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Subject[PATCH] scsi host cleanup 1/3 (base) (corrected)
I had diffed against a tree missing a compile fix this is the correct base
patch.

This is a resend of my previous patch clean ups to the scsi_host lists.

* Made function naming consistent with rest of SCSI
* Corrected a problem with driverfs registration to early. Also
changed from put_device to device_unregister.
* Fixed a regression in my previous patch that the scsi_host
list was not sorted by host number. When we get some device
naming this hack can be removed.
* Switch scsi host template, name, host lists to struct
list_head's.
* Moved all scsi_host related register / unregister functions
into hosts.c
* Added list accessor interface and created a function similar
to driverfs bus_for_each_dev.

The full patch is available at:
http://www-124.ibm.com/storageio/patches/2.5/scsi-host

-andmike
--
Michael Anderson
andmike@us.ibm.com

hosts.c | 890 +++++++++++++++++++++++++++++++++++++++++++++++++---------------
hosts.h | 97 +++---
2 files changed, 734 insertions(+), 253 deletions(-)
------

diff -Nru a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
--- a/drivers/scsi/hosts.c Thu Oct 17 00:53:47 2002
+++ b/drivers/scsi/hosts.c Thu Oct 17 00:53:47 2002
@@ -15,12 +15,15 @@
* Updated to reflect the new initialization scheme for the higher
* level of scsi drivers (sd/sr/st)
* September 17, 2000 Torben Mathiasen <tmm@image.dk>
+ *
+ * Restructured scsi_host lists and associated functions.
+ * September 04, 2002 Mike Anderson (andmike@us.ibm.com)
*/


/*
* This file contains the medium level SCSI
- * host interface initialization, as well as the scsi_hosts array of SCSI
+ * host interface initialization, as well as the scsi_hosts list of SCSI
* hosts currently present in the system.
*/

@@ -31,232 +34,711 @@
#include <linux/mm.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/smp_lock.h>

#define __KERNEL_SYSCALLS__

#include <linux/unistd.h>
+#include <asm/dma.h>

#include "scsi.h"
#include "hosts.h"

-/*
-static const char RCSid[] = "$Header: /vger/u4/cvs/linux/drivers/scsi/hosts.c,v 1.20 1996/12/12 19:18:32 davem Exp $";
-*/
+LIST_HEAD(scsi_host_tmpl_list);
+LIST_HEAD(scsi_host_hn_list);

-/*
- * The scsi host entries should be in the order you wish the
- * cards to be detected. A driver may appear more than once IFF
- * it can deal with being detected (and therefore initialized)
- * with more than one simultaneous host number, can handle being
- * reentrant, etc.
+LIST_HEAD(scsi_host_list);
+spinlock_t scsi_host_list_lock = SPIN_LOCK_UNLOCKED;
+
+struct Scsi_Device_Template * scsi_devicelist;
+
+static int scsi_host_next_hn; /* host_no for next new host */
+static int scsi_hosts_registered; /* cnt of registered scsi hosts */
+
+/**
+ * scsi_tp_for_each_host - call function for each scsi host off a template
+ * @shost_tp: a pointer to a scsi host template
+ * @callback: a pointer to callback function
*
- * They may appear in any order, as each SCSI host is told which host
- * number it is during detection.
- */
+ * Return value:
+ * 0 on Success / 1 on Failure
+ **/
+int scsi_tp_for_each_host(Scsi_Host_Template *shost_tp, int
+ (*callback)(struct Scsi_Host *shost))
+{
+ struct list_head *lh, *lh_sf;
+ struct Scsi_Host *shost;

-/*
- * When figure is run, we don't want to link to any object code. Since
- * the macro for each host will contain function pointers, we cannot
- * use it and instead must use a "blank" that does no such
- * idiocy.
- */
+ spin_lock(&scsi_host_list_lock);

-Scsi_Host_Template * scsi_hosts;
+ list_for_each_safe(lh, lh_sf, &scsi_host_list) {
+ shost = list_entry(lh, struct Scsi_Host, sh_list);
+ if (shost->hostt == shost_tp) {
+ spin_unlock(&scsi_host_list_lock);
+ callback(shost);
+ spin_lock(&scsi_host_list_lock);
+ }
+ }

+ spin_unlock(&scsi_host_list_lock);

-/*
- * Our semaphores and timeout counters, where size depends on
- * MAX_SCSI_HOSTS here.
- */
+ return 0;
+}

-Scsi_Host_Name * scsi_host_no_list;
-struct Scsi_Host * scsi_hostlist;
-struct Scsi_Device_Template * scsi_devicelist;
+/**
+ * scsi_host_generic_release - default release function for hosts
+ * @shost:
+ *
+ * Description:
+ * This is the default case for the release function. It should do
+ * the right thing for most correctly written host adapters.
+ **/
+static void scsi_host_generic_release(struct Scsi_Host *shost)
+{
+ if (shost->irq)
+ free_irq(shost->irq, NULL);
+ if (shost->dma_channel != 0xff)
+ free_dma(shost->dma_channel);
+ if (shost->io_port && shost->n_io_port)
+ release_region(shost->io_port, shost->n_io_port);
+}

-int max_scsi_hosts;
-int next_scsi_host;
+/**
+ * scsi_host_chk_and_release - check a scsi host for release and release
+ * @shost: a pointer to a scsi host to release
+ *
+ * Return value:
+ * 0 on Success / 1 on Failure
+ **/
+int scsi_host_chk_and_release(struct Scsi_Host *shost)
+{
+ int pcount;
+ Scsi_Device *sdev;
+ struct Scsi_Device_Template *sdev_tp;
+ Scsi_Cmnd *scmd;
+
+ /*
+ * Current policy is all shosts go away on unregister.
+ */
+ if (shost->hostt->module && GET_USE_COUNT(shost->hostt->module))
+ return 1;
+
+ /*
+ * FIXME Do ref counting. We force all of the devices offline to
+ * help prevent race conditions where other hosts/processors could
+ * try and get in and queue a command.
+ */
+ for (sdev = shost->host_queue; sdev; sdev = sdev->next)
+ sdev->online = FALSE;
+
+ for (sdev = shost->host_queue; sdev; sdev = sdev->next) {
+ /*
+ * Loop over all of the commands associated with the
+ * device. If any of them are busy, then set the state
+ * back to inactive and bail.
+ */
+ for (scmd = sdev->device_queue; scmd; scmd = scmd->next) {
+ if (scmd->request && scmd->request->rq_status !=
+ RQ_INACTIVE) {
+ printk(KERN_ERR "SCSI device not inactive"
+ "- rq_status=%d, target=%d, pid=%ld,"
+ "state=%d, owner=%d.\n",
+ scmd->request->rq_status,
+ scmd->target, scmd->pid,
+ scmd->state, scmd->owner);
+ for (sdev = shost->host_queue; sdev;
+ sdev = sdev->next) {
+ for (scmd = sdev->device_queue; scmd;
+ scmd = scmd->next)
+ if (scmd->request->rq_status ==
+ RQ_SCSI_DISCONNECTING)
+ scmd->request->rq_status = RQ_INACTIVE;
+ }
+ printk(KERN_ERR "Device busy???\n");
+ return 1;
+ }
+ /*
+ * No, this device is really free. Mark it as such, and
+ * continue on.
+ */
+ scmd->state = SCSI_STATE_DISCONNECTING;
+ if (scmd->request)
+ scmd->request->rq_status =
+ RQ_SCSI_DISCONNECTING; /* Mark as
+ busy */
+ }
+ }

-void
-scsi_unregister(struct Scsi_Host * sh){
- struct Scsi_Host * shpnt;
- Scsi_Host_Name *shn;
-
- if(scsi_hostlist == sh)
- scsi_hostlist = sh->next;
- else {
- shpnt = scsi_hostlist;
- while(shpnt->next != sh) shpnt = shpnt->next;
- shpnt->next = shpnt->next->next;
- }
-
- /*
- * We have to unregister the host from the scsi_host_no_list as well.
- * Decide by the host_no not by the name because most host drivers are
- * able to handle more than one adapters from the same kind (or family).
- */
- for ( shn=scsi_host_no_list; shn && (sh->host_no != shn->host_no);
- shn=shn->next);
- if (shn) shn->host_registered = 0;
- /* else {} : This should not happen, we should panic here... */
-
- /* If we are removing the last host registered, it is safe to reuse
- * its host number (this avoids "holes" at boot time) (DB)
- * It is also safe to reuse those of numbers directly below which have
- * been released earlier (to avoid some holes in numbering).
- */
- if(sh->host_no == max_scsi_hosts - 1) {
- while(--max_scsi_hosts >= next_scsi_host) {
- shpnt = scsi_hostlist;
- while(shpnt && shpnt->host_no != max_scsi_hosts - 1)
- shpnt = shpnt->next;
- if(shpnt)
- break;
- }
- }
- next_scsi_host--;
- kfree((char *) sh);
-}
-
-/* We call this when we come across a new host adapter. We only do this
- * once we are 100% sure that we want to use this host adapter - it is a
- * pain to reverse this, so we try to avoid it
- */
+ /*
+ * Next we detach the high level drivers from the Scsi_Device
+ * structures
+ */
+ for (sdev = shost->host_queue; sdev; sdev = sdev->next) {
+ for (sdev_tp = scsi_devicelist; sdev_tp;
+ sdev_tp = sdev_tp->next)
+ if (sdev_tp->detach)
+ (*sdev_tp->detach) (sdev);
+
+ /* If something still attached, punt */
+ if (sdev->attached) {
+ printk(KERN_ERR "Attached usage count = %d\n",
+ sdev->attached);
+ return 1;
+ }
+
+ if (shost->hostt->slave_detach)
+ (*shost->hostt->slave_detach) (sdev);
+
+ devfs_unregister(sdev->de);
+ device_unregister(&sdev->sdev_driverfs_dev);
+ }
+
+ /* Next we free up the Scsi_Cmnd structures for this host */
+
+ for (sdev = shost->host_queue; sdev;
+ sdev = shost->host_queue) {
+ scsi_release_commandblocks(sdev);
+ blk_cleanup_queue(&sdev->request_queue);
+ /* Next free up the Scsi_Device structures for this host */
+ shost->host_queue = sdev->next;
+ if (sdev->inquiry)
+ kfree(sdev->inquiry);
+ kfree(sdev);
+ }
+
+ /* Remove the instance of the individual hosts */
+ pcount = scsi_hosts_registered;
+ if (shost->hostt->release)
+ (*shost->hostt->release) (shost);
+ else {
+ scsi_host_generic_release(shost);
+ }
+
+ if (pcount == scsi_hosts_registered)
+ scsi_unregister(shost);
+
+ return 0;
+}
+
+/**
+ * scsi_unregister - unregister a scsi host
+ * @shost: scsi host to be unregistered
+ **/
+void scsi_unregister(struct Scsi_Host *shost)
+{
+ struct list_head *lh;
+ Scsi_Host_Name *shost_name;
+
+ /* Remove shost from scsi_host_list */
+ spin_lock(&scsi_host_list_lock);
+ list_del(&shost->sh_list);
+ spin_unlock(&scsi_host_list_lock);
+
+ /* Unregister from scsi_host_hn_list */
+ list_for_each(lh, &scsi_host_hn_list) {
+ shost_name = list_entry(lh, Scsi_Host_Name, shn_list);
+ if (shost->host_no == shost_name->host_no)
+ shost_name->host_registered = 0;
+ }
+
+ /*
+ * Next, kill the kernel error recovery thread for this host.
+ */
+ if (shost->ehandler) {
+ DECLARE_MUTEX_LOCKED(sem);
+ shost->eh_notify = &sem;
+ send_sig(SIGHUP, shost->ehandler, 1);
+ down(&sem);
+ shost->eh_notify = NULL;
+ }
+
+ scsi_hosts_registered--;
+ shost->hostt->present--;
+
+ /* Cleanup proc and driverfs */
+#ifdef CONFIG_PROC_FS
+ scsi_proc_host_rm(shost);
+ if (!shost->hostt->present)
+ remove_proc_entry(shost->hostt->proc_name, proc_scsi);
+#endif
+ device_unregister(&shost->host_driverfs_dev);
+
+ kfree(shost);
+}
+
+/**
+ * scsi_host_hn_add - allocate and add new Scsi_Host_Name
+ * @name: String to store in name field
+ *
+ * Return value:
+ * Pointer to a new Scsi_Host_Name
+ **/
+Scsi_Host_Name *scsi_host_hn_add(char *name)
+{
+ Scsi_Host_Name *shost_name;
+ int len;
+
+ len = strlen(name);
+ shost_name = kmalloc(sizeof(*shost_name), GFP_KERNEL);
+ if (!shost_name) {
+ printk(KERN_ERR "%s: out of memory at line %d.\n",
+ __FUNCTION__, __LINE__);
+ return NULL;
+ }
+ shost_name->name = kmalloc(len + 1, GFP_KERNEL);
+ if (!shost_name->name) {
+ kfree(shost_name);
+ printk(KERN_ERR "%s: out of memory at line %d.\n",
+ __FUNCTION__, __LINE__);
+ return NULL;
+ }
+
+ if (len)
+ strncpy(shost_name->name, name, len);
+ shost_name->name[len] = 0;
+ shost_name->host_no = scsi_host_next_hn++;
+ shost_name->host_registered = 0;
+ list_add_tail(&shost_name->shn_list, &scsi_host_hn_list);
+
+ return shost_name;
+}
+
+/**
+ * scsi_register - register a scsi host adapter instance.
+ * @shost_tp: pointer to scsi host template
+ * @xtr_bytes: extra bytes to allocate for driver
+ *
+ * Note:
+ * We call this when we come across a new host adapter. We only do
+ * this once we are 100% sure that we want to use this host adapter -
+ * it is a pain to reverse this, so we try to avoid it
+ *
+ * Return value:
+ * Pointer to a new Scsi_Host
+ **/
extern int blk_nohighio;
-struct Scsi_Host * scsi_register(Scsi_Host_Template * tpnt, int j)
+struct Scsi_Host * scsi_register(Scsi_Host_Template *shost_tp, int xtr_bytes)
{
- struct Scsi_Host * retval, *shpnt, *o_shp;
- Scsi_Host_Name *shn, *shn2;
- int flag_new = 1;
- const char * hname;
- size_t hname_len;
- retval = (struct Scsi_Host *)kmalloc(sizeof(struct Scsi_Host) + j,
- (tpnt->unchecked_isa_dma && j ?
- GFP_DMA : 0) | GFP_ATOMIC);
- if(retval == NULL)
- {
- printk("scsi: out of memory in scsi_register.\n");
- return NULL;
- }
-
- memset(retval, 0, sizeof(struct Scsi_Host) + j);
-
- /* trying to find a reserved entry (host_no) */
- hname = (tpnt->proc_name) ? tpnt->proc_name : "";
- hname_len = strlen(hname);
- for (shn = scsi_host_no_list;shn;shn = shn->next) {
- if (!(shn->host_registered) &&
- (hname_len > 0) && (0 == strncmp(hname, shn->name, hname_len))) {
- flag_new = 0;
- retval->host_no = shn->host_no;
- shn->host_registered = 1;
- break;
- }
- }
- spin_lock_init(&retval->default_lock);
- scsi_assign_lock(retval, &retval->default_lock);
- atomic_set(&retval->host_active,0);
- retval->host_busy = 0;
- retval->host_failed = 0;
- if (flag_new) {
- shn = (Scsi_Host_Name *) kmalloc(sizeof(Scsi_Host_Name), GFP_ATOMIC);
- if (!shn) {
- kfree(retval);
- printk(KERN_ERR "scsi: out of memory(2) in scsi_register.\n");
- return NULL;
- }
- shn->name = kmalloc(hname_len + 1, GFP_ATOMIC);
- if (hname_len > 0)
- strncpy(shn->name, hname, hname_len);
- shn->name[hname_len] = 0;
- shn->host_no = max_scsi_hosts++;
- shn->host_registered = 1;
- shn->next = NULL;
- if (scsi_host_no_list) {
- for (shn2 = scsi_host_no_list;shn2->next;shn2 = shn2->next)
- ;
- shn2->next = shn;
- }
- else
- scsi_host_no_list = shn;
- retval->host_no = shn->host_no;
- }
- next_scsi_host++;
- retval->host_queue = NULL;
- init_waitqueue_head(&retval->host_wait);
- retval->resetting = 0;
- retval->last_reset = 0;
- retval->irq = 0;
- retval->dma_channel = 0xff;
-
- /* These three are default values which can be overridden */
- retval->max_channel = 0;
- retval->max_id = 8;
- retval->max_lun = 8;
-
- /*
- * All drivers right now should be able to handle 12 byte commands.
- * Every so often there are requests for 16 byte commands, but individual
- * low-level drivers need to certify that they actually do something
- * sensible with such commands.
- */
- retval->max_cmd_len = 12;
-
- retval->unique_id = 0;
- retval->io_port = 0;
- retval->hostt = tpnt;
- retval->next = NULL;
- retval->in_recovery = 0;
- retval->ehandler = NULL; /* Initial value until the thing starts up. */
- retval->eh_notify = NULL; /* Who we notify when we exit. */
+ struct Scsi_Host *shost, *shost_scr;
+ Scsi_Host_Name *shost_name = NULL;
+ Scsi_Host_Name *shn = NULL;
+ char *hname;
+ size_t hname_len;
+ struct list_head *lh;
+ int gfp_mask;
+ DECLARE_MUTEX_LOCKED(sem);
+
+ gfp_mask = GFP_KERNEL;
+ if (shost_tp->unchecked_isa_dma && xtr_bytes)
+ gfp_mask |= __GFP_DMA;
+
+ shost = kmalloc(sizeof(struct Scsi_Host) + xtr_bytes, gfp_mask);
+ if (!shost) {
+ printk(KERN_ERR "%s: out of memory.\n", __FUNCTION__);
+ return NULL;
+ }

- retval->max_host_blocked = tpnt->max_host_blocked ? tpnt->max_host_blocked : SCSI_DEFAULT_HOST_BLOCKED;
+ memset(shost, 0, sizeof(struct Scsi_Host) + xtr_bytes);

- retval->host_blocked = 0;
- retval->host_self_blocked = FALSE;
+ /*
+ * Determine host number. Check reserved first before allocating
+ * new one
+ */
+ hname = (shost_tp->proc_name) ? shost_tp->proc_name : "";
+ hname_len = strlen(hname);
+
+ if (hname_len)
+ list_for_each(lh, &scsi_host_hn_list) {
+ shn = list_entry(lh, Scsi_Host_Name, shn_list);
+ if (!(shn->host_registered) &&
+ !strncmp(hname, shn->name, hname_len)) {
+ shost_name = shn;
+ break;
+ }
+ }
+
+ if (!shost_name) {
+ shost_name = scsi_host_hn_add(hname);
+ if (!shost_name) {
+ kfree(shost);
+ return NULL;
+ }
+ }
+
+ shost->host_no = shost_name->host_no;
+ shost_name->host_registered = 1;
+ scsi_hosts_registered++;
+
+ spin_lock_init(&shost->default_lock);
+ scsi_assign_lock(shost, &shost->default_lock);
+ atomic_set(&shost->host_active,0);
+
+ init_waitqueue_head(&shost->host_wait);
+ shost->dma_channel = 0xff;
+
+ /* These three are default values which can be overridden */
+ shost->max_channel = 0;
+ shost->max_id = 8;
+ shost->max_lun = 8;
+
+ /*
+ * All drivers right now should be able to handle 12 byte
+ * commands. Every so often there are requests for 16 byte
+ * commands, but individual low-level drivers need to certify that
+ * they actually do something sensible with such commands.
+ */
+ shost->max_cmd_len = 12;
+ shost->hostt = shost_tp;
+ shost->host_blocked = FALSE;
+ shost->host_self_blocked = FALSE;

#ifdef DEBUG
- printk("Register %x %x: %d\n", (int)retval, (int)retval->hostt, j);
+ printk("%s: %x %x: %d\n", __FUNCTION_ (int)shost,
+ (int)shost->hostt, xtr_bytes);
#endif

- /* The next six are the default values which can be overridden
- * if need be */
- retval->this_id = tpnt->this_id;
- retval->can_queue = tpnt->can_queue;
- retval->sg_tablesize = tpnt->sg_tablesize;
- retval->cmd_per_lun = tpnt->cmd_per_lun;
- retval->unchecked_isa_dma = tpnt->unchecked_isa_dma;
- retval->use_clustering = tpnt->use_clustering;
- if (!blk_nohighio)
- retval->highmem_io = tpnt->highmem_io;
-
- retval->max_sectors = tpnt->max_sectors;
- retval->use_blk_tcq = tpnt->use_blk_tcq;
-
- if(!scsi_hostlist)
- scsi_hostlist = retval;
- else {
- shpnt = scsi_hostlist;
- if (retval->host_no < shpnt->host_no) {
- retval->next = shpnt;
- wmb(); /* want all to see these writes in this order */
- scsi_hostlist = retval;
+ /*
+ * The next six are the default values which can be overridden if
+ * need be
+ */
+ shost->this_id = shost_tp->this_id;
+ shost->can_queue = shost_tp->can_queue;
+ shost->sg_tablesize = shost_tp->sg_tablesize;
+ shost->cmd_per_lun = shost_tp->cmd_per_lun;
+ shost->unchecked_isa_dma = shost_tp->unchecked_isa_dma;
+ shost->use_clustering = shost_tp->use_clustering;
+ if (!blk_nohighio)
+ shost->highmem_io = shost_tp->highmem_io;
+
+ shost->max_sectors = shost_tp->max_sectors;
+ shost->use_blk_tcq = shost_tp->use_blk_tcq;
+
+ spin_lock(&scsi_host_list_lock);
+ /*
+ * FIXME When device naming is complete remove this step that
+ * orders the scsi_host_list by host number and just do a
+ * list_add_tail.
+ */
+ list_for_each(lh, &scsi_host_list) {
+ shost_scr = list_entry(lh, struct Scsi_Host, sh_list);
+ if (shost->host_no < shost_scr->host_no) {
+ __list_add(&shost->sh_list, shost_scr->sh_list.prev,
+ &shost_scr->sh_list);
+ goto found;
+ }
+ }
+ list_add_tail(&shost->sh_list, &scsi_host_list);
+found:
+ spin_unlock(&scsi_host_list_lock);
+
+#ifdef CONFIG_PROC_FS
+ /* Add the new driver to /proc/scsi if not already there */
+ if (!shost_tp->proc_dir)
+ scsi_proc_host_mkdir(shost_tp);
+ scsi_proc_host_add(shost);
+#endif
+
+ strncpy(shost->host_driverfs_dev.name, shost_tp->proc_name,
+ DEVICE_NAME_SIZE-1);
+ sprintf(shost->host_driverfs_dev.bus_id, "scsi%d",
+ shost->host_no);
+
+ shost->eh_notify = &sem;
+ kernel_thread((int (*)(void *)) scsi_error_handler, (void *) shost, 0);
+ /*
+ * Now wait for the kernel error thread to initialize itself
+ * as it might be needed when we scan the bus.
+ */
+ down(&sem);
+ shost->eh_notify = NULL;
+
+ shost->hostt->present++;
+
+ return shost;
+}
+
+
+/**
+ * scsi_register_host - register a low level host driver
+ * @shost_tp: pointer to a scsi host driver template
+ *
+ * Return value:
+ * 0 on Success / 1 on Failure.
+ **/
+int scsi_register_host(Scsi_Host_Template *shost_tp)
+{
+ int cur_cnt;
+ Scsi_Device *sdev;
+ struct Scsi_Device_Template *sdev_tp;
+ struct list_head *lh;
+ struct Scsi_Host *shost;
+
+ /*
+ * Check no detect routine.
+ */
+ if (!shost_tp->detect)
+ return 1;
+
+ /* If max_sectors isn't set, default to max */
+ if (!shost_tp->max_sectors)
+ shost_tp->max_sectors = 1024;
+
+ cur_cnt = scsi_hosts_registered;
+
+ MOD_INC_USE_COUNT;
+
+ /*
+ * The detect routine must carefully spinunlock/spinlock if it
+ * enables interrupts, since all interrupt handlers do spinlock as
+ * well.
+ */
+
+ /*
+ * detect should do its own locking
+ * FIXME present is now set is scsi_register which breaks manual
+ * registration code below.
+ */
+ shost_tp->detect(shost_tp);
+
+ if (shost_tp->present) {
+ /*
+ * FIXME Who needs manual registration and why???
+ */
+ if (cur_cnt == scsi_hosts_registered) {
+ if (shost_tp->present > 1) {
+ printk(KERN_ERR "scsi: Failure to register"
+ "low-level scsi driver");
+ scsi_unregister_host(shost_tp);
+ return 1;
+ }
+ /*
+ * The low-level driver failed to register a driver.
+ * We can do this now.
+ */
+ if(scsi_register(shost_tp, 0)==NULL) {
+ printk(KERN_ERR "scsi: register failed.\n");
+ scsi_unregister_host(shost_tp);
+ return 1;
+ }
+ }
+
+ list_add_tail(&shost_tp->shtp_list, &scsi_host_tmpl_list);
+
+ /* The next step is to call scan_scsis here. This generates the
+ * Scsi_Devices entries
+ */
+ list_for_each(lh, &scsi_host_list) {
+ shost = list_entry(lh, struct Scsi_Host, sh_list);
+ if (shost->hostt == shost_tp) {
+ const char *dm_name;
+ if (shost_tp->info) {
+ dm_name = shost_tp->info(shost);
+ } else {
+ dm_name = shost_tp->name;
+ }
+ printk(KERN_INFO "scsi%d : %s\n",
+ shost->host_no, dm_name);
+
+ /* first register parent with driverfs */
+ device_register(&shost->host_driverfs_dev);
+ scan_scsis(shost, 0, 0, 0, 0);
+ }
+ }
+
+ for (sdev_tp = scsi_devicelist; sdev_tp;
+ sdev_tp = sdev_tp->next) {
+ if (sdev_tp->init && sdev_tp->dev_noticed)
+ (*sdev_tp->init) ();
+ }
+
+ /*
+ * Next we create the Scsi_Cmnd structures for this host
+ */
+ list_for_each(lh, &scsi_host_list) {
+ shost = list_entry(lh, struct Scsi_Host, sh_list);
+ for (sdev = shost->host_queue; sdev; sdev = sdev->next)
+ if (sdev->host->hostt == shost_tp) {
+ for (sdev_tp = scsi_devicelist;
+ sdev_tp;
+ sdev_tp = sdev_tp->next)
+ if (sdev_tp->attach)
+ (*sdev_tp->attach) (sdev);
+ if (sdev->attached) {
+ scsi_build_commandblocks(sdev);
+ if (sdev->current_queue_depth == 0)
+ goto out_of_space;
+ }
+ }
+ }
+
+ /* This does any final handling that is required. */
+ for (sdev_tp = scsi_devicelist; sdev_tp;
+ sdev_tp = sdev_tp->next) {
+ if (sdev_tp->finish && sdev_tp->nr_dev) {
+ (*sdev_tp->finish) ();
+ }
+ }
+ }
+
+ return 0;
+
+out_of_space:
+ scsi_unregister_host(shost_tp); /* easiest way to clean up?? */
+ return 1;
+}
+
+/**
+ * scsi_unregister_host - unregister a low level host adapter driver
+ * @shost_tp: scsi host template to unregister.
+ *
+ * Description:
+ * Similarly, this entry point should be called by a loadable module
+ * if it is trying to remove a low level scsi driver from the system.
+ *
+ * Return value:
+ * 0 on Success / 1 on Failure
+ *
+ * Notes:
+ * rmmod does not care what we return here the module will be
+ * removed.
+ **/
+int scsi_unregister_host(Scsi_Host_Template *shost_tp)
+{
+ int pcount;
+
+ /* get the big kernel lock, so we don't race with open() */
+ lock_kernel();
+
+ pcount = scsi_hosts_registered;
+
+ scsi_tp_for_each_host(shost_tp, scsi_host_chk_and_release);
+
+ if (pcount != scsi_hosts_registered)
+ printk(KERN_INFO "scsi : %d host%s left.\n", scsi_hosts_registered,
+ (scsi_hosts_registered == 1) ? "" : "s");
+
+ /*
+ * Remove it from the list if all
+ * hosts were successfully removed (ie preset == 0)
+ */
+ if (!shost_tp->present) {
+ list_del(&shost_tp->shtp_list);
+ }
+
+ MOD_DEC_USE_COUNT;
+
+ unlock_kernel();
+ return 0;
+
+}
+
+/**
+ * *scsi_host_get_next - get scsi host and inc ref count
+ * @shost: pointer to a Scsi_Host or NULL to start.
+ *
+ * Return value:
+ * A pointer to next Scsi_Host in list or NULL.
+ **/
+struct Scsi_Host *scsi_host_get_next(struct Scsi_Host *shost)
+{
+ struct list_head *lh = NULL;
+
+ spin_lock(&scsi_host_list_lock);
+ if (shost) {
+ /* XXX Dec ref on cur shost */
+ lh = shost->sh_list.next;
+ } else {
+ lh = scsi_host_list.next;
+ }
+
+ if (lh == &scsi_host_list) {
+ shost = (struct Scsi_Host *)NULL;
+ goto done;
+ }
+
+ shost = list_entry(lh, struct Scsi_Host, sh_list);
+ /* XXX Inc ref count */
+
+done:
+ spin_unlock(&scsi_host_list_lock);
+ return shost;
+}
+
+/**
+ * scsi_host_hn_get - get a Scsi_Host by host no and inc ref count
+ * @host_no: host number to locate
+ *
+ * Return value:
+ * A pointer to located Scsi_Host or NULL.
+ **/
+struct Scsi_Host *scsi_host_hn_get(unsigned short host_no)
+{
+ struct list_head *lh;
+ struct Scsi_Host *shost;
+
+ spin_lock(&scsi_host_list_lock);
+ list_for_each(lh, &scsi_host_list) {
+ shost = list_entry(lh, struct Scsi_Host, sh_list);
+ if (shost->host_no == host_no) {
+ /* XXX Inc ref count */
+ goto done;
+ }
+ }
+
+ shost = (struct Scsi_Host *)NULL;
+done:
+ spin_unlock(&scsi_host_list_lock);
+ return shost;
+}
+
+/**
+ * *scsi_host_put - dec a Scsi_Host ref count
+ * @shost: Pointer to Scsi_Host to dec.
+ **/
+void scsi_host_put(struct Scsi_Host *shost)
+{
+
+ /* XXX Get list lock */
+ /* XXX dec ref count */
+ /* XXX Release list lock */
+ return;
+}
+
+/**
+ * scsi_host_hn_init - init scsi host number list from string
+ * @shost_hn: string of scsi host driver names.
+ **/
+void __init scsi_host_hn_init(char *shost_hn)
+{
+ char *temp = shost_hn;
+
+ while (temp) {
+ while (*temp && (*temp != ':') && (*temp != ','))
+ temp++;
+ if (!*temp)
+ temp = NULL;
+ else
+ *temp++ = 0;
+ (void)scsi_host_hn_add(shost_hn);
+ shost_hn = temp;
+ }
+}
+
+/**
+ * scsi_host_no_release - free all entries in scsi host number list
+ **/
+void __exit scsi_host_hn_release()
+{
+ struct list_head *lh, *next;
+ Scsi_Host_Name *shn;
+
+ list_for_each_safe(lh, next, &scsi_host_hn_list) {
+ shn = list_entry(lh, Scsi_Host_Name, shn_list);
+ if (shn->name)
+ kfree(shn->name);
+ kfree(shn);
}
- else {
- for (o_shp = shpnt, shpnt = shpnt->next; shpnt;
- o_shp = shpnt, shpnt = shpnt->next) {
- if (retval->host_no < shpnt->host_no) {
- retval->next = shpnt;
- wmb();
- o_shp->next = retval;
- break;
- }
- }
- if (! shpnt)
- o_shp->next = retval;
- }
- }
-
- return retval;
}

void scsi_host_busy_inc(struct Scsi_Host *shost, Scsi_Device *sdev)
@@ -279,8 +761,7 @@
if (shost->in_recovery && (shost->host_busy == shost->host_failed)) {
up(shost->eh_wait);
SCSI_LOG_ERROR_RECOVERY(5, printk("Waking error handler"
- "thread (%d)\n",
- atomic_read(&shost->eh_wait->count)));
+ " thread\n"));
}
spin_unlock_irqrestore(shost->host_lock, flags);
}
@@ -295,8 +776,7 @@
if (shost->host_busy == shost->host_failed) {
up(shost->eh_wait);
SCSI_LOG_ERROR_RECOVERY(5, printk("Waking error handler"
- "thread (%d)\n",
- atomic_read(&shost->eh_wait->count)));
+ " thread\n"));
}
spin_unlock_irqrestore(shost->host_lock, flags);
}
diff -Nru a/drivers/scsi/hosts.h b/drivers/scsi/hosts.h
--- a/drivers/scsi/hosts.h Thu Oct 17 00:53:47 2002
+++ b/drivers/scsi/hosts.h Thu Oct 17 00:53:47 2002
@@ -16,15 +16,14 @@
* of the same type.
*
* Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
+ *
+ * Restructured scsi_host lists and associated functions.
+ * September 04, 2002 Mike Anderson (andmike@us.ibm.com)
*/

#ifndef _HOSTS_H
#define _HOSTS_H

-/*
- $Header: /vger/u4/cvs/linux/drivers/scsi/hosts.h,v 1.6 1997/01/19 23:07:13 davem Exp $
-*/
-
#include <linux/config.h>
#include <linux/proc_fs.h>
#include <linux/pci.h>
@@ -58,8 +57,7 @@
typedef struct SHT
{

- /* Used with loadable modules so we can construct a linked list. */
- struct SHT * next;
+ struct list_head shtp_list;

/* Used with loadable modules so that we know when it is safe to unload */
struct module * module;
@@ -374,7 +372,7 @@
* This information is private to the scsi mid-layer. Wrapping it in a
* struct private is a way of marking it in a sort of C++ type of way.
*/
- struct Scsi_Host * next;
+ struct list_head sh_list;
Scsi_Device * host_queue;
struct list_head all_scsi_hosts;
struct list_head my_devices;
@@ -510,28 +508,26 @@
* thing. This physical pseudo-device isn't real and won't be available
* from any high-level drivers.
*/
-extern void scsi_free_host_dev(Scsi_Device * SDpnt);
-extern Scsi_Device * scsi_get_host_dev(struct Scsi_Host * SHpnt);
+extern void scsi_free_host_dev(Scsi_Device *);
+extern Scsi_Device * scsi_get_host_dev(struct Scsi_Host *);

-extern void scsi_unblock_requests(struct Scsi_Host * SHpnt);
-extern void scsi_block_requests(struct Scsi_Host * SHpnt);
-extern void scsi_report_bus_reset(struct Scsi_Host * SHpnt, int channel);
+extern void scsi_unblock_requests(struct Scsi_Host *);
+extern void scsi_block_requests(struct Scsi_Host *);
+extern void scsi_report_bus_reset(struct Scsi_Host *, int);

typedef struct SHN
- {
- struct SHN * next;
- char * name;
- unsigned short host_no;
- unsigned short host_registered;
- } Scsi_Host_Name;
+{
+ struct list_head shn_list;
+ char *name;
+ unsigned short host_no;
+ unsigned short host_registered;
+} Scsi_Host_Name;

-extern Scsi_Host_Name * scsi_host_no_list;
-extern struct Scsi_Host * scsi_hostlist;
extern struct Scsi_Device_Template * scsi_devicelist;

-extern Scsi_Host_Template * scsi_hosts;
-
-extern void build_proc_dir_entries(Scsi_Host_Template *);
+extern void scsi_proc_host_mkdir(Scsi_Host_Template *);
+extern void scsi_proc_host_add(struct Scsi_Host *);
+extern void scsi_proc_host_rm(struct Scsi_Host *);

/*
* scsi_init initializes the scsi hosts.
@@ -540,34 +536,33 @@
extern int next_scsi_host;

unsigned int scsi_init(void);
-extern struct Scsi_Host * scsi_register(Scsi_Host_Template *, int j);
-extern void scsi_unregister(struct Scsi_Host * i);
-extern void scsi_register_blocked_host(struct Scsi_Host * SHpnt);
-extern void scsi_deregister_blocked_host(struct Scsi_Host * SHpnt);
+extern struct Scsi_Host * scsi_register(Scsi_Host_Template *, int);
+extern void scsi_unregister(struct Scsi_Host *);
+extern void scsi_register_blocked_host(struct Scsi_Host *);
+extern void scsi_deregister_blocked_host(struct Scsi_Host *);

-static inline void scsi_assign_lock(struct Scsi_Host *host, spinlock_t *lock)
+static inline void scsi_assign_lock(struct Scsi_Host *shost, spinlock_t *lock)
{
- host->host_lock = lock;
+ shost->host_lock = lock;
}

-static inline void scsi_set_pci_device(struct Scsi_Host *SHpnt,
+static inline void scsi_set_pci_device(struct Scsi_Host *shost,
struct pci_dev *pdev)
{
- SHpnt->pci_dev = pdev;
- SHpnt->host_driverfs_dev.parent=&pdev->dev;
+ shost->pci_dev = pdev;
+ shost->host_driverfs_dev.parent=&pdev->dev;
+
+ /* register parent with driverfs */
+ device_register(&shost->host_driverfs_dev);
}


/*
* Prototypes for functions/data in scsi_scan.c
*/
-extern void scan_scsis(struct Scsi_Host *shpnt,
- uint hardcoded,
- uint hchannel,
- uint hid,
- uint hlun);
+extern void scan_scsis(struct Scsi_Host *, uint, uint, uint, uint);

-extern void scsi_mark_host_reset(struct Scsi_Host *Host);
+extern void scsi_mark_host_reset(struct Scsi_Host *);

#define BLANK_HOST {"", 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}

@@ -596,7 +591,7 @@
struct device_driver scsi_driverfs_driver;
};

-void scsi_initialize_queue(Scsi_Device * SDpnt, struct Scsi_Host * SHpnt);
+void scsi_initialize_queue(Scsi_Device *, struct Scsi_Host *);


/*
@@ -607,6 +602,12 @@
extern int scsi_register_host(Scsi_Host_Template *);
extern int scsi_unregister_host(Scsi_Host_Template *);

+extern struct Scsi_Host *scsi_host_get_next(struct Scsi_Host *);
+extern struct Scsi_Host *scsi_host_hn_get(unsigned short);
+extern void scsi_host_put(struct Scsi_Host *);
+extern void scsi_host_hn_init(char *);
+extern void scsi_host_hn_release(void);
+
/*
* host_busy inc/dec/test functions
*/
@@ -614,7 +615,6 @@
extern void scsi_host_busy_dec_and_test(struct Scsi_Host *, Scsi_Device *);
extern void scsi_host_failed_inc_and_test(struct Scsi_Host *);

-
/*
* This is an ugly hack. If we expect to be able to load devices at run time,
* we need to leave extra room in some of the data structures. Doing a
@@ -643,21 +643,22 @@

/**
* scsi_find_device - find a device given the host
+ * @shost: SCSI host pointer
* @channel: SCSI channel (zero if only one channel)
* @pun: SCSI target number (physical unit number)
* @lun: SCSI Logical Unit Number
**/
-static inline Scsi_Device *scsi_find_device(struct Scsi_Host *host,
+static inline Scsi_Device *scsi_find_device(struct Scsi_Host *shost,
int channel, int pun, int lun) {
- Scsi_Device *SDpnt;
+ Scsi_Device *sdev;

- for(SDpnt = host->host_queue;
- SDpnt != NULL;
- SDpnt = SDpnt->next)
- if(SDpnt->channel == channel && SDpnt->id == pun
- && SDpnt->lun ==lun)
+ for (sdev = shost->host_queue;
+ sdev != NULL;
+ sdev = sdev->next)
+ if (sdev->channel == channel && sdev->id == pun
+ && sdev->lun ==lun)
break;
- return SDpnt;
+ return sdev;
}

#endif
-
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