2 files changed, 37 insertions, 2 deletions

diff --git a/arch/powerpc/include/asm/prom.h b/arch/powerpc/include/asm/prom.h
index 35c00d7a0cf8..825bd5998701 100644
--- a/arch/powerpc/include/asm/prom.h
+++ b/arch/powerpc/include/asm/prom.h
@@ -159,7 +159,10 @@ struct of_drconf_cell {
 #define OV5_PFO_HW_842          0x1140  /* PFO Compression Accelerator */
 #define OV5_PFO_HW_ENCR         0x1120  /* PFO Encryption Accelerator */
 #define OV5_SUB_PROCESSORS      0x1501  /* 1,2,or 4 Sub-Processors supported */
-#define OV5_XIVE_EXPLOIT        0x1701  /* XIVE exploitation supported */
+#define OV5_XIVE_SUPPORT        0x17C0  /* XIVE Exploitation Support Mask */
+#define OV5_XIVE_LEGACY         0x1700  /* XIVE legacy mode Only */
+#define OV5_XIVE_EXPLOIT        0x1740  /* XIVE exploitation mode Only */
+#define OV5_XIVE_EITHER         0x1780  /* XIVE legacy or exploitation mode */
 /* MMU Base Architecture */
 #define OV5_MMU_SUPPORT         0x18C0  /* MMU Mode Support Mask */
 #define OV5_MMU_HASH            0x1800  /* Hash MMU Only */
diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index 613f79f03877..02190e90c7ae 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -177,6 +177,7 @@ struct platform_support {
         bool hash_mmu;
         bool radix_mmu;
         bool radix_gtse;
+        bool xive;
 };
 
 /* Platforms codes are now obsolete in the kernel. Now only used within this
@@ -1041,6 +1042,27 @@ static void __init prom_parse_mmu_model(u8 val,
         }
 }
 
+static void __init prom_parse_xive_model(u8 val,
+                                         struct platform_support *support)
+{
+        switch (val) {
+        case OV5_FEAT(OV5_XIVE_EITHER): /* Either Available */
+                prom_debug("XIVE - either mode supported\n");
+                support->xive = true;
+                break;
+        case OV5_FEAT(OV5_XIVE_EXPLOIT): /* Only Exploitation mode */
+                prom_debug("XIVE - exploitation mode supported\n");
+                support->xive = true;
+                break;
+        case OV5_FEAT(OV5_XIVE_LEGACY): /* Only Legacy mode */
+                prom_debug("XIVE - legacy mode supported\n");
+                break;
+        default:
+                prom_debug("Unknown xive support option: 0x%x\n", val);
+                break;
+        }
+}
+
 static void __init prom_parse_platform_support(u8 index, u8 val,
                                                struct platform_support *support)
 {
@@ -1054,6 +1076,10 @@ static void __init prom_parse_platform_support(u8 index, u8 val,
                         support->radix_gtse = true;
                 }
                 break;
+        case OV5_INDX(OV5_XIVE_SUPPORT): /* Interrupt mode */
+                prom_parse_xive_model(val & OV5_FEAT(OV5_XIVE_SUPPORT),
+                                      support);
+                break;
         }
 }
 
@@ -1062,7 +1088,8 @@ static void __init prom_check_platform_support(void)
         struct platform_support supported = {
                 .hash_mmu = false,
                 .radix_mmu = false,
-                .radix_gtse = false
+                .radix_gtse = false,
+                .xive = false
         };
         int prop_len = prom_getproplen(prom.chosen,
                                        "ibm,arch-vec-5-platform-support");
@@ -1095,6 +1122,11 @@ static void __init prom_check_platform_support(void)
                 /* We're probably on a legacy hypervisor */
                 prom_debug("Assuming legacy hash support\n");
         }
+
+        if (supported.xive) {
+                prom_debug("Asking for XIVE\n");
+                ibm_architecture_vec.vec5.intarch = OV5_FEAT(OV5_XIVE_EXPLOIT);
+        }
 }
 
 static void __init prom_send_capabilities(void)