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acpi: Store CRC-32 hash of the _PLD in struct acpi_device

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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>
This commit is contained in:
Heikki Krogerus 2021-12-23 11:16:17 +03:00 committed by Greg Kroah-Hartman
parent 13068b7472
commit 882c982dad
2 changed files with 17 additions and 0 deletions
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16
drivers/acpi/scan.c
View file

@ -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)

1
include/acpi/acpi_bus.h
View file

@ -358,6 +358,7 @@ struct acpi_gpio_mapping;
/* Device */
struct acpi_device {
u32 pld_crc;
int device_type;
acpi_handle handle; /* no handle for fixed hardware */
struct fwnode_handle fwnode;