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authorCornelia Huck <cornelia.huck@de.ibm.com>2006-10-18 12:30:55 -0400
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2006-10-18 12:30:55 -0400
commit9b10fe5b70878fb4b7e3e1b300f1bff0c73d4e2e (patch)
tree83f982908f3490d4e73733fc885974cd99b50fa1
parent867dcd0f32b125f45a663f9374a36fb21193ab21 (diff)
[S390] cio: update documentation.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
-rw-r--r--Documentation/s390/CommonIO2
-rw-r--r--Documentation/s390/cds.txt52
-rw-r--r--Documentation/s390/driver-model.txt3
3 files changed, 28 insertions, 29 deletions
diff --git a/Documentation/s390/CommonIO b/Documentation/s390/CommonIO
index 59d1166d41ee..d684a6ac69a8 100644
--- a/Documentation/s390/CommonIO
+++ b/Documentation/s390/CommonIO
@@ -66,7 +66,7 @@ Command line parameters
66 66
67 When a device is un-ignored, device recognition and sensing is performed and 67 When a device is un-ignored, device recognition and sensing is performed and
68 the device driver will be notified if possible, so the device will become 68 the device driver will be notified if possible, so the device will become
69 available to the system. 69 available to the system. Note that un-ignoring is performed asynchronously.
70 70
71 You can also add ranges of devices to be ignored by piping to 71 You can also add ranges of devices to be ignored by piping to
72 /proc/cio_ignore; "add <device range>, <device range>, ..." will ignore the 72 /proc/cio_ignore; "add <device range>, <device range>, ..." will ignore the
diff --git a/Documentation/s390/cds.txt b/Documentation/s390/cds.txt
index d80e5733827d..32a96cc39215 100644
--- a/Documentation/s390/cds.txt
+++ b/Documentation/s390/cds.txt
@@ -174,14 +174,10 @@ read_dev_chars() - Read Device Characteristics
174 174
175This routine returns the characteristics for the device specified. 175This routine returns the characteristics for the device specified.
176 176
177The function is meant to be called with an irq handler in place; that is, 177The function is meant to be called with the device already enabled; that is,
178at earliest during set_online() processing. 178at earliest during set_online() processing.
179 179
180While the request is processed synchronously, the device interrupt 180The ccw_device must not be locked prior to calling read_dev_chars().
181handler is called for final ending status. In case of error situations the
182interrupt handler may recover appropriately. The device irq handler can
183recognize the corresponding interrupts by the interruption parameter be
1840x00524443. The ccw_device must not be locked prior to calling read_dev_chars().
185 181
186The function may be called enabled or disabled. 182The function may be called enabled or disabled.
187 183
@@ -410,26 +406,7 @@ individual flag meanings.
410 406
411Usage Notes : 407Usage Notes :
412 408
413Prior to call ccw_device_start() the device driver must assure disabled state, 409ccw_device_start() must be called disabled and with the ccw device lock held.
414i.e. the I/O mask value in the PSW must be disabled. This can be accomplished
415by calling local_save_flags( flags). The current PSW flags are preserved and
416can be restored by local_irq_restore( flags) at a later time.
417
418If the device driver violates this rule while running in a uni-processor
419environment an interrupt might be presented prior to the ccw_device_start()
420routine returning to the device driver main path. In this case we will end in a
421deadlock situation as the interrupt handler will try to obtain the irq
422lock the device driver still owns (see below) !
423
424The driver must assure to hold the device specific lock. This can be
425accomplished by
426
427(i) spin_lock(get_ccwdev_lock(cdev)), or
428(ii) spin_lock_irqsave(get_ccwdev_lock(cdev), flags)
429
430Option (i) should be used if the calling routine is running disabled for
431I/O interrupts (see above) already. Option (ii) obtains the device gate und
432puts the CPU into I/O disabled state by preserving the current PSW flags.
433 410
434The device driver is allowed to issue the next ccw_device_start() call from 411The device driver is allowed to issue the next ccw_device_start() call from
435within its interrupt handler already. It is not required to schedule a 412within its interrupt handler already. It is not required to schedule a
@@ -488,7 +465,7 @@ int ccw_device_resume(struct ccw_device *cdev);
488 465
489cdev - ccw_device the resume operation is requested for 466cdev - ccw_device the resume operation is requested for
490 467
491The resume_IO() function returns: 468The ccw_device_resume() function returns:
492 469
493 0 - suspended channel program is resumed 470 0 - suspended channel program is resumed
494-EBUSY - status pending 471-EBUSY - status pending
@@ -507,6 +484,8 @@ a long-running channel program or the device might require to initially issue
507a halt subchannel (HSCH) I/O command. For those purposes the ccw_device_halt() 484a halt subchannel (HSCH) I/O command. For those purposes the ccw_device_halt()
508command is provided. 485command is provided.
509 486
487ccw_device_halt() must be called disabled and with the ccw device lock held.
488
510int ccw_device_halt(struct ccw_device *cdev, 489int ccw_device_halt(struct ccw_device *cdev,
511 unsigned long intparm); 490 unsigned long intparm);
512 491
@@ -517,7 +496,7 @@ intparm : interruption parameter; value is only used if no I/O
517 496
518The ccw_device_halt() function returns : 497The ccw_device_halt() function returns :
519 498
520 0 - successful completion or request successfully initiated 499 0 - request successfully initiated
521-EBUSY - the device is currently busy, or status pending. 500-EBUSY - the device is currently busy, or status pending.
522-ENODEV - cdev invalid. 501-ENODEV - cdev invalid.
523-EINVAL - The device is not operational or the ccw device is not online. 502-EINVAL - The device is not operational or the ccw device is not online.
@@ -533,6 +512,23 @@ can then perform an appropriate action. Prior to interrupt of an outstanding
533read to a network device (with or without PCI flag) a ccw_device_halt() 512read to a network device (with or without PCI flag) a ccw_device_halt()
534is required to end the pending operation. 513is required to end the pending operation.
535 514
515ccw_device_clear() - Terminage I/O Request Processing
516
517In order to terminate all I/O processing at the subchannel, the clear subchannel
518(CSCH) command is used. It can be issued via ccw_device_clear().
519
520ccw_device_clear() must be called disabled and with the ccw device lock held.
521
522int ccw_device_clear(struct ccw_device *cdev, unsigned long intparm);
523
524cdev: ccw_device the clear operation is requested for
525intparm: interruption parameter (see ccw_device_halt())
526
527The ccw_device_clear() function returns:
528
529 0 - request successfully initiated
530-ENODEV - cdev invalid
531-EINVAL - The device is not operational or the ccw device is not online.
536 532
537Miscellaneous Support Routines 533Miscellaneous Support Routines
538 534
diff --git a/Documentation/s390/driver-model.txt b/Documentation/s390/driver-model.txt
index 62c082387aea..77bf450ec39b 100644
--- a/Documentation/s390/driver-model.txt
+++ b/Documentation/s390/driver-model.txt
@@ -239,6 +239,9 @@ status - Can be 'online' or 'offline'.
239 239
240type - The physical type of the channel path. 240type - The physical type of the channel path.
241 241
242shared - Whether the channel path is shared.
243
244cmg - The channel measurement group.
242 245
2433. System devices 2463. System devices
244----------------- 247-----------------