| Message ID | 158134056935.2963469.11427374783836284547.stgit@bahia.lan |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [v2] fdt: Delete nodes of devices removed between boot and CAS | expand |
On 11/02/2020 00:16, Greg Kurz wrote: > We recently fixed node creation at CAS in order to support early hotplug > of devices between boot and CAS. Let's handle node removal now to support > early hot *un*plug of devices. > > This is achieved by associating a generation number to each FDT received > from QEMU and tagging all nodes with this number in a "slof,from-fdt" > property. The generation number is kept in the fdt-generation# variable. > It starts at 0 for the initial boot time FDT, and it is incremented at > each subsequent CAS. All boot time nodes hence get "slof,from-fdt" == 0, > all nodes present at CAS get "slof,from-fdt" == 1 and so on in case the > guest calls CAS again. If a device gets hot unplugged before quiesce, we > hence can detect it doesn't have the right generation number and thus > delete the node from the DT. Note that this only affects nodes coming > from the FDT. Nodes created by SLOF don't have the "slof,from-fdt" > property, and therefore cannot be candidates to deletion. > > Signed-off-by: Greg Kurz <groug@kaod.org> > --- > v2: - global rewrite using a generation number which gets copied to > a "slof,from-fdt" property > - delete aliases in a separate loop Thanks, applied. > --- > board-qemu/slof/fdt.fs | 72 ++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 72 insertions(+) > > diff --git a/board-qemu/slof/fdt.fs b/board-qemu/slof/fdt.fs > index 66f8fe74d9dd..6a694c17517a 100644 > --- a/board-qemu/slof/fdt.fs > +++ b/board-qemu/slof/fdt.fs > @@ -13,6 +13,11 @@ > 1 VALUE fdt-debug > TRUE VALUE fdt-cas-fix? > 0 VALUE fdt-cas-pass > +0 VALUE fdt-generation# > + > +: fdt-update-from-fdt ( -- ) > + fdt-generation# encode-int s" slof,from-fdt" property > +; > > \ Bail out if no fdt > fdt-start 0 = IF -1 throw THEN > @@ -198,6 +203,8 @@ fdt-check-header > decode-int dup fdt-create-dec fdt-create-enc 2drop > THEN > > + fdt-update-from-fdt > + > finish-device > ; > > @@ -514,6 +521,9 @@ r> drop > swap ( newnode? a1 ) > > fdt-debug IF ." Current now: " pwd get-node ." = " . cr THEN > + fdt-cas-pass 0= IF > + fdt-update-from-fdt > + THEN > BEGIN > fdt-next-tag dup OF_DT_END_NODE <> > WHILE > @@ -584,8 +594,70 @@ r> drop > THEN > ; > > +: alias-dev-path ( xt -- dev-path len ) > + link> execute decode-string 2swap 2drop > +; > + > +: alias-name ( xt -- alias-name len ) > + link> >name name>string > +; > + > +: fdt-cas-alias-obsolete? ( xt -- true|false ) > + alias-dev-path find-node 0= > +; > + > +: (fdt-cas-delete-obsolete-aliases) ( xt -- ) > + dup IF > + dup @ > + recurse > + dup alias-name s" name" str= IF ELSE > + dup fdt-cas-alias-obsolete? IF > + fdt-debug IF ." Deleting obsolete alias: " dup alias-name type ." -> " dup alias-dev-path type cr THEN > + dup alias-name > + delete-property > + THEN > + THEN > + THEN > + drop > +; > + > +: fdt-cas-delete-obsolete-aliases ( -- ) > + s" /aliases" find-device > + get-node node>properties @ cell+ @ (fdt-cas-delete-obsolete-aliases) > + device-end > +; > + > +: fdt-cas-node-obsolete? ( node -- true|false) > + s" slof,from-fdt" rot get-package-property IF > + \ Not a QEMU originated node > + false > + ELSE > + decode-int nip nip fdt-generation# < > + THEN > +; > + > +: (fdt-cas-search-obsolete-nodes) ( start node -- ) > + dup IF > + dup child 2 pick swap recurse > + dup peer 2 pick swap recurse > + > + dup fdt-cas-node-obsolete? IF > + fdt-debug IF dup ." Deleting obsolete node: " dup .node ." = " . cr THEN > + dup delete-node > + THEN > + THEN > + 2drop > +; > + > +: fdt-cas-delete-obsolete-nodes ( start -- ) > + s" /" find-device get-node (fdt-cas-search-obsolete-nodes) > + fdt-cas-delete-obsolete-aliases > +; > + > : fdt-fix-cas-node ( start -- ) > + fdt-generation# 1+ to fdt-generation# > 0 to fdt-cas-pass dup (fdt-fix-cas-node) drop \ Add phandles > + dup fdt-cas-delete-obsolete-nodes \ Delete removed devices > 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 0 > drop >
diff --git a/board-qemu/slof/fdt.fs b/board-qemu/slof/fdt.fs index 66f8fe74d9dd..6a694c17517a 100644 --- a/board-qemu/slof/fdt.fs +++ b/board-qemu/slof/fdt.fs @@ -13,6 +13,11 @@ 1 VALUE fdt-debug TRUE VALUE fdt-cas-fix? 0 VALUE fdt-cas-pass +0 VALUE fdt-generation# + +: fdt-update-from-fdt ( -- ) + fdt-generation# encode-int s" slof,from-fdt" property +; \ Bail out if no fdt fdt-start 0 = IF -1 throw THEN @@ -198,6 +203,8 @@ fdt-check-header decode-int dup fdt-create-dec fdt-create-enc 2drop THEN + fdt-update-from-fdt + finish-device ; @@ -514,6 +521,9 @@ r> drop swap ( newnode? a1 ) fdt-debug IF ." Current now: " pwd get-node ." = " . cr THEN + fdt-cas-pass 0= IF + fdt-update-from-fdt + THEN BEGIN fdt-next-tag dup OF_DT_END_NODE <> WHILE @@ -584,8 +594,70 @@ r> drop THEN ; +: alias-dev-path ( xt -- dev-path len ) + link> execute decode-string 2swap 2drop +; + +: alias-name ( xt -- alias-name len ) + link> >name name>string +; + +: fdt-cas-alias-obsolete? ( xt -- true|false ) + alias-dev-path find-node 0= +; + +: (fdt-cas-delete-obsolete-aliases) ( xt -- ) + dup IF + dup @ + recurse + dup alias-name s" name" str= IF ELSE + dup fdt-cas-alias-obsolete? IF + fdt-debug IF ." Deleting obsolete alias: " dup alias-name type ." -> " dup alias-dev-path type cr THEN + dup alias-name + delete-property + THEN + THEN + THEN + drop +; + +: fdt-cas-delete-obsolete-aliases ( -- ) + s" /aliases" find-device + get-node node>properties @ cell+ @ (fdt-cas-delete-obsolete-aliases) + device-end +; + +: fdt-cas-node-obsolete? ( node -- true|false) + s" slof,from-fdt" rot get-package-property IF + \ Not a QEMU originated node + false + ELSE + decode-int nip nip fdt-generation# < + THEN +; + +: (fdt-cas-search-obsolete-nodes) ( start node -- ) + dup IF + dup child 2 pick swap recurse + dup peer 2 pick swap recurse + + dup fdt-cas-node-obsolete? IF + fdt-debug IF dup ." Deleting obsolete node: " dup .node ." = " . cr THEN + dup delete-node + THEN + THEN + 2drop +; + +: fdt-cas-delete-obsolete-nodes ( start -- ) + s" /" find-device get-node (fdt-cas-search-obsolete-nodes) + fdt-cas-delete-obsolete-aliases +; + : fdt-fix-cas-node ( start -- ) + fdt-generation# 1+ to fdt-generation# 0 to fdt-cas-pass dup (fdt-fix-cas-node) drop \ Add phandles + dup fdt-cas-delete-obsolete-nodes \ Delete removed devices 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 0 drop
We recently fixed node creation at CAS in order to support early hotplug of devices between boot and CAS. Let's handle node removal now to support early hot *un*plug of devices. This is achieved by associating a generation number to each FDT received from QEMU and tagging all nodes with this number in a "slof,from-fdt" property. The generation number is kept in the fdt-generation# variable. It starts at 0 for the initial boot time FDT, and it is incremented at each subsequent CAS. All boot time nodes hence get "slof,from-fdt" == 0, all nodes present at CAS get "slof,from-fdt" == 1 and so on in case the guest calls CAS again. If a device gets hot unplugged before quiesce, we hence can detect it doesn't have the right generation number and thus delete the node from the DT. Note that this only affects nodes coming from the FDT. Nodes created by SLOF don't have the "slof,from-fdt" property, and therefore cannot be candidates to deletion. Signed-off-by: Greg Kurz <groug@kaod.org> --- v2: - global rewrite using a generation number which gets copied to a "slof,from-fdt" property - delete aliases in a separate loop --- board-qemu/slof/fdt.fs | 72 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+)