[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>

1 files changed, 67 insertions, 54 deletions

diff --git a/drivers/pci/hotplug/cpqphp_core.c b/drivers/pci/hotplug/cpqphp_core.c
index 9aed8efe6a11..d3644709a035 100644
--- 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;
 }