Commit 29b33523 authored by James Morse's avatar James Morse Committed by liwei
Browse files

ACPI: Only enumerate enabled (or functional) devices 

maillist inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL


CVE: NA

---------------------------------

Today the ACPI enumeration code 'visits' all devices that are present.

This is a problem for arm64, where CPUs are always present, but not
always enabled. When a device-check occurs because the firmware-policy
has changed and a CPU is now enabled, the following error occurs:
| acpi ACPI0007:48: Enumeration failure

This is ultimately because acpi_dev_ready_for_enumeration() returns
true for a device that is not enabled. The ACPI Processor driver
will not register such CPUs as they are not 'decoding their resources'.

Change acpi_dev_ready_for_enumeration() to also check the enabled bit.
ACPI allows a device to be functional instead of maintaining the
present and enabled bit. Make this behaviour an explicit check with
a reference to the spec, and then check the present and enabled bits.
This is needed to avoid enumerating present && functional devices that
are not enabled.

Signed-off-by: default avatarJames Morse <james.morse@arm.com>
Tested-by: default avatarMiguel Luis <miguel.luis@oracle.com>
Tested-by: default avatarVishnu Pajjuri <vishnu@os.amperecomputing.com>
Tested-by: default avatarJianyong Wu <jianyong.wu@arm.com>
Signed-off-by: default avatarRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: default avatarJames Morse <james.morse@arm.com>
Signed-off-by: default avatarRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
Tested-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: default avatarliwei <liwei728@huawei.com>
parent f655b9d0

drivers/acpi/device_pm.c

+1 −1
Original line number Diff line number Diff line
@@ -313,7 +313,7 @@ int acpi_bus_init_power(struct acpi_device *device) 
		return -EINVAL;



	device->power.state = ACPI_STATE_UNKNOWN;

	if (!acpi_device_is_present(device)) {

	if (!acpi_dev_ready_for_enumeration(device)) {

		device->flags.initialized = false;

		return -ENXIO;

	}

drivers/acpi/device_sysfs.c

+1 −1
Original line number Diff line number Diff line
@@ -141,7 +141,7 @@ static int create_pnp_modalias(const struct acpi_device *acpi_dev, char *modalia 
	struct acpi_hardware_id *id;



	/* Avoid unnecessarily loading modules for non present devices. */

	if (!acpi_device_is_present(acpi_dev))

	if (!acpi_dev_ready_for_enumeration(acpi_dev))

		return 0;



	/*

drivers/acpi/internal.h

+0 −1
Original line number Diff line number Diff line
@@ -106,7 +106,6 @@ int acpi_device_setup_files(struct acpi_device *dev); 
void acpi_device_remove_files(struct acpi_device *dev);

void acpi_device_add_finalize(struct acpi_device *device);

void acpi_free_pnp_ids(struct acpi_device_pnp *pnp);

bool acpi_device_is_present(const struct acpi_device *adev);

bool acpi_device_is_battery(struct acpi_device *adev);

bool acpi_device_is_first_physical_node(struct acpi_device *adev,

					const struct device *dev);

drivers/acpi/property.c

+1 −1
Original line number Diff line number Diff line
@@ -1423,7 +1423,7 @@ static bool acpi_fwnode_device_is_available(const struct fwnode_handle *fwnode) 
	if (!is_acpi_device_node(fwnode))

		return false;



	return acpi_device_is_present(to_acpi_device_node(fwnode));

	return acpi_dev_ready_for_enumeration(to_acpi_device_node(fwnode));

}



static const void *

drivers/acpi/scan.c

+14 −10
Original line number Diff line number Diff line
@@ -304,7 +304,7 @@ static int acpi_scan_device_check(struct acpi_device *adev) 
	int error;



	acpi_bus_get_status(adev);

	if (acpi_device_is_present(adev)) {

	if (acpi_dev_ready_for_enumeration(adev)) {

		/*

		 * This function is only called for device objects for which

		 * matching scan handlers exist.  The only situation in which
@@ -338,7 +338,7 @@ static int acpi_scan_bus_check(struct acpi_device *adev, void *not_used) 
	int error;



	acpi_bus_get_status(adev);

	if (!acpi_device_is_present(adev)) {

	if (!acpi_dev_ready_for_enumeration(adev)) {

		acpi_scan_device_not_enumerated(adev);

		return 0;

	}
@@ -1917,11 +1917,6 @@ static bool acpi_device_should_be_hidden(acpi_handle handle) 
	return true;

}



bool acpi_device_is_present(const struct acpi_device *adev)

{

	return adev->status.present || adev->status.functional;

}



static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,

				       const char *idstr,

				       const struct acpi_device_id **matchid)
@@ -2384,16 +2379,25 @@ EXPORT_SYMBOL_GPL(acpi_dev_clear_dependencies); 
 * acpi_dev_ready_for_enumeration - Check if the ACPI device is ready for enumeration

 * @device: Pointer to the &struct acpi_device to check

 *

 * Check if the device is present and has no unmet dependencies.

 * Check if the device is functional or enabled and has no unmet dependencies.

 *

 * Return true if the device is ready for enumeratino. Otherwise, return false.

 * Return true if the device is ready for enumeration. Otherwise, return false.

 */

bool acpi_dev_ready_for_enumeration(const struct acpi_device *device)

{

	if (device->flags.honor_deps && device->dep_unmet)

		return false;



	return acpi_device_is_present(device);

	/*

	 * ACPI 6.5's 6.3.7 "_STA (Device Status)" allows firmware to return

	 * (!present && functional) for certain types of devices that should be

	 * enumerated. Note that the enabled bit can't be sert until the present

	 * bit is set.

	 */

	if (device->status.present)

		return device->status.enabled;

	else

		return device->status.functional;

}

EXPORT_SYMBOL_GPL(acpi_dev_ready_for_enumeration);