SLOF: virtio-scsi block driver code

Forth implementation for virtio-scsi as a block driver. Uses
scsi-support.fs for the scsi command protocol

Signed-off-by: Nikunj A. Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 160 insertions, 133 deletions

diff --git a/board-qemu/slof/virtio-scsi.fs b/board-qemu/slof/virtio-scsi.fs
index ae74f4d..bedfe76 100644
--- a/board-qemu/slof/virtio-scsi.fs
+++ b/board-qemu/slof/virtio-scsi.fs
@@ -12,178 +12,200 @@
 
 ." Populating " pwd cr
 
-0 CONSTANT virtio-scsi-debug
-1 CONSTANT virtio-scsi \ scsi-type for device address handling
+FALSE CONSTANT virtio-scsi-debug
 
-1 encode-int s" #address-cells" property
-1 encode-int s" #size-cells" property
+2 encode-int s" #address-cells" property
+0 encode-int s" #size-cells" property
 
-: decode-unit  1 hex-decode-unit ;
-: encode-unit  1 hex-encode-unit ;
-
-\ s" block" device-type
+: decode-unit 2 hex64-decode-unit ;
+: encode-unit 2 hex64-encode-unit ;
 
 FALSE VALUE initialized?
 
 /vd-len BUFFER: virtiodev
 virtiodev virtio-setup-vd
 
-STRUCT
-    100 FIELD >cdb-req
-constant /cdb-buf
+STRUCT \ virtio-scsi-config
+    /l FIELD vs-cfg>num-queues
+    /l FIELD vs-cfg>seg-max
+    /l FIELD vs-cfg>max-sectors
+    /l FIELD vs-cfg>cmd-per-lun
+    /l FIELD vs-cfg>event-info-size
+    /l FIELD vs-cfg>sense_size
+    /l FIELD vs-cfg>cdb-size
+    /w FIELD vs-cfg>max-channel
+    /w FIELD vs-cfg>max-target
+    /l FIELD vs-cfg>max-lun
+CONSTANT vs-cfg-length
+
+STRUCT \ virtio-scsi-req
+    8  FIELD vs-req>lun
+    8  FIELD vs-req>tag
+    /c FIELD vs-req>task-attr
+    /c FIELD vs-req>prio
+    /c FIELD vs-req>crn
+    20 FIELD vs-req>cdb
+CONSTANT vs-req-length
+
+STRUCT \ virtio-scsi-resp
+    /l FIELD vs-rsp>sense-len
+    /l FIELD vs-rsp>residual
+    /w FIELD vs-rsp>status-qualifier
+    /c FIELD vs-rsp>status
+    /c FIELD vs-rsp>response
+    60 FIELD vs-rsp>sense
+CONSTANT vs-rsp-length
+
+CREATE vs-req vs-req-length allot
+CREATE vs-rsp vs-rsp-length allot
 
 scsi-open
 
-CREATE sector d# 512 allot
-CREATE sectorlun d# 512 allot
-0 INSTANCE VALUE current-target
-CREATE cdb 100 allot
-
-: inquiry ( -- )
-    ff cdb >cdb-req scsi-build-inquiry
-    virtiodev current-target cdb sector ff virtio-scsi-send
-    0<> IF  ." Inquiry failed " cr FALSE EXIT THEN
-    TRUE
-;
+\ -----------------------------------------------------------
+\ Perform SCSI commands
+\ -----------------------------------------------------------
 
-: request-sense ( -- )
-    ff cdb >cdb-req scsi-build-request-sense
-    virtiodev current-target cdb sector ff virtio-scsi-send
-    0<> IF ." Error " cr FALSE EXIT THEN
-    sector scsi-get-sense-data
-;
+0 INSTANCE VALUE current-target
 
-: report-luns ( -- )
-    200 cdb >cdb-req scsi-build-report-luns
-    virtiodev current-target cdb sectorlun 200 virtio-scsi-send
-    0<> IF  ." Report-luns failed " cr request-sense FALSE EXIT THEN
-    virtio-scsi-debug IF
-	sectorlun 20 dump cr
+\ SCSI command. We do *NOT* implement the "standard" execute-command
+\ because that doesn't have a way to return the sense buffer back, and
+\ we do have auto-sense with some hosts. Instead we implement a made-up
+\ do-scsi-command.
+\
+\ Note: stat is -1 for "hw error" (ie, error queuing the command or
+\ getting the response).
+\
+\ A sense buffer is returned whenever the status is non-0 however
+\ if sense-len is 0 then no sense data is actually present
+\
+
+: execute-scsi-command ( buf-addr buf-len dir cmd-addr cmd-len -- ... )
+                       ( ... [ sense-buf sense-len ] stat )
+    \ Cleanup virtio request and response
+    vs-req vs-req-length erase
+    vs-rsp vs-rsp-length erase
+
+    \ Populate the request
+    current-target vs-req vs-req>lun x!
+    vs-req vs-req>cdb swap move
+
+    \ Send it
+    vs-req vs-rsp virtiodev
+    virtio-scsi-send
+
+    0 <> IF
+        ." VIRTIO-SCSI: Queuing failure !" cr
+        0 0 -1 EXIT
     THEN
-    TRUE
-;
 
-: test-unit-ready ( -- true | [ ascq asc sense-key false ] )
-    cdb >cdb-req scsi-build-test-unit-ready
-    virtiodev current-target cdb sector ff virtio-scsi-send
-    0<> IF
-	request-sense FALSE
-	EXIT THEN
-    TRUE
+    \ Check virtio response
+    vs-rsp vs-rsp>response c@ CASE
+        0 OF ENDOF			\ Good
+        5 OF drop 0 0 8 EXIT ENDOF	\ Busy
+        dup OF 0 0 -1 EXIT ENDOF	\ Anything else -> HW error
+    ENDCASE
+
+    \ Other error status
+    vs-rsp vs-rsp>status c@ dup 0<> IF
+        vs-rsp vs-rsp>sense-len l@ dup 0= IF
+            \ This relies on auto-sense from qemu... if that isn't always the
+            \ case we should request sense here
+            ." VIRTIO-SCSI: No sense data" cr
+	    0 EXIT
+        THEN
+        vs-rsp vs-rsp>sense swap
+        virtio-scsi-debug IF
+            over scsi-get-sense-data
+            ." VIRTIO-SCSI: Sense key [ " dup . ." ] " .sense-text
+	    ."  ASC,ASCQ: " . . cr
+        THEN
+       rot
+    THEN    
 ;
 
-: read-capacity ( -- TRUE | FALSE )
-    cdb >cdb-req scsi-build-read-cap-10
-    virtiodev current-target cdb sector ff virtio-scsi-send
-    0<> IF ." Error reading capacity virtio-scsi block " cr FALSE EXIT THEN
-    TRUE
-;
+\ --------------------------------
+\ Include the generic host helpers
+\ --------------------------------
 
-: get-media-event ( -- true | false )
-    cdb >cdb-req scsi-build-get-media-event
-    virtiodev current-target cdb sector ff virtio-scsi-send
-    0<> IF ." Error get-media-event " cr FALSE EXIT THEN
-    TRUE
-;
+" scsi-host-helpers.fs" included
 
-: start-stop-unit ( state# -- true | false )
-    cdb >cdb-req scsi-build-start-stop-unit
-    virtiodev current-target cdb sector ff virtio-scsi-send
-    0<> IF ." Error start-stop-unit " cr FALSE EXIT THEN
-    TRUE
+\ FIXME: Check max transfer coming from virtio config
+: max-transfer ( -- n )
+    10000 \ Larger value seem to have problems with some CDROMs
 ;
 
-: read-blocks ( address block# #blocks block-size -- [#read-blocks true] | false )
-    over *                          ( address block# #block len )
-    -rot tuck                       ( address len #block block# #block )
-    cdb >cdb-req scsi-build-read-10 ( address len #blocks )
-    -rot >r >r                      ( #block ) ( R: len address )
-    virtiodev current-target cdb r> r> virtio-scsi-send
-    0<> IF drop false ." Error reading virtio-scsi block " cr ABORT THEN
-    true
-;
+\ -----------------------------------------------------------
+\ SCSI scan at boot and child device support
+\ -----------------------------------------------------------
 
-: set-target ( srplun -- )
-    virtio-scsi-debug IF
-	dup ." Setting target " . cr
-    THEN
+\ We use SRP luns of the form 01000000 | (target << 8) | lun
+\ in the top 32 bits of the 64-bit LUN
+: (set-target)
     to current-target
 ;
-
-: wrapped-inquiry ( -- true | false )
-    inquiry not IF false EXIT THEN
-    \ Skip devices with PQ != 0
-    sector inquiry-data>peripheral c@ e0 and 0 =
+\ We obtain here a unit address on the stack, since our #address-cells
+\ is 2, the 64-bit srplun is split in two cells that we need to join
+\
+\ Note: This diverges a bit from the original OF scsi spec as the two
+\ cells are the 2 words of a 64-bit SRP LUN
+: set-address ( srplun.lo srplun.hi -- )
+    lxjoin (set-target)
 ;
 
-: initial-test-unit-ready ( -- true | [ ascq asc sense-key false ] )
-    0 0 0 false
-    3 0 DO
-        2drop 2drop
-	test-unit-ready dup IF UNLOOP EXIT THEN
-    LOOP
-;
+\ FIXME: Make these two common somewhat, possibly passing the
+\        unit "name" as an argument
 
-: compare-sense ( ascq asc key ascq2 asc2 key2 -- true | false )
-    3 pick =	    ( ascq asc key ascq2 asc2 keycmp )
-    swap 4 pick =   ( ascq asc key ascq2 keycmp asccmp )
-    rot 5 pick =    ( ascq asc key keycmp asccmp ascqcmp )
-    and and nip nip nip
+: make-disk-alias	( srplun -- )
+    " disk" find-alias 0<> IF drop THEN
+    get-node node>path
+    20 allot
+    " /disk@" string-cat                      \ srplun npath npathl
+    rot base @ >r hex (u.) r> base ! string-cat
+    " disk" 2swap set-alias
 ;
 
-#include "generic-cdrom.fs"
-
-: dev-prep-disk ( -- )
-    initial-test-unit-ready 0= IF
-	." Disk not ready!" cr
-        3drop
-    THEN
-;
-
-: dev-max-transfer ( -- n )
-    10000 \ Larger value seem to have problems with some CDROMs
-;
-
-: dev-get-capacity ( -- blocksize #blocks )
-    \ Make sure that there are zeros in the buffer in case something
-    \ goes wrong:
-    sector 10 erase
-    \ Now issue the read-capacity command
-    read-capacity not IF
-        0 0 EXIT
-    THEN
-    sector scsi-get-capacity-10
+: make-cdrom-alias	( srplun -- )
+    " cdrom" find-alias 0<> IF drop THEN
+    get-node node>path
+    20 allot
+    " /disk@" string-cat                      \ srplun npath npathl
+    rot base @ >r hex (u.) r> base ! string-cat
+    " cdrom" 2swap set-alias
 ;
 
-: dev-read-blocks  ( addr block# #blocks block-size -- [#blocks-read true] | false)
-    read-blocks
-;
-
-: virtio-scsi-create-disk	( srplun -- )
-    " disk" 0 virtio-scsi " generic-scsi-device.fs" included
+\ FIXME Remove use of "sector"
+: wrapped-inquiry ( -- true | false )
+    inquiry dup 0= IF drop false EXIT THEN
+    \ Skip devices with PQ != 0
+    inquiry-data>peripheral c@ e0 and 0 =
 ;
 
-: virtio-scsi-create-cdrom	( srplun -- )
-    " cdrom" 1 virtio-scsi " generic-scsi-device.fs" included
-;
+\ Get rid of that when report-lun returns an allocated buffer
+CREATE sectorlun d# 512 allot
 
 : virtio-scsi-find-disks      ( -- )
     ." VIRTIO-SCSI: Looking for devices" cr
-    0 set-target
+    0100000000000000 (set-target)
+    \ XXX FIXME: Iterate targets, not only luns, base code on vscsi
+    \ or better, make it generic (using an encode-target method that
+    \ takes ID,lun as argument maybe
     report-luns IF
-	sectorlun 8 +                     ( lunarray )
+    	sectorlun 200 move \ copy report-luns result to sectorlun
+                           \ will go away when report-lun returns
+                           \ an allocated block
+	sectorlun 8 +                    ( lunarray )
 	dup sectorlun l@ 3 >> 0 DO       ( lunarray lunarraycur )
-	    \ fixme: Read word, as virtio-scsi writes u16 luns
-	    dup w@ set-target wrapped-inquiry IF
+	    dup w@ 32 << 0100000000000000 or
+            (set-target) wrapped-inquiry IF
 		."   " current-target (u.) type ."  "
 		\ XXX FIXME: Check top bits to ignore unsupported units
 		\            and maybe provide better printout & more cases
 		\ XXX FIXME: Actually check for LUNs
 		sector inquiry-data>peripheral c@ CASE
-		    0   OF ." DISK     : " current-target virtio-scsi-create-disk ENDOF
-		    5   OF ." CD-ROM   : " current-target virtio-scsi-create-cdrom ENDOF
-		    7   OF ." OPTICAL  : " current-target virtio-scsi-create-cdrom ENDOF
-		    e   OF ." RED-BLOCK: " current-target virtio-scsi-create-disk ENDOF
+		    0   OF ." DISK     : " current-target make-disk-alias ENDOF
+		    5   OF ." CD-ROM   : " current-target make-cdrom-alias ENDOF
+		    7   OF ." OPTICAL  : " current-target make-cdrom-alias ENDOF
+		    e   OF ." RED-BLOCK: " current-target make-disk-alias ENDOF
 		    dup dup OF ." ? (" . 8 emit 29 emit 5 spaces ENDOF
 		ENDCASE
 		sector .inquiry-text cr
@@ -216,10 +238,10 @@ scsi-close        \ no further scsi words required
     virtiodev 2 queue-cmd-addr virtio-set-qaddr
 ;
 
-\ Set disk alias if none is set yet
+\ Set scsi alias if none is set yet
 : setup-alias
-    s" disk" find-alias 0= IF
-	s" disk" get-node node>path set-alias
+    s" scsi" find-alias 0= IF
+	s" scsi" get-node node>path set-alias
     ELSE
 	drop
     THEN
@@ -237,7 +259,7 @@ scsi-close        \ no further scsi words required
     dup to my-self
     \ Scan the VSCSI bus:
     virtiodev virtio-scsi-init
-    dup 0= IF
+    0= IF
 	setup-virt-queues
 	virtio-scsi-find-disks
 	setup-alias
@@ -249,4 +271,9 @@ scsi-close        \ no further scsi words required
     r> to my-self
 ;
 
+: virtio-scsi-add-disk
+    " scsi-disk.fs" included
+;
+
+virtio-scsi-add-disk
 virtio-scsi-init-and-scan