powerpc/eeh: Don't check RTAS token to get PE addr

RTAS token "ibm,get-config-addr-info" or ibm,get-config-addr-info2"
are used to retrieve the PE address according to PCI address, which
made up of domain/bus/slot/function. If we don't have those 2 tokens,
the domain/bus/slot/function would be used as the address for EEH
RTAS operations. Some older f/w might not have those 2 tokens and
that blocks the EEH functionality to be initialized. It was introduced
by commit e2af155c ("powerpc/eeh: pseries platform EEH initialization").

The patch skips the check on those 2 tokens so we can bring up EEH
functionality successfully. And domain/bus/slot/function will be
used as address for EEH RTAS operations.

Cc: <stable@vger.kernel.org> # v3.4+
Reported-by: NRobert Knight <knight@princeton.edu>
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Tested-by: NRobert Knight <knight@princeton.edu>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/platforms/pseries/eeh_pseries.c

@@ -83,7 +83,11 @@ static int pseries_eeh_init(void)
 	ibm_configure_pe		= rtas_token("ibm,configure-pe");
 	ibm_configure_bridge		= rtas_token("ibm,configure-bridge");
 
-	/* necessary sanity check */
+	/*
+	 * Necessary sanity check. We needn't check "get-config-addr-info"
+	 * and its variant since the old firmware probably support address
+	 * of domain/bus/slot/function for EEH RTAS operations.
+	 */
 	if (ibm_set_eeh_option == RTAS_UNKNOWN_SERVICE) {
 		pr_warning("%s: RTAS service <ibm,set-eeh-option> invalid\n",
 			__func__);
@@ -102,12 +106,6 @@ static int pseries_eeh_init(void)
 		pr_warning("%s: RTAS service <ibm,slot-error-detail> invalid\n",
 			__func__);
 		return -EINVAL;
-	} else if (ibm_get_config_addr_info2 == RTAS_UNKNOWN_SERVICE &&
-		   ibm_get_config_addr_info == RTAS_UNKNOWN_SERVICE) {
-		pr_warning("%s: RTAS service <ibm,get-config-addr-info2> and "
-			"<ibm,get-config-addr-info> invalid\n",
-			__func__);
-		return -EINVAL;
 	} else if (ibm_configure_pe == RTAS_UNKNOWN_SERVICE &&
 		   ibm_configure_bridge == RTAS_UNKNOWN_SERVICE) {
 		pr_warning("%s: RTAS service <ibm,configure-pe> and "