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authorMatthew R. Ochs <mrochs@linux.vnet.ibm.com>2017-06-22 05:16:13 +0300
committerMartin K. Petersen <martin.petersen@oracle.com>2017-06-26 22:01:12 +0300
commit9cf43a360450ddd758b0021d1b55f1cc5643b9ed (patch)
tree0d314def42874dd878a05dd713549d77dd255bd8 /Documentation/powerpc
parentefa1c818d3458fe97d8f83f40051518b44183234 (diff)
downloadlinux-9cf43a360450ddd758b0021d1b55f1cc5643b9ed.tar.xz
scsi: cxlflash: Support LUN provisioning
Adopt the SISLite AFU LUN provisioning capability to allow future CXL Flash adapters the ability to better manage storage. Update the SISLite header with the changes necessary to support LUN provision operations and create a host ioctl interface for user LUN management software. Also update the cxlflash documentation to describe this new host ioctl. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'Documentation/powerpc')
-rw-r--r--Documentation/powerpc/cxlflash.txt31
1 files changed, 31 insertions, 0 deletions
diff --git a/Documentation/powerpc/cxlflash.txt b/Documentation/powerpc/cxlflash.txt
index ee67021bbfe4..2d6297b4ad80 100644
--- a/Documentation/powerpc/cxlflash.txt
+++ b/Documentation/powerpc/cxlflash.txt
@@ -382,3 +382,34 @@ CXL Flash Driver Host IOCTLs
The structure definitions for these IOCTLs are available in:
uapi/scsi/cxlflash_ioctl.h
+
+HT_CXLFLASH_LUN_PROVISION
+-------------------------
+ This ioctl is used to create and delete persistent LUNs on cxlflash
+ devices that lack an external LUN management interface. It is only
+ valid when used with AFUs that support the LUN provision capability.
+
+ When sufficient space is available, LUNs can be created by specifying
+ the target port to host the LUN and a desired size in 4K blocks. Upon
+ success, the LUN ID and WWID of the created LUN will be returned and
+ the SCSI bus can be scanned to detect the change in LUN topology. Note
+ that partial allocations are not supported. Should a creation fail due
+ to a space issue, the target port can be queried for its current LUN
+ geometry.
+
+ To remove a LUN, the device must first be disassociated from the Linux
+ SCSI subsystem. The LUN deletion can then be initiated by specifying a
+ target port and LUN ID. Upon success, the LUN geometry associated with
+ the port will be updated to reflect new number of provisioned LUNs and
+ available capacity.
+
+ To query the LUN geometry of a port, the target port is specified and
+ upon success, the following information is presented:
+
+ - Maximum number of provisioned LUNs allowed for the port
+ - Current number of provisioned LUNs for the port
+ - Maximum total capacity of provisioned LUNs for the port (4K blocks)
+ - Current total capacity of provisioned LUNs for the port (4K blocks)
+
+ With this information, the number of available LUNs and capacity can be
+ can be calculated.