[PATCH v9 7/7] xen/arm: check for GICv3 platform support

[vijay.kilari@gmail.com]

From: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com>

ID_AA64PFR0_EL1 register provides information about GIC support.
Check for this register in GICv3 driver.

Also print GICv3 support information in boot log

Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com>
---
v9: - Correct error message
v8: - Rearranged prf64 structure member variables
v7: - return -ENODEV on lack GICv3 platform support instead of
      panic
---
 xen/arch/arm/gic-v3.c            |    7 +++++++
 xen/arch/arm/setup.c             |    5 +++--
 xen/include/asm-arm/cpufeature.h |    1 +
 xen/include/asm-arm/processor.h  |    4 ++--
 4 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/xen/arch/arm/gic-v3.c b/xen/arch/arm/gic-v3.c
index ca450f9..5465b88 100644
--- a/xen/arch/arm/gic-v3.c
+++ b/xen/arch/arm/gic-v3.c
@@ -39,6 +39,7 @@
 #include <asm/device.h>
 #include <asm/gic.h>
 #include <asm/gic_v3_defs.h>
+#include <asm/cpufeature.h>
 
 struct rdist_region {
     paddr_t base;
@@ -1158,6 +1159,12 @@ static int __init gicv3_init(struct dt_device_node *node, const void *data)
     int res, i;
     uint32_t reg;
 
+    if ( !cpu_has_gicv3 )
+    {
+        dprintk(XENLOG_ERR, "GICv3: driver requests system register support\n");
+        return -ENODEV;
+    }
+
     dt_device_set_used_by(node, DOMID_XEN);
 
     res = dt_device_get_address(node, 0, &gicv3.dbase, &gicv3.dbase_size);
diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index ddaef7e..2e80b5a 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -103,9 +103,10 @@ static void __init processor_id(void)
            cpu_has_el2_32 ? "64+32" : cpu_has_el2_64 ? "64" : "No",
            cpu_has_el1_32 ? "64+32" : cpu_has_el1_64 ? "64" : "No",
            cpu_has_el0_32 ? "64+32" : cpu_has_el0_64 ? "64" : "No");
-    printk("    Extensions:%s%s\n",
+    printk("    Extensions:%s%s%s\n",
            cpu_has_fp ? " FloatingPoint" : "",
-           cpu_has_simd ? " AdvancedSIMD" : "");
+           cpu_has_simd ? " AdvancedSIMD" : "",
+           cpu_has_gicv3 ? " GICv3-SysReg" : "");
 
     printk("  Debug Features: %016"PRIx64" %016"PRIx64"\n",
            boot_cpu_data.dbg64.bits[0], boot_cpu_data.dbg64.bits[1]);
diff --git a/xen/include/asm-arm/cpufeature.h b/xen/include/asm-arm/cpufeature.h
index 1d2c9c7..aec9173 100644
--- a/xen/include/asm-arm/cpufeature.h
+++ b/xen/include/asm-arm/cpufeature.h
@@ -15,6 +15,7 @@
 #define cpu_has_el3_64    (boot_cpu_feature64(el3) >= 1)
 #define cpu_has_fp        (boot_cpu_feature64(fp) == 0)
 #define cpu_has_simd      (boot_cpu_feature64(simd) == 0)
+#define cpu_has_gicv3     (boot_cpu_feature64(gic) == 1)
 #endif
 
 #define cpu_feature32(c, feat)         ((c)->pfr32.feat)
diff --git a/xen/include/asm-arm/processor.h b/xen/include/asm-arm/processor.h
index d83f593..1993af7 100644
--- a/xen/include/asm-arm/processor.h
+++ b/xen/include/asm-arm/processor.h
@@ -250,8 +250,8 @@ struct cpuinfo_arm {
             unsigned long el3:4;
             unsigned long fp:4;   /* Floating Point */
             unsigned long simd:4; /* Advanced SIMD */
-            unsigned long __res0:8;
-
+            unsigned long gic:4;  /* GIC support */
+            unsigned long __res0:4;
             unsigned long __res1;
         };
     } pfr64;
-- 
1.7.9.5