From de269129a48a2d590ba1d20c719e19d86e3ddb3f Mon Sep 17 00:00:00 2001
From: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Date: Tue, 5 Mar 2019 01:12:19 +0530
Subject: powerpc/hmi: Fix kernel hang when TB is in error state.
On TOD/TB errors timebase register stops/freezes until HMI error recovery
gets TOD/TB back into running state. On successful recovery, TB starts
running again and udelay() that relies on TB value continues to function
properly. But in case when HMI fails to recover from TOD/TB errors, the
TB register stay freezed. With TB not running the __delay() function
keeps looping and never return. If __delay() is called while in panic
path then system hangs and never reboots after panic.
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
arch/powerpc/include/asm/opal-api.h | 10 ++++++++++
1 file changed, 10 insertions(+)
(limited to 'arch/powerpc/include/asm/opal-api.h')
diff --git a/arch/powerpc/include/asm/opal-api.h b/arch/powerpc/include/asm/opal-api.h
index e1d118ac61dc..234fde15b37c 100644
--- a/arch/powerpc/include/asm/opal-api.h
+++ b/arch/powerpc/include/asm/opal-api.h
@@ -209,6 +209,7 @@
#define OPAL_SENSOR_GROUP_ENABLE 163
#define OPAL_PCI_GET_PBCQ_TUNNEL_BAR 164
#define OPAL_PCI_SET_PBCQ_TUNNEL_BAR 165
+#define OPAL_HANDLE_HMI2 166
#define OPAL_NX_COPROC_INIT 167
#define OPAL_XIVE_GET_VP_STATE 170
#define OPAL_LAST 170
@@ -635,6 +636,15 @@ struct OpalHMIEvent {
} u;
};
+/* OPAL_HANDLE_HMI2 out_flags */
+enum {
+ OPAL_HMI_FLAGS_TB_RESYNC = (1ull << 0), /* Timebase has been resynced */
+ OPAL_HMI_FLAGS_DEC_LOST = (1ull << 1), /* DEC lost, needs to be reprogrammed */
+ OPAL_HMI_FLAGS_HDEC_LOST = (1ull << 2), /* HDEC lost, needs to be reprogrammed */
+ OPAL_HMI_FLAGS_TOD_TB_FAIL = (1ull << 3), /* TOD/TB recovery failed. */
+ OPAL_HMI_FLAGS_NEW_EVENT = (1ull << 63), /* An event has been created */
+};
+
enum {
OPAL_P7IOC_DIAG_TYPE_NONE = 0,
OPAL_P7IOC_DIAG_TYPE_RGC = 1,
--
cgit