[Qemu-devel] [RFC PATCH 1/2] spapr: enumerate and add PCI device tree

[Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>]

All the PCI enumeration and device node creation was off-loaded to
SLOF. With PCI hotplug support, code needed to be added to add device
node. This creates multiple copy of the code one in SLOF and other in
hotplug code. To unify this, the patch adds the pci device node
creation in Qemu. For backward compatibility, a flag
"qemu,phb-enumerated" is added to the phb, suggesting to SLOF to not
do device node creation.

Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
---
 hw/ppc/spapr_pci.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 84 insertions(+), 9 deletions(-)

diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
index 3796d54..abf71f7 100644
--- a/hw/ppc/spapr_pci.c
+++ b/hw/ppc/spapr_pci.c
@@ -23,6 +23,7 @@
  * THE SOFTWARE.
  */
 #include "hw/hw.h"
+#include "hw/sysbus.h"
 #include "hw/pci/pci.h"
 #include "hw/pci/msi.h"
 #include "hw/pci/msix.h"
@@ -35,6 +36,7 @@
 #include "qemu/error-report.h"
 #include "qapi/qmp/qerror.h"
 
+#include "hw/pci/pci_bridge.h"
 #include "hw/pci/pci_bus.h"
 #include "hw/ppc/spapr_drc.h"
 #include "sysemu/device_tree.h"
@@ -938,7 +940,9 @@ static int spapr_populate_pci_child_dt(PCIDevice *dev, void *fdt, int offset,
      * processed by OF beforehand
      */
     _FDT(fdt_setprop_string(fdt, offset, "name", "pci"));
-    _FDT(fdt_setprop(fdt, offset, "ibm,loc-code", drc_name, strlen(drc_name)));
+    if (drc_name) {
+        _FDT(fdt_setprop(fdt, offset, "ibm,loc-code", drc_name, strlen(drc_name)));
+    }
     _FDT(fdt_setprop_cell(fdt, offset, "ibm,my-drc-index", drc_index));
 
     _FDT(fdt_setprop_cell(fdt, offset, "#address-cells",
@@ -994,10 +998,6 @@ static void spapr_phb_add_pci_device(sPAPRDRConnector *drc,
     void *fdt = NULL;
     int fdt_start_offset = 0;
 
-    /* boot-time devices get their device tree node created by SLOF, but for
-     * hotplugged devices we need QEMU to generate it so the guest can fetch
-     * it via RTAS
-     */
     if (dev->hotplugged) {
         fdt = spapr_create_pci_child_dt(phb, pdev, drc_index, drc_name,
                                         &fdt_start_offset);
@@ -1473,14 +1473,15 @@ PCIHostState *spapr_create_phb(sPAPREnvironment *spapr, int index)
     return PCI_HOST_BRIDGE(dev);
 }
 
-typedef struct sPAPRTCEDT {
+typedef struct sPAPRFDT {
     void *fdt;
     int node_off;
-} sPAPRTCEDT;
+    uint32_t index;
+} sPAPRFDT;
 
 static int spapr_phb_children_dt(Object *child, void *opaque)
 {
-    sPAPRTCEDT *p = opaque;
+    sPAPRFDT *p = opaque;
     sPAPRTCETable *tcet;
 
     tcet = (sPAPRTCETable *) object_dynamic_cast(child, TYPE_SPAPR_TCE_TABLE);
@@ -1496,6 +1497,73 @@ static int spapr_phb_children_dt(Object *child, void *opaque)
     return 1;
 }
 
+static void spapr_populate_pci_devices_dt(PCIBus *bus, PCIDevice *pdev, void *opaque)
+{
+    sPAPRFDT *p = opaque;
+    int ret, offset;
+    int slot = PCI_SLOT(pdev->devfn);
+    int func = PCI_FUNC(pdev->devfn);
+    char nodename[512];
+
+    if (func) {
+        sprintf(nodename, "pci@%d,%d", slot, func);
+    } else {
+        sprintf(nodename, "pci@%d", slot);
+    }
+    offset = fdt_add_subnode(p->fdt, p->node_off, nodename);
+    ret = spapr_populate_pci_child_dt(pdev, p->fdt, offset, p->index, 0, NULL);
+    g_assert(!ret);
+
+    if ((pci_default_read_config(pdev, PCI_HEADER_TYPE, 1) ==
+         PCI_HEADER_TYPE_BRIDGE)) {
+        PCIBus *sec_bus = pci_bridge_get_sec_bus(PCI_BRIDGE(pdev));
+        if(sec_bus) {
+            pci_for_each_device(sec_bus, pci_bus_num(sec_bus),
+                                spapr_populate_pci_devices_dt,
+                                &((sPAPRFDT){ .fdt = p->fdt, .node_off = offset , .index = p->index }));
+        }
+    }
+    return;
+}
+
+static void spapr_phb_pci_enumerate_bridge(PCIBus *bus, PCIDevice *pdev, void *opaque)
+{
+    unsigned short *bus_no = (unsigned short *) opaque;
+    unsigned short primary = *bus_no;
+    unsigned short secondary;
+    unsigned short subordinate = 0xff;
+
+    if ((pci_default_read_config(pdev, PCI_HEADER_TYPE, 1) ==
+         PCI_HEADER_TYPE_BRIDGE)) {
+        PCIBus *sec_bus = pci_bridge_get_sec_bus(PCI_BRIDGE(pdev));
+        secondary = *bus_no + 1;
+        pci_default_write_config(pdev, PCI_PRIMARY_BUS, primary, 1);
+        pci_default_write_config(pdev, PCI_SECONDARY_BUS, secondary, 1);
+        pci_default_write_config(pdev, PCI_SUBORDINATE_BUS, secondary, 1);
+        *bus_no = *bus_no + 1;
+        if (sec_bus) {
+            pci_default_write_config(pdev, PCI_PRIMARY_BUS, primary, 1);
+            pci_default_write_config(pdev, PCI_SECONDARY_BUS, secondary, 1);
+            pci_default_write_config(pdev, PCI_SUBORDINATE_BUS, subordinate, 1);
+            pci_for_each_device(sec_bus, pci_bus_num(sec_bus),
+                                spapr_phb_pci_enumerate_bridge,
+                                bus_no);
+            pci_default_write_config(pdev, PCI_SUBORDINATE_BUS, *bus_no, 1);
+        }
+    }
+}
+
+static void spapr_phb_pci_enumerate(sPAPRPHBState *phb)
+{
+    PCIBus *bus = PCI_HOST_BRIDGE(phb)->bus;
+    unsigned short bus_no = 0;
+
+    pci_for_each_device(bus, pci_bus_num(bus),
+                        spapr_phb_pci_enumerate_bridge,
+                        &bus_no);
+
+}
+
 int spapr_populate_pci_dt(sPAPRPHBState *phb,
                           uint32_t xics_phandle,
                           void *fdt)
@@ -1534,6 +1602,7 @@ int spapr_populate_pci_dt(sPAPRPHBState *phb,
     uint32_t interrupt_map_mask[] = {
         cpu_to_be32(b_ddddd(-1)|b_fff(0)), 0x0, 0x0, cpu_to_be32(-1)};
     uint32_t interrupt_map[PCI_SLOT_MAX * PCI_NUM_PINS][7];
+    PCIBus *bus = PCI_HOST_BRIDGE(phb)->bus;
 
     /* Start populating the FDT */
     sprintf(nodename, "pci@%" PRIx64, phb->buid);
@@ -1579,7 +1648,13 @@ int spapr_populate_pci_dt(sPAPRPHBState *phb,
                      sizeof(interrupt_map)));
 
     object_child_foreach(OBJECT(phb), spapr_phb_children_dt,
-                         &((sPAPRTCEDT){ .fdt = fdt, .node_off = bus_off }));
+                         &((sPAPRFDT){ .fdt = fdt, .node_off = bus_off }));
+
+    spapr_phb_pci_enumerate(phb);
+    _FDT(fdt_setprop_cell(fdt, bus_off, "qemu,phb-enumerated", 0x1));
+    pci_for_each_device(bus, pci_bus_num(bus),
+                        spapr_populate_pci_devices_dt,
+                        &((sPAPRFDT){ .fdt = fdt, .node_off = bus_off, .index = phb->index }));
 
     ret = spapr_drc_populate_dt(fdt, bus_off, OBJECT(phb),
                                 SPAPR_DR_CONNECTOR_TYPE_PCI);
-- 
1.8.3.1