Mar 13 2015

Staging: ft1000: Iterate list using list_for_each_entry 

Author: Somya Anand <somyaanand214@gmail.com>

Code using doubly linked list is iterated generally  using list_empty and
list_entry functions, but it can be better written using list_for_each_entry
macro.

This patch replaces the while loop containing list_empty and list_entry with
list_for_each_entry and list_for_each_entry_safe. list_for_each_entry is a
macro which is used to iterate over a list of given type. So while loop used to
iterate over a list can be replaced with list_for_each_entry macro. However, if
list_del is used in the loop, then list_for_each_entry_safe is a better choice.
This transformation is done by using the following coccinelle script.

@ rule1 @
expression E1;
identifier I1, I2;
type T;
iterator name list_for_each_entry;
@@

- while (list_empty(&E1) == 0)
+ list_for_each_entry (I1, &E1, I2)
 {
	...when != T *I1;
- 	I1 = list_entry(E1.next, T, I2);
    ...when != list_del(...);
       when != list_del_init(...);
 }

@ rule2  @
expression E1;
identifier I1, I2;
type T;
iterator name list_for_each_entry_safe;
@@
   T *I1;
+  T *tmp;
  ...
- while (list_empty(&E1) == 0)
+ list_for_each_entry_safe (I1, tmp, &E1, I2)
 {
	...when != T *I1;
- 	I1 = list_entry(E1.next, T, I2);
    ...
 }

Signed-off-by: Somya Anand 
Signed-off-by: Greg Kroah-Hartman 

---
 drivers/staging/ft1000/ft1000-pcmcia/ft1000_hw.c | 8 ++++----
 drivers/staging/ft1000/ft1000-usb/ft1000_debug.c | 4 ++--
 drivers/staging/ft1000/ft1000-usb/ft1000_hw.c    | 5 ++---
 3 files changed, 8 insertions(+), 9 deletions(-)
 
diff --git a/drivers/staging/ft1000/ft1000-pcmcia/ft1000_hw.c b/drivers/staging/ft1000/ft1000-pcmcia/ft1000_hw.c
index e4559ca..e5890db 100644
--- a/drivers/staging/ft1000/ft1000-pcmcia/ft1000_hw.c
+++ b/drivers/staging/ft1000/ft1000-pcmcia/ft1000_hw.c
@@ -364,6 +364,7 @@ static int ft1000_reset_card(struct net_device *dev)
 	int i;
 	unsigned long flags;
 	struct prov_record *ptr;
+	struct prov_record *tmp;
 
 	info->CardReady = 0;
 	info->ProgConStat = 0;
@@ -373,9 +374,8 @@ static int ft1000_reset_card(struct net_device *dev)
 	/* del_timer(&poll_timer); */
 
 	/* Make sure we free any memory reserve for provisioning */
-	while (list_empty(&info->prov_list) == 0) {
+	list_for_each_entry_safe(ptr, tmp, &info->prov_list, list) {
 		pr_debug("deleting provisioning record\n");
-		ptr = list_entry(info->prov_list.next, struct prov_record, list);
 		list_del(&ptr->list);
 		kfree(ptr->pprov_data);
 		kfree(ptr);
@@ -1973,6 +1973,7 @@ void stop_ft1000_card(struct net_device *dev)
 {
 	struct ft1000_info *info = netdev_priv(dev);
 	struct prov_record *ptr;
+	struct prov_record *tmp;
 	/* int cnt; */
 
 	info->CardReady = 0;
@@ -1981,8 +1982,7 @@ void stop_ft1000_card(struct net_device *dev)
 	ft1000_disable_interrupts(dev);
 
 	/* Make sure we free any memory reserve for provisioning */
-	while (list_empty(&info->prov_list) == 0) {
-		ptr = list_entry(info->prov_list.next, struct prov_record, list);
+	list_for_each_entry_safe(ptr, tmp, &info->prov_list, list) {
 		list_del(&ptr->list);
 		kfree(ptr->pprov_data);
 		kfree(ptr);
diff --git a/drivers/staging/ft1000/ft1000-usb/ft1000_debug.c b/drivers/staging/ft1000/ft1000-usb/ft1000_debug.c
index 7138523..b427825 100644
--- a/drivers/staging/ft1000/ft1000-usb/ft1000_debug.c
+++ b/drivers/staging/ft1000/ft1000-usb/ft1000_debug.c
@@ -742,6 +742,7 @@ static int ft1000_release(struct inode *inode, struct file *file)
 	struct ft1000_usb *ft1000dev;
 	int i;
 	struct dpram_blk *pdpram_blk;
+	struct dpram_blk *tmp;
 
 	dev = file->private_data;
 	info = netdev_priv(dev);
@@ -763,9 +764,8 @@ static int ft1000_release(struct inode *inode, struct file *file)
 	if (i == MAX_NUM_APP)
 		return 0;
 
-	while (list_empty(&ft1000dev->app_info[i].app_sqlist) == 0) {
+	list_for_each_entry_safe(pdpram_blk, tmp, &ft1000dev->app_info[i].app_sqlist, list) {
 		pr_debug("Remove and free memory queue up on slow queue\n");
-		pdpram_blk = list_entry(ft1000dev->app_info[i].app_sqlist.next, struct dpram_blk, list);
 		list_del(&pdpram_blk->list);
 		ft1000_free_buffer(pdpram_blk, &freercvpool);
 	}
diff --git a/drivers/staging/ft1000/ft1000-usb/ft1000_hw.c b/drivers/staging/ft1000/ft1000-usb/ft1000_hw.c
index 2620778..e6fb066 100644
--- a/drivers/staging/ft1000/ft1000-usb/ft1000_hw.c
+++ b/drivers/staging/ft1000/ft1000-usb/ft1000_hw.c
@@ -451,16 +451,15 @@ static int ft1000_reset_card(struct net_device *dev)
 	struct ft1000_usb *ft1000dev = info->priv;
 	u16 tempword;
 	struct prov_record *ptr;
+	struct prov_record *tmp;
 
 	ft1000dev->fCondResetPend = true;
 	info->CardReady = 0;
 	ft1000dev->fProvComplete = false;
 
 	/* Make sure we free any memory reserve for provisioning */
-	while (list_empty(&info->prov_list) == 0) {
+	list_for_each_entry_safe(ptr, tmp, &info->prov_list, list) {
 		pr_debug("deleting provisioning record\n");
-		ptr =
-			list_entry(info->prov_list.next, struct prov_record, list);
 		list_del(&ptr->list);
 		kfree(ptr->pprov_data);
 		kfree(ptr);

qlambert