diff options
| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-01-10 13:13:49 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-03-28 12:18:14 -0700 |
| commit | b842701f3d800a0fba3cee5ec4163a2356f3aaa5 (patch) | |
| tree | 52f6a3b9e68a24cbbb158ca20a16a62d3bf014cf | |
| parent | b0925a591f1359e64522a94d5fc56cc1df0abfa0 (diff) | |
ACPI: Rework acpi_get_child() to be more efficient
commit 33f767d767e9a684e9cd60704d4c049a2014c8d5 upstream.
Observe that acpi_get_child() doesn't need to use the helper
struct acpi_find_child structure and change it to work without it.
Also, using acpi_get_object_info() to get the output of _ADR for the
given device is overkill, because that function does much more than
just evaluating _ADR (let alone the additional memory allocation
done by it).
Moreover, acpi_get_child() doesn't need to loop any more once it has
found a matching handle, so make it stop in that case. To prevent
the results from changing, make it use do_acpi_find_child() as
a post-order callback.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Josh Boyer <jwboyer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/acpi/glue.c | 35 |
1 files changed, 13 insertions, 22 deletions
diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c index 35da18113216..e9e486f79b35 100644 --- a/drivers/acpi/glue.c +++ b/drivers/acpi/glue.c @@ -95,40 +95,31 @@ static int acpi_find_bridge_device(struct device *dev, acpi_handle * handle) return ret; } -/* Get device's handler per its address under its parent */ -struct acpi_find_child { - acpi_handle handle; - u64 address; -}; - -static acpi_status -do_acpi_find_child(acpi_handle handle, u32 lvl, void *context, void **rv) +static acpi_status do_acpi_find_child(acpi_handle handle, u32 lvl_not_used, + void *addr_p, void **ret_p) { + unsigned long long addr; acpi_status status; - struct acpi_device_info *info; - struct acpi_find_child *find = context; - - status = acpi_get_object_info(handle, &info); - if (ACPI_SUCCESS(status)) { - if ((info->address == find->address) - && (info->valid & ACPI_VALID_ADR)) - find->handle = handle; - kfree(info); + + status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &addr); + if (ACPI_SUCCESS(status) && addr == *((u64 *)addr_p)) { + *ret_p = handle; + return AE_CTRL_TERMINATE; } return AE_OK; } acpi_handle acpi_get_child(acpi_handle parent, u64 address) { - struct acpi_find_child find = { NULL, address }; + void *ret = NULL; if (!parent) return NULL; - acpi_walk_namespace(ACPI_TYPE_DEVICE, parent, - 1, do_acpi_find_child, NULL, &find, NULL); - return find.handle; -} + acpi_walk_namespace(ACPI_TYPE_DEVICE, parent, 1, NULL, + do_acpi_find_child, &address, &ret); + return (acpi_handle)ret; +} EXPORT_SYMBOL(acpi_get_child); static int acpi_bind_one(struct device *dev, acpi_handle handle) |