diff options
Diffstat (limited to 'Documentation/s390/cds.txt')
-rw-r--r-- | Documentation/s390/cds.txt | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/Documentation/s390/cds.txt b/Documentation/s390/cds.txt index 32a96cc39215..05a2b4f7e38f 100644 --- a/Documentation/s390/cds.txt +++ b/Documentation/s390/cds.txt | |||
@@ -98,7 +98,7 @@ The following chapters describe the I/O related interface routines the | |||
98 | Linux/390 common device support (CDS) provides to allow for device specific | 98 | Linux/390 common device support (CDS) provides to allow for device specific |
99 | driver implementations on the IBM ESA/390 hardware platform. Those interfaces | 99 | driver implementations on the IBM ESA/390 hardware platform. Those interfaces |
100 | intend to provide the functionality required by every device driver | 100 | intend to provide the functionality required by every device driver |
101 | implementaion to allow to drive a specific hardware device on the ESA/390 | 101 | implementation to allow to drive a specific hardware device on the ESA/390 |
102 | platform. Some of the interface routines are specific to Linux/390 and some | 102 | platform. Some of the interface routines are specific to Linux/390 and some |
103 | of them can be found on other Linux platforms implementations too. | 103 | of them can be found on other Linux platforms implementations too. |
104 | Miscellaneous function prototypes, data declarations, and macro definitions | 104 | Miscellaneous function prototypes, data declarations, and macro definitions |
@@ -114,7 +114,7 @@ the ESA/390 architecture has implemented a so called channel subsystem, that | |||
114 | provides a unified view of the devices physically attached to the systems. | 114 | provides a unified view of the devices physically attached to the systems. |
115 | Though the ESA/390 hardware platform knows about a huge variety of different | 115 | Though the ESA/390 hardware platform knows about a huge variety of different |
116 | peripheral attachments like disk devices (aka. DASDs), tapes, communication | 116 | peripheral attachments like disk devices (aka. DASDs), tapes, communication |
117 | controllers, etc. they can all by accessed by a well defined access method and | 117 | controllers, etc. they can all be accessed by a well defined access method and |
118 | they are presenting I/O completion a unified way : I/O interruptions. Every | 118 | they are presenting I/O completion a unified way : I/O interruptions. Every |
119 | single device is uniquely identified to the system by a so called subchannel, | 119 | single device is uniquely identified to the system by a so called subchannel, |
120 | where the ESA/390 architecture allows for 64k devices be attached. | 120 | where the ESA/390 architecture allows for 64k devices be attached. |
@@ -338,7 +338,7 @@ DOIO_REPORT_ALL - report all interrupt conditions | |||
338 | The ccw_device_start() function returns : | 338 | The ccw_device_start() function returns : |
339 | 339 | ||
340 | 0 - successful completion or request successfully initiated | 340 | 0 - successful completion or request successfully initiated |
341 | -EBUSY - The device is currently processing a previous I/O request, or ther is | 341 | -EBUSY - The device is currently processing a previous I/O request, or there is |
342 | a status pending at the device. | 342 | a status pending at the device. |
343 | -ENODEV - cdev is invalid, the device is not operational or the ccw_device is | 343 | -ENODEV - cdev is invalid, the device is not operational or the ccw_device is |
344 | not online. | 344 | not online. |
@@ -361,7 +361,7 @@ first: | |||
361 | -EIO: the common I/O layer terminated the request due to an error state | 361 | -EIO: the common I/O layer terminated the request due to an error state |
362 | 362 | ||
363 | If the concurrent sense flag in the extended status word in the irb is set, the | 363 | If the concurrent sense flag in the extended status word in the irb is set, the |
364 | field irb->scsw.count describes the numer of device specific sense bytes | 364 | field irb->scsw.count describes the number of device specific sense bytes |
365 | available in the extended control word irb->scsw.ecw[0]. No device sensing by | 365 | available in the extended control word irb->scsw.ecw[0]. No device sensing by |
366 | the device driver itself is required. | 366 | the device driver itself is required. |
367 | 367 | ||
@@ -410,7 +410,7 @@ ccw_device_start() must be called disabled and with the ccw device lock held. | |||
410 | 410 | ||
411 | The device driver is allowed to issue the next ccw_device_start() call from | 411 | The device driver is allowed to issue the next ccw_device_start() call from |
412 | within its interrupt handler already. It is not required to schedule a | 412 | within its interrupt handler already. It is not required to schedule a |
413 | bottom-half, unless an non deterministically long running error recovery procedure | 413 | bottom-half, unless a non deterministically long running error recovery procedure |
414 | or similar needs to be scheduled. During I/O processing the Linux/390 generic | 414 | or similar needs to be scheduled. During I/O processing the Linux/390 generic |
415 | I/O device driver support has already obtained the IRQ lock, i.e. the handler | 415 | I/O device driver support has already obtained the IRQ lock, i.e. the handler |
416 | must not try to obtain it again when calling ccw_device_start() or we end in a | 416 | must not try to obtain it again when calling ccw_device_start() or we end in a |
@@ -431,7 +431,7 @@ information prior to device-end the device driver urgently relies on. In this | |||
431 | case all I/O interruptions are presented to the device driver until final | 431 | case all I/O interruptions are presented to the device driver until final |
432 | status is recognized. | 432 | status is recognized. |
433 | 433 | ||
434 | If a device is able to recover from asynchronosly presented I/O errors, it can | 434 | If a device is able to recover from asynchronously presented I/O errors, it can |
435 | perform overlapping I/O using the DOIO_EARLY_NOTIFICATION flag. While some | 435 | perform overlapping I/O using the DOIO_EARLY_NOTIFICATION flag. While some |
436 | devices always report channel-end and device-end together, with a single | 436 | devices always report channel-end and device-end together, with a single |
437 | interrupt, others present primary status (channel-end) when the channel is | 437 | interrupt, others present primary status (channel-end) when the channel is |