[S390] cio: update documentation.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
parent
867dcd0f32
commit
9b10fe5b70
|
@ -66,7 +66,7 @@ Command line parameters
|
|||
|
||||
When a device is un-ignored, device recognition and sensing is performed and
|
||||
the device driver will be notified if possible, so the device will become
|
||||
available to the system.
|
||||
available to the system. Note that un-ignoring is performed asynchronously.
|
||||
|
||||
You can also add ranges of devices to be ignored by piping to
|
||||
/proc/cio_ignore; "add <device range>, <device range>, ..." will ignore the
|
||||
|
|
|
@ -174,14 +174,10 @@ read_dev_chars() - Read Device Characteristics
|
|||
|
||||
This routine returns the characteristics for the device specified.
|
||||
|
||||
The function is meant to be called with an irq handler in place; that is,
|
||||
The function is meant to be called with the device already enabled; that is,
|
||||
at earliest during set_online() processing.
|
||||
|
||||
While the request is processed synchronously, the device interrupt
|
||||
handler is called for final ending status. In case of error situations the
|
||||
interrupt handler may recover appropriately. The device irq handler can
|
||||
recognize the corresponding interrupts by the interruption parameter be
|
||||
0x00524443. The ccw_device must not be locked prior to calling read_dev_chars().
|
||||
The ccw_device must not be locked prior to calling read_dev_chars().
|
||||
|
||||
The function may be called enabled or disabled.
|
||||
|
||||
|
@ -410,26 +406,7 @@ individual flag meanings.
|
|||
|
||||
Usage Notes :
|
||||
|
||||
Prior to call ccw_device_start() the device driver must assure disabled state,
|
||||
i.e. the I/O mask value in the PSW must be disabled. This can be accomplished
|
||||
by calling local_save_flags( flags). The current PSW flags are preserved and
|
||||
can be restored by local_irq_restore( flags) at a later time.
|
||||
|
||||
If the device driver violates this rule while running in a uni-processor
|
||||
environment an interrupt might be presented prior to the ccw_device_start()
|
||||
routine returning to the device driver main path. In this case we will end in a
|
||||
deadlock situation as the interrupt handler will try to obtain the irq
|
||||
lock the device driver still owns (see below) !
|
||||
|
||||
The driver must assure to hold the device specific lock. This can be
|
||||
accomplished by
|
||||
|
||||
(i) spin_lock(get_ccwdev_lock(cdev)), or
|
||||
(ii) spin_lock_irqsave(get_ccwdev_lock(cdev), flags)
|
||||
|
||||
Option (i) should be used if the calling routine is running disabled for
|
||||
I/O interrupts (see above) already. Option (ii) obtains the device gate und
|
||||
puts the CPU into I/O disabled state by preserving the current PSW flags.
|
||||
ccw_device_start() must be called disabled and with the ccw device lock held.
|
||||
|
||||
The device driver is allowed to issue the next ccw_device_start() call from
|
||||
within its interrupt handler already. It is not required to schedule a
|
||||
|
@ -488,7 +465,7 @@ int ccw_device_resume(struct ccw_device *cdev);
|
|||
|
||||
cdev - ccw_device the resume operation is requested for
|
||||
|
||||
The resume_IO() function returns:
|
||||
The ccw_device_resume() function returns:
|
||||
|
||||
0 - suspended channel program is resumed
|
||||
-EBUSY - status pending
|
||||
|
@ -507,6 +484,8 @@ a long-running channel program or the device might require to initially issue
|
|||
a halt subchannel (HSCH) I/O command. For those purposes the ccw_device_halt()
|
||||
command is provided.
|
||||
|
||||
ccw_device_halt() must be called disabled and with the ccw device lock held.
|
||||
|
||||
int ccw_device_halt(struct ccw_device *cdev,
|
||||
unsigned long intparm);
|
||||
|
||||
|
@ -517,7 +496,7 @@ intparm : interruption parameter; value is only used if no I/O
|
|||
|
||||
The ccw_device_halt() function returns :
|
||||
|
||||
0 - successful completion or request successfully initiated
|
||||
0 - request successfully initiated
|
||||
-EBUSY - the device is currently busy, or status pending.
|
||||
-ENODEV - cdev invalid.
|
||||
-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
|
|||
read to a network device (with or without PCI flag) a ccw_device_halt()
|
||||
is required to end the pending operation.
|
||||
|
||||
ccw_device_clear() - Terminage I/O Request Processing
|
||||
|
||||
In order to terminate all I/O processing at the subchannel, the clear subchannel
|
||||
(CSCH) command is used. It can be issued via ccw_device_clear().
|
||||
|
||||
ccw_device_clear() must be called disabled and with the ccw device lock held.
|
||||
|
||||
int ccw_device_clear(struct ccw_device *cdev, unsigned long intparm);
|
||||
|
||||
cdev: ccw_device the clear operation is requested for
|
||||
intparm: interruption parameter (see ccw_device_halt())
|
||||
|
||||
The ccw_device_clear() function returns:
|
||||
|
||||
0 - request successfully initiated
|
||||
-ENODEV - cdev invalid
|
||||
-EINVAL - The device is not operational or the ccw device is not online.
|
||||
|
||||
Miscellaneous Support Routines
|
||||
|
||||
|
|
|
@ -239,6 +239,9 @@ status - Can be 'online' or 'offline'.
|
|||
|
||||
type - The physical type of the channel path.
|
||||
|
||||
shared - Whether the channel path is shared.
|
||||
|
||||
cmg - The channel measurement group.
|
||||
|
||||
3. System devices
|
||||
-----------------
|
||||
|
|
Loading…
Reference in a new issue