Documentation/powerpc/cxlflash.rst

38     operation at the device (LUN) level:
40         - Any flash device (LUN) can be configured to be accessed as a
43         - Any flash device (LUN) can be configured to be accessed from
46           either raw access to the entire LUN (referred to as direct
47           or physical LUN access) or access to a kernel/AFU-mediated
48           partition of the LUN (referred to as virtual LUN access). The
85     scsi block devices (/dev/sdb, /dev/sdc etc.) for each unique LUN
104     and the entire space for the LUN is available to the application.
131 CXL Flash Driver LUN IOCTLs
135     device (LUN) via user space access need to use the services provided
140     with the scsi disk device (/dev/sdb) that was created during LUN
205     This ioctl is responsible for transitioning the LUN to direct
213     requests to use the LUN in a different mode are denied.
218     is then able to use the handle to reference the LUN during I/O.
222     This ioctl is responsible for transitioning the LUN to virtual mode
230     requests to use the LUN in a different mode are denied.
235     user is then able to use the handle to reference the LUN during I/O.
237     By default, the virtual LUN is created with a size of 0. The user
239     the virtual LUN to a desired size. To avoid having to perform this
240     resize for the initial creation of the virtual LUN, the user has the
246     When a LUN is accessible from more than one port, this ioctl will
249     of an I/O error as the LUN can be reached over multiple paths.
254     LUN and will fail if invoked upon a LUN that is not in virtual
256     indicating the new size of the virtual LUN associated with the
260     driver and the AFU. An allocation table is kept for each LUN that is
261     operating in the virtual mode and used to program a LUN translation
273     reference to either a physical or virtual LUN. This can be
279     As part of the release process for virtual LUNs, the virtual LUN
281     associated with the virtual LUN reference.
332     where the changes affect the application (such as a LUN resize), the
335     The user calls in when they want to validate that a LUN hasn't been
341     verifying a LUN change (ie: size different) with sense data is
369     This ioctl is used to switch a LUN from a mode where it is available
371     exclusive user space access (superpipe). In case a LUN is visible
373     identify each LUN by its World Wide Node Name (WWNN).
393     devices that lack an external LUN management interface. It is only
394     valid when used with AFUs that support the LUN provision capability.
397     the target port to host the LUN and a desired size in 4K blocks. Upon
398     success, the LUN ID and WWID of the created LUN will be returned and
399     the SCSI bus can be scanned to detect the change in LUN topology. Note
401     to a space issue, the target port can be queried for its current LUN
404     To remove a LUN, the device must first be disassociated from the Linux
405     SCSI subsystem. The LUN deletion can then be initiated by specifying a
406     target port and LUN ID. Upon success, the LUN geometry associated with
410     To query the LUN geometry of a port, the target port is specified and