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authorVincenzo Frascino <vincenzo.frascino@arm.com>2021-03-15 13:20:18 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2021-04-11 10:56:40 +0100
commiteab0e6e17d876381b4d47996eef3b5fd46ea4011 (patch)
tree4f7cb7317d8fc663f009db7a37b6ff4a9a2eac54
parent65812c6921cc849d86811147038dd246fa0ea18c (diff)
arm64: mte: Report async tag faults before suspend
When MTE async mode is enabled TFSR_EL1 contains the accumulative asynchronous tag check faults for EL1 and EL0. During the suspend/resume operations the firmware might perform some operations that could change the state of the register resulting in a spurious tag check fault report. Report asynchronous tag faults before suspend and clear the TFSR_EL1 register after resume to prevent this to happen. Cc: Will Deacon <will@kernel.org> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://lore.kernel.org/r/20210315132019.33202-9-vincenzo.frascino@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
-rw-r--r--arch/arm64/include/asm/mte.h4
-rw-r--r--arch/arm64/kernel/mte.c16
-rw-r--r--arch/arm64/kernel/suspend.c3
3 files changed, 23 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/mte.h b/arch/arm64/include/asm/mte.h
index 9a929620ca5d..a38abc15186c 100644
--- a/arch/arm64/include/asm/mte.h
+++ b/arch/arm64/include/asm/mte.h
@@ -41,6 +41,7 @@ void mte_sync_tags(pte_t *ptep, pte_t pte);
void mte_copy_page_tags(void *kto, const void *kfrom);
void flush_mte_state(void);
void mte_thread_switch(struct task_struct *next);
+void mte_suspend_enter(void);
void mte_suspend_exit(void);
long set_mte_ctrl(struct task_struct *task, unsigned long arg);
long get_mte_ctrl(struct task_struct *task);
@@ -66,6 +67,9 @@ static inline void flush_mte_state(void)
static inline void mte_thread_switch(struct task_struct *next)
{
}
+static inline void mte_suspend_enter(void)
+{
+}
static inline void mte_suspend_exit(void)
{
}
diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c
index b6336fbe4c14..820bad94870e 100644
--- a/arch/arm64/kernel/mte.c
+++ b/arch/arm64/kernel/mte.c
@@ -265,6 +265,22 @@ void mte_thread_switch(struct task_struct *next)
mte_check_tfsr_el1();
}
+void mte_suspend_enter(void)
+{
+ if (!system_supports_mte())
+ return;
+
+ /*
+ * The barriers are required to guarantee that the indirect writes
+ * to TFSR_EL1 are synchronized before we report the state.
+ */
+ dsb(nsh);
+ isb();
+
+ /* Report SYS_TFSR_EL1 before suspend entry */
+ mte_check_tfsr_el1();
+}
+
void mte_suspend_exit(void)
{
if (!system_supports_mte())
diff --git a/arch/arm64/kernel/suspend.c b/arch/arm64/kernel/suspend.c
index d7564891ffe1..6fdc8292b4f5 100644
--- a/arch/arm64/kernel/suspend.c
+++ b/arch/arm64/kernel/suspend.c
@@ -91,6 +91,9 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
unsigned long flags;
struct sleep_stack_data state;
+ /* Report any MTE async fault before going to suspend */
+ mte_suspend_enter();
+
/*
* From this point debug exceptions are disabled to prevent
* updates to mdscr register (saved and restored along with