[PATCH v4 11/12] sched: Define and initialize a flag to identify valid PASID in the task

[Fenghua Yu]

From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>

The flag is defined for the task to identify if the task has a valid
PASID. Its initial value is 0 when the task is forked/cloned. It will
be used shortly.

Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Co-developed-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
---
v2:
- Add this patch to define the flag to identify valid PASID MSR (PeterZ)

 include/linux/sched.h | 3 +++
 kernel/fork.c         | 4 ++++
 2 files changed, 7 insertions(+)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index b62e6aaf28f0..1b5a6e5c74ca 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -801,6 +801,9 @@ struct task_struct {
 	/* Stalled due to lack of memory */
 	unsigned			in_memstall:1;
 #endif
+#ifdef CONFIG_IOMMU_SUPPORT
+	unsigned			has_valid_pasid:1;
+#endif
 
 	unsigned long			atomic_flags; /* Flags requiring atomic access. */
 
diff --git a/kernel/fork.c b/kernel/fork.c
index 43b5f112604d..0a962bebdf88 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -955,6 +955,10 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
 	tsk->use_memdelay = 0;
 #endif
 
+#ifdef CONFIG_IOMMU_SUPPORT
+	tsk->has_valid_pasid = 0;
+#endif
+
 #ifdef CONFIG_MEMCG
 	tsk->active_memcg = NULL;
 #endif
-- 
2.19.1