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 f0be389c7116..d80e5733827d 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. | |||
133 | In order not to introduce a new I/O concept to the common Linux code, | 133 | In order not to introduce a new I/O concept to the common Linux code, |
134 | Linux/390 preserves the IRQ concept and semantically maps the ESA/390 | 134 | Linux/390 preserves the IRQ concept and semantically maps the ESA/390 |
135 | subchannels to Linux as IRQs. This allows Linux/390 to support up to 64k | 135 | subchannels to Linux as IRQs. This allows Linux/390 to support up to 64k |
136 | different IRQs, uniquely representig a single device each. | 136 | different IRQs, uniquely representing a single device each. |
137 | 137 | ||
138 | Up to kernel 2.4, Linux/390 used to provide interfaces via the IRQ (subchannel). | 138 | Up to kernel 2.4, Linux/390 used to provide interfaces via the IRQ (subchannel). |
139 | For internal use of the common I/O layer, these are still there. However, | 139 | 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 | |||
143 | of those devices is uniquely defined by a so called subchannel by the ESA/390 | 143 | of those devices is uniquely defined by a so called subchannel by the ESA/390 |
144 | channel subsystem. While the subchannel numbers are system generated, each | 144 | channel subsystem. While the subchannel numbers are system generated, each |
145 | subchannel also takes a user defined attribute, the so called device number. | 145 | subchannel also takes a user defined attribute, the so called device number. |
146 | Both subchannel number and device number can not exceed 65535. During driverfs | 146 | Both subchannel number and device number cannot exceed 65535. During driverfs |
147 | initialisation, the information about control unit type and device types that | 147 | initialisation, the information about control unit type and device types that |
148 | imply specific I/O commands (channel command words - CCWs) in order to operate | 148 | imply specific I/O commands (channel command words - CCWs) in order to operate |
149 | the device are gathered. Device drivers can retrieve this set of hardware | 149 | 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. | |||
177 | The function is meant to be called with an irq handler in place; that is, | 177 | The function is meant to be called with an irq handler in place; that is, |
178 | at earliest during set_online() processing. | 178 | at earliest during set_online() processing. |
179 | 179 | ||
180 | While the request is procesed synchronously, the device interrupt | 180 | While the request is processed synchronously, the device interrupt |
181 | handler is called for final ending status. In case of error situations the | 181 | handler is called for final ending status. In case of error situations the |
182 | interrupt handler may recover appropriately. The device irq handler can | 182 | interrupt handler may recover appropriately. The device irq handler can |
183 | recognize the corresponding interrupts by the interruption parameter be | 183 | recognize the corresponding interrupts by the interruption parameter be |
184 | 0x00524443.The ccw_device must not be locked prior to calling read_dev_chars(). | 184 | 0x00524443. The ccw_device must not be locked prior to calling read_dev_chars(). |
185 | 185 | ||
186 | The function may be called enabled or disabled. | 186 | The function may be called enabled or disabled. |
187 | 187 | ||
@@ -325,7 +325,7 @@ with the following CCW flags values defined : | |||
325 | 325 | ||
326 | CCW_FLAG_DC - data chaining | 326 | CCW_FLAG_DC - data chaining |
327 | CCW_FLAG_CC - command chaining | 327 | CCW_FLAG_CC - command chaining |
328 | CCW_FLAG_SLI - suppress incorrct length | 328 | CCW_FLAG_SLI - suppress incorrect length |
329 | CCW_FLAG_SKIP - skip | 329 | CCW_FLAG_SKIP - skip |
330 | CCW_FLAG_PCI - PCI | 330 | CCW_FLAG_PCI - PCI |
331 | CCW_FLAG_IDA - indirect addressing | 331 | CCW_FLAG_IDA - indirect addressing |
@@ -348,7 +348,7 @@ The ccw_device_start() function returns : | |||
348 | not online. | 348 | not online. |
349 | 349 | ||
350 | When the I/O request completes, the CDS first level interrupt handler will | 350 | When the I/O request completes, the CDS first level interrupt handler will |
351 | accumalate the status in a struct irb and then call the device interrupt handler. | 351 | accumulate the status in a struct irb and then call the device interrupt handler. |
352 | The intparm field will contain the value the device driver has associated with a | 352 | The intparm field will contain the value the device driver has associated with a |
353 | particular I/O request. If a pending device status was recognized, | 353 | particular I/O request. If a pending device status was recognized, |
354 | intparm will be set to 0 (zero). This may happen during I/O initiation or delayed | 354 | 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. | |||
433 | 433 | ||
434 | The device driver is allowed to issue the next ccw_device_start() call from | 434 | The device driver is allowed to issue the next ccw_device_start() call from |
435 | within its interrupt handler already. It is not required to schedule a | 435 | within its interrupt handler already. It is not required to schedule a |
436 | bottom-half, unless an non deterministicly long running error recovery procedure | 436 | bottom-half, unless an non deterministically long running error recovery procedure |
437 | or similar needs to be scheduled. During I/O processing the Linux/390 generic | 437 | or similar needs to be scheduled. During I/O processing the Linux/390 generic |
438 | I/O device driver support has already obtained the IRQ lock, i.e. the handler | 438 | I/O device driver support has already obtained the IRQ lock, i.e. the handler |
439 | must not try to obtain it again when calling ccw_device_start() or we end in a | 439 | must not try to obtain it again when calling ccw_device_start() or we end in a |