fdt: Fix updating the tree at H_CAS

The previous approach to merge the QEMU FDT into the existing tree and
then patch it turned to be broken as we patch properties based on their
names only so we patch not just what QEMU provides (which was
the intention) but also all properties SLOF created. This breaks one of
them - "interrupt-map" - it is created by QEMU for a PHB but SLOF creates
it for PCI bridges and since they have different sizes, patching phandles
at fixed offset fails.

Rather than skipping certain nodes in the SLOF tree, this uses different
approach: now we read the QEMU FDT in 3 passes:
1. find all phandle/linux-phandle properties and store these in the SLOF
internal tree to allow phandle->node lookup later;
2. walk through all FDT properties, patch them if needed using
phandles from the SLOF tree and save patched values in SLOF properties;
3. delete phandle/linux-phandle properties created in 1. This is safe
as SLOF does not create these properties anyway.

Fixes: 44d06f9e68cf ("fdt: Update phandles after H_CAS")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>

2 files changed, 117 insertions, 7 deletions

diff --git a/board-qemu/slof/archsupport.fs b/board-qemu/slof/archsupport.fs
index 6512d57..fc48830 100644
--- a/board-qemu/slof/archsupport.fs
+++ b/board-qemu/slof/archsupport.fs
@@ -33,7 +33,6 @@
 	    fdt-check-header
 	    fdt-struct fdt-fix-cas-node
 	    fdt-fix-cas-success NOT       ( memaddr err? )
-	    s" /" find-node fdt-fix-phandles
 	ELSE
 	    FALSE
 	THEN
diff --git a/board-qemu/slof/fdt.fs b/board-qemu/slof/fdt.fs
index 5ece270..fc39a82 100644
--- a/board-qemu/slof/fdt.fs
+++ b/board-qemu/slof/fdt.fs
@@ -12,6 +12,7 @@
 
 0 VALUE fdt-debug
 TRUE VALUE fdt-cas-fix?
+0 VALUE fdt-cas-pass
 
 \ Bail out if no fdt
 fdt-start 0 = IF -1 throw THEN
@@ -294,6 +295,81 @@ fdt-claim-reserve
     2drop 2drop
 ;
 
+: (phandle>node) ( phandle current -- node|0 )
+    dup s" phandle" rot get-property 0= IF
+	decode-int nip nip ( phandle current phandle-prop )
+	2 pick = IF
+	    fdt-debug IF ."        Found phandle; " dup . ."  <= " over . cr THEN
+	    nip            ( current )
+	    EXIT
+	THEN
+    ELSE
+	dup s" linux-phandle" rot get-property 0= IF
+	    decode-int nip nip ( phandle current phandle-prop )
+	    2 pick = IF
+		fdt-debug IF ."        Found linux-phandle; " dup . ."  <= " over . cr THEN
+		nip            ( current )
+		EXIT
+	    THEN
+	THEN
+    THEN
+    child BEGIN
+	dup
+    WHILE
+	2dup
+	RECURSE
+	?dup 0<> IF
+	    nip nip
+	    EXIT
+	THEN
+	PEER
+    REPEAT
+    2drop 0
+;
+
+: phandle>node ( phandle -- node ) s" /" find-node (phandle>node)  ;
+
+: (fdt-patch-phandles) ( prop-addr prop-len -- )
+    BEGIN
+        dup
+    WHILE                   ( prop-addr prop-len )
+        over l@ phandle>node
+	?dup 0<> IF
+	    fdt-debug IF ."     ### Patching phandle=" 2 pick l@ . cr THEN
+	    2 pick l!
+            TRUE TO (fdt-phandle-replaced)
+        THEN
+        4 - swap 4 + swap
+    REPEAT
+    2drop
+;
+
+: (fdt-patch-interrupt-map) ( prop-addr prop-len -- )
+    \ interrupt-controller phandle is expected to be the same accross the map
+    over 10 + l@ phandle>node ?dup 0= IF 2drop EXIT THEN
+    -rot
+    fdt-debug IF ."      ### Patching interrupt-map: " over 10 + l@ . ."  => " 2 pick . cr THEN
+
+    TRUE TO (fdt-phandle-replaced)
+    BEGIN
+        dup
+    WHILE                   ( newph prop-addr prop-len )
+	2 pick 2 pick 10 + l!
+        1c - swap 1c  + swap
+    REPEAT
+    3drop
+;
+
+: fdt-patch-phandles ( prop-addr prop-len nameadd namelen -- )
+   2dup s" interrupt-map" str= IF 2drop (fdt-patch-interrupt-map) EXIT THEN
+   2dup s" interrupt-parent" str= IF 2drop (fdt-patch-phandles) EXIT THEN
+   2dup s" ibm,gpu" str= IF 2drop (fdt-patch-phandles) EXIT THEN
+   2dup s" ibm,npu" str= IF 2drop (fdt-patch-phandles) EXIT THEN
+   2dup s" ibm,nvlink" str= IF 2drop (fdt-patch-phandles) EXIT THEN
+   2dup s" memory-region" str= IF 2drop (fdt-patch-phandles) EXIT THEN
+   4drop
+;
+
 \ Replace one phandle "old" with a phandle "new" in "node" and recursively
 \ in its child nodes:
 : fdt-replace-all-phandles ( old new node -- )
@@ -394,6 +470,12 @@ r> drop
     find-node ?dup 0 <> IF set-node THEN
 ;
 
+: str=phandle? ( s len -- true|false )
+    2dup s" phandle" str= >r
+    s" linux,phandle" str=
+    r> or
+;
+
 : (fdt-fix-cas-node) ( start -- end )
     recursive
     fdt-next-tag dup OF_DT_BEGIN_NODE <> IF
@@ -414,7 +496,7 @@ r> drop
     2dup find-node ?dup 0 <> IF
 	set-node 2drop
     ELSE
-	fdt-debug IF ." Node not found, creating " 2dup type cr THEN
+	fdt-debug IF ." Creating node: " 2dup type cr THEN
 	fdt-create-cas-node
     THEN
     fdt-debug IF ." Current  now: " pwd cr THEN
@@ -422,22 +504,48 @@ r> drop
 	fdt-next-tag dup OF_DT_END_NODE <>
     WHILE
 	dup OF_DT_PROP = IF
-	    fdt-debug IF ." Found property " cr THEN
 	    drop dup		( drop tag, dup addr     : a1 a1 )
 	    dup l@ dup rot 4 +	( fetch size, stack is   : a1 s s a2)
 	    dup l@ swap 4 +	( fetch nameid, stack is : a1 s s i a3 )
 	    rot			( we now have: a1 s i a3 s )
 	    fdt-encode-prop rot	( a1 s pa ps i)
 	    fdt-fetch-string		( a1 s pa ps na ns )
-	    property
-	    fdt-debug IF ." Setting property done " cr THEN
+
+	    fdt-cas-pass CASE
+	    0 OF
+		2dup str=phandle? IF
+		    fdt-debug IF 4dup ."   Phandle: " type ." =" swap ." @" . ."  " .d ."  bytes" cr THEN
+		    property
+		ELSE
+		    4drop
+		THEN
+	    ENDOF
+	    1 OF
+		2dup str=phandle? not IF
+		    fdt-debug IF 4dup ."   Property: "  type ." =" swap ." @" . ."  " .d ."  bytes" cr THEN
+		    4dup fdt-patch-phandles
+		    property
+		ELSE
+		    4drop
+		THEN
+	    ENDOF
+	    2 OF
+		2dup str=phandle? IF
+		    fdt-debug IF 4dup ."   Deleting: " type ." =" swap ." @" . ."  " .d ."  bytes" cr THEN
+		    delete-property
+		    2drop
+		ELSE
+		    4drop
+		THEN
+	    ENDOF
+	    ENDCASE
+
 	    + 8 + 3 + fffffffc and
 	ELSE dup OF_DT_BEGIN_NODE = IF
 		drop			( drop tag )
 		4 -
 		(fdt-fix-cas-node)
 		get-parent set-node
-		fdt-debug IF ." Returning back " pwd cr THEN
 	    ELSE
 		." Error " cr
 		drop
@@ -450,7 +558,10 @@ r> drop
 ;
 
 : fdt-fix-cas-node ( start -- )
-    (fdt-fix-cas-node) drop
+    0 to fdt-cas-pass dup (fdt-fix-cas-node) drop \ Add phandles
+    1 to fdt-cas-pass dup (fdt-fix-cas-node) drop \ Patch+add other properties
+    2 to fdt-cas-pass dup (fdt-fix-cas-node) drop \ Delete phandles from pass 1
+    drop
 ;
 
 : fdt-fix-cas-success