From 882c982dada4d53079c56de94ccbce1e21cc675f Mon Sep 17 00:00:00 2001 From: Heikki Krogerus Date: Thu, 23 Dec 2021 11:16:17 +0300 Subject: 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 Signed-off-by: Heikki Krogerus Link: https://lore.kernel.org/r/20211223081620.45479-3-heikki.krogerus@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/acpi/scan.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'drivers/acpi/scan.c') 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 #include #include +#include #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) -- cgit v1.2.3