[Qemu-devel] [PATCH 2/2] [v3] target-ppc: Enhance CPU nodes of device tree to be PAPR compliant.

[Prerna Saxena <prerna@linux.vnet.ibm.com>]

From: Prerna Saxena <prerna@linux.vnet.ibm.com>
Date: Thu, 8 Aug 2013 06:38:03 +0530
Subject: [PATCH 2/2] Enhance CPU nodes of device tree to be PAPR compliant.

This is based on patch from Andreas which enables the default CPU with KVM
to show up as "-cpu <type>", such as "POWER7_V2.3@0"

While this is definitely, more descriptive, PAPR mandates the device tree CPU
node names to be of the form : "PowerPC,<name>" where <name> should not have
underscores.
Hence replacing the CPU model (which has underscores) with CPU alias.

With this patch, the CPU nodes of device tree show up as :
/proc/device-tree/cpus/PowerPC,POWER7@0/...
/proc/device-tree/cpus/PowerPC,POWER7@4/...

Signed-off-by: Prerna Saxena <prerna@linux.vnet.ibm.com>
---
 hw/ppc/spapr.c | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 59e2fea..8efd84e 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -43,6 +43,7 @@
 #include "hw/pci-host/spapr.h"
 #include "hw/ppc/xics.h"
 #include "hw/pci/msi.h"
+#include "cpu-models.h"
 
 #include "hw/pci/pci.h"
 
@@ -80,6 +81,8 @@
 
 #define HTAB_SIZE(spapr)        (1ULL << ((spapr)->htab_shift))
 
+#define PPC_DEVTREE_STR         "PowerPC,"
+
 sPAPREnvironment *spapr;
 
 int spapr_allocate_irq(int hint, bool lsi)
@@ -322,9 +325,16 @@ static void *spapr_create_fdt_skel(const char *cpu_model,
     _FDT((fdt_property_cell(fdt, "#address-cells", 0x1)));
     _FDT((fdt_property_cell(fdt, "#size-cells", 0x0)));
 
-    modelname = g_strdup(cpu_model);
+    /*
+     * PAPR convention mandates that
+     * Device tree nodes must be named as:
+     * PowerPC,CPU-NAME@...
+     * Also, CPU-NAME must not have underscores.(hence use of CPU-ALIAS)
+     */
+
+    modelname = g_strdup_printf(PPC_DEVTREE_STR "%s", cpu_model);
 
-    for (i = 0; i < strlen(modelname); i++) {
+    for (i = strlen(PPC_DEVTREE_STR); i < strlen(modelname); i++) {
         modelname[i] = toupper(modelname[i]);
     }
 
@@ -1315,6 +1325,14 @@ static void ppc_spapr_init(QEMUMachineInitArgs *args)
 
         cpu_model = g_strndup(parent_name,
             strlen(parent_name) - strlen("-" TYPE_POWERPC_CPU));
+
+        for (i = 0; ppc_cpu_aliases[i].model != NULL; i++) {
+            if (strcmp(ppc_cpu_aliases[i].model, cpu_model) == 0) {
+                g_free(cpu_model);
+                cpu_model = g_strndup(ppc_cpu_aliases[i].alias,
+                                strlen(ppc_cpu_aliases[i].alias));
+            }
+        }
     }
 
     /* Prepare the device tree */
-- 
1.7.11.4



-- 
Prerna Saxena

Linux Technology Centre,
IBM Systems and Technology Lab,
Bangalore, India