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Diffstat (limited to 'Documentation/powerpc/cxlflash.txt')
| -rw-r--r-- | Documentation/powerpc/cxlflash.txt | 31 |
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. |