pseries: Populate "/chosen/linux,stdout-path" in the FDT

There is a device tree property "/chosen/linux,stdout-path" which indicates
which device should be used as stdout - ie. "the console".

Currently we don't specify anything, which means both firmware and Linux
choose something arbitrarily. Use the routine we added in the last patch
to pick a default vty and specify it as stdout.

Currently SLOF doesn't use the property, but we are hoping to update it
to do so.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
(cherry picked from commit 68f3a94c64bbaaf8c7f2daa70de1b5d87a432f86)

hw/spapr.c

@@ -351,6 +351,8 @@ static void spapr_finalize_fdt(sPAPREnvironment *spapr,
         fprintf(stderr, "Couldn't set up RTAS device tree properties\n");
     }
 
+    spapr_populate_chosen_stdout(fdt, spapr->vio_bus);
+
     _FDT((fdt_pack(fdt)));
 
     cpu_physical_memory_write(fdt_addr, fdt, fdt_totalsize(fdt));

hw/spapr_vio.c

@@ -806,4 +806,38 @@ out:
 
     return ret;
 }
+
+int spapr_populate_chosen_stdout(void *fdt, VIOsPAPRBus *bus)
+{
+    VIOsPAPRDevice *dev;
+    char *name, *path;
+    int ret, offset;
+
+    dev = spapr_vty_get_default(bus);
+    if (!dev)
+        return 0;
+
+    offset = fdt_path_offset(fdt, "/chosen");
+    if (offset < 0) {
+        return offset;
+    }
+
+    name = vio_format_dev_name(dev);
+    if (!name) {
+        return -ENOMEM;
+    }
+
+    if (asprintf(&path, "/vdevice/%s", name) < 0) {
+        path = NULL;
+        ret = -ENOMEM;
+        goto out;
+    }
+
+    ret = fdt_setprop_string(fdt, offset, "linux,stdout-path", path);
+out:
+    free(name);
+    free(path);
+
+    return ret;
+}
 #endif /* CONFIG_FDT */

hw/spapr_vio.h

@@ -83,6 +83,7 @@ extern VIOsPAPRBus *spapr_vio_bus_init(void);
 extern VIOsPAPRDevice *spapr_vio_find_by_reg(VIOsPAPRBus *bus, uint32_t reg);
 extern void spapr_vio_bus_register_withprop(VIOsPAPRDeviceInfo *info);
 extern int spapr_populate_vdevice(VIOsPAPRBus *bus, void *fdt);
+extern int spapr_populate_chosen_stdout(void *fdt, VIOsPAPRBus *bus);
 
 extern int spapr_vio_signal(VIOsPAPRDevice *dev, target_ulong mode);
 
@@ -108,6 +109,8 @@ void spapr_vty_create(VIOsPAPRBus *bus, uint32_t reg, CharDriverState *chardev);
 void spapr_vlan_create(VIOsPAPRBus *bus, uint32_t reg, NICInfo *nd);
 void spapr_vscsi_create(VIOsPAPRBus *bus, uint32_t reg);
 
+VIOsPAPRDevice *spapr_vty_get_default(VIOsPAPRBus *bus);
+
 int spapr_tce_set_bypass(uint32_t unit, uint32_t enable);
 void spapr_vio_quiesce(void);
 

hw/spapr_vty.c

@@ -156,7 +156,7 @@ static VIOsPAPRDeviceInfo spapr_vty = {
     },
 };
 
-static VIOsPAPRDevice *spapr_vty_get_default(VIOsPAPRBus *bus)
+VIOsPAPRDevice *spapr_vty_get_default(VIOsPAPRBus *bus)
 {
     VIOsPAPRDevice *sdev, *selected;
     DeviceState *iter;