Commit baa0c019 authored by Prakash, Prashanth's avatar Prakash, Prashanth Committed by Rafael J. Wysocki
Browse files

ACPI / bus: Support for platform initiated graceful shutdown 



This patch adds support for platform initited graceful shutdown as
described in sections 5.6.6(Table-143) and 6.3.5.1 of ACPI 6.1 spec

The OSPM will get a graceful shutdown request via a Notify operator
on \_SB device with a value of 0x81 per section 5.6.6. Following the
shutdown request from platform the OSPM needs to follow the
processing sequence as described in section 6.2.5.1.

v3
* Switched to regular work with delays from delayed work
* Dropped changes to actypes.h
* Small style changes

v2
* Switched from standalone driver to a simple notify handler

v1
* Initial

Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: default avatarPrashanth Prakash <pprakash@codeaurora.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 3af03f77

drivers/acpi/bus.c

+54 −0
Original line number Diff line number Diff line
@@ -30,6 +30,9 @@ 
#include <linux/acpi.h>

#include <linux/slab.h>

#include <linux/regulator/machine.h>

#include <linux/workqueue.h>

#include <linux/reboot.h>

#include <linux/delay.h>

#ifdef CONFIG_X86

#include <asm/mpspec.h>

#endif
@@ -470,6 +473,56 @@ static void acpi_device_remove_notify_handler(struct acpi_device *device) 
					   acpi_device_notify);

}



/* Handle events targeting \_SB device (at present only graceful shutdown) */



#define ACPI_SB_NOTIFY_SHUTDOWN_REQUEST 0x81

#define ACPI_SB_INDICATE_INTERVAL	10000



static void sb_notify_work(struct work_struct *dummy)

{

	acpi_handle sb_handle;



	orderly_poweroff(true);



	/*

	 * After initiating graceful shutdown, the ACPI spec requires OSPM

	 * to evaluate _OST method once every 10seconds to indicate that

	 * the shutdown is in progress

	 */

	acpi_get_handle(NULL, "\\_SB", &sb_handle);

	while (1) {

		pr_info("Graceful shutdown in progress.\n");

		acpi_evaluate_ost(sb_handle, ACPI_OST_EC_OSPM_SHUTDOWN,

				ACPI_OST_SC_OS_SHUTDOWN_IN_PROGRESS, NULL);

		msleep(ACPI_SB_INDICATE_INTERVAL);

	}

}



static void acpi_sb_notify(acpi_handle handle, u32 event, void *data)

{

	static DECLARE_WORK(acpi_sb_work, sb_notify_work);



	if (event == ACPI_SB_NOTIFY_SHUTDOWN_REQUEST) {

		if (!work_busy(&acpi_sb_work))

			schedule_work(&acpi_sb_work);

	} else

		pr_warn("event %x is not supported by \\_SB device\n", event);

}



static int __init acpi_setup_sb_notify_handler(void)

{

	acpi_handle sb_handle;



	if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &sb_handle)))

		return -ENXIO;



	if (ACPI_FAILURE(acpi_install_notify_handler(sb_handle, ACPI_DEVICE_NOTIFY,

						acpi_sb_notify, NULL)))

		return -EINVAL;



	return 0;

}



/* --------------------------------------------------------------------------

                             Device Matching

   -------------------------------------------------------------------------- */
@@ -1118,6 +1171,7 @@ static int __init acpi_init(void) 
	acpi_sleep_proc_init();

	acpi_wakeup_device_init();

	acpi_debugger_init();

	acpi_setup_sb_notify_handler();

	return 0;

}

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