powerpc/eeh: pseries platform EEH reset PE

On RTAS compliant pSeries platform, there is a dedicated RTAS call
(ibm,set-slot-reset) to reset the specified PE. Furthermore, two
types of resets are supported: hot and fundamental. the type of
reset is to be used actually depends on the included PCI device's
requirements.

The patch implements resetting PE on pSeries platform through RTAS
call. Besides, it has been abstracted through struct eeh_ops::reset
so that EEH core components could support multiple platforms in future.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/include/asm/eeh.h

@@ -49,6 +49,9 @@ struct device_node;
 #define EEH_STATE_DMA_ACTIVE	(1 << 4)	/* Active DMA		*/
 #define EEH_STATE_MMIO_ENABLED	(1 << 5)	/* MMIO enabled		*/
 #define EEH_STATE_DMA_ENABLED	(1 << 6)	/* DMA enabled		*/
+#define EEH_RESET_DEACTIVATE	0	/* Deactivate the PE reset	*/
+#define EEH_RESET_HOT		1	/* Hot reset			*/
+#define EEH_RESET_FUNDAMENTAL	3	/* Fundamental reset		*/
 
 struct eeh_ops {
 	char *name;