[PATCH] PCI Hotplug: acpiphp: clean up list traversals

From: Alex Chiang
Date: Mon Oct 26 2009 - 23:25:34 EST


Using list_for_each_entry instead of list_for_each allows us to
enhance readability and minorly reduce some stack usage.

Signed-off-by: Alex Chiang <achiang@xxxxxx>
---
This is 2.6.33 material, thanks.

acpiphp_glue.c | 58 ++++++++++++++++-----------------------------------------
1 file changed, 17 insertions(+), 41 deletions(-)

---
diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index 58d25a1..f2c49b9 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -311,17 +311,13 @@ static void init_bridge_misc(struct acpiphp_bridge *bridge)
/* find acpiphp_func from acpiphp_bridge */
static struct acpiphp_func *acpiphp_bridge_handle_to_function(acpi_handle handle)
{
- struct list_head *node, *l;
struct acpiphp_bridge *bridge;
struct acpiphp_slot *slot;
struct acpiphp_func *func;

- list_for_each(node, &bridge_list) {
- bridge = list_entry(node, struct acpiphp_bridge, list);
+ list_for_each_entry(bridge, &bridge_list, list) {
for (slot = bridge->slots; slot; slot = slot->next) {
- list_for_each(l, &slot->funcs) {
- func = list_entry(l, struct acpiphp_func,
- sibling);
+ list_for_each_entry(func, &slot->funcs, sibling) {
if (func->handle == handle)
return func;
}
@@ -495,21 +491,19 @@ static int add_bridge(acpi_handle handle)

static struct acpiphp_bridge *acpiphp_handle_to_bridge(acpi_handle handle)
{
- struct list_head *head;
- list_for_each(head, &bridge_list) {
- struct acpiphp_bridge *bridge = list_entry(head,
- struct acpiphp_bridge, list);
+ struct acpiphp_bridge *bridge;
+
+ list_for_each_entry(bridge, &bridge_list, list)
if (bridge->handle == handle)
return bridge;
- }

return NULL;
}

static void cleanup_bridge(struct acpiphp_bridge *bridge)
{
- struct list_head *list, *tmp;
- struct acpiphp_slot *slot;
+ struct acpiphp_slot *slot, *next;
+ struct acpiphp_func *func, *tmp;
acpi_status status;
acpi_handle handle = bridge->handle;

@@ -530,10 +524,8 @@ static void cleanup_bridge(struct acpiphp_bridge *bridge)

slot = bridge->slots;
while (slot) {
- struct acpiphp_slot *next = slot->next;
- list_for_each_safe (list, tmp, &slot->funcs) {
- struct acpiphp_func *func;
- func = list_entry(list, struct acpiphp_func, sibling);
+ next = slot->next;
+ list_for_each_entry_safe(func, tmp, &slot->funcs, sibling) {
if (is_dock_device(func->handle)) {
unregister_hotplug_dock_device(func->handle);
unregister_dock_notifier(&func->nb);
@@ -545,7 +537,7 @@ static void cleanup_bridge(struct acpiphp_bridge *bridge)
if (ACPI_FAILURE(status))
err("failed to remove notify handler\n");
}
- list_del(list);
+ list_del(&func->sibling);
kfree(func);
}
acpiphp_unregister_hotplug_slot(slot);
@@ -794,16 +786,13 @@ static int power_on_slot(struct acpiphp_slot *slot)
{
acpi_status status;
struct acpiphp_func *func;
- struct list_head *l;
int retval = 0;

/* if already enabled, just skip */
if (slot->flags & SLOT_POWEREDON)
goto err_exit;

- list_for_each (l, &slot->funcs) {
- func = list_entry(l, struct acpiphp_func, sibling);
-
+ list_for_each_entry(func, &slot->funcs, sibling) {
if (func->flags & FUNC_HAS_PS0) {
dbg("%s: executing _PS0\n", __func__);
status = acpi_evaluate_object(func->handle, "_PS0", NULL, NULL);
@@ -829,7 +818,6 @@ static int power_off_slot(struct acpiphp_slot *slot)
{
acpi_status status;
struct acpiphp_func *func;
- struct list_head *l;

int retval = 0;

@@ -837,9 +825,7 @@ static int power_off_slot(struct acpiphp_slot *slot)
if ((slot->flags & SLOT_POWEREDON) == 0)
goto err_exit;

- list_for_each (l, &slot->funcs) {
- func = list_entry(l, struct acpiphp_func, sibling);
-
+ list_for_each_entry(func, &slot->funcs, sibling) {
if (func->flags & FUNC_HAS_PS3) {
status = acpi_evaluate_object(func->handle, "_PS3", NULL, NULL);
if (ACPI_FAILURE(status)) {
@@ -966,7 +952,6 @@ static int __ref enable_device(struct acpiphp_slot *slot)
{
struct pci_dev *dev;
struct pci_bus *bus = slot->bridge->pci_bus;
- struct list_head *l;
struct acpiphp_func *func;
int retval = 0;
int num, max, pass;
@@ -1006,10 +991,8 @@ static int __ref enable_device(struct acpiphp_slot *slot)
}
}

- list_for_each (l, &slot->funcs) {
- func = list_entry(l, struct acpiphp_func, sibling);
+ list_for_each_entry(func, &slot->funcs, sibling)
acpiphp_bus_add(func);
- }

pci_bus_assign_resources(bus);
acpiphp_sanitize_bus(bus);
@@ -1019,8 +1002,7 @@ static int __ref enable_device(struct acpiphp_slot *slot)
pci_enable_bridges(bus);
pci_bus_add_devices(bus);

- list_for_each (l, &slot->funcs) {
- func = list_entry(l, struct acpiphp_func, sibling);
+ list_for_each_entry(func, &slot->funcs, sibling) {
dev = pci_get_slot(bus, PCI_DEVFN(slot->device,
func->function));
if (!dev)
@@ -1119,12 +1101,9 @@ static unsigned int get_slot_status(struct acpiphp_slot *slot)
acpi_status status;
unsigned long long sta = 0;
u32 dvid;
- struct list_head *l;
struct acpiphp_func *func;

- list_for_each (l, &slot->funcs) {
- func = list_entry(l, struct acpiphp_func, sibling);
-
+ list_for_each_entry(func, &slot->funcs, sibling) {
if (func->flags & FUNC_HAS_STA) {
status = acpi_evaluate_integer(func->handle, "_STA", NULL, &sta);
if (ACPI_SUCCESS(status) && sta)
@@ -1152,13 +1131,10 @@ int acpiphp_eject_slot(struct acpiphp_slot *slot)
{
acpi_status status;
struct acpiphp_func *func;
- struct list_head *l;
struct acpi_object_list arg_list;
union acpi_object arg;

- list_for_each (l, &slot->funcs) {
- func = list_entry(l, struct acpiphp_func, sibling);
-
+ list_for_each_entry(func, &slot->funcs, sibling) {
/* We don't want to call _EJ0 on non-existing functions. */
if ((func->flags & FUNC_HAS_EJ0)) {
/* _EJ0 method take one argument */
@@ -1542,7 +1518,7 @@ int __init acpiphp_get_num_slots(void)
struct acpiphp_bridge *bridge;
int num_slots = 0;

- list_for_each_entry (bridge, &bridge_list, list) {
+ list_for_each_entry(bridge, &bridge_list, list) {
dbg("Bus %04x:%02x has %d slot%s\n",
pci_domain_nr(bridge->pci_bus),
bridge->pci_bus->number, bridge->nr_slots,
--
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