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Diffstat (limited to 'include/linux/mmu_notifier.h')
-rw-r--r--include/linux/mmu_notifier.h30
1 files changed, 27 insertions, 3 deletions
diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index b25dc9db19fc..2d07a1ed5a31 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -2,6 +2,7 @@
#ifndef _LINUX_MMU_NOTIFIER_H
#define _LINUX_MMU_NOTIFIER_H
+#include <linux/types.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/mm_types.h>
@@ -10,6 +11,9 @@
struct mmu_notifier;
struct mmu_notifier_ops;
+/* mmu_notifier_ops flags */
+#define MMU_INVALIDATE_DOES_NOT_BLOCK (0x01)
+
#ifdef CONFIG_MMU_NOTIFIER
/*
@@ -27,6 +31,15 @@ struct mmu_notifier_mm {
struct mmu_notifier_ops {
/*
+ * Flags to specify behavior of callbacks for this MMU notifier.
+ * Used to determine which context an operation may be called.
+ *
+ * MMU_INVALIDATE_DOES_NOT_BLOCK: invalidate_range_* callbacks do not
+ * block
+ */
+ int flags;
+
+ /*
* Called either by mmu_notifier_unregister or when the mm is
* being destroyed by exit_mmap, always before all pages are
* freed. This can run concurrently with other mmu notifier
@@ -137,6 +150,10 @@ struct mmu_notifier_ops {
* page. Pages will no longer be referenced by the linux
* address space but may still be referenced by sptes until
* the last refcount is dropped.
+ *
+ * If both of these callbacks cannot block, and invalidate_range
+ * cannot block, mmu_notifier_ops.flags should have
+ * MMU_INVALIDATE_DOES_NOT_BLOCK set.
*/
void (*invalidate_range_start)(struct mmu_notifier *mn,
struct mm_struct *mm,
@@ -159,12 +176,13 @@ struct mmu_notifier_ops {
* external TLB range needs to be flushed. For more in depth
* discussion on this see Documentation/vm/mmu_notifier.txt
*
- * The invalidate_range() function is called under the ptl
- * spin-lock and not allowed to sleep.
- *
* Note that this function might be called with just a sub-range
* of what was passed to invalidate_range_start()/end(), if
* called between those functions.
+ *
+ * If this callback cannot block, and invalidate_range_{start,end}
+ * cannot block, mmu_notifier_ops.flags should have
+ * MMU_INVALIDATE_DOES_NOT_BLOCK set.
*/
void (*invalidate_range)(struct mmu_notifier *mn, struct mm_struct *mm,
unsigned long start, unsigned long end);
@@ -218,6 +236,7 @@ extern void __mmu_notifier_invalidate_range_end(struct mm_struct *mm,
bool only_end);
extern void __mmu_notifier_invalidate_range(struct mm_struct *mm,
unsigned long start, unsigned long end);
+extern bool mm_has_blockable_invalidate_notifiers(struct mm_struct *mm);
static inline void mmu_notifier_release(struct mm_struct *mm)
{
@@ -457,6 +476,11 @@ static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
{
}
+static inline bool mm_has_blockable_invalidate_notifiers(struct mm_struct *mm)
+{
+ return false;
+}
+
static inline void mmu_notifier_mm_init(struct mm_struct *mm)
{
}