Commit 882c982d authored by Heikki Krogerus's avatar Heikki Krogerus Committed by Greg Kroah-Hartman
Browse files

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: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: default avatarHeikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20211223081620.45479-3-heikki.krogerus@linux.intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 13068b74

drivers/acpi/scan.c

+16 −0
Original line number Diff line number Diff line
@@ -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)

include/acpi/acpi_bus.h

+1 −0
Original line number Diff line number Diff line
@@ -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;