EEH refactoring 1

Hello everyone,

Here is a set of some small, mostly idempotent, changes to improve maintainability in some of the EEH code, primarily in eeh_driver.c.

I've kept them all small to aid review but perhaps they should be squashed down before being applied.

Cheers,
Sam.

Patch set changelog follows:

====== v1 -> v2: ======

Patch 1/9: powerpc/eeh: Remove eeh_handle_event()

Patch 2/9: powerpc/eeh: Manage EEH_PE_RECOVERING inside eeh_handle_normal_event()

Patch 3/9: powerpc/eeh: Fix misleading comment in __eeh_addr_cache_get_device()

Patch 4/9: powerpc/eeh: Remove misleading test in eeh_handle_normal_event()

Patch 5/9: powerpc/eeh: Rename frozen_bus to bus in eeh_handle_normal_event()

Patch 6/9: powerpc/eeh: Clarify arguments to eeh_reset_device()
* Re-ordered parameters to eeh_reset_device() to keep pe first.
* Changed eeh_aware_driver to driver_eeh_aware.

Patch 7/9: powerpc/eeh: Remove always-true tests in eeh_reset_device()

Patch 8/9: powerpc/eeh: Factor out common code eeh_reset_device()
* In one case, added braces to "if" to match "else".

Patch 9/9: powerpc/eeh: Add eeh_state_active() helper

====== v1: ======

Patch 1/9: powerpc/eeh: Remove eeh_handle_event()
Patch 2/9: powerpc/eeh: Manage EEH_PE_RECOVERING inside eeh_handle_normal_event() Patch 3/9: powerpc/eeh: Fix misleading comment in __eeh_addr_cache_get_device() Patch 4/9: powerpc/eeh: Remove misleading test in eeh_handle_normal_event() Patch 5/9: powerpc/eeh: Rename frozen_bus to bus in eeh_handle_normal_event() Patch 6/9: powerpc/eeh: Clarify arguments to eeh_reset_device() Patch 7/9: powerpc/eeh: Remove always-true tests in eeh_reset_device() Patch 8/9: powerpc/eeh: Factor out common code eeh_reset_device() Patch 9/9: powerpc/eeh: Add eeh_state_active() helper

Sam Bobroff (9):
powerpc/eeh: Remove eeh_handle_event()
powerpc/eeh: Manage EEH_PE_RECOVERING inside eeh_handle_normal_event() powerpc/eeh: Fix misleading comment in __eeh_addr_cache_get_device() powerpc/eeh: Remove misleading test in eeh_handle_normal_event() powerpc/eeh: Rename frozen_bus to bus in eeh_handle_normal_event() powerpc/eeh: Clarify arguments to eeh_reset_device() powerpc/eeh: Remove always-true tests in eeh_reset_device() powerpc/eeh: Factor out common code eeh_reset_device() powerpc/eeh: Add eeh_state_active() helper

 arch/powerpc/include/asm/eeh.h               |   6 ++
 arch/powerpc/include/asm/eeh_event.h         |   3 +-
 arch/powerpc/kernel/eeh.c                    |  19 ++--
 arch/powerpc/kernel/eeh_cache.c              |   3 +-
 arch/powerpc/kernel/eeh_driver.c             | 137 +++++++++++----------------
 arch/powerpc/kernel/eeh_event.c              |   6 +-
 arch/powerpc/platforms/powernv/eeh-powernv.c |   9 +-
 7 files changed, 72 insertions(+), 111 deletions(-)

The function eeh_handle_event(pe) does nothing other than switching between calling eeh_handle_normal_event(pe) and eeh_handle_special_event(). However it is only called in two places, one where pe can't be NULL and the other where it must be NULL (see eeh_event_handler()) so it does nothing but obscure the flow of control.

So, remove it.

Signed-off-by Sam Bobroff <[email protected]>

---
 arch/powerpc/include/asm/eeh_event.h |  3 ++-
 arch/powerpc/kernel/eeh_driver.c     | 42 +++++++++++++-----------------------
 arch/powerpc/kernel/eeh_event.c      |  4 ++--
 3 files changed, 19 insertions(+), 30 deletions(-)

arch/powerpc/include/asm/eeh_event.h +2 -1

index 1e551a2d6f82..0a168038882d 100644
@@ -34,7 +34,8 @@ struct eeh_event {
 int eeh_event_init(void);
 int eeh_send_failure_event(struct eeh_pe *pe);
 void eeh_remove_event(struct eeh_pe *pe, bool force);
-void eeh_handle_event(struct eeh_pe *pe);
+bool eeh_handle_normal_event(struct eeh_pe *pe);
+void eeh_handle_special_event(void);
 
 #endif /* __KERNEL__ */
 #endif /* ASM_POWERPC_EEH_EVENT_H */

arch/powerpc/kernel/eeh_driver.c +15 -27

index 0c0b66fc5bfb..51b21c97910f 100644
@@ -738,9 +738,22 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus,
  * Attempts to recover the given PE.  If recovery fails or the PE has failed
  * too many times, remove the PE.
  *
+ * While PHB detects address or data parity errors on particular PCI
+ * slot, the associated PE will be frozen. Besides, DMA's occurring
+ * to wild addresses (which usually happen due to bugs in device
+ * drivers or in PCI adapter firmware) can cause EEH error. #SERR,
+ * #PERR or other misc PCI-related errors also can trigger EEH errors.
+ *
+ * Recovery process consists of unplugging the device driver (which
+ * generated hotplug events to userspace), then issuing a PCI #RST to
+ * the device, then reconfiguring the PCI config space for all bridges
+ * & devices under this slot, and then finally restarting the device
+ * drivers (which cause a second set of hotplug events to go out to
+ * userspace).
+ *
  * Returns true if @pe should no longer be used, else false.
  */
-static bool eeh_handle_normal_event(struct eeh_pe *pe)
+bool eeh_handle_normal_event(struct eeh_pe *pe)
 {
 	struct pci_bus *frozen_bus;
 	struct eeh_dev *edev, *tmp;

@@ -942,7 +955,7 @@ static bool eeh_handle_normal_event(struct eeh_pe *pe)
  * specific PE.  Iterates through possible failures and handles them as
  * necessary.
  */
-static void eeh_handle_special_event(void)
+void eeh_handle_special_event(void)
 {
 	struct eeh_pe *pe, *phb_pe;
 	struct pci_bus *bus;

@@ -1049,28 +1062,3 @@ static void eeh_handle_special_event(void)
 			break;
 	} while (rc != EEH_NEXT_ERR_NONE);
 }
-
-/**
- * eeh_handle_event - Reset a PCI device after hard lockup.
- * @pe: EEH PE
- *
- * While PHB detects address or data parity errors on particular PCI
- * slot, the associated PE will be frozen. Besides, DMA's occurring
- * to wild addresses (which usually happen due to bugs in device
- * drivers or in PCI adapter firmware) can cause EEH error. #SERR,
- * #PERR or other misc PCI-related errors also can trigger EEH errors.
- *
- * Recovery process consists of unplugging the device driver (which
- * generated hotplug events to userspace), then issuing a PCI #RST to
- * the device, then reconfiguring the PCI config space for all bridges
- * & devices under this slot, and then finally restarting the device
- * drivers (which cause a second set of hotplug events to go out to
- * userspace).
- */
-void eeh_handle_event(struct eeh_pe *pe)
-{
-	if (pe)
-		eeh_handle_normal_event(pe);
-	else
-		eeh_handle_special_event();
-}

arch/powerpc/kernel/eeh_event.c +2 -2

index accbf8b5fd46..872bcfe8f90e 100644
@@ -81,10 +81,10 @@ static int eeh_event_handler(void * dummy)
 				pr_info("EEH: Detected PCI bus error on "
 					"PHB#%x-PE#%x\n",
 					pe->phb->global_number, pe->addr);
-			eeh_handle_event(pe);
+			eeh_handle_normal_event(pe);
 			eeh_pe_state_clear(pe, EEH_PE_RECOVERING);
 		} else {
-			eeh_handle_event(NULL);
+			eeh_handle_special_event();
 		}
 
 		kfree(event);

Currently the EEH_PE_RECOVERING flag for a PE is managed by both the caller and callee of eeh_handle_normal_event() (among other places not considered here). This is complicated by the fact that the PE may or may not have been invalidated by the call.

So move the callee's handling into eeh_handle_normal_event(), which clarifies it and allows the return type to be changed to void (because it no longer needs to indicate at the PE has been invalidated).

This should not change behaviour except in eeh_event_handler() where it was previously possible to cause eeh_pe_state_clear() to be called on an invalid PE, which is now avoided.

Signed-off-by Sam Bobroff <[email protected]>

---
 arch/powerpc/include/asm/eeh_event.h |  2 +-
 arch/powerpc/kernel/eeh_driver.c     | 29 +++++++++++------------------
 arch/powerpc/kernel/eeh_event.c      |  2 --
 3 files changed, 12 insertions(+), 21 deletions(-)

arch/powerpc/include/asm/eeh_event.h +1 -1

index 0a168038882d..9884e872686f 100644
@@ -34,7 +34,7 @@ struct eeh_event {
 int eeh_event_init(void);
 int eeh_send_failure_event(struct eeh_pe *pe);
 void eeh_remove_event(struct eeh_pe *pe, bool force);
-bool eeh_handle_normal_event(struct eeh_pe *pe);
+void eeh_handle_normal_event(struct eeh_pe *pe);
 void eeh_handle_special_event(void);
 
 #endif /* __KERNEL__ */

arch/powerpc/kernel/eeh_driver.c +11 -18

index 51b21c97910f..5b7a5ed4db4d 100644
@@ -733,7 +733,8 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus,
 
 /**
  * eeh_handle_normal_event - Handle EEH events on a specific PE
- * @pe: EEH PE
+ * @pe: EEH PE - which should not be used after we return, as it may
+ * have been invalidated.
  *
  * Attempts to recover the given PE.  If recovery fails or the PE has failed
  * too many times, remove the PE.

@@ -750,10 +751,8 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus,
  * & devices under this slot, and then finally restarting the device
  * drivers (which cause a second set of hotplug events to go out to
  * userspace).
- *
- * Returns true if @pe should no longer be used, else false.
  */
-bool eeh_handle_normal_event(struct eeh_pe *pe)
+void eeh_handle_normal_event(struct eeh_pe *pe)
 {
 	struct pci_bus *frozen_bus;
 	struct eeh_dev *edev, *tmp;

@@ -765,9 +764,11 @@ bool eeh_handle_normal_event(struct eeh_pe *pe)
 	if (!frozen_bus) {
 		pr_err("%s: Cannot find PCI bus for PHB#%x-PE#%x\n",
 			__func__, pe->phb->global_number, pe->addr);
-		return false;
+		return;
 	}
 
+	eeh_pe_state_mark(pe, EEH_PE_RECOVERING);
+
 	eeh_pe_update_time_stamp(pe);
 	pe->freeze_count++;
 	if (pe->freeze_count > eeh_max_freezes) {

@@ -904,7 +905,7 @@ bool eeh_handle_normal_event(struct eeh_pe *pe)
 	pr_info("EEH: Notify device driver to resume\n");
 	eeh_pe_dev_traverse(pe, eeh_report_resume, NULL);
 
-	return false;
+	goto final;
 
 hard_fail:
 	/*

@@ -940,12 +941,12 @@ bool eeh_handle_normal_event(struct eeh_pe *pe)
 			pci_lock_rescan_remove();
 			pci_hp_remove_devices(frozen_bus);
 			pci_unlock_rescan_remove();
-
 			/* The passed PE should no longer be used */
-			return true;
+			return;
 		}
 	}
-	return false;
+final:
+	eeh_pe_state_clear(pe, EEH_PE_RECOVERING);
 }
 
 /**

@@ -1018,15 +1019,7 @@ void eeh_handle_special_event(void)
 		 */
 		if (rc == EEH_NEXT_ERR_FROZEN_PE ||
 		    rc == EEH_NEXT_ERR_FENCED_PHB) {
-			/*
-			 * eeh_handle_normal_event() can make the PE stale if it
-			 * determines that the PE cannot possibly be recovered.
-			 * Don't modify the PE state if that's the case.
-			 */
-			if (eeh_handle_normal_event(pe))
-				continue;
-
-			eeh_pe_state_clear(pe, EEH_PE_RECOVERING);
+			eeh_handle_normal_event(pe);
 		} else {
 			pci_lock_rescan_remove();
 			list_for_each_entry(hose, &hose_list, list_node) {

arch/powerpc/kernel/eeh_event.c +0 -2

index 872bcfe8f90e..61c9356bf9c9 100644
@@ -73,7 +73,6 @@ static int eeh_event_handler(void * dummy)
 		/* We might have event without binding PE */
 		pe = event->pe;
 		if (pe) {
-			eeh_pe_state_mark(pe, EEH_PE_RECOVERING);
 			if (pe->type & EEH_PE_PHB)
 				pr_info("EEH: Detected error on PHB#%x\n",
 					 pe->phb->global_number);

@@ -82,7 +81,6 @@ static int eeh_event_handler(void * dummy)
 					"PHB#%x-PE#%x\n",
 					pe->phb->global_number, pe->addr);
 			eeh_handle_normal_event(pe);
-			eeh_pe_state_clear(pe, EEH_PE_RECOVERING);
 		} else {
 			eeh_handle_special_event();
 		}

Commit "0ba178888b05 powerpc/eeh: Remove reference to PCI device" removed a call to pci_dev_get() from __eeh_addr_cache_get_device() but did not update the comment to match.

Signed-off-by Sam Bobroff <[email protected]>

---
 arch/powerpc/kernel/eeh_cache.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

arch/powerpc/kernel/eeh_cache.c +1 -2

index d4cc26618809..201943d54a6e 100644
@@ -84,8 +84,7 @@ static inline struct eeh_dev *__eeh_addr_cache_get_device(unsigned long addr)
  * @addr: mmio (PIO) phys address or i/o port number
  *
  * Given an mmio phys address, or a port number, find a pci device
- * that implements this address.  Be sure to pci_dev_put the device
- * when finished.  I/O port numbers are assumed to be offset
+ * that implements this address.  I/O port numbers are assumed to be offset
  * from zero (that is, they do *not* have pci_io_addr added in).
  * It is safe to call this function within an interrupt.
  */

Remove a test that checks if "frozen_bus" is NULL, because it cannot have changed since it was tested at the start of the function and so must be true here.

Signed-off-by Sam Bobroff <[email protected]>

---
 arch/powerpc/kernel/eeh_driver.c | 24 +++++++++++-------------
 1 file changed, 11 insertions(+), 13 deletions(-)

arch/powerpc/kernel/eeh_driver.c +11 -13

index 5b7a5ed4db4d..04a5d9db5499 100644
@@ -930,20 +930,18 @@ void eeh_handle_normal_event(struct eeh_pe *pe)
 	 * all removed devices correctly to avoid access
 	 * the their PCI config any more.
 	 */
-	if (frozen_bus) {
-		if (pe->type & EEH_PE_VF) {
-			eeh_pe_dev_traverse(pe, eeh_rmv_device, NULL);
-			eeh_pe_dev_mode_mark(pe, EEH_DEV_REMOVED);
-		} else {
-			eeh_pe_state_clear(pe, EEH_PE_PRI_BUS);
-			eeh_pe_dev_mode_mark(pe, EEH_DEV_REMOVED);
+	if (pe->type & EEH_PE_VF) {
+		eeh_pe_dev_traverse(pe, eeh_rmv_device, NULL);
+		eeh_pe_dev_mode_mark(pe, EEH_DEV_REMOVED);
+	} else {
+		eeh_pe_state_clear(pe, EEH_PE_PRI_BUS);
+		eeh_pe_dev_mode_mark(pe, EEH_DEV_REMOVED);
 
-			pci_lock_rescan_remove();
-			pci_hp_remove_devices(frozen_bus);
-			pci_unlock_rescan_remove();
-			/* The passed PE should no longer be used */
-			return;
-		}
+		pci_lock_rescan_remove();
+		pci_hp_remove_devices(frozen_bus);
+		pci_unlock_rescan_remove();
+		/* The passed PE should no longer be used */
+		return;
 	}
 final:
 	eeh_pe_state_clear(pe, EEH_PE_RECOVERING);

The name "frozen_bus" is misleading: it's not necessarily frozen, it's just the PE's PCI bus.

Signed-off-by Sam Bobroff <[email protected]>

---
 arch/powerpc/kernel/eeh_driver.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

arch/powerpc/kernel/eeh_driver.c +5 -5

index 04a5d9db5499..cb584d72b0a5 100644
@@ -754,14 +754,14 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus,
  */
 void eeh_handle_normal_event(struct eeh_pe *pe)
 {
-	struct pci_bus *frozen_bus;
+	struct pci_bus *bus;
 	struct eeh_dev *edev, *tmp;
 	int rc = 0;
 	enum pci_ers_result result = PCI_ERS_RESULT_NONE;
 	struct eeh_rmv_data rmv_data = {LIST_HEAD_INIT(rmv_data.edev_list), 0};
 
-	frozen_bus = eeh_pe_bus_get(pe);
-	if (!frozen_bus) {
+	bus = eeh_pe_bus_get(pe);
+	if (!bus) {
 		pr_err("%s: Cannot find PCI bus for PHB#%x-PE#%x\n",
 			__func__, pe->phb->global_number, pe->addr);
 		return;

@@ -820,7 +820,7 @@ void eeh_handle_normal_event(struct eeh_pe *pe)
 	 */
 	if (result == PCI_ERS_RESULT_NONE) {
 		pr_info("EEH: Reset with hotplug activity\n");
-		rc = eeh_reset_device(pe, frozen_bus, NULL);
+		rc = eeh_reset_device(pe, bus, NULL);
 		if (rc) {
 			pr_warn("%s: Unable to reset, err=%d\n",
 				__func__, rc);

@@ -938,7 +938,7 @@ void eeh_handle_normal_event(struct eeh_pe *pe)
 		eeh_pe_dev_mode_mark(pe, EEH_DEV_REMOVED);
 
 		pci_lock_rescan_remove();
-		pci_hp_remove_devices(frozen_bus);
+		pci_hp_remove_devices(bus);
 		pci_unlock_rescan_remove();
 		/* The passed PE should no longer be used */
 		return;

It is currently difficult to understand the behaviour of eeh_reset_device() due to the way it's parameters are used. In particular, when 'bus' is NULL, it's value is still necessary so the same value is looked up again locally under a different name ('frozen_bus') but behaviour is changed.

To clarify this, add a new parameter 'driver_eeh_aware', and have the caller set it when it would have passed NULL for 'bus' and always pass a value for 'bus'. Then change any test that was on 'bus' to one on '!driver_eeh_aware' and replace uses of 'frozen_bus' with 'bus'.

Also update the function's comment.

This should not change behaviour.

Signed-off-by Sam Bobroff <[email protected]>

---
 arch/powerpc/kernel/eeh_driver.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

arch/powerpc/kernel/eeh_driver.c +11 -9

index cb584d72b0a5..07437d765434 100644
@@ -619,17 +619,19 @@ int eeh_pe_reset_and_recover(struct eeh_pe *pe)
 
 /**
  * eeh_reset_device - Perform actual reset of a pci slot
+ * @driver_eeh_aware: Does the device's driver provide EEH support?
  * @pe: EEH PE
  * @bus: PCI bus corresponding to the isolcated slot
+ * @rmv_data: Optional, list to record removed devices
  *
  * This routine must be called to do reset on the indicated PE.
  * During the reset, udev might be invoked because those affected
  * PCI devices will be removed and then added.
  */
 static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus,
-				struct eeh_rmv_data *rmv_data)
+			    struct eeh_rmv_data *rmv_data,
+			    bool driver_eeh_aware)
 {
-	struct pci_bus *frozen_bus = eeh_pe_bus_get(pe);
 	time64_t tstamp;
 	int cnt, rc;
 	struct eeh_dev *edev;

@@ -645,7 +647,7 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus,
 	 * into pci_hp_add_devices().
 	 */
 	eeh_pe_state_mark(pe, EEH_PE_KEEP);
-	if (bus) {
+	if (!driver_eeh_aware) {
 		if (pe->type & EEH_PE_VF) {
 			eeh_pe_dev_traverse(pe, eeh_rmv_device, NULL);
 		} else {

@@ -653,7 +655,7 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus,
 			pci_hp_remove_devices(bus);
 			pci_unlock_rescan_remove();
 		}
-	} else if (frozen_bus) {
+	} else if (bus) {
 		eeh_pe_dev_traverse(pe, eeh_rmv_device, rmv_data);
 	}
 

@@ -689,7 +691,7 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus,
 	 * the device up before the scripts have taken it down,
 	 * potentially weird things happen.
 	 */
-	if (bus) {
+	if (!driver_eeh_aware) {
 		pr_info("EEH: Sleep 5s ahead of complete hotplug\n");
 		ssleep(5);
 

@@ -706,7 +708,7 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus,
 			eeh_pe_state_clear(pe, EEH_PE_PRI_BUS);
 			pci_hp_add_devices(bus);
 		}
-	} else if (frozen_bus && rmv_data->removed) {
+	} else if (bus && rmv_data->removed) {
 		pr_info("EEH: Sleep 5s ahead of partial hotplug\n");
 		ssleep(5);
 

@@ -715,7 +717,7 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus,
 		if (pe->type & EEH_PE_VF)
 			eeh_add_virt_device(edev, NULL);
 		else
-			pci_hp_add_devices(frozen_bus);
+			pci_hp_add_devices(bus);
 	}
 	eeh_pe_state_clear(pe, EEH_PE_KEEP);
 

@@ -820,7 +822,7 @@ void eeh_handle_normal_event(struct eeh_pe *pe)
 	 */
 	if (result == PCI_ERS_RESULT_NONE) {
 		pr_info("EEH: Reset with hotplug activity\n");
-		rc = eeh_reset_device(pe, bus, NULL);
+		rc = eeh_reset_device(pe, bus, NULL, false);
 		if (rc) {
 			pr_warn("%s: Unable to reset, err=%d\n",
 				__func__, rc);

@@ -872,7 +874,7 @@ void eeh_handle_normal_event(struct eeh_pe *pe)
 	/* If any device called out for a reset, then reset the slot */
 	if (result == PCI_ERS_RESULT_NEED_RESET) {
 		pr_info("EEH: Reset without hotplug activity\n");
-		rc = eeh_reset_device(pe, NULL, &rmv_data);
+		rc = eeh_reset_device(pe, bus, &rmv_data, true);
 		if (rc) {
 			pr_warn("%s: Cannot reset, err=%d\n",
 				__func__, rc);

eeh_reset_device() tests the value of 'bus' more than once but the only caller, eeh_handle_normal_device() does this test itself and will never pass NULL.

So, remove the dead tests.

This should not change behaviour.

Signed-off-by Sam Bobroff <[email protected]>

---
 arch/powerpc/kernel/eeh_driver.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

arch/powerpc/kernel/eeh_driver.c +2 -2

index 07437d765434..93fc22e791fa 100644
@@ -655,7 +655,7 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus,
 			pci_hp_remove_devices(bus);
 			pci_unlock_rescan_remove();
 		}
-	} else if (bus) {
+	} else {
 		eeh_pe_dev_traverse(pe, eeh_rmv_device, rmv_data);
 	}
 

@@ -708,7 +708,7 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus,
 			eeh_pe_state_clear(pe, EEH_PE_PRI_BUS);
 			pci_hp_add_devices(bus);
 		}
-	} else if (bus && rmv_data->removed) {
+	} else if (rmv_data->removed) {
 		pr_info("EEH: Sleep 5s ahead of partial hotplug\n");
 		ssleep(5);
 

The caller will always pass NULL for 'rmv_data' when 'eeh_aware_driver' is true, so the first two calls to eeh_pe_dev_traverse() can be combined without changing behaviour as can the two arms of the final 'if' block.

This should not change behaviour.

Signed-off-by Sam Bobroff <[email protected]>

---
====== v2 -> v3: ======
Corrected two missed cases of eeh_aware_driver -> driver_eeh_aware.

 arch/powerpc/kernel/eeh_driver.c | 32 ++++++++++----------------------
 1 file changed, 10 insertions(+), 22 deletions(-)

arch/powerpc/kernel/eeh_driver.c +10 -22

index 93fc22e791fa..43ceb6263cd8 100644
@@ -647,16 +647,12 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus,
 	 * into pci_hp_add_devices().
 	 */
 	eeh_pe_state_mark(pe, EEH_PE_KEEP);
-	if (!driver_eeh_aware) {
-		if (pe->type & EEH_PE_VF) {
-			eeh_pe_dev_traverse(pe, eeh_rmv_device, NULL);
-		} else {
-			pci_lock_rescan_remove();
-			pci_hp_remove_devices(bus);
-			pci_unlock_rescan_remove();
-		}
-	} else {
+	if (driver_eeh_aware || (pe->type & EEH_PE_VF)) {
 		eeh_pe_dev_traverse(pe, eeh_rmv_device, rmv_data);
+	} else {
+		pci_lock_rescan_remove();
+		pci_hp_remove_devices(bus);
+		pci_unlock_rescan_remove();
 	}
 
 	/*

@@ -691,8 +687,9 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus,
 	 * the device up before the scripts have taken it down,
 	 * potentially weird things happen.
 	 */
-	if (!driver_eeh_aware) {
-		pr_info("EEH: Sleep 5s ahead of complete hotplug\n");
+	if (!driver_eeh_aware || rmv_data->removed) {
+		pr_info("EEH: Sleep 5s ahead of %s hotplug\n",
+			(driver_eeh_aware ? "partial" : "complete"));
 		ssleep(5);
 
 		/*

@@ -705,19 +702,10 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus,
 		if (pe->type & EEH_PE_VF) {
 			eeh_add_virt_device(edev, NULL);
 		} else {
-			eeh_pe_state_clear(pe, EEH_PE_PRI_BUS);
+			if (!driver_eeh_aware)
+				eeh_pe_state_clear(pe, EEH_PE_PRI_BUS);
 			pci_hp_add_devices(bus);
 		}
-	} else if (rmv_data->removed) {
-		pr_info("EEH: Sleep 5s ahead of partial hotplug\n");
-		ssleep(5);
-
-		edev = list_first_entry(&pe->edevs, struct eeh_dev, list);
-		eeh_pe_traverse(pe, eeh_pe_detach_dev, NULL);
-		if (pe->type & EEH_PE_VF)
-			eeh_add_virt_device(edev, NULL);
-		else
-			pci_hp_add_devices(bus);
 	}
 	eeh_pe_state_clear(pe, EEH_PE_KEEP);
 

Checking for a "fully active" device state requires testing two flag bits, which is open coded in several places, so add a function to do it.

Signed-off-by Sam Bobroff <[email protected]>

---
 arch/powerpc/include/asm/eeh.h               |  6 ++++++
 arch/powerpc/kernel/eeh.c                    | 19 ++++++-------------
 arch/powerpc/platforms/powernv/eeh-powernv.c |  9 ++-------
 3 files changed, 14 insertions(+), 20 deletions(-)

arch/powerpc/include/asm/eeh.h +6 -0

index fd37cc101f4f..c2266ca61853 100644
@@ -256,6 +256,12 @@ static inline void eeh_serialize_unlock(unsigned long flags)
 	raw_spin_unlock_irqrestore(&confirm_error_lock, flags);
 }
 
+static inline bool eeh_state_active(int state)
+{
+	return (state & (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE))
+	== (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE);
+}
+
 typedef void *(*eeh_traverse_func)(void *data, void *flag);
 void eeh_set_pe_aux_size(int size);
 int eeh_phb_pe_create(struct pci_controller *phb);

arch/powerpc/kernel/eeh.c +6 -13

index 2b9df0040d6b..bc640e4c5ca5 100644
@@ -394,9 +394,7 @@ static int eeh_phb_check_failure(struct eeh_pe *pe)
 	/* Check PHB state */
 	ret = eeh_ops->get_state(phb_pe, NULL);
 	if ((ret < 0) ||
-	    (ret == EEH_STATE_NOT_SUPPORT) ||
-	    (ret & (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE)) ==
-	    (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE)) {
+	    (ret == EEH_STATE_NOT_SUPPORT) || eeh_state_active(ret)) {
 		ret = 0;
 		goto out;
 	}

@@ -433,7 +431,6 @@ static int eeh_phb_check_failure(struct eeh_pe *pe)
 int eeh_dev_check_failure(struct eeh_dev *edev)
 {
 	int ret;
-	int active_flags = (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE);
 	unsigned long flags;
 	struct device_node *dn;
 	struct pci_dev *dev;

@@ -525,8 +522,7 @@ int eeh_dev_check_failure(struct eeh_dev *edev)
 	 * state, PE is in good state.
 	 */
 	if ((ret < 0) ||
-	    (ret == EEH_STATE_NOT_SUPPORT) ||
-	    ((ret & active_flags) == active_flags)) {
+	    (ret == EEH_STATE_NOT_SUPPORT) || eeh_state_active(ret)) {
 		eeh_stats.false_positives++;
 		pe->false_positives++;
 		rc = 0;

@@ -546,8 +542,7 @@ int eeh_dev_check_failure(struct eeh_dev *edev)
 
 		/* Frozen parent PE ? */
 		ret = eeh_ops->get_state(parent_pe, NULL);
-		if (ret > 0 &&
-		    (ret & active_flags) != active_flags)
+		if (ret > 0 && !eeh_state_active(ret))
 			pe = parent_pe;
 
 		/* Next parent level */

@@ -888,7 +883,6 @@ static void *eeh_set_dev_freset(void *data, void *flag)
  */
 int eeh_pe_reset_full(struct eeh_pe *pe)
 {
-	int active_flags = (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE);
 	int reset_state = (EEH_PE_RESET | EEH_PE_CFG_BLOCKED);
 	int type = EEH_RESET_HOT;
 	unsigned int freset = 0;

@@ -919,7 +913,7 @@ int eeh_pe_reset_full(struct eeh_pe *pe)
 
 		/* Wait until the PE is in a functioning state */
 		state = eeh_ops->wait_state(pe, PCI_BUS_RESET_WAIT_MSEC);
-		if ((state & active_flags) == active_flags)
+		if (eeh_state_active(state))
 			break;
 
 		if (state < 0) {

@@ -1352,16 +1346,15 @@ static int eeh_pe_change_owner(struct eeh_pe *pe)
 	struct eeh_dev *edev, *tmp;
 	struct pci_dev *pdev;
 	struct pci_device_id *id;
-	int flags, ret;
+	int ret;
 
 	/* Check PE state */
-	flags = (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE);
 	ret = eeh_ops->get_state(pe, NULL);
 	if (ret < 0 || ret == EEH_STATE_NOT_SUPPORT)
 		return 0;
 
 	/* Unfrozen PE, nothing to do */
-	if ((ret & flags) == flags)
+	if (eeh_state_active(ret))
 		return 0;
 
 	/* Frozen PE, check if it needs PE level reset */

arch/powerpc/platforms/powernv/eeh-powernv.c +2 -7

index 33c86c1a1720..ddfc3544d285 100644
@@ -1425,11 +1425,8 @@ static int pnv_eeh_get_pe(struct pci_controller *hose,
 	dev_pe = dev_pe->parent;
 	while (dev_pe && !(dev_pe->type & EEH_PE_PHB)) {
 		int ret;
-		int active_flags = (EEH_STATE_MMIO_ACTIVE |
-				    EEH_STATE_DMA_ACTIVE);
-
 		ret = eeh_ops->get_state(dev_pe, NULL);
-		if (ret <= 0 || (ret & active_flags) == active_flags) {
+		if (ret <= 0 || eeh_state_active(ret)) {
 			dev_pe = dev_pe->parent;
 			continue;
 		}

@@ -1463,7 +1460,6 @@ static int pnv_eeh_next_error(struct eeh_pe **pe)
 	struct eeh_pe *phb_pe, *parent_pe;
 	__be64 frozen_pe_no;
 	__be16 err_type, severity;
-	int active_flags = (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE);
 	long rc;
 	int state, ret = EEH_NEXT_ERR_NONE;
 

@@ -1626,8 +1622,7 @@ static int pnv_eeh_next_error(struct eeh_pe **pe)
 
 				/* Frozen parent PE ? */
 				state = eeh_ops->get_state(parent_pe, NULL);
-				if (state > 0 &&
-				    (state & active_flags) != active_flags)
+				if (state > 0 && !eeh_state_active(state))
 					*pe = parent_pe;
 
 				/* Next parent level */

The function eeh_handle_event(pe) does nothing other than switching between calling eeh_handle_normal_event(pe) and eeh_handle_special_event(). However it is only called in two places, one where pe can't be NULL and the other where it must be NULL (see eeh_event_handler()) so it does nothing but obscure the flow of control.

So, remove it.

Signed-off-by Sam Bobroff <[email protected]>

Reviewed-by Alexey Kardashevskiy <[email protected]>