1 files changed, 462 insertions, 0 deletions

diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
new file mode 100644
index 000000000000..ba347576d99b
--- /dev/null
+++ b/drivers/scsi/hosts.c
@@ -0,0 +1,462 @@
+/*
+ *  hosts.c Copyright (C) 1992 Drew Eckhardt
+ *          Copyright (C) 1993, 1994, 1995 Eric Youngdale
+ *          Copyright (C) 2002-2003 Christoph Hellwig
+ *
+ *  mid to lowlevel SCSI driver interface
+ *      Initial versions: Drew Eckhardt
+ *      Subsequent revisions: Eric Youngdale
+ *
+ *  <drew@colorado.edu>
+ *
+ *  Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
+ *  Added QLOGIC QLA1280 SCSI controller kernel host support. 
+ *     August 4, 1999 Fred Lewis, Intel DuPont
+ *
+ *  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)
+ */
+
+#include <linux/module.h>
+#include <linux/blkdev.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/completion.h>
+#include <linux/transport_class.h>
+
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_transport.h>
+
+#include "scsi_priv.h"
+#include "scsi_logging.h"
+
+
+static int scsi_host_next_hn;		/* host_no for next new host */
+
+
+static void scsi_host_cls_release(struct class_device *class_dev)
+{
+	put_device(&class_to_shost(class_dev)->shost_gendev);
+}
+
+static struct class shost_class = {
+	.name		= "scsi_host",
+	.release	= scsi_host_cls_release,
+};
+
+/**
+ * scsi_host_cancel - cancel outstanding IO to this host
+ * @shost:	pointer to struct Scsi_Host
+ * recovery:	recovery requested to run.
+ **/
+void scsi_host_cancel(struct Scsi_Host *shost, int recovery)
+{
+	struct scsi_device *sdev;
+
+	set_bit(SHOST_CANCEL, &shost->shost_state);
+	shost_for_each_device(sdev, shost) {
+		scsi_device_cancel(sdev, recovery);
+	}
+	wait_event(shost->host_wait, (!test_bit(SHOST_RECOVERY,
+						&shost->shost_state)));
+}
+
+/**
+ * scsi_remove_host - remove a scsi host
+ * @shost:	a pointer to a scsi host to remove
+ **/
+void scsi_remove_host(struct Scsi_Host *shost)
+{
+	scsi_forget_host(shost);
+	scsi_host_cancel(shost, 0);
+	scsi_proc_host_rm(shost);
+
+	set_bit(SHOST_DEL, &shost->shost_state);
+
+	transport_unregister_device(&shost->shost_gendev);
+	class_device_unregister(&shost->shost_classdev);
+	device_del(&shost->shost_gendev);
+}
+EXPORT_SYMBOL(scsi_remove_host);
+
+/**
+ * scsi_add_host - add a scsi host
+ * @shost:	scsi host pointer to add
+ * @dev:	a struct device of type scsi class
+ *
+ * Return value: 
+ * 	0 on success / != 0 for error
+ **/
+int scsi_add_host(struct Scsi_Host *shost, struct device *dev)
+{
+	struct scsi_host_template *sht = shost->hostt;
+	int error = -EINVAL;
+
+	printk(KERN_INFO "scsi%d : %s\n", shost->host_no,
+			sht->info ? sht->info(shost) : sht->name);
+
+	if (!shost->can_queue) {
+		printk(KERN_ERR "%s: can_queue = 0 no longer supported\n",
+				sht->name);
+		goto out;
+	}
+
+	if (!shost->shost_gendev.parent)
+		shost->shost_gendev.parent = dev ? dev : &platform_bus;
+
+	error = device_add(&shost->shost_gendev);
+	if (error)
+		goto out;
+
+	set_bit(SHOST_ADD, &shost->shost_state);
+	get_device(shost->shost_gendev.parent);
+
+	error = class_device_add(&shost->shost_classdev);
+	if (error)
+		goto out_del_gendev;
+
+	get_device(&shost->shost_gendev);
+
+	if (shost->transportt->host_size &&
+	    (shost->shost_data = kmalloc(shost->transportt->host_size,
+					 GFP_KERNEL)) == NULL)
+		goto out_del_classdev;
+
+	if (shost->transportt->create_work_queue) {
+		snprintf(shost->work_q_name, KOBJ_NAME_LEN, "scsi_wq_%d",
+			shost->host_no);
+		shost->work_q = create_singlethread_workqueue(
+					shost->work_q_name);
+		if (!shost->work_q)
+			goto out_free_shost_data;
+	}
+
+	error = scsi_sysfs_add_host(shost);
+	if (error)
+		goto out_destroy_host;
+
+	scsi_proc_host_add(shost);
+	return error;
+
+ out_destroy_host:
+	if (shost->work_q)
+		destroy_workqueue(shost->work_q);
+ out_free_shost_data:
+	kfree(shost->shost_data);
+ out_del_classdev:
+	class_device_del(&shost->shost_classdev);
+ out_del_gendev:
+	device_del(&shost->shost_gendev);
+ out:
+	return error;
+}
+EXPORT_SYMBOL(scsi_add_host);
+
+static void scsi_host_dev_release(struct device *dev)
+{
+	struct Scsi_Host *shost = dev_to_shost(dev);
+	struct device *parent = dev->parent;
+
+	if (shost->ehandler) {
+		DECLARE_COMPLETION(sem);
+		shost->eh_notify = &sem;
+		shost->eh_kill = 1;
+		up(shost->eh_wait);
+		wait_for_completion(&sem);
+		shost->eh_notify = NULL;
+	}
+
+	if (shost->work_q)
+		destroy_workqueue(shost->work_q);
+
+	scsi_proc_hostdir_rm(shost->hostt);
+	scsi_destroy_command_freelist(shost);
+	kfree(shost->shost_data);
+
+	/*
+	 * Some drivers (eg aha1542) do scsi_register()/scsi_unregister()
+	 * during probing without performing a scsi_set_device() in between.
+	 * In this case dev->parent is NULL.
+	 */
+	if (parent)
+		put_device(parent);
+	kfree(shost);
+}
+
+/**
+ * scsi_host_alloc - register a scsi host adapter instance.
+ * @sht:	pointer to scsi host template
+ * @privsize:	extra bytes to allocate for driver
+ *
+ * Note:
+ * 	Allocate a new Scsi_Host and perform basic initialization.
+ * 	The host is not published to the scsi midlayer until scsi_add_host
+ * 	is called.
+ *
+ * Return value:
+ * 	Pointer to a new Scsi_Host
+ **/
+struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
+{
+	struct Scsi_Host *shost;
+	int gfp_mask = GFP_KERNEL, rval;
+	DECLARE_COMPLETION(complete);
+
+	if (sht->unchecked_isa_dma && privsize)
+		gfp_mask |= __GFP_DMA;
+
+        /* Check to see if this host has any error handling facilities */
+        if (!sht->eh_strategy_handler && !sht->eh_abort_handler &&
+	    !sht->eh_device_reset_handler && !sht->eh_bus_reset_handler &&
+            !sht->eh_host_reset_handler) {
+		printk(KERN_ERR "ERROR: SCSI host `%s' has no error handling\n"
+				"ERROR: This is not a safe way to run your "
+				        "SCSI host\n"
+				"ERROR: The error handling must be added to "
+				"this driver\n", sht->proc_name);
+		dump_stack();
+        }
+
+	shost = kmalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask);
+	if (!shost)
+		return NULL;
+	memset(shost, 0, sizeof(struct Scsi_Host) + privsize);
+
+	spin_lock_init(&shost->default_lock);
+	scsi_assign_lock(shost, &shost->default_lock);
+	INIT_LIST_HEAD(&shost->__devices);
+	INIT_LIST_HEAD(&shost->__targets);
+	INIT_LIST_HEAD(&shost->eh_cmd_q);
+	INIT_LIST_HEAD(&shost->starved_list);
+	init_waitqueue_head(&shost->host_wait);
+
+	init_MUTEX(&shost->scan_mutex);
+
+	shost->host_no = scsi_host_next_hn++; /* XXX(hch): still racy */
+	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;
+
+	/* Give each shost a default transportt */
+	shost->transportt = &blank_transport_template;
+
+	/*
+	 * 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 = sht;
+	shost->this_id = sht->this_id;
+	shost->can_queue = sht->can_queue;
+	shost->sg_tablesize = sht->sg_tablesize;
+	shost->cmd_per_lun = sht->cmd_per_lun;
+	shost->unchecked_isa_dma = sht->unchecked_isa_dma;
+	shost->use_clustering = sht->use_clustering;
+	shost->ordered_flush = sht->ordered_flush;
+	shost->ordered_tag = sht->ordered_tag;
+
+	/*
+	 * hosts/devices that do queueing must support ordered tags
+	 */
+	if (shost->can_queue > 1 && shost->ordered_flush) {
+		printk(KERN_ERR "scsi: ordered flushes don't support queueing\n");
+		shost->ordered_flush = 0;
+	}
+
+	if (sht->max_host_blocked)
+		shost->max_host_blocked = sht->max_host_blocked;
+	else
+		shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
+
+	/*
+	 * If the driver imposes no hard sector transfer limit, start at
+	 * machine infinity initially.
+	 */
+	if (sht->max_sectors)
+		shost->max_sectors = sht->max_sectors;
+	else
+		shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
+
+	/*
+	 * assume a 4GB boundary, if not set
+	 */
+	if (sht->dma_boundary)
+		shost->dma_boundary = sht->dma_boundary;
+	else
+		shost->dma_boundary = 0xffffffff;
+
+	rval = scsi_setup_command_freelist(shost);
+	if (rval)
+		goto fail_kfree;
+
+	device_initialize(&shost->shost_gendev);
+	snprintf(shost->shost_gendev.bus_id, BUS_ID_SIZE, "host%d",
+		shost->host_no);
+	shost->shost_gendev.release = scsi_host_dev_release;
+
+	class_device_initialize(&shost->shost_classdev);
+	shost->shost_classdev.dev = &shost->shost_gendev;
+	shost->shost_classdev.class = &shost_class;
+	snprintf(shost->shost_classdev.class_id, BUS_ID_SIZE, "host%d",
+		  shost->host_no);
+
+	shost->eh_notify = &complete;
+	rval = kernel_thread(scsi_error_handler, shost, 0);
+	if (rval < 0)
+		goto fail_destroy_freelist;
+	wait_for_completion(&complete);
+	shost->eh_notify = NULL;
+
+	scsi_proc_hostdir_add(shost->hostt);
+	return shost;
+
+ fail_destroy_freelist:
+	scsi_destroy_command_freelist(shost);
+ fail_kfree:
+	kfree(shost);
+	return NULL;
+}
+EXPORT_SYMBOL(scsi_host_alloc);
+
+struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize)
+{
+	struct Scsi_Host *shost = scsi_host_alloc(sht, privsize);
+
+	if (!sht->detect) {
+		printk(KERN_WARNING "scsi_register() called on new-style "
+				    "template for driver %s\n", sht->name);
+		dump_stack();
+	}
+
+	if (shost)
+		list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts);
+	return shost;
+}
+EXPORT_SYMBOL(scsi_register);
+
+void scsi_unregister(struct Scsi_Host *shost)
+{
+	list_del(&shost->sht_legacy_list);
+	scsi_host_put(shost);
+}
+EXPORT_SYMBOL(scsi_unregister);
+
+/**
+ * scsi_host_lookup - get a reference to a Scsi_Host by host no
+ *
+ * @hostnum:	host number to locate
+ *
+ * Return value:
+ *	A pointer to located Scsi_Host or NULL.
+ **/
+struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
+{
+	struct class *class = &shost_class;
+	struct class_device *cdev;
+	struct Scsi_Host *shost = ERR_PTR(-ENXIO), *p;
+
+	down_read(&class->subsys.rwsem);
+	list_for_each_entry(cdev, &class->children, node) {
+		p = class_to_shost(cdev);
+		if (p->host_no == hostnum) {
+			shost = scsi_host_get(p);
+			break;
+		}
+	}
+	up_read(&class->subsys.rwsem);
+
+	return shost;
+}
+EXPORT_SYMBOL(scsi_host_lookup);
+
+/**
+ * scsi_host_get - inc a Scsi_Host ref count
+ * @shost:	Pointer to Scsi_Host to inc.
+ **/
+struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
+{
+	if (test_bit(SHOST_DEL, &shost->shost_state) ||
+		!get_device(&shost->shost_gendev))
+		return NULL;
+	return shost;
+}
+EXPORT_SYMBOL(scsi_host_get);
+
+/**
+ * scsi_host_put - dec a Scsi_Host ref count
+ * @shost:	Pointer to Scsi_Host to dec.
+ **/
+void scsi_host_put(struct Scsi_Host *shost)
+{
+	put_device(&shost->shost_gendev);
+}
+EXPORT_SYMBOL(scsi_host_put);
+
+int scsi_init_hosts(void)
+{
+	return class_register(&shost_class);
+}
+
+void scsi_exit_hosts(void)
+{
+	class_unregister(&shost_class);
+}
+
+int scsi_is_host_device(const struct device *dev)
+{
+	return dev->release == scsi_host_dev_release;
+}
+EXPORT_SYMBOL(scsi_is_host_device);
+
+/**
+ * scsi_queue_work - Queue work to the Scsi_Host workqueue.
+ * @shost:	Pointer to Scsi_Host.
+ * @work:	Work to queue for execution.
+ *
+ * Return value:
+ * 	0 on success / != 0 for error
+ **/
+int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
+{
+	if (unlikely(!shost->work_q)) {
+		printk(KERN_ERR
+			"ERROR: Scsi host '%s' attempted to queue scsi-work, "
+			"when no workqueue created.\n", shost->hostt->name);
+		dump_stack();
+
+		return -EINVAL;
+	}
+
+	return queue_work(shost->work_q, work);
+}
+EXPORT_SYMBOL_GPL(scsi_queue_work);
+
+/**
+ * scsi_flush_work - Flush a Scsi_Host's workqueue.
+ * @shost:	Pointer to Scsi_Host.
+ **/
+void scsi_flush_work(struct Scsi_Host *shost)
+{
+	if (!shost->work_q) {
+		printk(KERN_ERR
+			"ERROR: Scsi host '%s' attempted to flush scsi-work, "
+			"when no workqueue created.\n", shost->hostt->name);
+		dump_stack();
+		return;
+	}
+
+	flush_workqueue(shost->work_q);
+}
+EXPORT_SYMBOL_GPL(scsi_flush_work);