diff options
| author | Heikki Krogerus <heikki.krogerus@linux.intel.com> | 2021-12-23 11:16:17 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-12-30 14:13:03 +0300 |
| commit | 882c982dada4d53079c56de94ccbce1e21cc675f (patch) | |
| tree | a7cb441f7f9b3a71bd3a1049e49ecd13495e2091 /drivers/acpi | |
| parent | 13068b7472f9720f807fe72b9bf3f76b9fd6d6ab (diff) | |
| download | linux-882c982dada4d53079c56de94ccbce1e21cc675f.tar.xz | |
acpi: Store CRC-32 hash of the _PLD in struct acpi_device
Storing CRC-32 hash of the Physical Location of Device
object (_PLD) with devices that have it. The hash is stored
to a new struct acpi_device member "pld_crc".
The hash makes it easier to find devices that share a
location, as there is no need to evaluate the entire object
every time. Knowledge about devices that share a location
can be used in device drivers that need to know the
connections to other components inside a system. USB3 ports
will for example always share their location with a USB2
port.
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20211223081620.45479-3-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/scan.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 2c80765670bc..e86e216894c4 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -19,6 +19,7 @@ #include <linux/dma-map-ops.h> #include <linux/platform_data/x86/apple.h> #include <linux/pgtable.h> +#include <linux/crc32.h> #include "internal.h" @@ -654,6 +655,19 @@ static int acpi_tie_acpi_dev(struct acpi_device *adev) return 0; } +static void acpi_store_pld_crc(struct acpi_device *adev) +{ + struct acpi_pld_info *pld; + acpi_status status; + + status = acpi_get_physical_device_location(adev->handle, &pld); + if (ACPI_FAILURE(status)) + return; + + adev->pld_crc = crc32(~0, pld, sizeof(*pld)); + ACPI_FREE(pld); +} + static int __acpi_device_add(struct acpi_device *device, void (*release)(struct device *)) { @@ -712,6 +726,8 @@ static int __acpi_device_add(struct acpi_device *device, if (device->wakeup.flags.valid) list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list); + acpi_store_pld_crc(device); + mutex_unlock(&acpi_device_lock); if (device->parent) |