From 1e86c400c84e9c8ecf286acedab825141805e94c Mon Sep 17 00:00:00 2001
From: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Date: Thu, 28 Mar 2019 18:56:23 +0800
Subject: [PATCH] sdei_watchdog: clear EOI of the secure timer before kdump

euler inclusion
category: feature
Bugzilla: 12567
CVE: N/A

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

When we panic in hardlockup, the secure timer interrupt remains activate
because firmware clear eoi after dispatch is completed. This will cause
arm_arch_timer interrupt failed to trigger in the second kernel.

This patch add a new SMC helper to clear eoi of a certain interrupt and
clear eoi of the secure timer before booting the second kernel.

Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
 arch/arm64/kernel/machine_kexec.c | 10 ++++++++++
 arch/arm64/kernel/watchdog_sdei.c |  6 ++++++
 drivers/firmware/arm_sdei.c       |  6 ++++++
 include/linux/arm_sdei.h          |  1 +
 include/linux/nmi.h               |  6 ++++++
 include/uapi/linux/arm_sdei.h     |  1 +
 6 files changed, 30 insertions(+)

diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c
index 922add8adb74..3c0e9383d7e0 100644
--- a/arch/arm64/kernel/machine_kexec.c
+++ b/arch/arm64/kernel/machine_kexec.c
@@ -13,6 +13,7 @@
 #include <linux/irq.h>
 #include <linux/kernel.h>
 #include <linux/kexec.h>
+#include <linux/nmi.h>
 #include <linux/page-flags.h>
 #include <linux/smp.h>
 
@@ -260,6 +261,15 @@ void machine_crash_shutdown(struct pt_regs *regs)
 	/* shutdown non-crashing cpus */
 	crash_smp_send_stop();
 
+	/*
+	 * when we panic in hardlockup detected by sdei_watchdog, the secure
+	 * timer interrupt remains activate here because firmware clear eoi
+	 * after dispatch is completed. This will cause arm_arch_timer
+	 * interrupt failed to trigger in the second kernel. So we clear eoi
+	 * of the secure timer before booting the second kernel.
+	 */
+	sdei_watchdog_clear_eoi();
+
 	/* for crashing cpu */
 	crash_save_cpu(regs, smp_processor_id());
 	machine_kexec_mask_interrupts();
diff --git a/arch/arm64/kernel/watchdog_sdei.c b/arch/arm64/kernel/watchdog_sdei.c
index e36c4d398893..99ab9bdfdee6 100644
--- a/arch/arm64/kernel/watchdog_sdei.c
+++ b/arch/arm64/kernel/watchdog_sdei.c
@@ -80,6 +80,12 @@ static int __init disable_sdei_nmi_watchdog_setup(char *str)
 }
 __setup("disable_sdei_nmi_watchdog", disable_sdei_nmi_watchdog_setup);
 
+void sdei_watchdog_clear_eoi(void)
+{
+	if (sdei_watchdog_registered)
+		sdei_api_clear_eoi(SDEI_NMI_WATCHDOG_HWIRQ);
+}
+
 int __init watchdog_nmi_probe(void)
 {
 	int ret;
diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c
index 14029c54b70b..9231acf5d2e3 100644
--- a/drivers/firmware/arm_sdei.c
+++ b/drivers/firmware/arm_sdei.c
@@ -200,6 +200,12 @@ int sdei_api_event_interrupt_bind(int hwirq)
 	return (int)event_number;
 }
 
+int sdei_api_clear_eoi(int hwirq)
+{
+	return invoke_sdei_fn(SDEI_1_0_FN_SDEI_CLEAR_EOI, hwirq, 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,
diff --git a/include/linux/arm_sdei.h b/include/linux/arm_sdei.h
index fd735c1284da..990f4234b244 100644
--- a/include/linux/arm_sdei.h
+++ b/include/linux/arm_sdei.h
@@ -41,6 +41,7 @@ int sdei_event_disable(u32 event_num);
 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);
 
 #ifdef CONFIG_ARM_SDE_INTERFACE
 /* For use by arch code when CPU hotplug notifiers are not appropriate. */
diff --git a/include/linux/nmi.h b/include/linux/nmi.h
index f65cfbb5d46c..5e1facadc0aa 100644
--- a/include/linux/nmi.h
+++ b/include/linux/nmi.h
@@ -225,4 +225,10 @@ extern int proc_watchdog_cpumask(struct ctl_table *, int,
 #include <asm/nmi.h>
 #endif
 
+#ifdef CONFIG_SDEI_WATCHDOG
+void sdei_watchdog_clear_eoi(void);
+#else
+static inline void sdei_watchdog_clear_eoi(void) { }
+#endif
+
 #endif
diff --git a/include/uapi/linux/arm_sdei.h b/include/uapi/linux/arm_sdei.h
index af0630ba5437..9a810e7883ed 100644
--- a/include/uapi/linux/arm_sdei.h
+++ b/include/uapi/linux/arm_sdei.h
@@ -24,6 +24,7 @@
 #define SDEI_1_0_FN_SDEI_INTERRUPT_RELEASE		SDEI_1_0_FN(0x0E)
 #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(0xD0)
 
 #define SDEI_VERSION_MAJOR_SHIFT			48
 #define SDEI_VERSION_MAJOR_MASK				0x7fff
-- 
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