513 lines
12 KiB
C
513 lines
12 KiB
C
/*
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* hosts.c Copyright (C) 1992 Drew Eckhardt
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* Copyright (C) 1993, 1994, 1995 Eric Youngdale
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* Copyright (C) 2002-2003 Christoph Hellwig
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*
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* mid to lowlevel SCSI driver interface
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* Initial versions: Drew Eckhardt
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* Subsequent revisions: Eric Youngdale
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*
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* <drew@colorado.edu>
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*
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* Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
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* Added QLOGIC QLA1280 SCSI controller kernel host support.
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* August 4, 1999 Fred Lewis, Intel DuPont
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*
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* Updated to reflect the new initialization scheme for the higher
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* level of scsi drivers (sd/sr/st)
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* September 17, 2000 Torben Mathiasen <tmm@image.dk>
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*
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* Restructured scsi_host lists and associated functions.
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* September 04, 2002 Mike Anderson (andmike@us.ibm.com)
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*/
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#include <linux/module.h>
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#include <linux/blkdev.h>
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#include <linux/kernel.h>
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#include <linux/kthread.h>
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#include <linux/string.h>
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#include <linux/mm.h>
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#include <linux/init.h>
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#include <linux/completion.h>
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#include <linux/transport_class.h>
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#include <scsi/scsi_device.h>
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#include <scsi/scsi_host.h>
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#include <scsi/scsi_transport.h>
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#include "scsi_priv.h"
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#include "scsi_logging.h"
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static int scsi_host_next_hn; /* host_no for next new host */
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static void scsi_host_cls_release(struct class_device *class_dev)
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{
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put_device(&class_to_shost(class_dev)->shost_gendev);
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}
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static struct class shost_class = {
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.name = "scsi_host",
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.release = scsi_host_cls_release,
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};
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/**
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* scsi_host_set_state - Take the given host through the host
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* state model.
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* @shost: scsi host to change the state of.
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* @state: state to change to.
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*
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* Returns zero if unsuccessful or an error if the requested
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* transition is illegal.
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**/
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int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state)
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{
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enum scsi_host_state oldstate = shost->shost_state;
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if (state == oldstate)
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return 0;
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switch (state) {
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case SHOST_CREATED:
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/* There are no legal states that come back to
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* created. This is the manually initialised start
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* state */
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goto illegal;
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case SHOST_RUNNING:
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switch (oldstate) {
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case SHOST_CREATED:
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case SHOST_RECOVERY:
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break;
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default:
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goto illegal;
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}
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break;
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case SHOST_RECOVERY:
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switch (oldstate) {
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case SHOST_RUNNING:
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break;
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default:
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goto illegal;
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}
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break;
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case SHOST_CANCEL:
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switch (oldstate) {
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case SHOST_CREATED:
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case SHOST_RUNNING:
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break;
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default:
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goto illegal;
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}
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break;
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case SHOST_DEL:
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switch (oldstate) {
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case SHOST_CANCEL:
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break;
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default:
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goto illegal;
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}
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break;
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}
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shost->shost_state = state;
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return 0;
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illegal:
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SCSI_LOG_ERROR_RECOVERY(1,
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dev_printk(KERN_ERR, &shost->shost_gendev,
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"Illegal host state transition"
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"%s->%s\n",
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scsi_host_state_name(oldstate),
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scsi_host_state_name(state)));
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return -EINVAL;
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}
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EXPORT_SYMBOL(scsi_host_set_state);
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/**
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* scsi_remove_host - remove a scsi host
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* @shost: a pointer to a scsi host to remove
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**/
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void scsi_remove_host(struct Scsi_Host *shost)
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{
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down(&shost->scan_mutex);
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scsi_host_set_state(shost, SHOST_CANCEL);
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up(&shost->scan_mutex);
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scsi_forget_host(shost);
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scsi_proc_host_rm(shost);
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scsi_host_set_state(shost, SHOST_DEL);
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transport_unregister_device(&shost->shost_gendev);
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class_device_unregister(&shost->shost_classdev);
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device_del(&shost->shost_gendev);
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}
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EXPORT_SYMBOL(scsi_remove_host);
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/**
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* scsi_add_host - add a scsi host
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* @shost: scsi host pointer to add
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* @dev: a struct device of type scsi class
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*
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* Return value:
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* 0 on success / != 0 for error
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**/
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int scsi_add_host(struct Scsi_Host *shost, struct device *dev)
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{
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struct scsi_host_template *sht = shost->hostt;
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int error = -EINVAL;
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printk(KERN_INFO "scsi%d : %s\n", shost->host_no,
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sht->info ? sht->info(shost) : sht->name);
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if (!shost->can_queue) {
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printk(KERN_ERR "%s: can_queue = 0 no longer supported\n",
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sht->name);
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goto out;
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}
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if (!shost->shost_gendev.parent)
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shost->shost_gendev.parent = dev ? dev : &platform_bus;
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error = device_add(&shost->shost_gendev);
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if (error)
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goto out;
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scsi_host_set_state(shost, SHOST_RUNNING);
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get_device(shost->shost_gendev.parent);
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error = class_device_add(&shost->shost_classdev);
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if (error)
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goto out_del_gendev;
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get_device(&shost->shost_gendev);
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if (shost->transportt->host_size &&
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(shost->shost_data = kmalloc(shost->transportt->host_size,
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GFP_KERNEL)) == NULL)
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goto out_del_classdev;
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if (shost->transportt->create_work_queue) {
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snprintf(shost->work_q_name, KOBJ_NAME_LEN, "scsi_wq_%d",
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shost->host_no);
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shost->work_q = create_singlethread_workqueue(
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shost->work_q_name);
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if (!shost->work_q)
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goto out_free_shost_data;
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}
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error = scsi_sysfs_add_host(shost);
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if (error)
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goto out_destroy_host;
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scsi_proc_host_add(shost);
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return error;
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out_destroy_host:
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if (shost->work_q)
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destroy_workqueue(shost->work_q);
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out_free_shost_data:
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kfree(shost->shost_data);
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out_del_classdev:
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class_device_del(&shost->shost_classdev);
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out_del_gendev:
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device_del(&shost->shost_gendev);
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out:
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return error;
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}
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EXPORT_SYMBOL(scsi_add_host);
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static void scsi_host_dev_release(struct device *dev)
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{
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struct Scsi_Host *shost = dev_to_shost(dev);
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struct device *parent = dev->parent;
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if (shost->ehandler)
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kthread_stop(shost->ehandler);
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if (shost->work_q)
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destroy_workqueue(shost->work_q);
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scsi_proc_hostdir_rm(shost->hostt);
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scsi_destroy_command_freelist(shost);
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kfree(shost->shost_data);
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if (parent)
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put_device(parent);
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kfree(shost);
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}
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/**
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* scsi_host_alloc - register a scsi host adapter instance.
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* @sht: pointer to scsi host template
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* @privsize: extra bytes to allocate for driver
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*
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* Note:
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* Allocate a new Scsi_Host and perform basic initialization.
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* The host is not published to the scsi midlayer until scsi_add_host
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* is called.
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*
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* Return value:
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* Pointer to a new Scsi_Host
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**/
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struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
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{
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struct Scsi_Host *shost;
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int gfp_mask = GFP_KERNEL, rval;
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if (sht->unchecked_isa_dma && privsize)
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gfp_mask |= __GFP_DMA;
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/* Check to see if this host has any error handling facilities */
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if (!sht->eh_strategy_handler && !sht->eh_abort_handler &&
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!sht->eh_device_reset_handler && !sht->eh_bus_reset_handler &&
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!sht->eh_host_reset_handler) {
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printk(KERN_ERR "ERROR: SCSI host `%s' has no error handling\n"
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"ERROR: This is not a safe way to run your "
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"SCSI host\n"
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"ERROR: The error handling must be added to "
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"this driver\n", sht->proc_name);
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dump_stack();
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}
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shost = kmalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask);
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if (!shost)
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return NULL;
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memset(shost, 0, sizeof(struct Scsi_Host) + privsize);
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spin_lock_init(&shost->default_lock);
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scsi_assign_lock(shost, &shost->default_lock);
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shost->shost_state = SHOST_CREATED;
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INIT_LIST_HEAD(&shost->__devices);
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INIT_LIST_HEAD(&shost->__targets);
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INIT_LIST_HEAD(&shost->eh_cmd_q);
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INIT_LIST_HEAD(&shost->starved_list);
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init_waitqueue_head(&shost->host_wait);
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init_MUTEX(&shost->scan_mutex);
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shost->host_no = scsi_host_next_hn++; /* XXX(hch): still racy */
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shost->dma_channel = 0xff;
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/* These three are default values which can be overridden */
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shost->max_channel = 0;
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shost->max_id = 8;
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shost->max_lun = 8;
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/* Give each shost a default transportt */
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shost->transportt = &blank_transport_template;
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/*
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* All drivers right now should be able to handle 12 byte
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* commands. Every so often there are requests for 16 byte
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* commands, but individual low-level drivers need to certify that
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* they actually do something sensible with such commands.
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*/
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shost->max_cmd_len = 12;
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shost->hostt = sht;
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shost->this_id = sht->this_id;
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shost->can_queue = sht->can_queue;
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shost->sg_tablesize = sht->sg_tablesize;
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shost->cmd_per_lun = sht->cmd_per_lun;
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shost->unchecked_isa_dma = sht->unchecked_isa_dma;
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shost->use_clustering = sht->use_clustering;
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shost->ordered_flush = sht->ordered_flush;
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shost->ordered_tag = sht->ordered_tag;
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/*
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* hosts/devices that do queueing must support ordered tags
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*/
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if (shost->can_queue > 1 && shost->ordered_flush) {
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printk(KERN_ERR "scsi: ordered flushes don't support queueing\n");
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shost->ordered_flush = 0;
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}
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if (sht->max_host_blocked)
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shost->max_host_blocked = sht->max_host_blocked;
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else
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shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
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/*
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* If the driver imposes no hard sector transfer limit, start at
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* machine infinity initially.
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*/
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if (sht->max_sectors)
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shost->max_sectors = sht->max_sectors;
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else
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shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
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/*
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* assume a 4GB boundary, if not set
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*/
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if (sht->dma_boundary)
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shost->dma_boundary = sht->dma_boundary;
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else
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shost->dma_boundary = 0xffffffff;
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rval = scsi_setup_command_freelist(shost);
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if (rval)
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goto fail_kfree;
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device_initialize(&shost->shost_gendev);
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snprintf(shost->shost_gendev.bus_id, BUS_ID_SIZE, "host%d",
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shost->host_no);
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shost->shost_gendev.release = scsi_host_dev_release;
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class_device_initialize(&shost->shost_classdev);
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shost->shost_classdev.dev = &shost->shost_gendev;
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shost->shost_classdev.class = &shost_class;
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snprintf(shost->shost_classdev.class_id, BUS_ID_SIZE, "host%d",
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shost->host_no);
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shost->ehandler = kthread_run(scsi_error_handler, shost,
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"scsi_eh_%d", shost->host_no);
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if (IS_ERR(shost->ehandler)) {
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rval = PTR_ERR(shost->ehandler);
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goto fail_destroy_freelist;
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}
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scsi_proc_hostdir_add(shost->hostt);
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return shost;
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fail_destroy_freelist:
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scsi_destroy_command_freelist(shost);
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fail_kfree:
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kfree(shost);
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return NULL;
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}
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EXPORT_SYMBOL(scsi_host_alloc);
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struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize)
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{
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struct Scsi_Host *shost = scsi_host_alloc(sht, privsize);
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if (!sht->detect) {
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printk(KERN_WARNING "scsi_register() called on new-style "
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"template for driver %s\n", sht->name);
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dump_stack();
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}
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if (shost)
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list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts);
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return shost;
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}
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EXPORT_SYMBOL(scsi_register);
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void scsi_unregister(struct Scsi_Host *shost)
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{
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list_del(&shost->sht_legacy_list);
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scsi_host_put(shost);
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}
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EXPORT_SYMBOL(scsi_unregister);
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/**
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* scsi_host_lookup - get a reference to a Scsi_Host by host no
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*
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* @hostnum: host number to locate
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*
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* Return value:
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* A pointer to located Scsi_Host or NULL.
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**/
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struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
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{
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struct class *class = &shost_class;
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struct class_device *cdev;
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struct Scsi_Host *shost = ERR_PTR(-ENXIO), *p;
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down_read(&class->subsys.rwsem);
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list_for_each_entry(cdev, &class->children, node) {
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p = class_to_shost(cdev);
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if (p->host_no == hostnum) {
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shost = scsi_host_get(p);
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break;
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}
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}
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up_read(&class->subsys.rwsem);
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return shost;
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}
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EXPORT_SYMBOL(scsi_host_lookup);
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/**
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* scsi_host_get - inc a Scsi_Host ref count
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* @shost: Pointer to Scsi_Host to inc.
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**/
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struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
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{
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if ((shost->shost_state == SHOST_DEL) ||
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!get_device(&shost->shost_gendev))
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return NULL;
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return shost;
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}
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EXPORT_SYMBOL(scsi_host_get);
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/**
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* scsi_host_put - dec a Scsi_Host ref count
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* @shost: Pointer to Scsi_Host to dec.
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**/
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void scsi_host_put(struct Scsi_Host *shost)
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{
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put_device(&shost->shost_gendev);
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}
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EXPORT_SYMBOL(scsi_host_put);
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int scsi_init_hosts(void)
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{
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return class_register(&shost_class);
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}
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void scsi_exit_hosts(void)
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{
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class_unregister(&shost_class);
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}
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int scsi_is_host_device(const struct device *dev)
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{
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return dev->release == scsi_host_dev_release;
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}
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EXPORT_SYMBOL(scsi_is_host_device);
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/**
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* scsi_queue_work - Queue work to the Scsi_Host workqueue.
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* @shost: Pointer to Scsi_Host.
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* @work: Work to queue for execution.
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*
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* Return value:
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* 0 on success / != 0 for error
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**/
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int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
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{
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if (unlikely(!shost->work_q)) {
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printk(KERN_ERR
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"ERROR: Scsi host '%s' attempted to queue scsi-work, "
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"when no workqueue created.\n", shost->hostt->name);
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dump_stack();
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return -EINVAL;
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}
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return queue_work(shost->work_q, work);
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}
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EXPORT_SYMBOL_GPL(scsi_queue_work);
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/**
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* scsi_flush_work - Flush a Scsi_Host's workqueue.
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* @shost: Pointer to Scsi_Host.
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**/
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void scsi_flush_work(struct Scsi_Host *shost)
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{
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if (!shost->work_q) {
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printk(KERN_ERR
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"ERROR: Scsi host '%s' attempted to flush scsi-work, "
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"when no workqueue created.\n", shost->hostt->name);
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dump_stack();
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return;
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}
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flush_workqueue(shost->work_q);
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}
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EXPORT_SYMBOL_GPL(scsi_flush_work);
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