powerpc/eeh: Cleanup eeh_ops.wait_state()

The wait_state member of eeh_ops does not need to be platform
dependent; it's just logic around eeh_ops.get_state(). Therefore,
merge the two (slightly different!) platform versions into a new
function, eeh_wait_state() and remove the eeh_ops member.

While doing this, also correct:
* The wait logic, so that it never waits longer than max_wait.
* The wait logic, so that it never waits less than
  EEH_STATE_MIN_WAIT_TIME.
* One call site where the result is treated like a bit field before
  it's checked for negative error values.
* In pseries_eeh_get_state(), rename the "state" parameter to "delay"
  because that's what it is.

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

3 files changed, 56 insertions, 6 deletions

diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index 12e5311d06ed..6cae6b56ffd6 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c
@@ -681,7 +681,7 @@ int eeh_pci_enable(struct eeh_pe *pe, int function)
 
 	/* Check if the request is finished successfully */
 	if (active_flag) {
-		rc = eeh_ops->wait_state(pe, PCI_BUS_RESET_WAIT_MSEC);
+		rc = eeh_wait_state(pe, PCI_BUS_RESET_WAIT_MSEC);
 		if (rc < 0)
 			return rc;
 
@@ -920,16 +920,15 @@ int eeh_pe_reset_full(struct eeh_pe *pe)
 			break;
 
 		/* Wait until the PE is in a functioning state */
-		state = eeh_ops->wait_state(pe, PCI_BUS_RESET_WAIT_MSEC);
-		if (eeh_state_active(state))
-			break;
-
+		state = eeh_wait_state(pe, PCI_BUS_RESET_WAIT_MSEC);
 		if (state < 0) {
 			pr_warn("%s: Unrecoverable slot failure on PHB#%x-PE#%x",
 				__func__, pe->phb->global_number, pe->addr);
 			ret = -ENOTRECOVERABLE;
 			break;
 		}
+		if (eeh_state_active(state))
+			break;
 
 		/* Set error in case this is our last attempt */
 		ret = -EIO;
diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c
index c827617613c1..e7f757cd839b 100644
--- a/arch/powerpc/kernel/eeh_driver.c
+++ b/arch/powerpc/kernel/eeh_driver.c
@@ -836,7 +836,7 @@ void eeh_handle_normal_event(struct eeh_pe *pe)
 	/* Get the current PCI slot state. This can take a long time,
 	 * sometimes over 300 seconds for certain systems.
 	 */
-	rc = eeh_ops->wait_state(pe, MAX_WAIT_FOR_RECOVERY*1000);
+	rc = eeh_wait_state(pe, MAX_WAIT_FOR_RECOVERY*1000);
 	if (rc < 0 || rc == EEH_STATE_NOT_SUPPORT) {
 		pr_warn("EEH: Permanent failure\n");
 		goto hard_fail;
diff --git a/arch/powerpc/kernel/eeh_pe.c b/arch/powerpc/kernel/eeh_pe.c
index e43dcefbe73f..6fa2032e0594 100644
--- a/arch/powerpc/kernel/eeh_pe.c
+++ b/arch/powerpc/kernel/eeh_pe.c
@@ -109,6 +109,57 @@ int eeh_phb_pe_create(struct pci_controller *phb)
 }
 
 /**
+ * eeh_wait_state - Wait for PE state
+ * @pe: EEH PE
+ * @max_wait: maximal period in millisecond
+ *
+ * Wait for the state of associated PE. It might take some time
+ * to retrieve the PE's state.
+ */
+int eeh_wait_state(struct eeh_pe *pe, int max_wait)
+{
+	int ret;
+	int mwait;
+
+	/*
+	 * According to PAPR, the state of PE might be temporarily
+	 * unavailable. Under the circumstance, we have to wait
+	 * for indicated time determined by firmware. The maximal
+	 * wait time is 5 minutes, which is acquired from the original
+	 * EEH implementation. Also, the original implementation
+	 * also defined the minimal wait time as 1 second.
+	 */
+#define EEH_STATE_MIN_WAIT_TIME	(1000)
+#define EEH_STATE_MAX_WAIT_TIME	(300 * 1000)
+
+	while (1) {
+		ret = eeh_ops->get_state(pe, &mwait);
+
+		if (ret != EEH_STATE_UNAVAILABLE)
+			return ret;
+
+		if (max_wait <= 0) {
+			pr_warn("%s: Timeout when getting PE's state (%d)\n",
+				__func__, max_wait);
+			return EEH_STATE_NOT_SUPPORT;
+		}
+
+		if (mwait < EEH_STATE_MIN_WAIT_TIME) {
+			pr_warn("%s: Firmware returned bad wait value %d\n",
+				__func__, mwait);
+			mwait = EEH_STATE_MIN_WAIT_TIME;
+		} else if (mwait > EEH_STATE_MAX_WAIT_TIME) {
+			pr_warn("%s: Firmware returned too long wait value %d\n",
+				__func__, mwait);
+			mwait = EEH_STATE_MAX_WAIT_TIME;
+		}
+
+		msleep(min(mwait, max_wait));
+		max_wait -= mwait;
+	}
+}
+
+/**
  * eeh_phb_pe_get - Retrieve PHB PE based on the given PHB
  * @phb: PCI controller
  *