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drivers/pci/hotplug: Remove likely() and unlikely() in powernv driver
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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: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Gavin Shan authored and Michael Ellerman committed Sep 29, 2016
1 parent 313483d commit 149ba66
Showing 1 changed file with 28 additions and 28 deletions.
56 changes: 28 additions & 28 deletions drivers/pci/hotplug/pnv_php.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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));

Expand Down Expand Up @@ -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;
}

Expand All @@ -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;
Expand All @@ -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));
Expand All @@ -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;
Expand All @@ -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);
Expand All @@ -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;
Expand Down Expand Up @@ -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) {
Expand All @@ -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;
Expand All @@ -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 {
Expand All @@ -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;
Expand Down Expand Up @@ -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 */
Expand All @@ -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)
Expand All @@ -423,15 +423,15 @@ 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)
goto scan;

/* 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:
Expand Down Expand Up @@ -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 */
Expand Down Expand Up @@ -567,15 +567,15 @@ 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;
}

/* 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;
Expand Down Expand Up @@ -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;
Expand Down

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