1 files changed, 21 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index b642b0562f5a..d019b081df9d 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -194,6 +194,27 @@ static int __init opal_register_exception_handlers(void)
          * fwnmi area at 0x7000 to provide the glue space to OPAL
          */
         glue = 0x7000;
+
+        /*
+         * Check if we are running on newer firmware that exports
+         * OPAL_HANDLE_HMI token. If yes, then don't ask OPAL to patch
+         * the HMI interrupt and we catch it directly in Linux.
+         *
+         * For older firmware (i.e currently released POWER8 System Firmware
+         * as of today <= SV810_087), we fallback to old behavior and let OPAL
+         * patch the HMI vector and handle it inside OPAL firmware.
+         *
+         * For newer firmware (in development/yet to be released) we will
+         * start catching/handling HMI directly in Linux.
+         */
+        if (!opal_check_token(OPAL_HANDLE_HMI)) {
+                pr_info("opal: Old firmware detected, OPAL handles HMIs.\n");
+                opal_register_exception_handler(
+                                OPAL_HYPERVISOR_MAINTENANCE_HANDLER,
+                                0, glue);
+                glue += 128;
+        }
+
         opal_register_exception_handler(OPAL_SOFTPATCH_HANDLER, 0, glue);
 #endif