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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/scsi/hosts.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/scsi/hosts.c')
-rw-r--r--drivers/scsi/hosts.c462
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 @@
1/*
2 * hosts.c Copyright (C) 1992 Drew Eckhardt
3 * Copyright (C) 1993, 1994, 1995 Eric Youngdale
4 * Copyright (C) 2002-2003 Christoph Hellwig
5 *
6 * mid to lowlevel SCSI driver interface
7 * Initial versions: Drew Eckhardt
8 * Subsequent revisions: Eric Youngdale
9 *
10 * <drew@colorado.edu>
11 *
12 * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
13 * Added QLOGIC QLA1280 SCSI controller kernel host support.
14 * August 4, 1999 Fred Lewis, Intel DuPont
15 *
16 * Updated to reflect the new initialization scheme for the higher
17 * level of scsi drivers (sd/sr/st)
18 * September 17, 2000 Torben Mathiasen <tmm@image.dk>
19 *
20 * Restructured scsi_host lists and associated functions.
21 * September 04, 2002 Mike Anderson (andmike@us.ibm.com)
22 */
23
24#include <linux/module.h>
25#include <linux/blkdev.h>
26#include <linux/kernel.h>
27#include <linux/string.h>
28#include <linux/mm.h>
29#include <linux/init.h>
30#include <linux/completion.h>
31#include <linux/transport_class.h>
32
33#include <scsi/scsi_device.h>
34#include <scsi/scsi_host.h>
35#include <scsi/scsi_transport.h>
36
37#include "scsi_priv.h"
38#include "scsi_logging.h"
39
40
41static int scsi_host_next_hn; /* host_no for next new host */
42
43
44static void scsi_host_cls_release(struct class_device *class_dev)
45{
46 put_device(&class_to_shost(class_dev)->shost_gendev);
47}
48
49static struct class shost_class = {
50 .name = "scsi_host",
51 .release = scsi_host_cls_release,
52};
53
54/**
55 * scsi_host_cancel - cancel outstanding IO to this host
56 * @shost: pointer to struct Scsi_Host
57 * recovery: recovery requested to run.
58 **/
59void scsi_host_cancel(struct Scsi_Host *shost, int recovery)
60{
61 struct scsi_device *sdev;
62
63 set_bit(SHOST_CANCEL, &shost->shost_state);
64 shost_for_each_device(sdev, shost) {
65 scsi_device_cancel(sdev, recovery);
66 }
67 wait_event(shost->host_wait, (!test_bit(SHOST_RECOVERY,
68 &shost->shost_state)));
69}
70
71/**
72 * scsi_remove_host - remove a scsi host
73 * @shost: a pointer to a scsi host to remove
74 **/
75void scsi_remove_host(struct Scsi_Host *shost)
76{
77 scsi_forget_host(shost);
78 scsi_host_cancel(shost, 0);
79 scsi_proc_host_rm(shost);
80
81 set_bit(SHOST_DEL, &shost->shost_state);
82
83 transport_unregister_device(&shost->shost_gendev);
84 class_device_unregister(&shost->shost_classdev);
85 device_del(&shost->shost_gendev);
86}
87EXPORT_SYMBOL(scsi_remove_host);
88
89/**
90 * scsi_add_host - add a scsi host
91 * @shost: scsi host pointer to add
92 * @dev: a struct device of type scsi class
93 *
94 * Return value:
95 * 0 on success / != 0 for error
96 **/
97int scsi_add_host(struct Scsi_Host *shost, struct device *dev)
98{
99 struct scsi_host_template *sht = shost->hostt;
100 int error = -EINVAL;
101
102 printk(KERN_INFO "scsi%d : %s\n", shost->host_no,
103 sht->info ? sht->info(shost) : sht->name);
104
105 if (!shost->can_queue) {
106 printk(KERN_ERR "%s: can_queue = 0 no longer supported\n",
107 sht->name);
108 goto out;
109 }
110
111 if (!shost->shost_gendev.parent)
112 shost->shost_gendev.parent = dev ? dev : &platform_bus;
113
114 error = device_add(&shost->shost_gendev);
115 if (error)
116 goto out;
117
118 set_bit(SHOST_ADD, &shost->shost_state);
119 get_device(shost->shost_gendev.parent);
120
121 error = class_device_add(&shost->shost_classdev);
122 if (error)
123 goto out_del_gendev;
124
125 get_device(&shost->shost_gendev);
126
127 if (shost->transportt->host_size &&
128 (shost->shost_data = kmalloc(shost->transportt->host_size,
129 GFP_KERNEL)) == NULL)
130 goto out_del_classdev;
131
132 if (shost->transportt->create_work_queue) {
133 snprintf(shost->work_q_name, KOBJ_NAME_LEN, "scsi_wq_%d",
134 shost->host_no);
135 shost->work_q = create_singlethread_workqueue(
136 shost->work_q_name);
137 if (!shost->work_q)
138 goto out_free_shost_data;
139 }
140
141 error = scsi_sysfs_add_host(shost);
142 if (error)
143 goto out_destroy_host;
144
145 scsi_proc_host_add(shost);
146 return error;
147
148 out_destroy_host:
149 if (shost->work_q)
150 destroy_workqueue(shost->work_q);
151 out_free_shost_data:
152 kfree(shost->shost_data);
153 out_del_classdev:
154 class_device_del(&shost->shost_classdev);
155 out_del_gendev:
156 device_del(&shost->shost_gendev);
157 out:
158 return error;
159}
160EXPORT_SYMBOL(scsi_add_host);
161
162static void scsi_host_dev_release(struct device *dev)
163{
164 struct Scsi_Host *shost = dev_to_shost(dev);
165 struct device *parent = dev->parent;
166
167 if (shost->ehandler) {
168 DECLARE_COMPLETION(sem);
169 shost->eh_notify = &sem;
170 shost->eh_kill = 1;
171 up(shost->eh_wait);
172 wait_for_completion(&sem);
173 shost->eh_notify = NULL;
174 }
175
176 if (shost->work_q)
177 destroy_workqueue(shost->work_q);
178
179 scsi_proc_hostdir_rm(shost->hostt);
180 scsi_destroy_command_freelist(shost);
181 kfree(shost->shost_data);
182
183 /*
184 * Some drivers (eg aha1542) do scsi_register()/scsi_unregister()
185 * during probing without performing a scsi_set_device() in between.
186 * In this case dev->parent is NULL.
187 */
188 if (parent)
189 put_device(parent);
190 kfree(shost);
191}
192
193/**
194 * scsi_host_alloc - register a scsi host adapter instance.
195 * @sht: pointer to scsi host template
196 * @privsize: extra bytes to allocate for driver
197 *
198 * Note:
199 * Allocate a new Scsi_Host and perform basic initialization.
200 * The host is not published to the scsi midlayer until scsi_add_host
201 * is called.
202 *
203 * Return value:
204 * Pointer to a new Scsi_Host
205 **/
206struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
207{
208 struct Scsi_Host *shost;
209 int gfp_mask = GFP_KERNEL, rval;
210 DECLARE_COMPLETION(complete);
211
212 if (sht->unchecked_isa_dma && privsize)
213 gfp_mask |= __GFP_DMA;
214
215 /* Check to see if this host has any error handling facilities */
216 if (!sht->eh_strategy_handler && !sht->eh_abort_handler &&
217 !sht->eh_device_reset_handler && !sht->eh_bus_reset_handler &&
218 !sht->eh_host_reset_handler) {
219 printk(KERN_ERR "ERROR: SCSI host `%s' has no error handling\n"
220 "ERROR: This is not a safe way to run your "
221 "SCSI host\n"
222 "ERROR: The error handling must be added to "
223 "this driver\n", sht->proc_name);
224 dump_stack();
225 }
226
227 shost = kmalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask);
228 if (!shost)
229 return NULL;
230 memset(shost, 0, sizeof(struct Scsi_Host) + privsize);
231
232 spin_lock_init(&shost->default_lock);
233 scsi_assign_lock(shost, &shost->default_lock);
234 INIT_LIST_HEAD(&shost->__devices);
235 INIT_LIST_HEAD(&shost->__targets);
236 INIT_LIST_HEAD(&shost->eh_cmd_q);
237 INIT_LIST_HEAD(&shost->starved_list);
238 init_waitqueue_head(&shost->host_wait);
239
240 init_MUTEX(&shost->scan_mutex);
241
242 shost->host_no = scsi_host_next_hn++; /* XXX(hch): still racy */
243 shost->dma_channel = 0xff;
244
245 /* These three are default values which can be overridden */
246 shost->max_channel = 0;
247 shost->max_id = 8;
248 shost->max_lun = 8;
249
250 /* Give each shost a default transportt */
251 shost->transportt = &blank_transport_template;
252
253 /*
254 * All drivers right now should be able to handle 12 byte
255 * commands. Every so often there are requests for 16 byte
256 * commands, but individual low-level drivers need to certify that
257 * they actually do something sensible with such commands.
258 */
259 shost->max_cmd_len = 12;
260 shost->hostt = sht;
261 shost->this_id = sht->this_id;
262 shost->can_queue = sht->can_queue;
263 shost->sg_tablesize = sht->sg_tablesize;
264 shost->cmd_per_lun = sht->cmd_per_lun;
265 shost->unchecked_isa_dma = sht->unchecked_isa_dma;
266 shost->use_clustering = sht->use_clustering;
267 shost->ordered_flush = sht->ordered_flush;
268 shost->ordered_tag = sht->ordered_tag;
269
270 /*
271 * hosts/devices that do queueing must support ordered tags
272 */
273 if (shost->can_queue > 1 && shost->ordered_flush) {
274 printk(KERN_ERR "scsi: ordered flushes don't support queueing\n");
275 shost->ordered_flush = 0;
276 }
277
278 if (sht->max_host_blocked)
279 shost->max_host_blocked = sht->max_host_blocked;
280 else
281 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
282
283 /*
284 * If the driver imposes no hard sector transfer limit, start at
285 * machine infinity initially.
286 */
287 if (sht->max_sectors)
288 shost->max_sectors = sht->max_sectors;
289 else
290 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
291
292 /*
293 * assume a 4GB boundary, if not set
294 */
295 if (sht->dma_boundary)
296 shost->dma_boundary = sht->dma_boundary;
297 else
298 shost->dma_boundary = 0xffffffff;
299
300 rval = scsi_setup_command_freelist(shost);
301 if (rval)
302 goto fail_kfree;
303
304 device_initialize(&shost->shost_gendev);
305 snprintf(shost->shost_gendev.bus_id, BUS_ID_SIZE, "host%d",
306 shost->host_no);
307 shost->shost_gendev.release = scsi_host_dev_release;
308
309 class_device_initialize(&shost->shost_classdev);
310 shost->shost_classdev.dev = &shost->shost_gendev;
311 shost->shost_classdev.class = &shost_class;
312 snprintf(shost->shost_classdev.class_id, BUS_ID_SIZE, "host%d",
313 shost->host_no);
314
315 shost->eh_notify = &complete;
316 rval = kernel_thread(scsi_error_handler, shost, 0);
317 if (rval < 0)
318 goto fail_destroy_freelist;
319 wait_for_completion(&complete);
320 shost->eh_notify = NULL;
321
322 scsi_proc_hostdir_add(shost->hostt);
323 return shost;
324
325 fail_destroy_freelist:
326 scsi_destroy_command_freelist(shost);
327 fail_kfree:
328 kfree(shost);
329 return NULL;
330}
331EXPORT_SYMBOL(scsi_host_alloc);
332
333struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize)
334{
335 struct Scsi_Host *shost = scsi_host_alloc(sht, privsize);
336
337 if (!sht->detect) {
338 printk(KERN_WARNING "scsi_register() called on new-style "
339 "template for driver %s\n", sht->name);
340 dump_stack();
341 }
342
343 if (shost)
344 list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts);
345 return shost;
346}
347EXPORT_SYMBOL(scsi_register);
348
349void scsi_unregister(struct Scsi_Host *shost)
350{
351 list_del(&shost->sht_legacy_list);
352 scsi_host_put(shost);
353}
354EXPORT_SYMBOL(scsi_unregister);
355
356/**
357 * scsi_host_lookup - get a reference to a Scsi_Host by host no
358 *
359 * @hostnum: host number to locate
360 *
361 * Return value:
362 * A pointer to located Scsi_Host or NULL.
363 **/
364struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
365{
366 struct class *class = &shost_class;
367 struct class_device *cdev;
368 struct Scsi_Host *shost = ERR_PTR(-ENXIO), *p;
369
370 down_read(&class->subsys.rwsem);
371 list_for_each_entry(cdev, &class->children, node) {
372 p = class_to_shost(cdev);
373 if (p->host_no == hostnum) {
374 shost = scsi_host_get(p);
375 break;
376 }
377 }
378 up_read(&class->subsys.rwsem);
379
380 return shost;
381}
382EXPORT_SYMBOL(scsi_host_lookup);
383
384/**
385 * scsi_host_get - inc a Scsi_Host ref count
386 * @shost: Pointer to Scsi_Host to inc.
387 **/
388struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
389{
390 if (test_bit(SHOST_DEL, &shost->shost_state) ||
391 !get_device(&shost->shost_gendev))
392 return NULL;
393 return shost;
394}
395EXPORT_SYMBOL(scsi_host_get);
396
397/**
398 * scsi_host_put - dec a Scsi_Host ref count
399 * @shost: Pointer to Scsi_Host to dec.
400 **/
401void scsi_host_put(struct Scsi_Host *shost)
402{
403 put_device(&shost->shost_gendev);
404}
405EXPORT_SYMBOL(scsi_host_put);
406
407int scsi_init_hosts(void)
408{
409 return class_register(&shost_class);
410}
411
412void scsi_exit_hosts(void)
413{
414 class_unregister(&shost_class);
415}
416
417int scsi_is_host_device(const struct device *dev)
418{
419 return dev->release == scsi_host_dev_release;
420}
421EXPORT_SYMBOL(scsi_is_host_device);
422
423/**
424 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
425 * @shost: Pointer to Scsi_Host.
426 * @work: Work to queue for execution.
427 *
428 * Return value:
429 * 0 on success / != 0 for error
430 **/
431int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
432{
433 if (unlikely(!shost->work_q)) {
434 printk(KERN_ERR
435 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
436 "when no workqueue created.\n", shost->hostt->name);
437 dump_stack();
438
439 return -EINVAL;
440 }
441
442 return queue_work(shost->work_q, work);
443}
444EXPORT_SYMBOL_GPL(scsi_queue_work);
445
446/**
447 * scsi_flush_work - Flush a Scsi_Host's workqueue.
448 * @shost: Pointer to Scsi_Host.
449 **/
450void scsi_flush_work(struct Scsi_Host *shost)
451{
452 if (!shost->work_q) {
453 printk(KERN_ERR
454 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
455 "when no workqueue created.\n", shost->hostt->name);
456 dump_stack();
457 return;
458 }
459
460 flush_workqueue(shost->work_q);
461}
462EXPORT_SYMBOL_GPL(scsi_flush_work);