powerpc/eeh: Trace eeh device from I/O cache

The idea comes from Benjamin Herrenschmidt. The eeh cache helps
fetching the pci device according to the given I/O address. Since
the eeh cache is serving for eeh, it's reasonable for eeh cache
to trace eeh device except pci device.

The patch make eeh cache to trace eeh device. Also, the major
eeh entry function eeh_dn_check_failure has been renamed to
eeh_dev_check_failure since it will take eeh device as input
parameter.

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

2 files changed, 22 insertions, 25 deletions

diff --git a/arch/powerpc/platforms/pseries/eeh.c b/arch/powerpc/platforms/pseries/eeh.c
index 4bdc278c2fd..9e618424b18 100644
--- a/arch/powerpc/platforms/pseries/eeh.c
+++ b/arch/powerpc/platforms/pseries/eeh.c
@@ -270,9 +270,8 @@ static inline unsigned long eeh_token_to_phys(unsigned long token)
 }
 
 /**
- * eeh_dn_check_failure - Check if all 1's data is due to EEH slot freeze
- * @dn: device node
- * @dev: pci device, if known
+ * eeh_dev_check_failure - Check if all 1's data is due to EEH slot freeze
+ * @edev: eeh device
  *
  * Check for an EEH failure for the given device node.  Call this
  * routine if the result of a read was all 0xff's and you want to
@@ -284,12 +283,13 @@ static inline unsigned long eeh_token_to_phys(unsigned long token)
  *
  * It is safe to call this routine in an interrupt context.
  */
-int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev)
+int eeh_dev_check_failure(struct eeh_dev *edev)
 {
 	int ret;
 	unsigned long flags;
+	struct device_node *dn;
+	struct pci_dev *dev;
 	struct eeh_pe *pe;
-	struct eeh_dev *edev;
 	int rc = 0;
 	const char *location;
 
@@ -298,15 +298,12 @@ int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev)
 	if (!eeh_subsystem_enabled)
 		return 0;
 
-	if (dn) {
-		edev = of_node_to_eeh_dev(dn);
-	} else if (dev) {
-		edev = pci_dev_to_eeh_dev(dev);
-		dn = pci_device_to_OF_node(dev);
-	} else {
+	if (!edev) {
 		eeh_stats.no_dn++;
 		return 0;
 	}
+	dn = eeh_dev_to_of_node(edev);
+	dev = eeh_dev_to_pci_dev(edev);
 	pe = edev->pe;
 
 	/* Access to IO BARs might get this far and still not want checking. */
@@ -393,7 +390,7 @@ dn_unlock:
 	return rc;
 }
 
-EXPORT_SYMBOL_GPL(eeh_dn_check_failure);
+EXPORT_SYMBOL_GPL(eeh_dev_check_failure);
 
 /**
  * eeh_check_failure - Check if all 1's data is due to EEH slot freeze
@@ -410,21 +407,19 @@ EXPORT_SYMBOL_GPL(eeh_dn_check_failure);
 unsigned long eeh_check_failure(const volatile void __iomem *token, unsigned long val)
 {
 	unsigned long addr;
-	struct pci_dev *dev;
-	struct device_node *dn;
+	struct eeh_dev *edev;
 
 	/* Finding the phys addr + pci device; this is pretty quick. */
 	addr = eeh_token_to_phys((unsigned long __force) token);
-	dev = pci_addr_cache_get_device(addr);
-	if (!dev) {
+	edev = pci_addr_cache_get_device(addr);
+	if (!edev) {
 		eeh_stats.no_device++;
 		return val;
 	}
 
-	dn = pci_device_to_OF_node(dev);
-	eeh_dn_check_failure(dn, dev);
+	eeh_dev_check_failure(edev);
 
-	pci_dev_put(dev);
+	pci_dev_put(eeh_dev_to_pci_dev(edev));
 	return val;
 }
 
diff --git a/arch/powerpc/platforms/pseries/eeh_cache.c b/arch/powerpc/platforms/pseries/eeh_cache.c
index a1910579d7a..6c5ef757f4d 100644
--- a/arch/powerpc/platforms/pseries/eeh_cache.c
+++ b/arch/powerpc/platforms/pseries/eeh_cache.c
@@ -50,6 +50,7 @@ struct pci_io_addr_range {
 	struct rb_node rb_node;
 	unsigned long addr_lo;
 	unsigned long addr_hi;
+	struct eeh_dev *edev;
 	struct pci_dev *pcidev;
 	unsigned int flags;
 };
@@ -59,7 +60,7 @@ static struct pci_io_addr_cache {
 	spinlock_t piar_lock;
 } pci_io_addr_cache_root;
 
-static inline struct pci_dev *__pci_addr_cache_get_device(unsigned long addr)
+static inline struct eeh_dev *__pci_addr_cache_get_device(unsigned long addr)
 {
 	struct rb_node *n = pci_io_addr_cache_root.rb_root.rb_node;
 
@@ -74,7 +75,7 @@ static inline struct pci_dev *__pci_addr_cache_get_device(unsigned long addr)
 				n = n->rb_right;
 			} else {
 				pci_dev_get(piar->pcidev);
-				return piar->pcidev;
+				return piar->edev;
 			}
 		}
 	}
@@ -92,15 +93,15 @@ static inline struct pci_dev *__pci_addr_cache_get_device(unsigned long addr)
  * from zero (that is, they do *not* have pci_io_addr added in).
  * It is safe to call this function within an interrupt.
  */
-struct pci_dev *pci_addr_cache_get_device(unsigned long addr)
+struct eeh_dev *pci_addr_cache_get_device(unsigned long addr)
 {
-	struct pci_dev *dev;
+	struct eeh_dev *edev;
 	unsigned long flags;
 
 	spin_lock_irqsave(&pci_io_addr_cache_root.piar_lock, flags);
-	dev = __pci_addr_cache_get_device(addr);
+	edev = __pci_addr_cache_get_device(addr);
 	spin_unlock_irqrestore(&pci_io_addr_cache_root.piar_lock, flags);
-	return dev;
+	return edev;
 }
 
 #ifdef DEBUG
@@ -158,6 +159,7 @@ pci_addr_cache_insert(struct pci_dev *dev, unsigned long alo,
 	pci_dev_get(dev);
 	piar->addr_lo = alo;
 	piar->addr_hi = ahi;
+	piar->edev = pci_dev_to_eeh_dev(dev);
 	piar->pcidev = dev;
 	piar->flags = flags;