mmu_notifier: add the callback for mmu_notifier_invalidate_range()
Now that the mmu_notifier_invalidate_range() calls are in place, add the
callback to allow subsystems to register against it.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Rik van Riel <riel@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Jay Cornwall <Jay.Cornwall@amd.com>
Cc: Oded Gabbay <Oded.Gabbay@amd.com>
Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index 966da2b..94d19f6 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -98,11 +98,11 @@
/*
* invalidate_range_start() and invalidate_range_end() must be
* paired and are called only when the mmap_sem and/or the
- * locks protecting the reverse maps are held. The subsystem
- * must guarantee that no additional references are taken to
- * the pages in the range established between the call to
- * invalidate_range_start() and the matching call to
- * invalidate_range_end().
+ * locks protecting the reverse maps are held. If the subsystem
+ * can't guarantee that no additional references are taken to
+ * the pages in the range, it has to implement the
+ * invalidate_range() notifier to remove any references taken
+ * after invalidate_range_start().
*
* Invalidation of multiple concurrent ranges may be
* optionally permitted by the driver. Either way the
@@ -144,6 +144,29 @@
void (*invalidate_range_end)(struct mmu_notifier *mn,
struct mm_struct *mm,
unsigned long start, unsigned long end);
+
+ /*
+ * invalidate_range() is either called between
+ * invalidate_range_start() and invalidate_range_end() when the
+ * VM has to free pages that where unmapped, but before the
+ * pages are actually freed, or outside of _start()/_end() when
+ * a (remote) TLB is necessary.
+ *
+ * If invalidate_range() is used to manage a non-CPU TLB with
+ * shared page-tables, it not necessary to implement the
+ * invalidate_range_start()/end() notifiers, as
+ * invalidate_range() alread catches the points in time when an
+ * external TLB range needs to be flushed.
+ *
+ * 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.
+ */
+ void (*invalidate_range)(struct mmu_notifier *mn, struct mm_struct *mm,
+ unsigned long start, unsigned long end);
};
/*
@@ -190,6 +213,8 @@
unsigned long start, unsigned long end);
extern void __mmu_notifier_invalidate_range_end(struct mm_struct *mm,
unsigned long start, unsigned long end);
+extern void __mmu_notifier_invalidate_range(struct mm_struct *mm,
+ unsigned long start, unsigned long end);
static inline void mmu_notifier_release(struct mm_struct *mm)
{
@@ -245,6 +270,8 @@
static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
unsigned long start, unsigned long end)
{
+ if (mm_has_notifiers(mm))
+ __mmu_notifier_invalidate_range(mm, start, end);
}
static inline void mmu_notifier_mm_init(struct mm_struct *mm)