pci: Use QEMU created PCI device nodes

PCI Enumeration has been part of SLOF. Now with hotplug code addition
in QEMU, it makes more sense to have this code in one place,
i.e. QEMU.

Adding routines to walk through the device nodes created by QEMU. SLOF
will now configure the device/bridges and program the BARs for
communicating with the devices.

Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>

board-qemu/slof/pci-phb.fs

@@ -282,6 +282,41 @@ setup-puid
    THEN
 ;
 
+: phb-pci-walk-bridge ( -- )
+    phb-debug? IF ."   Calling pci-walk-bridge " pwd cr THEN
+
+    get-node child ?dup 0= IF EXIT THEN    \ get and check if we have children
+    0 to pci-device-slots                  \ reset slot array to unpoppulated
+    BEGIN
+        dup                                \ Continue as long as there are children
+    WHILE
+        dup set-node                       \ Set child node as current node
+        my-space pci-set-slot              \ set the slot bit
+        my-space pci-htype@                \ read HEADER-Type
+        7f and                             \ Mask bit 7 - multifunction device
+        CASE
+            0 OF my-space pci-device-setup ENDOF  \ | set up the device
+            1 OF my-space pci-bridge-setup ENDOF  \ | set up the bridge
+            dup OF my-space pci-htype@ pci-out ENDOF
+        ENDCASE
+        peer
+    REPEAT drop
+    get-parent set-node
+;
+
+\ Landing routing to probe the popuated device tree
+: phb-pci-probe-bus ( busnr -- )
+    drop phb-pci-walk-bridge
+;
+
+\ Stub routine, as qemu has enumerated, we already have the device
+\ properties set.
+: phb-pci-device-props ( addr -- )
+    dup pci-class-name device-name
+    dup pci-device-assigned-addresses-prop
+    drop
+;
+
 \ Scan the child nodes of the pci root node to assign bars, fixup
 \ properties etc.
 : phb-setup-children
@@ -289,7 +324,14 @@ setup-puid
    my-puid TO puid                  \ Set current puid
    phb-parse-ranges
    1 TO pci-hotplug-enabled
-   1 0 (probe-pci-host-bridge)
+   s" qemu,phb-enumerated" get-node get-property 0<> IF
+       1 0 (probe-pci-host-bridge)
+   ELSE
+       2drop
+       ['] phb-pci-probe-bus TO func-pci-probe-bus
+       ['] phb-pci-device-props TO func-pci-device-props
+       phb-pci-walk-bridge          \ PHB device tree is already populated.
+   THEN
    r> TO puid                       \ Restore previous puid
 ;
 phb-setup-children

slof/fs/pci-properties.fs

@@ -651,6 +651,8 @@
         r> TO pci-device-slots          \ and reset the slot array
 ;
 
+DEFER func-pci-device-props
+
 \ used for an gerneric device set up
 \ if a device has no special handling for setup
 \ the device file (pci-device_VENDOR_DEVICE.fs) can call
@@ -659,6 +661,8 @@
         dup assign-all-device-bars      \ calc all BARs
         dup pci-set-irq-line            \ set the interrupt pin
         dup pci-set-capabilities        \ set up the capabilities
-        dup pci-device-props            \ and generate all properties
+        dup func-pci-device-props       \ and generate all properties
         drop                            \ forget the config-addr
 ;
+
+' pci-device-props TO func-pci-device-props