[PATCH] read_slot_reset_state2 rtas call

[Paul Mackerras]

Nathan Fontenot writes:

> This patch attempts to use the newer rtas call if available and falls
> back the older version otherwise.  This will maintain EEH slot checking
> capabilities on all future and current firmware levels.

David Howells pointed out that one of the read_slot_reset_state calls
wasn't checking the return value, so here's a version of the patch
that does.  I'll send this to akpm later.

Paul.

diff -urN linux-2.5/arch/ppc64/kernel/eeh.c test/arch/ppc64/kernel/eeh.c
--- linux-2.5/arch/ppc64/kernel/eeh.c	2004-10-26 16:06:41.000000000 +1000
+++ test/arch/ppc64/kernel/eeh.c	2004-11-25 22:24:59.681460824 +1100
@@ -95,6 +95,7 @@
 static int ibm_set_eeh_option;
 static int ibm_set_slot_reset;
 static int ibm_read_slot_reset_state;
+static int ibm_read_slot_reset_state2;
 static int ibm_slot_error_detail;
 
 static int eeh_subsystem_enabled;
@@ -407,6 +408,27 @@
 }
 
 /**
+ * read_slot_reset_state - Read the reset state of a device node's slot
+ * @dn: device node to read
+ * @rets: array to return results in
+ */
+static int read_slot_reset_state(struct device_node *dn, int rets[])
+{
+	int token, outputs;
+
+	if (ibm_read_slot_reset_state2 != RTAS_UNKNOWN_SERVICE) {
+		token = ibm_read_slot_reset_state2;
+		outputs = 4;
+	} else {
+		token = ibm_read_slot_reset_state;
+		outputs = 3;
+	}
+	
+	return rtas_call(token, 3, outputs, rets, dn->eeh_config_addr, 
+			 BUID_HI(dn->phb->buid), BUID_LO(dn->phb->buid));
+}
+
+/**
  * eeh_panic - call panic() for an eeh event that cannot be handled.
  * The philosophy of this routine is that it is better to panic and
  * halt the OS than it is to risk possible data corruption by
@@ -508,7 +530,7 @@
 int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev)
 {
 	int ret;
-	int rets[2];
+	int rets[3];
 	unsigned long flags;
 	int rc, reset_state;
 	struct eeh_event  *event;
@@ -539,11 +561,8 @@
 		atomic_inc(&eeh_fail_count);
 		if (atomic_read(&eeh_fail_count) >= EEH_MAX_FAILS) {
 			/* re-read the slot reset state */
-			rets[0] = -1;
-			rtas_call(ibm_read_slot_reset_state, 3, 3, rets,
-				  dn->eeh_config_addr,
-				  BUID_HI(dn->phb->buid),
-				  BUID_LO(dn->phb->buid));
+			if (read_slot_reset_state(dn, rets) != 0)
+				rets[0] = -1;	/* reset state unknown */
 			eeh_panic(dev, rets[0]);
 		}
 		return 0;
@@ -556,10 +575,7 @@
 	 * function zero of a multi-function device.
 	 * In any case they must share a common PHB.
 	 */
-	ret = rtas_call(ibm_read_slot_reset_state, 3, 3, rets,
-			dn->eeh_config_addr, BUID_HI(dn->phb->buid),
-			BUID_LO(dn->phb->buid));
-
+	ret = read_slot_reset_state(dn, rets);
 	if (!(ret == 0 && rets[1] == 1 && (rets[0] == 2 || rets[0] == 4))) {
 		__get_cpu_var(false_positives)++;
 		return 0;
@@ -755,6 +771,7 @@
 
 	ibm_set_eeh_option = rtas_token("ibm,set-eeh-option");
 	ibm_set_slot_reset = rtas_token("ibm,set-slot-reset");
+	ibm_read_slot_reset_state2 = rtas_token("ibm,read-slot-reset-state2");
 	ibm_read_slot_reset_state = rtas_token("ibm,read-slot-reset-state");
 	ibm_slot_error_detail = rtas_token("ibm,slot-error-detail");