diff options
Diffstat (limited to 'Documentation/s390/cds.txt')
| -rw-r--r-- | Documentation/s390/cds.txt | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/Documentation/s390/cds.txt b/Documentation/s390/cds.txt index f0be389c71169..d80e5733827d2 100644 --- a/Documentation/s390/cds.txt +++ b/Documentation/s390/cds.txt @@ -133,7 +133,7 @@ determine the device driver owning the device that raised the interrupt. In order not to introduce a new I/O concept to the common Linux code, Linux/390 preserves the IRQ concept and semantically maps the ESA/390 subchannels to Linux as IRQs. This allows Linux/390 to support up to 64k -different IRQs, uniquely representig a single device each. +different IRQs, uniquely representing a single device each. Up to kernel 2.4, Linux/390 used to provide interfaces via the IRQ (subchannel). For internal use of the common I/O layer, these are still there. However, @@ -143,7 +143,7 @@ During its startup the Linux/390 system checks for peripheral devices. Each of those devices is uniquely defined by a so called subchannel by the ESA/390 channel subsystem. While the subchannel numbers are system generated, each subchannel also takes a user defined attribute, the so called device number. -Both subchannel number and device number can not exceed 65535. During driverfs +Both subchannel number and device number cannot exceed 65535. During driverfs initialisation, the information about control unit type and device types that imply specific I/O commands (channel command words - CCWs) in order to operate the device are gathered. Device drivers can retrieve this set of hardware @@ -177,11 +177,11 @@ This routine returns the characteristics for the device specified. The function is meant to be called with an irq handler in place; that is, at earliest during set_online() processing. -While the request is procesed synchronously, the device interrupt +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(). +0x00524443. The ccw_device must not be locked prior to calling read_dev_chars(). The function may be called enabled or disabled. @@ -325,7 +325,7 @@ with the following CCW flags values defined : CCW_FLAG_DC - data chaining CCW_FLAG_CC - command chaining -CCW_FLAG_SLI - suppress incorrct length +CCW_FLAG_SLI - suppress incorrect length CCW_FLAG_SKIP - skip CCW_FLAG_PCI - PCI CCW_FLAG_IDA - indirect addressing @@ -348,7 +348,7 @@ The ccw_device_start() function returns : not online. When the I/O request completes, the CDS first level interrupt handler will -accumalate the status in a struct irb and then call the device interrupt handler. +accumulate the status in a struct irb and then call the device interrupt handler. The intparm field will contain the value the device driver has associated with a particular I/O request. If a pending device status was recognized, intparm will be set to 0 (zero). This may happen during I/O initiation or delayed @@ -433,7 +433,7 @@ puts the CPU into I/O disabled state by preserving the current PSW flags. 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 -bottom-half, unless an non deterministicly long running error recovery procedure +bottom-half, unless an non deterministically long running error recovery procedure or similar needs to be scheduled. During I/O processing the Linux/390 generic I/O device driver support has already obtained the IRQ lock, i.e. the handler must not try to obtain it again when calling ccw_device_start() or we end in a |