi,
* and for host adapters that support multiple busses
@@ -509,26 +641,26 @@ struct Scsi_Host {
/*
* The maximum length of SCSI commands that this host can accept.
* Probably 12 for most host adapters, but could be 16 for others.
+ * or 260 if the driver supports variable length cdbs.
* For drivers that don't set this field, a value of 12 is
- * assumed. I am leaving this as a number rather than a bit
- * because you never know what subsequent SCSI standards might do
- * (i.e. could there be a 20 byte or a 24-byte command a few years
- * down the road?).
+ * assumed.
*/
- unsigned char max_cmd_len;
+ unsigned short max_cmd_len;
int this_id;
int can_queue;
short cmd_per_lun;
short unsigned int sg_tablesize;
+ short unsigned int sg_prot_tablesize;
short unsigned int max_sectors;
unsigned long dma_boundary;
/*
* Used to assign serial numbers to the cmds.
* Protected by the host lock.
*/
- unsigned long cmd_serial_number, cmd_pid;
+ unsigned long cmd_serial_number;
+ unsigned active_mode:2;
unsigned unchecked_isa_dma:1;
unsigned use_clustering:1;
unsigned use_blk_tcq:1;
@@ -542,23 +674,39 @@ struct Scsi_Host {
/*
* Host uses correct SCSI ordering not PC ordering. The bit is
* set for the minority of drivers whose authors actually read
- * the spec ;)
+ * the spec ;).
*/
unsigned reverse_ordering:1;
/*
- * ordered write support
+ * Ordered write support
*/
- unsigned ordered_flush:1;
unsigned ordered_tag:1;
+ /* Task mgmt function in progress */
+ unsigned tmf_in_progress:1;
+
+ /* Asynchronous scan in progress */
+ unsigned async_scan:1;
+
+ /* Don't resume host in EH */
+ unsigned eh_noresume:1;
+
+ /* The controller does not support WRITE SAME */
+ unsigned no_write_same:1;
+
/*
* Optional work queue to be utilized by the transport
*/
- char work_q_name[KOBJ_NAME_LEN];
+ char work_q_name[20];
struct workqueue_struct *work_q;
/*
+ * Task management function work queue
+ */
+ struct workqueue_struct *tmf_work_q;
+
+ /*
* Host has rejected a command because it was busy.
*/
unsigned int host_blocked;
@@ -568,6 +716,16 @@ struct Scsi_Host {
*/
unsigned int max_host_blocked;
+ /* Protection Information */
+ unsigned int prot_capabilities;
+ unsigned char prot_guard_type;
+
+ /*
+ * q used for scsi_tgt msgs, async events or any other requests that
+ * need to be processed in userspace
+ */
+ struct request_queue *uspace_req_q;
+
/* legacy crap */
unsigned long base;
unsigned long io_port;
@@ -579,8 +737,7 @@ struct Scsi_Host {
enum scsi_host_state shost_state;
/* ldm bits */
- struct device shost_gendev;
- struct class_device shost_classdev;
+ struct device shost_gendev, shost_dev;
/*
* List of hosts per template.
@@ -598,6 +755,12 @@ struct Scsi_Host {
void *shost_data;
/*
+ * Points to the physical bus device we'd use to do DMA
+ * Needed just in case we have virtual hosts.
+ */
+ struct device *dma_dev;
+
+ /*
* We should ensure that this is aligned, both for better performance
* and also because some compilers (m68k) don't automatically force
* alignment to a long boundary.
@@ -607,11 +770,15 @@ struct Scsi_Host {
};
#define class_to_shost(d) \
- container_of(d, struct Scsi_Host, shost_classdev)
+ container_of(d, struct Scsi_Host, shost_dev)
#define shost_printk(prefix, shost, fmt, a...) \
dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a)
+static inline void *shost_priv(struct Scsi_Host *shost)
+{
+ return (void *)shost->hostdata;
+}
int scsi_is_host_device(const struct device *);
@@ -629,14 +796,17 @@ static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
{
return shost->shost_state == SHOST_RECOVERY ||
shost->shost_state == SHOST_CANCEL_RECOVERY ||
- shost->shost_state == SHOST_DEL_RECOVERY;
+ shost->shost_state == SHOST_DEL_RECOVERY ||
+ shost->tmf_in_progress;
}
extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
extern void scsi_flush_work(struct Scsi_Host *);
extern struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *, int);
-extern int __must_check scsi_add_host(struct Scsi_Host *, struct device *);
+extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *,
+ struct device *,
+ struct device *);
extern void scsi_scan_host(struct Scsi_Host *);
extern void scsi_rescan_device(struct device *);
extern void scsi_remove_host(struct Scsi_Host *);
@@ -644,12 +814,14 @@ extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
extern void scsi_host_put(struct Scsi_Host *t);
extern struct Scsi_Host *scsi_host_lookup(unsigned short);
extern const char *scsi_host_state_name(enum scsi_host_state);
+extern void scsi_cmd_get_serial(struct Scsi_Host *, struct scsi_cmnd *);
extern u64 scsi_calculate_bounce_limit(struct Scsi_Host *);
-static inline void scsi_assign_lock(struct Scsi_Host *shost, spinlock_t *lock)
+static inline int __must_check scsi_add_host(struct Scsi_Host *host,
+ struct device *dev)
{
- shost->host_lock = lock;
+ return scsi_add_host_with_dma(host, dev, dev);
}
static inline struct device *scsi_get_device(struct Scsi_Host *shost)
@@ -663,13 +835,17 @@ static inline struct device *scsi_get_device(struct Scsi_Host *shost)
**/
static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)
{
- return shost->shost_state == SHOST_RUNNING;
+ return shost->shost_state == SHOST_RUNNING ||
+ shost->shost_state == SHOST_RECOVERY;
}
extern void scsi_unblock_requests(struct Scsi_Host *);
extern void scsi_block_requests(struct Scsi_Host *);
struct class_container;
+
+extern struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost,
+ void (*) (struct request_queue *));
/*
* These two functions are used to allocate and free a pseudo device
* which will connect to the host adapter itself rather than any
@@ -680,6 +856,97 @@ struct class_container;
extern void scsi_free_host_dev(struct scsi_device *);
extern struct scsi_device *scsi_get_host_dev(struct Scsi_Host *);
+/*
+ * DIF defines the exchange of protection information between
+ * initiator and SBC block device.
+ *
+ * DIX defines the exchange of protection information between OS and
+ * initiator.
+ */
+enum scsi_host_prot_capabilities {
+ SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */
+ SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */
+ SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */
+
+ SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */
+ SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */
+ SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */
+ SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */
+};
+
+/*
+ * SCSI hosts which support the Data Integrity Extensions must
+ * indicate their capabilities by setting the prot_capabilities using
+ * this call.
+ */
+static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask)
+{
+ shost->prot_capabilities = mask;
+}
+
+static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost)
+{
+ return shost->prot_capabilities;
+}
+
+static inline int scsi_host_prot_dma(struct Scsi_Host *shost)
+{
+ return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION;
+}
+
+static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type)
+{
+ static unsigned char cap[] = { 0,
+ SHOST_DIF_TYPE1_PROTECTION,
+ SHOST_DIF_TYPE2_PROTECTION,
+ SHOST_DIF_TYPE3_PROTECTION };
+
+ if (target_type >= ARRAY_SIZE(cap))
+ return 0;
+
+ return shost->prot_capabilities & cap[target_type] ? target_type : 0;
+}
+
+static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type)
+{
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+ static unsigned char cap[] = { SHOST_DIX_TYPE0_PROTECTION,
+ SHOST_DIX_TYPE1_PROTECTION,
+ SHOST_DIX_TYPE2_PROTECTION,
+ SHOST_DIX_TYPE3_PROTECTION };
+
+ if (target_type >= ARRAY_SIZE(cap))
+ return 0;
+
+ return shost->prot_capabilities & cap[target_type];
+#endif
+ return 0;
+}
+
+/*
+ * All DIX-capable initiators must support the T10-mandated CRC
+ * checksum. Controllers can optionally implement the IP checksum
+ * scheme which has much lower impact on system performance. Note
+ * that the main rationale for the checksum is to match integrity
+ * metadata with data. Detecting bit errors are a job for ECC memory
+ * and buses.
+ */
+
+enum scsi_host_guard_type {
+ SHOST_DIX_GUARD_CRC = 1 << 0,
+ SHOST_DIX_GUARD_IP = 1 << 1,
+};
+
+static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type)
+{
+ shost->prot_guard_type = type;
+}
+
+static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost)
+{
+ return shost->prot_guard_type;
+}
+
/* legacy interfaces */
extern struct Scsi_Host *scsi_register(struct scsi_host_template *, int);
extern void scsi_unregister(struct Scsi_Host *);