PCI: Change memory allocation for acpiphp slots

Change memory allocation for acpiphp slots

Change the "struct slot" that acpiphp uses for managing it's slots to
directly contain the memory for the needed struct hotplug_slot_info and
the slot's name. This way we need only two memory allocations per slot
instead of four.

While we are at it: make_slot_name() is just a wrapper around snprintf()
knowing the right arguments to call it. Since the function makes just one
function call and is only called from one place I inlined it by hand.

Finally this fixes a possible bug waiting for someone to hit it. There were
two unused local variables in acpiphp_register_hotplug_slot(). gcc did not
find them because they were used in memory allocations with sizeof(*var).
They had the same types as the target of the allocation, but nevertheless
this was just weird.
Signed-off-by: NRolf Eike Beer <eike-hotplug@sf-tec.de>
Acked-by: NMatthew Wilcox <matthew@wil.cx>
Signed-off-by: NKristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/pci/hotplug/acpiphp.h

@@ -62,10 +62,10 @@ struct acpiphp_slot;
 struct slot {
 	struct hotplug_slot	*hotplug_slot;
 	struct acpiphp_slot	*acpi_slot;
+	struct hotplug_slot_info info;
+	char name[SLOT_NAME_SIZE];
 };
 
-
-
 /**
  * struct acpiphp_bridge - PCI bridge information
  *

drivers/pci/hotplug/acpiphp_core.c

@@ -312,18 +312,6 @@ static int __init init_acpi(void)
 	return retval;
 }
 
-
-/**
- * make_slot_name - make a slot name that appears in pcihpfs
- * @slot: slot to name
- *
- */
-static void make_slot_name(struct slot *slot)
-{
-	snprintf(slot->hotplug_slot->name, SLOT_NAME_SIZE, "%u",
-		 slot->acpi_slot->sun);
-}
-
 /**
  * release_slot - free up the memory used by a slot
  * @hotplug_slot: slot to free
@@ -334,8 +322,6 @@ static void release_slot(struct hotplug_slot *hotplug_slot)
 
 	dbg("%s - physical_slot = %s\n", __FUNCTION__, hotplug_slot->name);
 
-	kfree(slot->hotplug_slot->info);
-	kfree(slot->hotplug_slot->name);
 	kfree(slot->hotplug_slot);
 	kfree(slot);
 }
@@ -344,26 +330,19 @@ static void release_slot(struct hotplug_slot *hotplug_slot)
 int acpiphp_register_hotplug_slot(struct acpiphp_slot *acpiphp_slot)
 {
 	struct slot *slot;
-	struct hotplug_slot *hotplug_slot;
-	struct hotplug_slot_info *hotplug_slot_info;
 	int retval = -ENOMEM;
 
 	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
 	if (!slot)
 		goto error;
 
-	slot->hotplug_slot = kzalloc(sizeof(*hotplug_slot), GFP_KERNEL);
+	slot->hotplug_slot = kzalloc(sizeof(*slot->hotplug_slot), GFP_KERNEL);
 	if (!slot->hotplug_slot)
 		goto error_slot;
 
-	slot->hotplug_slot->info = kzalloc(sizeof(*hotplug_slot_info),
-					   GFP_KERNEL);
-	if (!slot->hotplug_slot->info)
-		goto error_hpslot;
+	slot->hotplug_slot->info = &slot->info;
 
-	slot->hotplug_slot->name = kzalloc(SLOT_NAME_SIZE, GFP_KERNEL);
-	if (!slot->hotplug_slot->name)
-		goto error_info;
+	slot->hotplug_slot->name = slot->name;
 
 	slot->hotplug_slot->private = slot;
 	slot->hotplug_slot->release = &release_slot;
@@ -378,21 +357,17 @@ int acpiphp_register_hotplug_slot(struct acpiphp_slot *acpiphp_slot)
 	slot->hotplug_slot->info->cur_bus_speed = PCI_SPEED_UNKNOWN;
 
 	acpiphp_slot->slot = slot;
-	make_slot_name(slot);
+	snprintf(slot->name, sizeof(slot->name), "%u", slot->acpi_slot->sun);
 
 	retval = pci_hp_register(slot->hotplug_slot);
 	if (retval) {
 		err("pci_hp_register failed with error %d\n", retval);
-		goto error_name;
+		goto error_hpslot;
  	}
 
 	info("Slot [%s] registered\n", slot->hotplug_slot->name);
 
 	return 0;
-error_name:
-	kfree(slot->hotplug_slot->name);
-error_info:
-	kfree(slot->hotplug_slot->info);
 error_hpslot:
 	kfree(slot->hotplug_slot);
 error_slot: