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ACPI: Optimize acpi_get_pci_rootbridge_handle() to boot faster

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Move acpi_get_pci_rootbridge_handle() from glue.c to pci_root.c and get the
root bridge ACPI handles by searching the &acpi_pci_roots list instead of
walking through the ACPI name space.  This significantly reduces boot time
on large I/O systems.

Signed-off-by: Justin Chen <justin.chen@hp.com>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Justin Chen 2006-12-06 10:17:10 -07:00 committed by Len Brown
parent a8b3485287
commit d91a007847
2 changed files with 13 additions and 123 deletions
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123
drivers/acpi/glue.c
View File

@ -86,129 +86,6 @@ static int acpi_find_bridge_device(struct device *dev, acpi_handle * handle)
return ret;
}
/* Get PCI root bridge's handle from its segment and bus number */
struct acpi_find_pci_root {
unsigned int seg;
unsigned int bus;
acpi_handle handle;
};
static acpi_status
do_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
{
unsigned long *busnr = data;
struct acpi_resource_address64 address;
if (resource->type != ACPI_RESOURCE_TYPE_ADDRESS16 &&
resource->type != ACPI_RESOURCE_TYPE_ADDRESS32 &&
resource->type != ACPI_RESOURCE_TYPE_ADDRESS64)
return AE_OK;
acpi_resource_to_address64(resource, &address);
if ((address.address_length > 0) &&
(address.resource_type == ACPI_BUS_NUMBER_RANGE))
*busnr = address.minimum;
return AE_OK;
}
static int get_root_bridge_busnr(acpi_handle handle)
{
acpi_status status;
unsigned long bus, bbn;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
status = acpi_evaluate_integer(handle, METHOD_NAME__BBN, NULL,
&bbn);
if (status == AE_NOT_FOUND) {
/* Assume bus = 0 */
printk(KERN_INFO PREFIX
"Assume root bridge [%s] bus is 0\n",
(char *)buffer.pointer);
status = AE_OK;
bbn = 0;
}
if (ACPI_FAILURE(status)) {
bbn = -ENODEV;
goto exit;
}
if (bbn > 0)
goto exit;
/* _BBN in some systems return 0 for all root bridges */
bus = -1;
status = acpi_walk_resources(handle, METHOD_NAME__CRS,
do_root_bridge_busnr_callback, &bus);
/* If _CRS failed, we just use _BBN */
if (ACPI_FAILURE(status) || (bus == -1))
goto exit;
/* We select _CRS */
if (bbn != bus) {
printk(KERN_INFO PREFIX
"_BBN and _CRS returns different value for %s. Select _CRS\n",
(char *)buffer.pointer);
bbn = bus;
}
exit:
kfree(buffer.pointer);
return (int)bbn;
}
static acpi_status
find_pci_rootbridge(acpi_handle handle, u32 lvl, void *context, void **rv)
{
struct acpi_find_pci_root *find = (struct acpi_find_pci_root *)context;
unsigned long seg, bus;
acpi_status status;
int tmp;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
status = acpi_evaluate_integer(handle, METHOD_NAME__SEG, NULL, &seg);
if (status == AE_NOT_FOUND) {
/* Assume seg = 0 */
status = AE_OK;
seg = 0;
}
if (ACPI_FAILURE(status)) {
status = AE_CTRL_DEPTH;
goto exit;
}
tmp = get_root_bridge_busnr(handle);
if (tmp < 0) {
printk(KERN_ERR PREFIX
"Find root bridge failed for %s\n",
(char *)buffer.pointer);
status = AE_CTRL_DEPTH;
goto exit;
}
bus = tmp;
if (seg == find->seg && bus == find->bus)
{
find->handle = handle;
status = AE_CTRL_TERMINATE;
}
else
status = AE_OK;
exit:
kfree(buffer.pointer);
return status;
}
acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
{
struct acpi_find_pci_root find = { seg, bus, NULL };
acpi_get_devices(PCI_ROOT_HID_STRING, find_pci_rootbridge, &find, NULL);
return find.handle;
}
EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);
/* Get device's handler per its address under its parent */
struct acpi_find_child {
acpi_handle handle;

13
drivers/acpi/pci_root.c
View File

@ -117,6 +117,19 @@ void acpi_pci_unregister_driver(struct acpi_pci_driver *driver)
EXPORT_SYMBOL(acpi_pci_unregister_driver);
acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
{
struct acpi_pci_root *tmp;
list_for_each_entry(tmp, &acpi_pci_roots, node) {
if ((tmp->id.segment == (u16) seg) && (tmp->id.bus == (u16) bus))
return tmp->device->handle;
}
return NULL;
}
EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);
static acpi_status
get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
{