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authorHeikki Krogerus <heikki.krogerus@linux.intel.com>2021-12-23 11:16:17 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-12-30 14:13:03 +0300
commit882c982dada4d53079c56de94ccbce1e21cc675f (patch)
treea7cb441f7f9b3a71bd3a1049e49ecd13495e2091 /drivers/acpi
parent13068b7472f9720f807fe72b9bf3f76b9fd6d6ab (diff)
downloadlinux-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.c16
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)