[SLOF] [PATCH 2/2] board-qemu: add private hcall to inform host on "phandle" update

[Greg Kurz]

The "interrupt-map" property in each PHB node references the "phandle"
property of the "interrupt-controller" node. This is used by the guest
OS to setup IRQs for any PCI device plugged into the PHB. QEMU sets this
property to an arbitrary value in the flattened DT passed to SLOF.

Since commit 82954d4c1088, SLOF has some generic code to convert all
references to any "phandle" property to a SLOF specific value.

This is is perfectly okay for coldplug devices, since the guest OS only
sees the converted value in "interrupt-map". It is a problem though for
hotplug devices. Since they don't go through SLOF, the guest OS receives
the arbitrary value set by QEMU and fails to setup IRQs.

In order to support PHB hotplug, this patch introduces a new private
hcall, which allows SLOF to tell QEMU that a "phandle" was converted
from an old value to a new value.

Suggested-by: Thomas Huth <thuth at redhat.com>
Signed-off-by: Greg Kurz <groug at kaod.org>
---
 board-qemu/slof/fdt.fs    |   14 +++++++++++---
 lib/libhvcall/hvcall.code |    6 ++++++
 lib/libhvcall/hvcall.in   |    1 +
 lib/libhvcall/libhvcall.h |    1 +
 4 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/board-qemu/slof/fdt.fs b/board-qemu/slof/fdt.fs
index 8d4635f30495..8ce0a59879ac 100644
--- a/board-qemu/slof/fdt.fs
+++ b/board-qemu/slof/fdt.fs
@@ -316,14 +316,22 @@ fdt-claim-reserve
    s" phandle" r@ get-property 0= IF
       decode-int                       ( p-addr2 p-len2 val )
       \ ." found phandle: " dup . cr
-      r@ s" /" find-node               ( p-addr2 p-len2 val node root )  
-      fdt-replace-all-phandles         ( p-addr2 p-len2 )
-      2drop
+      dup                              ( p-addr2 p-len2 val val )
+      r@ s" /" find-node               ( p-addr2 p-len2 val val node root )
+      fdt-replace-all-phandles         ( p-addr2 p-len2 val )
+      -rot 2drop                       ( val )
       (fdt-phandle-replaced) IF
          r@ set-node
          s" phandle" delete-property
          s" linux,phandle" delete-property
+         r@ swap hv-update-phandle dup 0 <> IF
+	    \ Ignore hcall not implemented error, print error otherwise
+	    dup -2 <> IF ." HV-UPDATE-PHANDLE error: " . cr ELSE drop THEN
+         ELSE
+	    drop
+         THEN
       ELSE
+         drop
          diagnostic-mode? IF
             cr ." Warning: Did not replace phandle in " r@ node>path type cr
          THEN
diff --git a/lib/libhvcall/hvcall.code b/lib/libhvcall/hvcall.code
index 0ff50f27e8a9..9f4d53c7237b 100644
--- a/lib/libhvcall/hvcall.code
+++ b/lib/libhvcall/hvcall.code
@@ -129,3 +129,9 @@ PRIM(check_X2d_and_X2d_patch_X2d_sc1)
 
 	patch_broken_sc1((void*)start, (void*)end, (void*)patch_ins);
 MIRP
+
+PRIM(hv_X2d_update_X2d_phandle)
+	uint32_t old_phandle = TOS.u; POP;
+	uint32_t new_phandle = TOS.u;
+	TOS.u = hv_generic(KVMPPC_H_UPDATE_PHANDLE, old_phandle, new_phandle);
+MIRP
diff --git a/lib/libhvcall/hvcall.in b/lib/libhvcall/hvcall.in
index 4437b77f001d..ab7513af8977 100644
--- a/lib/libhvcall/hvcall.in
+++ b/lib/libhvcall/hvcall.in
@@ -31,4 +31,5 @@ cod(RX!)
 cod(hv-logical-memop)
 cod(hv-cas)
 cod(hv-rtas-update)
+cod(hv-update-phandle)
 cod(get-print-version)
diff --git a/lib/libhvcall/libhvcall.h b/lib/libhvcall/libhvcall.h
index b2ea3f6bf944..5776a2b772f7 100644
--- a/lib/libhvcall/libhvcall.h
+++ b/lib/libhvcall/libhvcall.h
@@ -25,6 +25,7 @@
 /* Client Architecture support */
 #define KVMPPC_H_CAS            (KVMPPC_HCALL_BASE + 0x2)
 #define KVMPPC_H_RTAS_UPDATE    (KVMPPC_HCALL_BASE + 0x3)
+#define KVMPPC_H_UPDATE_PHANDLE (KVMPPC_HCALL_BASE + 0x4)
 
 #ifndef __ASSEMBLY__