Commit 149ba66a authored by Gavin Shan's avatar Gavin Shan Committed by Michael Ellerman
Browse files

drivers/pci/hotplug: Remove likely() and unlikely() in powernv driver 



This removes likely() and unlikely() in pnv_php.c as the code isn't
running in hot path. Those macros to affect CPU's branch stream don't
help a lot for performance. I used them to identify the cases are
likely or unlikely to happen. No logical changes introduced.

Signed-off-by: default avatarGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 313483dd

drivers/pci/hotplug/pnv_php.c

+28 −28
Original line number Diff line number Diff line
@@ -122,7 +122,7 @@ static void pnv_php_detach_device_nodes(struct device_node *parent) 


		of_node_put(dn);

		refcount = atomic_read(&dn->kobj.kref.refcount);

		if (unlikely(refcount != 1))

		if (refcount != 1)

			pr_warn("Invalid refcount %d on <%s>\n",

				refcount, of_node_full_name(dn));
@@ -184,11 +184,11 @@ static int pnv_php_populate_changeset(struct of_changeset *ocs, 


	for_each_child_of_node(dn, child) {

		ret = of_changeset_attach_node(ocs, child);

		if (unlikely(ret))

		if (ret)

			break;



		ret = pnv_php_populate_changeset(ocs, child);

		if (unlikely(ret))

		if (ret)

			break;

	}
@@ -201,7 +201,7 @@ static void *pnv_php_add_one_pdn(struct device_node *dn, void *data) 
	struct pci_dn *pdn;



	pdn = pci_add_device_node_info(hose, dn);

	if (unlikely(!pdn))

	if (!pdn)

		return ERR_PTR(-ENOMEM);



	return NULL;
@@ -224,21 +224,21 @@ static int pnv_php_add_devtree(struct pnv_php_slot *php_slot) 
	 * fits the real size.

	 */

	fdt1 = kzalloc(0x10000, GFP_KERNEL);

	if (unlikely(!fdt1)) {

	if (!fdt1) {

		ret = -ENOMEM;

		dev_warn(&php_slot->pdev->dev, "Cannot alloc FDT blob\n");

		goto out;

	}



	ret = pnv_pci_get_device_tree(php_slot->dn->phandle, fdt1, 0x10000);

	if (unlikely(ret)) {

	if (ret) {

		dev_warn(&php_slot->pdev->dev, "Error %d getting FDT blob\n",

			 ret);

		goto free_fdt1;

	}



	fdt = kzalloc(fdt_totalsize(fdt1), GFP_KERNEL);

	if (unlikely(!fdt)) {

	if (!fdt) {

		ret = -ENOMEM;

		dev_warn(&php_slot->pdev->dev, "Cannot %d bytes memory\n",

			 fdt_totalsize(fdt1));
@@ -248,7 +248,7 @@ static int pnv_php_add_devtree(struct pnv_php_slot *php_slot) 
	/* Unflatten device tree blob */

	memcpy(fdt, fdt1, fdt_totalsize(fdt1));

	dt = of_fdt_unflatten_tree(fdt, php_slot->dn, NULL);

	if (unlikely(!dt)) {

	if (!dt) {

		ret = -EINVAL;

		dev_warn(&php_slot->pdev->dev, "Cannot unflatten FDT\n");

		goto free_fdt;
@@ -258,7 +258,7 @@ static int pnv_php_add_devtree(struct pnv_php_slot *php_slot) 
	of_changeset_init(&php_slot->ocs);

	pnv_php_reverse_nodes(php_slot->dn);

	ret = pnv_php_populate_changeset(&php_slot->ocs, php_slot->dn);

	if (unlikely(ret)) {

	if (ret) {

		pnv_php_reverse_nodes(php_slot->dn);

		dev_warn(&php_slot->pdev->dev, "Error %d populating changeset\n",

			 ret);
@@ -267,7 +267,7 @@ static int pnv_php_add_devtree(struct pnv_php_slot *php_slot) 


	php_slot->dn->child = NULL;

	ret = of_changeset_apply(&php_slot->ocs);

	if (unlikely(ret)) {

	if (ret) {

		dev_warn(&php_slot->pdev->dev, "Error %d applying changeset\n",

			 ret);

		goto destroy_changeset;
@@ -301,7 +301,7 @@ int pnv_php_set_slot_power_state(struct hotplug_slot *slot, 
	int ret;



	ret = pnv_pci_set_power_state(php_slot->id, state, &msg);

	if (likely(ret > 0)) {

	if (ret > 0) {

		if (be64_to_cpu(msg.params[1]) != php_slot->dn->phandle	||

		    be64_to_cpu(msg.params[2]) != state			||

		    be64_to_cpu(msg.params[3]) != OPAL_SUCCESS) {
@@ -311,7 +311,7 @@ int pnv_php_set_slot_power_state(struct hotplug_slot *slot, 
				 be64_to_cpu(msg.params[3]));

			return -ENOMSG;

		}

	} else if (unlikely(ret < 0)) {

	} else if (ret < 0) {

		dev_warn(&php_slot->pdev->dev, "Error %d powering %s\n",

			 ret, (state == OPAL_PCI_SLOT_POWER_ON) ? "on" : "off");

		return ret;
@@ -338,7 +338,7 @@ static int pnv_php_get_power_state(struct hotplug_slot *slot, u8 *state) 
	 * be on.

	 */

	ret = pnv_pci_get_power_state(php_slot->id, &power_state);

	if (unlikely(ret)) {

	if (ret) {

		dev_warn(&php_slot->pdev->dev, "Error %d getting power status\n",

			 ret);

	} else {
@@ -360,7 +360,7 @@ static int pnv_php_get_adapter_state(struct hotplug_slot *slot, u8 *state) 
	 * get that, it will fail back to be empty.

	 */

	ret = pnv_pci_get_presence_state(php_slot->id, &presence);

	if (likely(ret >= 0)) {

	if (ret >= 0) {

		*state = presence;

		slot->info->adapter_status = presence;

		ret = 0;
@@ -393,7 +393,7 @@ static int pnv_php_enable(struct pnv_php_slot *php_slot, bool rescan) 


	/* Retrieve slot presence status */

	ret = pnv_php_get_adapter_state(slot, &presence);

	if (unlikely(ret))

	if (ret)

		return ret;



	/* Proceed if there have nothing behind the slot */
@@ -414,7 +414,7 @@ static int pnv_php_enable(struct pnv_php_slot *php_slot, bool rescan) 
		php_slot->power_state_check = true;



		ret = pnv_php_get_power_state(slot, &power_status);

		if (unlikely(ret))

		if (ret)

			return ret;



		if (power_status != OPAL_PCI_SLOT_POWER_ON)
@@ -423,7 +423,7 @@ static int pnv_php_enable(struct pnv_php_slot *php_slot, bool rescan) 


	/* Check the power status. Scan the slot if it is already on */

	ret = pnv_php_get_power_state(slot, &power_status);

	if (unlikely(ret))

	if (ret)

		return ret;



	if (power_status == OPAL_PCI_SLOT_POWER_ON)
@@ -431,7 +431,7 @@ static int pnv_php_enable(struct pnv_php_slot *php_slot, bool rescan) 


	/* Power is off, turn it on and then scan the slot */

	ret = pnv_php_set_slot_power_state(slot, OPAL_PCI_SLOT_POWER_ON);

	if (unlikely(ret))

	if (ret)

		return ret;



scan:
@@ -515,27 +515,27 @@ static struct pnv_php_slot *pnv_php_alloc_slot(struct device_node *dn) 
	uint64_t id;



	label = of_get_property(dn, "ibm,slot-label", NULL);

	if (unlikely(!label))

	if (!label)

		return NULL;



	if (pnv_pci_get_slot_id(dn, &id))

		return NULL;



	bus = pci_find_bus_by_node(dn);

	if (unlikely(!bus))

	if (!bus)

		return NULL;



	php_slot = kzalloc(sizeof(*php_slot), GFP_KERNEL);

	if (unlikely(!php_slot))

	if (!php_slot)

		return NULL;



	php_slot->name = kstrdup(label, GFP_KERNEL);

	if (unlikely(!php_slot->name)) {

	if (!php_slot->name) {

		kfree(php_slot);

		return NULL;

	}



	if (likely(dn->child && PCI_DN(dn->child)))

	if (dn->child && PCI_DN(dn->child))

		php_slot->slot_no = PCI_SLOT(PCI_DN(dn->child)->devfn);

	else

		php_slot->slot_no = -1;   /* Placeholder slot */
@@ -567,7 +567,7 @@ static int pnv_php_register_slot(struct pnv_php_slot *php_slot) 


	/* Check if the slot is registered or not */

	parent = pnv_php_find_slot(php_slot->dn);

	if (unlikely(parent)) {

	if (parent) {

		pnv_php_put_slot(parent);

		return -EEXIST;

	}
@@ -575,7 +575,7 @@ static int pnv_php_register_slot(struct pnv_php_slot *php_slot) 
	/* Register PCI slot */

	ret = pci_hp_register(&php_slot->slot, php_slot->bus,

			      php_slot->slot_no, php_slot->name);

	if (unlikely(ret)) {

	if (ret) {

		dev_warn(&php_slot->pdev->dev, "Error %d registering slot\n",

			 ret);

		return ret;
@@ -625,15 +625,15 @@ static int pnv_php_register_one(struct device_node *dn) 
		return -ENXIO;



	php_slot = pnv_php_alloc_slot(dn);

	if (unlikely(!php_slot))

	if (!php_slot)

		return -ENODEV;



	ret = pnv_php_register_slot(php_slot);

	if (unlikely(ret))

	if (ret)

		goto free_slot;



	ret = pnv_php_enable(php_slot, false);

	if (unlikely(ret))

	if (ret)

		goto unregister_slot;



	return 0;

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