powerpc/eeh: Use safe list traversal when walking EEH devices

Currently, we're trasversing the EEH devices list using list_for_each_entry().
That's not safe enough because the EEH devices might be removed from
its parent PE while doing iteration. The patch replaces that with
list_for_each_entry_safe().
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/include/asm/eeh.h

@@ -74,8 +74,8 @@ struct eeh_pe {
 	struct list_head child;		/* Child PEs			*/
 };
 
-#define eeh_pe_for_each_dev(pe, edev) \
-		list_for_each_entry(edev, &pe->edevs, list)
+#define eeh_pe_for_each_dev(pe, edev, tmp) \
+		list_for_each_entry_safe(edev, tmp, &pe->edevs, list)
 
 /*
  * The struct is used to trace EEH state for the associated

arch/powerpc/kernel/eeh.c

@@ -231,7 +231,7 @@ static size_t eeh_gather_pci_data(struct eeh_dev *edev, char * buf, size_t len)
 void eeh_slot_error_detail(struct eeh_pe *pe, int severity)
 {
 	size_t loglen = 0;
-	struct eeh_dev *edev;
+	struct eeh_dev *edev, *tmp;
 	bool valid_cfg_log = true;
 
 	/*
@@ -251,7 +251,7 @@ void eeh_slot_error_detail(struct eeh_pe *pe, int severity)
 		eeh_pe_restore_bars(pe);
 
 		pci_regs_buf[0] = 0;
-		eeh_pe_for_each_dev(pe, edev) {
+		eeh_pe_for_each_dev(pe, edev, tmp) {
 			loglen += eeh_gather_pci_data(edev, pci_regs_buf + loglen,
 						      EEH_PCI_REGS_LOG_LEN - loglen);
 		}

arch/powerpc/kernel/eeh_pe.c

@@ -176,7 +176,7 @@ void *eeh_pe_dev_traverse(struct eeh_pe *root,
 		eeh_traverse_func fn, void *flag)
 {
 	struct eeh_pe *pe;
-	struct eeh_dev *edev;
+	struct eeh_dev *edev, *tmp;
 	void *ret;
 
 	if (!root) {
@@ -186,7 +186,7 @@ void *eeh_pe_dev_traverse(struct eeh_pe *root,
 
 	/* Traverse root PE */
 	for (pe = root; pe; pe = eeh_pe_next(pe, root)) {
-		eeh_pe_for_each_dev(pe, edev) {
+		eeh_pe_for_each_dev(pe, edev, tmp) {
 			ret = fn(edev, flag);
 			if (ret)
 				return ret;
@@ -501,7 +501,7 @@ static void *__eeh_pe_state_mark(void *data, void *flag)
 {
 	struct eeh_pe *pe = (struct eeh_pe *)data;
 	int state = *((int *)flag);
-	struct eeh_dev *tmp;
+	struct eeh_dev *edev, *tmp;
 	struct pci_dev *pdev;
 
 	/*
@@ -511,8 +511,8 @@ static void *__eeh_pe_state_mark(void *data, void *flag)
 	 * the PCI device driver.
 	 */
 	pe->state |= state;
-	eeh_pe_for_each_dev(pe, tmp) {
-		pdev = eeh_dev_to_pci_dev(tmp);
+	eeh_pe_for_each_dev(pe, edev, tmp) {
+		pdev = eeh_dev_to_pci_dev(edev);
 		if (pdev)
 			pdev->error_state = pci_channel_io_frozen;
 	}