Commit 13ddc127 authored by Xiongfeng Wang's avatar Xiongfeng Wang Committed by Zheng Zengkai
Browse files

sdei_watchdog: set secure timer period base on 'watchdog_thresh' 



hulk inclusion
category: feature
bugzilla: 48046
CVE: NA

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

The period of the secure timer is set to 3s by BIOS. That means the
secure timer interrupt will trigger every 3 seconds. To further decrease
the NMI watchdog's effect on performance, this patch set the period of
the secure timer base on 'watchdog_thresh'. This variable is initiallized
to 10s. We can also set the period at runtime by modifying
'/proc/sys/kernel/watchdog_thresh'

Signed-off-by: default avatarXiongfeng Wang <wangxiongfeng2@huawei.com>
Reviewed-by: default avatarHanjun Guo <guohanjun@huawei.com>
Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: default avatarXiongfeng Wang <wangxiongfeng2@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent 75ac7be9

arch/arm64/kernel/watchdog_sdei.c

+15 −0
Original line number Diff line number Diff line
@@ -30,7 +30,11 @@ int watchdog_nmi_enable(unsigned int cpu) 
	if (!sdei_watchdog_registered)

		return -EINVAL;



#ifdef CONFIG_HARDLOCKUP_CHECK_TIMESTAMP

	refresh_hld_last_timestamp();

#endif



	sdei_api_set_secure_timer_period(watchdog_thresh);



	ret = sdei_api_event_enable(sdei_watchdog_event_num);

	if (ret) {
@@ -104,6 +108,17 @@ int __init watchdog_nmi_probe(void) 
		return sdei_watchdog_event_num;

	}



	/*

	 * After we introduced 'sdei_api_set_secure_timer_period', we disselect

	 * 'CONFIG_HARDLOCKUP_CHECK_TIMESTAMP'. So we need to make sure that

	 * firmware can set the period of the secure timer and the timer

	 * interrupt doesn't trigger too soon.

	 */

	if (sdei_api_set_secure_timer_period(watchdog_thresh)) {

		pr_err("Firmware doesn't support setting the secure timer period, please update your BIOS !\n");

		return -EINVAL;

	}



	on_each_cpu(sdei_nmi_watchdog_bind, NULL, true);



	ret = sdei_event_register(sdei_watchdog_event_num,

drivers/firmware/arm_sdei.c

+6 −0
Original line number Diff line number Diff line
@@ -203,6 +203,12 @@ int sdei_api_clear_eoi(int hwirq) 
			NULL);

}



int sdei_api_set_secure_timer_period(int sec)

{

	return invoke_sdei_fn(SDEI_1_0_FN_SET_SECURE_TIMER_PERIOD, sec, 0, 0, 0,

			0, NULL);

}



static int sdei_api_event_get_info(u32 event, u32 info, u64 *result)

{

	return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_GET_INFO, event, info, 0,

include/linux/arm_sdei.h

+1 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ int sdei_api_event_interrupt_bind(int hwirq); 
int sdei_api_event_disable(u32 event_num);

int sdei_api_event_enable(u32 event_num);

int sdei_api_clear_eoi(int hwirq);

int sdei_api_set_secure_timer_period(int sec);



/* GHES register/unregister helpers */

int sdei_register_ghes(struct ghes *ghes, sdei_event_callback *normal_cb,

include/uapi/linux/arm_sdei.h

+1 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#define SDEI_1_0_FN_SDEI_PRIVATE_RESET			SDEI_1_0_FN(0x11)

#define SDEI_1_0_FN_SDEI_SHARED_RESET			SDEI_1_0_FN(0x12)

#define SDEI_1_0_FN_SDEI_CLEAR_EOI			SDEI_1_0_FN(0x18)

#define SDEI_1_0_FN_SET_SECURE_TIMER_PERIOD		SDEI_1_0_FN(0x19)



#define SDEI_VERSION_MAJOR_SHIFT			48

#define SDEI_VERSION_MAJOR_MASK				0x7fff

lib/Kconfig.debug

+0 −1
Original line number Diff line number Diff line
@@ -968,7 +968,6 @@ config SDEI_WATCHDOG 
	bool "SDEI NMI Watchdog support"

	depends on ARM_SDE_INTERFACE

	select HAVE_HARDLOCKUP_DETECTOR_ARCH

	select HARDLOCKUP_CHECK_TIMESTAMP

	select HARDLOCKUP_DETECTOR



#