SRP task management function codes

[Elliott, Robert]

* From the T10 Reflector (t10 at t10.org), posted by:
* "Elliott, Robert" <Robert.Elliott at compaq.com>
*
One clarification noted by George Penokie: FCP-2 does treat it as an encoded
field (the header is "bit", not "value").

Unfortunately, the encodings don't exactly match SPI-4.

SPI-4 08h = bit 3 = LOGICAL UNIT RESET
SPI-4 10h = bit 4 = reserved

FCP-2 08h = bit 3 = reserved
FCP-2 10h = bit 4 = LOGICAL UNIT RESET


Adding the other SCSI protocols, SBP-2 encodes them this way (along with
other protocol-specific functions):
B ABORT TASK
C ABORT TASK SET
D Reserved for future standardization
E LOGICAL UNIT RESET
F TARGET RESET

And SST has a bitwise version:
bit 7 TERMINATE TASK
bit 6 CLEAR ACA
bit 5 TARGET RESET
bit 4 reserved
bit 3 reserved
bit 2 CLEAR TASK SET
bit 1 ABORT TASK SET 
bit 0 reserved


---
Rob Elliott, Compaq Server Storage
Robert.Elliott at compaq.com


> -----Original Message-----
> From: Elliott, Robert 
> Sent: Monday, May 21, 2001 1:52 PM
> To: 't10 at t10.org'
> Subject: SRP task management function codes
> 
> 
> * From the T10 Reflector (t10 at t10.org), posted by:
> * "Elliott, Robert" <Robert.Elliott at compaq.com>
> *
> SRP revision 4 includes an editor's note about Table 16 on 
> page 30, the list
> of task management functions.  Why is this table using 
> bitwise assignment?
> SPI-4 did it this way, but FCP-2 and iSCSI just treat it as an encoded
> field.  I suggest encoding the values as:
> 1 ABORT TASK
> 2 ABORT TASK SET
> 3 CLEAR ACA
> 4 CLEAR TASK SET
> 5 LOGICAL UNIT RESET
> All others reserved
> 
> 
> SRP revision 4:
> 01h The task manager shall perform an ABORT TASK function (see SAM-2).
> 02h The task manager shall perform an ABORT TASK SET function 
> (see SAM-2).
> 04h The task manager shall perform a CLEAR TASK SET function 
> (see SAM-2).
> 08h The task manager shall perform a LOGICAL UNIT RESET function (see
> SAM-2).
> 20h Reserved.
> 40h The task manager shall perform a CLEAR ACA function (see SAM-2).
> All other values reserved The task manager shall terminate 
> the task with a
> GOOD status. The packetized failure code shall be set to TASK 
> MANAGEMENT
> FUNCTION NOT SUPPORTED.
> 
> SPI-4 revision 5:
> 00h Indicates no task management requests for the current task.
> 01h The task manager shall abort the task as defined in the ABORT TASK
> message (see 16.5.2).
> 02h The task manager shall abort the task set as defined in 
> the ABORT TASK
> SET message (see 16.5.3).
> 04h The task manager shall clear the task set as defined in 
> the CLEAR TASK
> SET message (see 16.5.5).
> 08h The task manager shall perform a hard logical unit reset to of the
> selected logical unit as defined in the LOGICAL UNIT RESET 
> message (see
> 16.5.6).
> 20h The task manager shall perform a hard target reset as 
> defined in the
> TARGET RESET message (see 16.5.7).
> 40h The task manager shall perform a clear ACA as defined in 
> the CLEAR ACA
> message (see 16.5.4).
> All other values reserved The task manager shall terminate 
> the task with a
> GOOD status. The packetized failure code shall be set to TASK 
> MANAGEMENT
> FUNCTION NOT SUPPORTED.
> 
> FCP-2 revision 7:
(bit numbers)
> 7 obsolete
> 6 CLEAR ACA
> 5 TARGET RESET
> 4 LOGICAL UNIT RESET
> 3 reserved
> 2 CLEAR TASK SET
> 1 ABORT TASK SET
> 0 reserved
> 
> iSCSI revision 6:
>       1    Abort Task - aborts the task identified by the 
> Referenced Task
> Tag field. 
>       2    Abort Task Set - aborts all Tasks issued by this 
> initiator on the
> Logical Unit. 
>       3    Clear ACA - clears the Auto Contingent Allegiance 
> condition. 
>       4    Clear Task Set - Aborts all Tasks (from all 
> initiators) for the
> Logical Unit. 
>       5    Logical Unit Reset 
>       6    Target Warm Reset 
>       7    Target Cold Reset 
> 
> ---
> Rob Elliott, Compaq Server Storage
> Robert.Elliott at compaq.com
> 
> 
> 
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