powerpc/eeh: Freeze PE before PE reset

The patch adds one more option (EEH_OPT_FREEZE_PE) to set_option()
method to proactively freeze PE, which will be issued before resetting
pass-throughed PE to drop MMIO access during reset because it's
always contributing to recursive EEH error.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h
index c79869d..59d3e2a 100644
--- a/arch/powerpc/include/asm/eeh.h
+++ b/arch/powerpc/include/asm/eeh.h
@@ -172,6 +172,7 @@
 #define EEH_OPT_ENABLE		1	/* EEH enable	*/
 #define EEH_OPT_THAW_MMIO	2	/* MMIO enable	*/
 #define EEH_OPT_THAW_DMA	3	/* DMA enable	*/
+#define EEH_OPT_FREEZE_PE	4	/* Freeze PE	*/
 #define EEH_STATE_UNAVAILABLE	(1 << 0)	/* State unavailable	*/
 #define EEH_STATE_NOT_SUPPORT	(1 << 1)	/* EEH not supported	*/
 #define EEH_STATE_RESET_ACTIVE	(1 << 2)	/* Active reset		*/