3 files changed, 20 insertions, 3 deletions

diff --git a/arch/ppc64/kernel/head.S b/arch/ppc64/kernel/head.S
index fe05f3fbf9d0..92a744c31ab1 100644
--- a/arch/ppc64/kernel/head.S
+++ b/arch/ppc64/kernel/head.S
@@ -922,7 +922,9 @@ fp_unavailable_common:
 altivec_unavailable_common:
         EXCEPTION_PROLOG_COMMON(0xf20, PACA_EXGEN)
 #ifdef CONFIG_ALTIVEC
+BEGIN_FTR_SECTION
         bne     .load_up_altivec        /* if from user, just load it up */
+END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 #endif
         bl      .save_nvgprs
         addi    r3,r1,STACK_FRAME_OVERHEAD
diff --git a/arch/ppc64/kernel/prom.c b/arch/ppc64/kernel/prom.c
index 01739d5c47c7..b08aac68baff 100644
--- a/arch/ppc64/kernel/prom.c
+++ b/arch/ppc64/kernel/prom.c
@@ -885,6 +885,7 @@ static int __init early_init_dt_scan_cpus(unsigned long node,
                                           const char *full_path, void *data)
 {
         char *type = get_flat_dt_prop(node, "device_type", NULL);
+        u32 *prop;
 
         /* We are scanning "cpu" nodes only */
         if (type == NULL || strcmp(type, "cpu") != 0)
@@ -916,6 +917,20 @@ static int __init early_init_dt_scan_cpus(unsigned long node,
                 }
         }
 
+        /* Check if we have a VMX and eventually update CPU features */
+        prop = (u32 *)get_flat_dt_prop(node, "ibm,vmx", NULL);
+        if (prop && (*prop) > 0) {
+                cur_cpu_spec->cpu_features |= CPU_FTR_ALTIVEC;
+                cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_ALTIVEC;
+        }
+
+        /* Same goes for Apple's "altivec" property */
+        prop = (u32 *)get_flat_dt_prop(node, "altivec", NULL);
+        if (prop) {
+                cur_cpu_spec->cpu_features |= CPU_FTR_ALTIVEC;
+                cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_ALTIVEC;
+        }
+
         return 0;
 }
 
@@ -1104,7 +1119,9 @@ void __init early_init_devtree(void *params)
 
         DBG("Scanning CPUs ...\n");
 
-        /* Retreive hash table size from flattened tree */
+        /* Retreive hash table size from flattened tree plus other
+         * CPU related informations (altivec support, boot CPU ID, ...)
+         */
         scan_flat_dt(early_init_dt_scan_cpus, NULL);
 
         /* If hash size wasn't obtained above, we calculate it now based on
diff --git a/arch/ppc64/kernel/traps.c b/arch/ppc64/kernel/traps.c
index 10fc61f3f6a4..7e52cb2605e0 100644
--- a/arch/ppc64/kernel/traps.c
+++ b/arch/ppc64/kernel/traps.c
@@ -450,14 +450,12 @@ void kernel_fp_unavailable_exception(struct pt_regs *regs)
 
 void altivec_unavailable_exception(struct pt_regs *regs)
 {
-#ifndef CONFIG_ALTIVEC
         if (user_mode(regs)) {
                 /* A user program has executed an altivec instruction,
                    but this kernel doesn't support altivec. */
                 _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
                 return;
         }
-#endif
         printk(KERN_EMERG "Unrecoverable VMX/Altivec Unavailable Exception "
                           "%lx at %lx\n", regs->trap, regs->nip);
         die("Unrecoverable VMX/Altivec Unavailable Exception", regs, SIGABRT);