[Qemu-devel] [RFC PATCH 2/2] spapr: populate ibm,loc-code

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

Each hardware instance has a platform unique location code.  The OF
device tree that describes a part of a hardware entity must include
the “ibm,loc-code” property with a value that represents the location
code for that hardware entity.

Populate ibm,loc-code.
1) PCI passthru devices need to identify with its own ibm,loc-code
   available on the host.
2) Emulated devices encode as following:
   qemu_<name>:<phb-index>:<slot>.<fn>

Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
---
 hw/ppc/spapr_pci.c | 85 +++++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 75 insertions(+), 10 deletions(-)

diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
index abf71f7..c69e732 100644
--- a/hw/ppc/spapr_pci.c
+++ b/hw/ppc/spapr_pci.c
@@ -744,6 +744,70 @@ static AddressSpace *spapr_pci_dma_iommu(PCIBus *bus, void *opaque, int devfn)
     return &phb->iommu_as;
 }
 
+static bool spapr_phb_vfio_get_devspec_value(PCIDevice *pdev, char **value)
+{
+    char *host;
+    char path[PATH_MAX];
+
+    host = object_property_get_str(OBJECT(pdev), "host", NULL);
+    if (!host) {
+        return false;
+    }
+
+    snprintf(path, sizeof(path), "/sys/bus/pci/devices/%s/devspec", host);
+    g_free(host);
+
+    return g_file_get_contents(path, value, NULL, NULL);
+}
+
+static char *spapr_phb_vfio_get_loc_code(sPAPRPHBState *sphb,  PCIDevice *pdev)
+{
+    char path[PATH_MAX], *buf = NULL;
+
+    /* We have a vfio host bridge lets get the path. */
+    if (!spapr_phb_vfio_get_devspec_value(pdev, &buf)) {
+        return NULL;
+    }
+
+    snprintf(path, sizeof(path), "/proc/device-tree%s/ibm,loc-code", buf);
+    g_free(buf);
+
+    if (g_file_get_contents(path, &buf, NULL, NULL)) {
+        return buf;
+    } else {
+        return NULL;
+    }
+}
+
+static char *spapr_phb_get_loc_code(sPAPRPHBState *sphb,  PCIDevice *pdev)
+{
+    char *path = g_malloc(PATH_MAX);
+
+    if (!path) {
+        return NULL;
+    }
+
+    /*
+     * For non-vfio devices and failures make up the location code out
+     * of the name, slot and function.
+     *
+     *       qemu_<name>:<phb-index>:<slot>.<fn>
+     */
+    snprintf(path, PATH_MAX, "qemu_%s:%02d:%02d.%1d", pdev->name,
+             sphb->index, PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn));
+    return path;
+}
+
+
+static char *spapr_ibm_get_loc_code(sPAPRPHBState *sphb, PCIDevice *pdev)
+{
+    if (object_dynamic_cast(OBJECT(pdev), "vfio-pci") != NULL) {
+        return spapr_phb_vfio_get_loc_code(sphb, pdev);
+    } else {
+        return spapr_phb_get_loc_code(sphb, pdev);
+    }
+}
+
 /* Macros to operate with address in OF binding to PCI */
 #define b_x(x, p, l)    (((x) & ((1<<(l))-1)) << (p))
 #define b_n(x)          b_x((x), 31, 1) /* 0 if relocatable */
@@ -873,12 +937,12 @@ static void populate_resource_props(PCIDevice *d, ResourceProps *rp)
 }
 
 static int spapr_populate_pci_child_dt(PCIDevice *dev, void *fdt, int offset,
-                                       int phb_index, int drc_index,
-                                       const char *drc_name)
+                                       sPAPRPHBState *phb, int drc_index)
 {
     ResourceProps rp;
     bool is_bridge = false;
     int pci_status;
+    char *buf = NULL;
 
     if (pci_default_read_config(dev, PCI_HEADER_TYPE, 1) ==
         PCI_HEADER_TYPE_BRIDGE) {
@@ -940,8 +1004,10 @@ 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"));
-    if (drc_name) {
-        _FDT(fdt_setprop(fdt, offset, "ibm,loc-code", drc_name, strlen(drc_name)));
+    buf = spapr_ibm_get_loc_code(phb, dev);
+    if (buf) {
+        _FDT(fdt_setprop_string(fdt, offset, "ibm,loc-code", buf));
+        g_free(buf);
     }
     _FDT(fdt_setprop_cell(fdt, offset, "ibm,my-drc-index", drc_index));
 
@@ -978,8 +1044,7 @@ static void *spapr_create_pci_child_dt(sPAPRPHBState *phb, PCIDevice *dev,
         sprintf(nodename, "pci@%d", slot);
     }
     offset = fdt_add_subnode(fdt, 0, nodename);
-    ret = spapr_populate_pci_child_dt(dev, fdt, offset, phb->index, drc_index,
-                                      drc_name);
+    ret = spapr_populate_pci_child_dt(dev, fdt, offset, phb, drc_index);
     g_assert(!ret);
 
     *dt_offset = offset;
@@ -1476,7 +1541,7 @@ PCIHostState *spapr_create_phb(sPAPREnvironment *spapr, int index)
 typedef struct sPAPRFDT {
     void *fdt;
     int node_off;
-    uint32_t index;
+    sPAPRPHBState *sphb;
 } sPAPRFDT;
 
 static int spapr_phb_children_dt(Object *child, void *opaque)
@@ -1511,7 +1576,7 @@ static void spapr_populate_pci_devices_dt(PCIBus *bus, PCIDevice *pdev, void *op
         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);
+    ret = spapr_populate_pci_child_dt(pdev, p->fdt, offset, p->sphb, 0);
     g_assert(!ret);
 
     if ((pci_default_read_config(pdev, PCI_HEADER_TYPE, 1) ==
@@ -1520,7 +1585,7 @@ static void spapr_populate_pci_devices_dt(PCIBus *bus, PCIDevice *pdev, void *op
         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 }));
+                                &((sPAPRFDT){ .fdt = p->fdt, .node_off = offset , .sphb = p->sphb }));
         }
     }
     return;
@@ -1654,7 +1719,7 @@ int spapr_populate_pci_dt(sPAPRPHBState *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 }));
+                        &((sPAPRFDT){ .fdt = fdt, .node_off = bus_off, .sphb = phb }));
 
     ret = spapr_drc_populate_dt(fdt, bus_off, OBJECT(phb),
                                 SPAPR_DR_CONNECTOR_TYPE_PCI);
-- 
1.8.3.1