Cornelia Huck

cornelia.huck@de.ibm.com

2007 IBM Corp. This documentation is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA For more details see the file COPYING in the source distribution of Linux. This document describes the interfaces available for device drivers that drive s390 based channel attached I/O devices. This includes interfaces for interaction with the hardware and interfaces for interacting with the common driver core. Those interfaces are provided by the s390 common I/O layer. The document assumes a familarity with the technical terms associated with the s390 channel I/O architecture. For a description of this architecture, please refer to the "z/Architecture: Principles of Operation", IBM publication no. SA22-7832. While most I/O devices on a s390 system are typically driven through the channel I/O mechanism described here, there are various other methods (like the diag interface). These are out of the scope of this document. Some additional information can also be found in the kernel source under Documentation/s390/driver-model.txt. The ccw bus typically contains the majority of devices available to a s390 system. Named after the channel command word (ccw), the basic command structure used to address its devices, the ccw bus contains so-called channel attached devices. They are addressed via I/O subchannels, visible on the css bus. A device driver for channel-attached devices, however, will never interact with the subchannel directly, but only via the I/O device on the ccw bus, the ccw device. Some hardware structures have been translated into C structures for use by the common I/O layer and device drivers. For more information on the hardware structures represented here, please consult the Principles of Operation. Kernel Hackers Manual July 2017 struct ccw1 9 4.1.27 struct ccw1 channel command word struct ccw1 { __u8 cmd_code; __u8 flags; __u16 count; __u32 cda; }; cmd_code command code flags flags, like IDA addressing, etc. count byte count cda data address The ccw is the basic structure to build channel programs that perform operations with the device or the control unit. Only Format-1 channel command words are supported. Kernel Hackers Manual July 2017 struct erw 9 4.1.27 struct erw extended report word struct erw { __u32 res0:3; __u32 auth:1; __u32 pvrf:1; __u32 cpt:1; __u32 fsavf:1; __u32 cons:1; __u32 scavf:1; __u32 fsaf:1; __u32 scnt:6; __u32 res16:16; }; res0 reserved auth authorization check pvrf path-verification-required flag cpt channel-path timeout fsavf failing storage address validity flag cons concurrent sense scavf secondary ccw address validity flag fsaf failing storage address format scnt sense count, if cons == 1 res16 reserved Kernel Hackers Manual July 2017 struct erw_eadm 9 4.1.27 struct erw_eadm EADM Subchannel extended report word struct erw_eadm { __u32 b:1; __u32 r:1; }; b aob error r arsb error Kernel Hackers Manual July 2017 struct sublog 9 4.1.27 struct sublog subchannel logout area struct sublog { __u32 res0:1; __u32 esf:7; __u32 lpum:8; __u32 arep:1; __u32 fvf:5; __u32 sacc:2; __u32 termc:2; __u32 devsc:1; __u32 serr:1; __u32 ioerr:1; __u32 seqc:3; }; res0 reserved esf extended status flags lpum last path used mask arep ancillary report fvf field-validity flags sacc storage access code termc termination code devsc device-status check serr secondary error ioerr i/o-error alert seqc sequence code Kernel Hackers Manual July 2017 struct esw0 9 4.1.27 struct esw0 Format 0 Extended Status Word (ESW) struct esw0 { struct sublog sublog; struct erw erw; __u32 faddr[2]; __u32 saddr; }; sublog subchannel logout erw extended report word faddr[2] failing storage address saddr secondary ccw address Kernel Hackers Manual July 2017 struct esw1 9 4.1.27 struct esw1 Format 1 Extended Status Word (ESW) struct esw1 { __u8 zero0; __u8 lpum; __u16 zero16; struct erw erw; __u32 zeros[3]; }; zero0 reserved zeros lpum last path used mask zero16 reserved zeros erw extended report word zeros[3] three fullwords of zeros Kernel Hackers Manual July 2017 struct esw2 9 4.1.27 struct esw2 Format 2 Extended Status Word (ESW) struct esw2 { __u8 zero0; __u8 lpum; __u16 dcti; struct erw erw; __u32 zeros[3]; }; zero0 reserved zeros lpum last path used mask dcti device-connect-time interval erw extended report word zeros[3] three fullwords of zeros Kernel Hackers Manual July 2017 struct esw3 9 4.1.27 struct esw3 Format 3 Extended Status Word (ESW) struct esw3 { __u8 zero0; __u8 lpum; __u16 res; struct erw erw; __u32 zeros[3]; }; zero0 reserved zeros lpum last path used mask res reserved erw extended report word zeros[3] three fullwords of zeros Kernel Hackers Manual July 2017 struct esw_eadm 9 4.1.27 struct esw_eadm EADM Subchannel Extended Status Word (ESW) struct esw_eadm { __u32 sublog; struct erw_eadm erw; }; sublog subchannel logout erw extended report word Kernel Hackers Manual July 2017 struct irb 9 4.1.27 struct irb interruption response block struct irb { union scsw scsw; union esw; __u8 ecw[32]; }; scsw subchannel status word esw extended status word ecw[32] extended control word The irb that is handed to the device driver when an interrupt occurs. For solicited interrupts, the common I/O layer already performs checks whether a field is valid; a field not being valid is always passed as 0. If a unit check occurred, ecw may contain sense data; this is retrieved by the common I/O layer itself if the device doesn't support concurrent sense (so that the device driver never needs to perform basic sene itself). For unsolicited interrupts, the irb is passed as-is (expect for sense data, if applicable). Kernel Hackers Manual July 2017 struct ciw 9 4.1.27 struct ciw command information word (CIW) layout struct ciw { __u32 et:2; __u32 reserved:2; __u32 ct:4; __u32 cmd:8; __u32 count:16; }; et entry type reserved reserved bits ct command type cmd command code count command count Kernel Hackers Manual July 2017 struct ccw_dev_id 9 4.1.27 struct ccw_dev_id unique identifier for ccw devices struct ccw_dev_id { u8 ssid; u16 devno; }; ssid subchannel set id devno device number This structure is not directly based on any hardware structure. The hardware identifies a device by its device number and its subchannel, which is in turn identified by its id. In order to get a unique identifier for ccw devices across subchannel sets, struct ccw_dev_id has been introduced. Kernel Hackers Manual July 2017 ccw_dev_id_is_equal 9 4.1.27 ccw_dev_id_is_equal compare two ccw_dev_ids int ccw_dev_id_is_equal struct ccw_dev_id * dev_id1 struct ccw_dev_id * dev_id2 dev_id1 a ccw_dev_id dev_id2 another ccw_dev_id 1 if the two structures are equal field-by-field, 0 if not. any Devices that want to initiate channel I/O need to attach to the ccw bus. Interaction with the driver core is done via the common I/O layer, which provides the abstractions of ccw devices and ccw device drivers. The functions that initiate or terminate channel I/O all act upon a ccw device structure. Device drivers must not bypass those functions or strange side effects may happen. Kernel Hackers Manual July 2017 struct ccw_device 9 4.1.27 struct ccw_device channel attached device struct ccw_device { spinlock_t * ccwlock; struct ccw_device_id id; struct ccw_driver * drv; struct device dev; int online; void (* handler) (struct ccw_device *, unsigned long, struct irb *); }; ccwlock pointer to device lock id id of this device drv ccw driver for this device dev embedded device structure online online status of device handler interrupt handler handler is a member of the device rather than the driver since a driver can have different interrupt handlers for different ccw devices (multi-subchannel drivers). Kernel Hackers Manual July 2017 struct ccw_driver 9 4.1.27 struct ccw_driver device driver for channel attached devices struct ccw_driver { struct ccw_device_id * ids; int (* probe) (struct ccw_device *); void (* remove) (struct ccw_device *); int (* set_online) (struct ccw_device *); int (* set_offline) (struct ccw_device *); int (* notify) (struct ccw_device *, int); void (* path_event) (struct ccw_device *, int *); void (* shutdown) (struct ccw_device *); int (* prepare) (struct ccw_device *); void (* complete) (struct ccw_device *); int (* freeze) (struct ccw_device *); int (* thaw) (struct ccw_device *); int (* restore) (struct ccw_device *); enum uc_todo (* uc_handler) (struct ccw_device *, struct irb *); struct device_driver driver; enum interruption_class int_class; }; ids ids supported by this driver probe function called on probe remove function called on remove set_online called when setting device online set_offline called when setting device offline notify notify driver of device state changes path_event notify driver of channel path events shutdown called at device shutdown prepare prepare for pm state transition complete undo work done in prepare freeze callback for freezing during hibernation snapshotting thaw undo work done in freeze restore callback for restoring after hibernation uc_handler callback for unit check handler driver embedded device driver structure int_class interruption class to use for accounting interrupts Kernel Hackers Manual July 2017 ccw_device_set_offline 9 4.1.27 ccw_device_set_offline disable a ccw device for I/O int ccw_device_set_offline struct ccw_device * cdev cdev target ccw device This function calls the driver's set_offline function for cdev, if given, and then disables cdev. 0 on success and a negative error value on failure. enabled, ccw device lock not held Kernel Hackers Manual July 2017 ccw_device_set_online 9 4.1.27 ccw_device_set_online enable a ccw device for I/O int ccw_device_set_online struct ccw_device * cdev cdev target ccw device This function first enables cdev and then calls the driver's set_online function for cdev, if given. If set_online returns an error, cdev is disabled again. 0 on success and a negative error value on failure. enabled, ccw device lock not held Kernel Hackers Manual July 2017 get_ccwdev_by_dev_id 9 4.1.27 get_ccwdev_by_dev_id obtain device from a ccw device id struct ccw_device * get_ccwdev_by_dev_id struct ccw_dev_id * dev_id dev_id id of the device to be searched This function searches all devices attached to the ccw bus for a device matching dev_id. If a device is found its reference count is increased and returned; else NULL is returned. Kernel Hackers Manual July 2017 get_ccwdev_by_busid 9 4.1.27 get_ccwdev_by_busid obtain device from a bus id struct ccw_device * get_ccwdev_by_busid struct ccw_driver * cdrv const char * bus_id cdrv driver the device is owned by bus_id bus id of the device to be searched This function searches all devices owned by cdrv for a device with a bus id matching bus_id. If a match is found, its reference count of the found device is increased and it is returned; else NULL is returned. Kernel Hackers Manual July 2017 ccw_driver_register 9 4.1.27 ccw_driver_register register a ccw driver int ccw_driver_register struct ccw_driver * cdriver cdriver driver to be registered This function is mainly a wrapper around driver_register. 0 on success and a negative error value on failure. Kernel Hackers Manual July 2017 ccw_driver_unregister 9 4.1.27 ccw_driver_unregister deregister a ccw driver void ccw_driver_unregister struct ccw_driver * cdriver cdriver driver to be deregistered This function is mainly a wrapper around driver_unregister. Kernel Hackers Manual July 2017 ccw_device_siosl 9 4.1.27 ccw_device_siosl initiate logging int ccw_device_siosl struct ccw_device * cdev cdev ccw device This function is used to invoke model-dependent logging within the channel subsystem. Kernel Hackers Manual July 2017 ccw_device_set_options_mask 9 4.1.27 ccw_device_set_options_mask set some options and unset the rest int ccw_device_set_options_mask struct ccw_device * cdev unsigned long flags cdev device for which the options are to be set flags options to be set All flags specified in flags are set, all flags not specified in flags are cleared. 0 on success, -EINVAL on an invalid flag combination. Kernel Hackers Manual July 2017 ccw_device_set_options 9 4.1.27 ccw_device_set_options set some options int ccw_device_set_options struct ccw_device * cdev unsigned long flags cdev device for which the options are to be set flags options to be set All flags specified in flags are set, the remainder is left untouched. 0 on success, -EINVAL if an invalid flag combination would ensue. Kernel Hackers Manual July 2017 ccw_device_clear_options 9 4.1.27 ccw_device_clear_options clear some options void ccw_device_clear_options struct ccw_device * cdev unsigned long flags cdev device for which the options are to be cleared flags options to be cleared All flags specified in flags are cleared, the remainder is left untouched. Kernel Hackers Manual July 2017 ccw_device_is_pathgroup 9 4.1.27 ccw_device_is_pathgroup determine if paths to this device are grouped int ccw_device_is_pathgroup struct ccw_device * cdev cdev ccw device Return non-zero if there is a path group, zero otherwise. Kernel Hackers Manual July 2017 ccw_device_is_multipath 9 4.1.27 ccw_device_is_multipath determine if device is operating in multipath mode int ccw_device_is_multipath struct ccw_device * cdev cdev ccw device Return non-zero if device is operating in multipath mode, zero otherwise. Kernel Hackers Manual July 2017 ccw_device_clear 9 4.1.27 ccw_device_clear terminate I/O request processing int ccw_device_clear struct ccw_device * cdev unsigned long intparm cdev target ccw device intparm interruption parameter; value is only used if no I/O is outstanding, otherwise the intparm associated with the I/O request is returned ccw_device_clear calls csch on cdev's subchannel. 0 on success, -ENODEV on device not operational, -EINVAL on invalid device state. Interrupts disabled, ccw device lock held Kernel Hackers Manual July 2017 ccw_device_start_key 9 4.1.27 ccw_device_start_key start a s390 channel program with key int ccw_device_start_key struct ccw_device * cdev struct ccw1 * cpa unsigned long intparm __u8 lpm __u8 key unsigned long flags cdev target ccw device cpa logical start address of channel program intparm user specific interruption parameter; will be presented back to cdev's interrupt handler. Allows a device driver to associate the interrupt with a particular I/O request. lpm defines the channel path to be used for a specific I/O request. A value of 0 will make cio use the opm. key storage key to be used for the I/O flags additional flags; defines the action to be performed for I/O processing. Start a S/390 channel program. When the interrupt arrives, the IRQ handler is called, either immediately, delayed (dev-end missing, or sense required) or never (no IRQ handler registered). 0, if the operation was successful; -EBUSY, if the device is busy, or status pending; -EACCES, if no path specified in lpm is operational; -ENODEV, if the device is not operational. Interrupts disabled, ccw device lock held Kernel Hackers Manual July 2017 ccw_device_start_timeout_key 9 4.1.27 ccw_device_start_timeout_key start a s390 channel program with timeout and key int ccw_device_start_timeout_key struct ccw_device * cdev struct ccw1 * cpa unsigned long intparm __u8 lpm __u8 key unsigned long flags int expires cdev target ccw device cpa logical start address of channel program intparm user specific interruption parameter; will be presented back to cdev's interrupt handler. Allows a device driver to associate the interrupt with a particular I/O request. lpm defines the channel path to be used for a specific I/O request. A value of 0 will make cio use the opm. key storage key to be used for the I/O flags additional flags; defines the action to be performed for I/O processing. expires timeout value in jiffies Start a S/390 channel program. When the interrupt arrives, the IRQ handler is called, either immediately, delayed (dev-end missing, or sense required) or never (no IRQ handler registered). This function notifies the device driver if the channel program has not completed during the time specified by expires. If a timeout occurs, the channel program is terminated via xsch, hsch or csch, and the device's interrupt handler will be called with an irb containing ERR_PTR(-ETIMEDOUT). 0, if the operation was successful; -EBUSY, if the device is busy, or status pending; -EACCES, if no path specified in lpm is operational; -ENODEV, if the device is not operational. Interrupts disabled, ccw device lock held Kernel Hackers Manual July 2017 ccw_device_start 9 4.1.27 ccw_device_start start a s390 channel program int ccw_device_start struct ccw_device * cdev struct ccw1 * cpa unsigned long intparm __u8 lpm unsigned long flags cdev target ccw device cpa logical start address of channel program intparm user specific interruption parameter; will be presented back to cdev's interrupt handler. Allows a device driver to associate the interrupt with a particular I/O request. lpm defines the channel path to be used for a specific I/O request. A value of 0 will make cio use the opm. flags additional flags; defines the action to be performed for I/O processing. Start a S/390 channel program. When the interrupt arrives, the IRQ handler is called, either immediately, delayed (dev-end missing, or sense required) or never (no IRQ handler registered). 0, if the operation was successful; -EBUSY, if the device is busy, or status pending; -EACCES, if no path specified in lpm is operational; -ENODEV, if the device is not operational. Interrupts disabled, ccw device lock held Kernel Hackers Manual July 2017 ccw_device_start_timeout 9 4.1.27 ccw_device_start_timeout start a s390 channel program with timeout int ccw_device_start_timeout struct ccw_device * cdev struct ccw1 * cpa unsigned long intparm __u8 lpm unsigned long flags int expires cdev target ccw device cpa logical start address of channel program intparm user specific interruption parameter; will be presented back to cdev's interrupt handler. Allows a device driver to associate the interrupt with a particular I/O request. lpm defines the channel path to be used for a specific I/O request. A value of 0 will make cio use the opm. flags additional flags; defines the action to be performed for I/O processing. expires timeout value in jiffies Start a S/390 channel program. When the interrupt arrives, the IRQ handler is called, either immediately, delayed (dev-end missing, or sense required) or never (no IRQ handler registered). This function notifies the device driver if the channel program has not completed during the time specified by expires. If a timeout occurs, the channel program is terminated via xsch, hsch or csch, and the device's interrupt handler will be called with an irb containing ERR_PTR(-ETIMEDOUT). 0, if the operation was successful; -EBUSY, if the device is busy, or status pending; -EACCES, if no path specified in lpm is operational; -ENODEV, if the device is not operational. Interrupts disabled, ccw device lock held Kernel Hackers Manual July 2017 ccw_device_halt 9 4.1.27 ccw_device_halt halt I/O request processing int ccw_device_halt struct ccw_device * cdev unsigned long intparm cdev target ccw device intparm interruption parameter; value is only used if no I/O is outstanding, otherwise the intparm associated with the I/O request is returned ccw_device_halt calls hsch on cdev's subchannel. 0 on success, -ENODEV on device not operational, -EINVAL on invalid device state, -EBUSY on device busy or interrupt pending. Interrupts disabled, ccw device lock held Kernel Hackers Manual July 2017 ccw_device_resume 9 4.1.27 ccw_device_resume resume channel program execution int ccw_device_resume struct ccw_device * cdev cdev target ccw device ccw_device_resume calls rsch on cdev's subchannel. 0 on success, -ENODEV on device not operational, -EINVAL on invalid device state, -EBUSY on device busy or interrupt pending. Interrupts disabled, ccw device lock held Kernel Hackers Manual July 2017 ccw_device_get_ciw 9 4.1.27 ccw_device_get_ciw Search for CIW command in extended sense data. struct ciw * ccw_device_get_ciw struct ccw_device * cdev __u32 ct cdev ccw device to inspect ct command type to look for During SenseID, command information words (CIWs) describing special commands available to the device may have been stored in the extended sense data. This function searches for CIWs of a specified command type in the extended sense data. NULL if no extended sense data has been stored or if no CIW of the specified command type could be found, else a pointer to the CIW of the specified command type. Kernel Hackers Manual July 2017 ccw_device_get_path_mask 9 4.1.27 ccw_device_get_path_mask get currently available paths __u8 ccw_device_get_path_mask struct ccw_device * cdev cdev ccw device to be queried 0 if no subchannel for the device is available, else the mask of currently available paths for the ccw device's subchannel. Kernel Hackers Manual July 2017 ccw_device_get_chp_desc 9 4.1.27 ccw_device_get_chp_desc return newly allocated channel-path descriptor struct channel_path_desc * ccw_device_get_chp_desc struct ccw_device * cdev int chp_idx cdev device to obtain the descriptor for chp_idx index of the channel path On success return a newly allocated copy of the channel-path description data associated with the given channel path. Return NULL on error. Kernel Hackers Manual July 2017 ccw_device_get_id 9 4.1.27 ccw_device_get_id obtain a ccw device id void ccw_device_get_id struct ccw_device * cdev struct ccw_dev_id * dev_id cdev device to obtain the id for dev_id where to fill in the values Kernel Hackers Manual July 2017 ccw_device_tm_start_key 9 4.1.27 ccw_device_tm_start_key perform start function int ccw_device_tm_start_key struct ccw_device * cdev struct tcw * tcw unsigned long intparm u8 lpm u8 key cdev ccw device on which to perform the start function tcw transport-command word to be started intparm user defined parameter to be passed to the interrupt handler lpm mask of paths to use key storage key to use for storage access Start the tcw on the given ccw device. Return zero on success, non-zero otherwise. Kernel Hackers Manual July 2017 ccw_device_tm_start_timeout_key 9 4.1.27 ccw_device_tm_start_timeout_key perform start function int ccw_device_tm_start_timeout_key struct ccw_device * cdev struct tcw * tcw unsigned long intparm u8 lpm u8 key int expires cdev ccw device on which to perform the start function tcw transport-command word to be started intparm user defined parameter to be passed to the interrupt handler lpm mask of paths to use key storage key to use for storage access expires time span in jiffies after which to abort request Start the tcw on the given ccw device. Return zero on success, non-zero otherwise. Kernel Hackers Manual July 2017 ccw_device_tm_start 9 4.1.27 ccw_device_tm_start perform start function int ccw_device_tm_start struct ccw_device * cdev struct tcw * tcw unsigned long intparm u8 lpm cdev ccw device on which to perform the start function tcw transport-command word to be started intparm user defined parameter to be passed to the interrupt handler lpm mask of paths to use Start the tcw on the given ccw device. Return zero on success, non-zero otherwise. Kernel Hackers Manual July 2017 ccw_device_tm_start_timeout 9 4.1.27 ccw_device_tm_start_timeout perform start function int ccw_device_tm_start_timeout struct ccw_device * cdev struct tcw * tcw unsigned long intparm u8 lpm int expires cdev ccw device on which to perform the start function tcw transport-command word to be started intparm user defined parameter to be passed to the interrupt handler lpm mask of paths to use expires time span in jiffies after which to abort request Start the tcw on the given ccw device. Return zero on success, non-zero otherwise. Kernel Hackers Manual July 2017 ccw_device_get_mdc 9 4.1.27 ccw_device_get_mdc accumulate max data count int ccw_device_get_mdc struct ccw_device * cdev u8 mask cdev ccw device for which the max data count is accumulated mask mask of paths to use Return the number of 64K-bytes blocks all paths at least support for a transport command. Return values <= 0 indicate failures. Kernel Hackers Manual July 2017 ccw_device_tm_intrg 9 4.1.27 ccw_device_tm_intrg perform interrogate function int ccw_device_tm_intrg struct ccw_device * cdev cdev ccw device on which to perform the interrogate function Perform an interrogate function on the given ccw device. Return zero on success, non-zero otherwise. Kernel Hackers Manual July 2017 ccw_device_get_schid 9 4.1.27 ccw_device_get_schid obtain a subchannel id void ccw_device_get_schid struct ccw_device * cdev struct subchannel_id * schid cdev device to obtain the id for schid where to fill in the values The channel-measurement facility provides a means to collect measurement data which is made available by the channel subsystem for each channel attached device. .//arch/s390/include/asm/cmb.h Document generation inconsistency The template for this document tried to insert the structured comment from the file .//arch/s390/include/asm/cmb.h at this point, but none was found. This dummy section is inserted to allow generation to continue. Kernel Hackers Manual July 2017 enable_cmf 9 4.1.27 enable_cmf switch on the channel measurement for a specific device int enable_cmf struct ccw_device * cdev cdev The ccw device to be enabled Returns 0 for success or a negative error value. non-atomic Kernel Hackers Manual July 2017 disable_cmf 9 4.1.27 disable_cmf switch off the channel measurement for a specific device int disable_cmf struct ccw_device * cdev cdev The ccw device to be disabled Returns 0 for success or a negative error value. non-atomic Kernel Hackers Manual July 2017 cmf_read 9 4.1.27 cmf_read read one value from the current channel measurement block u64 cmf_read struct ccw_device * cdev int index cdev the channel to be read index the index of the value to be read Returns the value read or 0 if the value cannot be read. any Kernel Hackers Manual July 2017 cmf_readall 9 4.1.27 cmf_readall read the current channel measurement block int cmf_readall struct ccw_device * cdev struct cmbdata * data cdev the channel to be read data a pointer to a data block that will be filled Returns 0 on success, a negative error value otherwise. any The ccwgroup bus only contains artificial devices, created by the user. Many networking devices (e.g. qeth) are in fact composed of several ccw devices (like read, write and data channel for qeth). The ccwgroup bus provides a mechanism to create a meta-device which contains those ccw devices as slave devices and can be associated with the netdevice. Kernel Hackers Manual July 2017 struct ccwgroup_device 9 4.1.27 struct ccwgroup_device ccw group device struct ccwgroup_device { enum state; unsigned int count; struct device dev; struct work_struct ungroup_work; struct ccw_device * cdev[0]; }; state online/offline state count number of attached slave devices dev embedded device structure ungroup_work work to be done when a ccwgroup notifier has action type BUS_NOTIFY_UNBIND_DRIVER cdev[0] variable number of slave devices, allocated as needed Kernel Hackers Manual July 2017 struct ccwgroup_driver 9 4.1.27 struct ccwgroup_driver driver for ccw group devices struct ccwgroup_driver { int (* setup) (struct ccwgroup_device *); void (* remove) (struct ccwgroup_device *); int (* set_online) (struct ccwgroup_device *); int (* set_offline) (struct ccwgroup_device *); void (* shutdown) (struct ccwgroup_device *); int (* prepare) (struct ccwgroup_device *); void (* complete) (struct ccwgroup_device *); int (* freeze) (struct ccwgroup_device *); int (* thaw) (struct ccwgroup_device *); int (* restore) (struct ccwgroup_device *); struct device_driver driver; }; setup function called during device creation to setup the device remove function called on remove set_online function called when device is set online set_offline function called when device is set offline shutdown function called when device is shut down prepare prepare for pm state transition complete undo work done in prepare freeze callback for freezing during hibernation snapshotting thaw undo work done in freeze restore callback for restoring after hibernation driver embedded driver structure Kernel Hackers Manual July 2017 ccwgroup_set_online 9 4.1.27 ccwgroup_set_online enable a ccwgroup device int ccwgroup_set_online struct ccwgroup_device * gdev gdev target ccwgroup device This function attempts to put the ccwgroup device into the online state. 0 on success and a negative error value on failure. Kernel Hackers Manual July 2017 ccwgroup_set_offline 9 4.1.27 ccwgroup_set_offline disable a ccwgroup device int ccwgroup_set_offline struct ccwgroup_device * gdev gdev target ccwgroup device This function attempts to put the ccwgroup device into the offline state. 0 on success and a negative error value on failure. Kernel Hackers Manual July 2017 ccwgroup_create_dev 9 4.1.27 ccwgroup_create_dev create and register a ccw group device int ccwgroup_create_dev struct device * parent struct ccwgroup_driver * gdrv int num_devices const char * buf parent parent device for the new device gdrv driver for the new group device num_devices number of slave devices buf buffer containing comma separated bus ids of slave devices Create and register a new ccw group device as a child of parent. Slave devices are obtained from the list of bus ids given in buf. 0 on success and an error code on failure. non-atomic Kernel Hackers Manual July 2017 ccwgroup_driver_register 9 4.1.27 ccwgroup_driver_register register a ccw group driver int ccwgroup_driver_register struct ccwgroup_driver * cdriver cdriver driver to be registered This function is mainly a wrapper around driver_register. Kernel Hackers Manual July 2017 ccwgroup_driver_unregister 9 4.1.27 ccwgroup_driver_unregister deregister a ccw group driver void ccwgroup_driver_unregister struct ccwgroup_driver * cdriver cdriver driver to be deregistered This function is mainly a wrapper around driver_unregister. Kernel Hackers Manual July 2017 ccwgroup_probe_ccwdev 9 4.1.27 ccwgroup_probe_ccwdev probe function for slave devices int ccwgroup_probe_ccwdev struct ccw_device * cdev cdev ccw device to be probed This is a dummy probe function for ccw devices that are slave devices in a ccw group device. always 0 Kernel Hackers Manual July 2017 ccwgroup_remove_ccwdev 9 4.1.27 ccwgroup_remove_ccwdev remove function for slave devices void ccwgroup_remove_ccwdev struct ccw_device * cdev cdev ccw device to be removed This is a remove function for ccw devices that are slave devices in a ccw group device. It sets the ccw device offline and also deregisters the embedding ccw group device. Some interfaces are available to other drivers that do not necessarily have anything to do with the busses described above, but still are indirectly using basic infrastructure in the common I/O layer. One example is the support for adapter interrupts. Kernel Hackers Manual July 2017 register_adapter_interrupt 9 4.1.27 register_adapter_interrupt register adapter interrupt handler int register_adapter_interrupt struct airq_struct * airq airq pointer to adapter interrupt descriptor Returns 0 on success, or -EINVAL. Kernel Hackers Manual July 2017 unregister_adapter_interrupt 9 4.1.27 unregister_adapter_interrupt unregister adapter interrupt handler void unregister_adapter_interrupt struct airq_struct * airq airq pointer to adapter interrupt descriptor Kernel Hackers Manual July 2017 airq_iv_create 9 4.1.27 airq_iv_create create an interrupt vector struct airq_iv * airq_iv_create unsigned long bits unsigned long flags bits number of bits in the interrupt vector flags allocation flags Returns a pointer to an interrupt vector structure Kernel Hackers Manual July 2017 airq_iv_release 9 4.1.27 airq_iv_release release an interrupt vector void airq_iv_release struct airq_iv * iv iv pointer to interrupt vector structure Kernel Hackers Manual July 2017 airq_iv_alloc 9 4.1.27 airq_iv_alloc allocate irq bits from an interrupt vector unsigned long airq_iv_alloc struct airq_iv * iv unsigned long num iv pointer to an interrupt vector structure num number of consecutive irq bits to allocate Returns the bit number of the first irq in the allocated block of irqs, or -1UL if no bit is available or the AIRQ_IV_ALLOC flag has not been specified Kernel Hackers Manual July 2017 airq_iv_free 9 4.1.27 airq_iv_free free irq bits of an interrupt vector void airq_iv_free struct airq_iv * iv unsigned long bit unsigned long num iv pointer to interrupt vector structure bit number of the first irq bit to free num number of consecutive irq bits to free Kernel Hackers Manual July 2017 airq_iv_scan 9 4.1.27 airq_iv_scan scan interrupt vector for non-zero bits unsigned long airq_iv_scan struct airq_iv * iv unsigned long start unsigned long end iv pointer to interrupt vector structure start bit number to start the search end bit number to end the search Returns the bit number of the next non-zero interrupt bit, or -1UL if the scan completed without finding any more any non-zero bits.