[PATCH] PCI: Reduce nr of ptr derefs in drivers/pci/hotplug/cpqphp_core.c

Here's a small patch to reduce the nr of pointer dereferences in
drivers/pci/hotplug/cpqphp_core.c

Benefits of this patch:
 - micro speed optimization due to fewer pointer derefs
 - generated code is slightly smaller
 - tiny line length and whitespace cleanup
 - better readability

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/pci/hotplug/cpqphp_core.c b/drivers/pci/hotplug/cpqphp_core.c
index 9aed8ef..d364470 100644 (file)
--- a/drivers/pci/hotplug/cpqphp_core.c
+++ b/drivers/pci/hotplug/cpqphp_core.c
@@ -327,7 +327,9 @@ static int ctrl_slot_setup(struct controller *ctrl,
                        void __iomem *smbios_start,
                        void __iomem *smbios_table)
 {
-       struct slot *new_slot;
+       struct slot *slot;
+       struct hotplug_slot *hotplug_slot;
+       struct hotplug_slot_info *hotplug_slot_info;
        u8 number_of_slots;
        u8 slot_device;
        u8 slot_number;
@@ -345,93 +347,105 @@ static int ctrl_slot_setup(struct controller *ctrl,
        slot_number = ctrl->first_slot;
 
        while (number_of_slots) {
-               new_slot = kmalloc(sizeof(*new_slot), GFP_KERNEL);
-               if (!new_slot)
+               slot = kmalloc(sizeof(*slot), GFP_KERNEL);
+               if (!slot)
                        goto error;
 
-               memset(new_slot, 0, sizeof(struct slot));
-               new_slot->hotplug_slot = kmalloc(sizeof(*(new_slot->hotplug_slot)),
+               memset(slot, 0, sizeof(struct slot));
+               slot->hotplug_slot = kmalloc(sizeof(*(slot->hotplug_slot)),
                                                GFP_KERNEL);
-               if (!new_slot->hotplug_slot)
+               if (!slot->hotplug_slot)
                        goto error_slot;
-               memset(new_slot->hotplug_slot, 0, sizeof(struct hotplug_slot));
+               hotplug_slot = slot->hotplug_slot;
+               memset(hotplug_slot, 0, sizeof(struct hotplug_slot));
 
-               new_slot->hotplug_slot->info =
-                               kmalloc(sizeof(*(new_slot->hotplug_slot->info)),
+               hotplug_slot->info =
+                               kmalloc(sizeof(*(hotplug_slot->info)),
                                                        GFP_KERNEL);
-               if (!new_slot->hotplug_slot->info)
+               if (!hotplug_slot->info)
                        goto error_hpslot;
-               memset(new_slot->hotplug_slot->info, 0,
+               hotplug_slot_info = hotplug_slot->info;
+               memset(hotplug_slot_info, 0,
                                sizeof(struct hotplug_slot_info));
-               new_slot->hotplug_slot->name = kmalloc(SLOT_NAME_SIZE, GFP_KERNEL);
-               if (!new_slot->hotplug_slot->name)
+               hotplug_slot->name = kmalloc(SLOT_NAME_SIZE, GFP_KERNEL);
+
+               if (!hotplug_slot->name)
                        goto error_info;
 
-               new_slot->ctrl = ctrl;
-               new_slot->bus = ctrl->bus;
-               new_slot->device = slot_device;
-               new_slot->number = slot_number;
-               dbg("slot->number = %d\n",new_slot->number);
+               slot->ctrl = ctrl;
+               slot->bus = ctrl->bus;
+               slot->device = slot_device;
+               slot->number = slot_number;
+               dbg("slot->number = %d\n", slot->number);
 
                slot_entry = get_SMBIOS_entry(smbios_start, smbios_table, 9,
                                        slot_entry);
 
-               while (slot_entry && (readw(slot_entry + SMBIOS_SLOT_NUMBER) != new_slot->number)) {
+               while (slot_entry && (readw(slot_entry + SMBIOS_SLOT_NUMBER) !=
+                               slot->number)) {
                        slot_entry = get_SMBIOS_entry(smbios_start,
                                                smbios_table, 9, slot_entry);
                }
 
-               new_slot->p_sm_slot = slot_entry;
+               slot->p_sm_slot = slot_entry;
 
-               init_timer(&new_slot->task_event);
-               new_slot->task_event.expires = jiffies + 5 * HZ;
-               new_slot->task_event.function = cpqhp_pushbutton_thread;
+               init_timer(&slot->task_event);
+               slot->task_event.expires = jiffies + 5 * HZ;
+               slot->task_event.function = cpqhp_pushbutton_thread;
 
                //FIXME: these capabilities aren't used but if they are
                //       they need to be correctly implemented
-               new_slot->capabilities |= PCISLOT_REPLACE_SUPPORTED;
-               new_slot->capabilities |= PCISLOT_INTERLOCK_SUPPORTED;
+               slot->capabilities |= PCISLOT_REPLACE_SUPPORTED;
+               slot->capabilities |= PCISLOT_INTERLOCK_SUPPORTED;
 
-               if (is_slot64bit(new_slot))
-                       new_slot->capabilities |= PCISLOT_64_BIT_SUPPORTED;
-               if (is_slot66mhz(new_slot))
-                       new_slot->capabilities |= PCISLOT_66_MHZ_SUPPORTED;
+               if (is_slot64bit(slot))
+                       slot->capabilities |= PCISLOT_64_BIT_SUPPORTED;
+               if (is_slot66mhz(slot))
+                       slot->capabilities |= PCISLOT_66_MHZ_SUPPORTED;
                if (ctrl->speed == PCI_SPEED_66MHz)
-                       new_slot->capabilities |= PCISLOT_66_MHZ_OPERATION;
+                       slot->capabilities |= PCISLOT_66_MHZ_OPERATION;
 
-               ctrl_slot = slot_device - (readb(ctrl->hpc_reg + SLOT_MASK) >> 4);
+               ctrl_slot =
+                       slot_device - (readb(ctrl->hpc_reg + SLOT_MASK) >> 4);
 
                // Check presence
-               new_slot->capabilities |= ((((~tempdword) >> 23) | ((~tempdword) >> 15)) >> ctrl_slot) & 0x02;
+               slot->capabilities |=
+                       ((((~tempdword) >> 23) |
+                        ((~tempdword) >> 15)) >> ctrl_slot) & 0x02;
                // Check the switch state
-               new_slot->capabilities |= ((~tempdword & 0xFF) >> ctrl_slot) & 0x01;
+               slot->capabilities |=
+                       ((~tempdword & 0xFF) >> ctrl_slot) & 0x01;
                // Check the slot enable
-               new_slot->capabilities |= ((read_slot_enable(ctrl) << 2) >> ctrl_slot) & 0x04;
+               slot->capabilities |=
+                       ((read_slot_enable(ctrl) << 2) >> ctrl_slot) & 0x04;
 
                /* register this slot with the hotplug pci core */
-               new_slot->hotplug_slot->release = &release_slot;
-               new_slot->hotplug_slot->private = new_slot;
-               make_slot_name(new_slot->hotplug_slot->name, SLOT_NAME_SIZE, new_slot);
-               new_slot->hotplug_slot->ops = &cpqphp_hotplug_slot_ops;
+               hotplug_slot->release = &release_slot;
+               hotplug_slot->private = slot;
+               make_slot_name(hotplug_slot->name, SLOT_NAME_SIZE, slot);
+               hotplug_slot->ops = &cpqphp_hotplug_slot_ops;
                
-               new_slot->hotplug_slot->info->power_status = get_slot_enabled(ctrl, new_slot);
-               new_slot->hotplug_slot->info->attention_status = cpq_get_attention_status(ctrl, new_slot);
-               new_slot->hotplug_slot->info->latch_status = cpq_get_latch_status(ctrl, new_slot);
-               new_slot->hotplug_slot->info->adapter_status = get_presence_status(ctrl, new_slot);
+               hotplug_slot_info->power_status = get_slot_enabled(ctrl, slot);
+               hotplug_slot_info->attention_status =
+                       cpq_get_attention_status(ctrl, slot);
+               hotplug_slot_info->latch_status =
+                       cpq_get_latch_status(ctrl, slot);
+               hotplug_slot_info->adapter_status =
+                       get_presence_status(ctrl, slot);
                
-               dbg ("registering bus %d, dev %d, number %d, "
+               dbg("registering bus %d, dev %d, number %d, "
                                "ctrl->slot_device_offset %d, slot %d\n",
-                               new_slot->bus, new_slot->device,
-                               new_slot->number, ctrl->slot_device_offset,
+                               slot->bus, slot->device,
+                               slot->number, ctrl->slot_device_offset,
                                slot_number);
-               result = pci_hp_register (new_slot->hotplug_slot);
+               result = pci_hp_register(hotplug_slot);
                if (result) {
-                       err ("pci_hp_register failed with error %d\n", result);
+                       err("pci_hp_register failed with error %d\n", result);
                        goto error_name;
                }
                
-               new_slot->next = ctrl->slot;
-               ctrl->slot = new_slot;
+               slot->next = ctrl->slot;
+               ctrl->slot = slot;
 
                number_of_slots--;
                slot_device++;
@@ -439,15 +453,14 @@ static int ctrl_slot_setup(struct controller *ctrl,
        }
 
        return 0;
-
 error_name:
-       kfree(new_slot->hotplug_slot->name);
+       kfree(hotplug_slot->name);
 error_info:
-       kfree(new_slot->hotplug_slot->info);
+       kfree(hotplug_slot_info);
 error_hpslot:
-       kfree(new_slot->hotplug_slot);
+       kfree(hotplug_slot);
 error_slot:
-       kfree(new_slot);
+       kfree(slot);
 error:
        return result;
 }