[PATCH] PCI Hotplug: Convert error paths in ibmphp to use goto

This patch converts the error paths in several functions in ibmphp to use
goto to the end of the function to kill code duplication.

It also kills some memsets of pointer members of a struct where the struct
itself is freed directly after.

This one has 2 modification from the first version: the if is back as
discussed and one extra long line (>> 150 chars) is wrapped now.

drivers/pci/hotplug/ibmphp_ebda.c

@@ -89,36 +89,34 @@ static struct controller *alloc_ebda_hpc (u32 slot_count, u32 bus_count)
 
 	controller = kmalloc (sizeof (struct controller), GFP_KERNEL);
 	if (!controller)
-		return NULL;
+		goto error;
 	memset (controller, 0, sizeof (*controller));
 
 	slots = kmalloc (sizeof (struct ebda_hpc_slot) * slot_count, GFP_KERNEL);
-	if (!slots) {
-		kfree (controller);
-		return NULL;
-	}
+	if (!slots)
+		goto error_contr;
 	memset (slots, 0, sizeof (*slots) * slot_count);
 	controller->slots = slots;
 
 	buses = kmalloc (sizeof (struct ebda_hpc_bus) * bus_count, GFP_KERNEL);
-	if (!buses) {
-		kfree (controller->slots);
-		kfree (controller);
-		return NULL;
-	}
+	if (!buses)
+		goto error_slots;
 	memset (buses, 0, sizeof (*buses) * bus_count);
 	controller->buses = buses;
 
 	return controller;
+error_slots:
+	kfree(controller->slots);
+error_contr:
+	kfree(controller);
+error:
+	return NULL;
 }
 
 static void free_ebda_hpc (struct controller *controller)
 {
 	kfree (controller->slots);
-	controller->slots = NULL;
 	kfree (controller->buses);
-	controller->buses = NULL;
-	controller->ctrl_dev = NULL;
 	kfree (controller);
 }
 
@@ -286,7 +284,8 @@ static void __init print_ebda_hpc (void)
 int __init ibmphp_access_ebda (void)
 {
 	u8 format, num_ctlrs, rio_complete, hs_complete;
-	u16 ebda_seg, num_entries, next_offset, offset, blk_id, sub_addr, rc, re, rc_id, re_id, base;
+	u16 ebda_seg, num_entries, next_offset, offset, blk_id, sub_addr, re, rc_id, re_id, base;
+	int rc = 0;
 
 
 	rio_complete = 0;
@@ -324,10 +323,8 @@ int __init ibmphp_access_ebda (void)
 			format = readb (io_mem + offset);
 
 			offset += 1;
-			if (format != 4) {
-				iounmap (io_mem);
-				return -ENODEV;
-			}
+			if (format != 4)
+				goto error_nodev;
 			debug ("hot blk format: %x\n", format);
 			/* hot swap sub blk */
 			base = offset;
@@ -339,18 +336,16 @@ int __init ibmphp_access_ebda (void)
 			rc_id = readw (io_mem + sub_addr); 	/* sub blk id */
 
 			sub_addr += 2;
-			if (rc_id != 0x5243) {
-				iounmap (io_mem);
-				return -ENODEV;
-			}
+			if (rc_id != 0x5243)
+				goto error_nodev;
 			/* rc sub blk signature  */
 			num_ctlrs = readb (io_mem + sub_addr);
 
 			sub_addr += 1;
 			hpc_list_ptr = alloc_ebda_hpc_list ();
 			if (!hpc_list_ptr) {
-				iounmap (io_mem);
-				return -ENOMEM;
+				rc = -ENOMEM;
+				goto out;
 			}
 			hpc_list_ptr->format = format;
 			hpc_list_ptr->num_ctlrs = num_ctlrs;
@@ -361,16 +356,15 @@ int __init ibmphp_access_ebda (void)
 			debug ("offset of hpc data structure enteries: %x\n ", sub_addr);
 
 			sub_addr = base + re;	/* re sub blk */
+			/* FIXME: rc is never used/checked */
 			rc = readw (io_mem + sub_addr);	/* next sub blk */
 
 			sub_addr += 2;
 			re_id = readw (io_mem + sub_addr);	/* sub blk id */
 
 			sub_addr += 2;
-			if (re_id != 0x5245) {
-				iounmap (io_mem);
-				return -ENODEV;
-			}
+			if (re_id != 0x5245)
+				goto error_nodev;
 
 			/* signature of re */
 			num_entries = readw (io_mem + sub_addr);
@@ -378,8 +372,8 @@ int __init ibmphp_access_ebda (void)
 			sub_addr += 2;	/* offset of RSRC_ENTRIES blk */
 			rsrc_list_ptr = alloc_ebda_rsrc_list ();
 			if (!rsrc_list_ptr ) {
-				iounmap (io_mem);
-				return -ENOMEM;
+				rc = -ENOMEM;
+				goto out;
 			}
 			rsrc_list_ptr->format = format;
 			rsrc_list_ptr->num_entries = num_entries;
@@ -391,9 +385,8 @@ int __init ibmphp_access_ebda (void)
 			debug ("offset of rsrc data structure enteries: %x\n ", sub_addr);
 
 			hs_complete = 1;
-		}
-		/* found rio table */
-		else if (blk_id == 0x4752) {
+		} else {
+		/* found rio table, blk_id == 0x4752 */
 			debug ("now enter io table ---\n");
 			debug ("rio blk id: %x\n", blk_id);
 
@@ -406,41 +399,36 @@ int __init ibmphp_access_ebda (void)
 			rio_table_ptr->riodev_count = readb (io_mem + offset + 2);
 			rio_table_ptr->offset = offset +3 ;
 			
-			debug ("info about rio table hdr ---\n");
-			debug ("ver_num: %x\nscal_count: %x\nriodev_count: %x\noffset of rio table: %x\n ", rio_table_ptr->ver_num, rio_table_ptr->scal_count, rio_table_ptr->riodev_count, rio_table_ptr->offset);
+			debug("info about rio table hdr ---\n");
+			debug("ver_num: %x\nscal_count: %x\nriodev_count: %x\noffset of rio table: %x\n ",
+				rio_table_ptr->ver_num, rio_table_ptr->scal_count,
+				rio_table_ptr->riodev_count, rio_table_ptr->offset);
 
 			rio_complete = 1;
 		}
 	}
 
-	if (!hs_complete && !rio_complete) {
-		iounmap (io_mem);
-		return -ENODEV;
-	}
+	if (!hs_complete && !rio_complete)
+		goto error_nodev;
 
 	if (rio_table_ptr) {
-		if (rio_complete == 1 && rio_table_ptr->ver_num == 3) {
+		if (rio_complete && rio_table_ptr->ver_num == 3) {
 			rc = ebda_rio_table ();
-			if (rc) {
-				iounmap (io_mem);
-				return rc;
-			}
+			if (rc)
+				goto out;
 		}
 	}
 	rc = ebda_rsrc_controller ();
-	if (rc) {
-		iounmap (io_mem);
-		return rc;
-	}
+	if (rc)
+		goto out;
 
 	rc = ebda_rsrc_rsrc ();
-	if (rc) {
-		iounmap (io_mem);
-		return rc;
-	}
-
+	goto out;
+error_nodev:
+	rc = -ENODEV;
+out:
 	iounmap (io_mem);
-	return 0;
+	return rc;
 }
 
 /*