[PATCH v12 04/29] mmu_notifier: allow range invalidation to exclude a specific mmu_notifier

From: JÃrÃme Glisse
Date: Tue Mar 08 2016 - 14:47:24 EST


This patch allow to invalidate a range while excluding call to a specific
mmu_notifier which allow for a subsystem to invalidate a range for everyone
but itself.

Signed-off-by: JÃrÃme Glisse <jglisse@xxxxxxxxxx>
---
include/linux/mmu_notifier.h | 66 ++++++++++++++++++++++++++++++++++++++++----
mm/mmu_notifier.c | 16 +++++++++--
2 files changed, 73 insertions(+), 9 deletions(-)

diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index 9e65a3f..acebf00 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -309,11 +309,15 @@ extern void __mmu_notifier_invalidate_page(struct mm_struct *mm,
struct page *page,
enum mmu_event event);
extern void __mmu_notifier_invalidate_range_start(struct mm_struct *mm,
- struct mmu_notifier_range *range);
+ struct mmu_notifier_range *range,
+ const struct mmu_notifier *exclude);
extern void __mmu_notifier_invalidate_range_end(struct mm_struct *mm,
- struct mmu_notifier_range *range);
+ struct mmu_notifier_range *range,
+ const struct mmu_notifier *exclude);
extern void __mmu_notifier_invalidate_range(struct mm_struct *mm,
- unsigned long start, unsigned long end);
+ unsigned long start,
+ unsigned long end,
+ const struct mmu_notifier *exclude);
extern bool mmu_notifier_range_inactive(struct mm_struct *mm,
unsigned long start,
unsigned long end);
@@ -375,21 +379,49 @@ static inline void mmu_notifier_invalidate_range_start(struct mm_struct *mm,
struct mmu_notifier_range *range)
{
if (mm_has_notifiers(mm))
- __mmu_notifier_invalidate_range_start(mm, range);
+ __mmu_notifier_invalidate_range_start(mm, range, NULL);
}

static inline void mmu_notifier_invalidate_range_end(struct mm_struct *mm,
struct mmu_notifier_range *range)
{
if (mm_has_notifiers(mm))
- __mmu_notifier_invalidate_range_end(mm, range);
+ __mmu_notifier_invalidate_range_end(mm, range, NULL);
}

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);
+ __mmu_notifier_invalidate_range(mm, start, end, NULL);
+}
+
+static inline void mmu_notifier_invalidate_range_start_excluding(
+ struct mm_struct *mm,
+ struct mmu_notifier_range *range,
+ const struct mmu_notifier *exclude)
+{
+ if (mm_has_notifiers(mm))
+ __mmu_notifier_invalidate_range_start(mm, range, exclude);
+}
+
+static inline void mmu_notifier_invalidate_range_end_excluding(
+ struct mm_struct *mm,
+ struct mmu_notifier_range *range,
+ const struct mmu_notifier *exclude)
+{
+ if (mm_has_notifiers(mm))
+ __mmu_notifier_invalidate_range_end(mm, range, exclude);
+}
+
+static inline void mmu_notifier_invalidate_range_excluding(
+ struct mm_struct *mm,
+ unsigned long start,
+ unsigned long end,
+ const struct mmu_notifier *exclude)
+{
+ if (mm_has_notifiers(mm))
+ __mmu_notifier_invalidate_range(mm, start, end, exclude);
}

static inline void mmu_notifier_mm_init(struct mm_struct *mm)
@@ -561,6 +593,28 @@ static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
{
}

+static inline void mmu_notifier_invalidate_range_start_excluding(
+ struct mm_struct *mm,
+ struct mmu_notifier_range *range,
+ const struct mmu_notifier *exclude)
+{
+}
+
+static inline void mmu_notifier_invalidate_range_end_excluding(
+ struct mm_struct *mm,
+ struct mmu_notifier_range *range,
+ const struct mmu_notifier *exclude)
+{
+}
+
+static inline void mmu_notifier_invalidate_range_excluding(
+ struct mm_struct *mm,
+ unsigned long start,
+ unsigned long end,
+ const struct mmu_notifier *exclude)
+{
+}
+
static inline void mmu_notifier_mm_init(struct mm_struct *mm)
{
}
diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
index 316e4a9..651246f 100644
--- a/mm/mmu_notifier.c
+++ b/mm/mmu_notifier.c
@@ -192,7 +192,8 @@ void __mmu_notifier_invalidate_page(struct mm_struct *mm,
}

void __mmu_notifier_invalidate_range_start(struct mm_struct *mm,
- struct mmu_notifier_range *range)
+ struct mmu_notifier_range *range,
+ const struct mmu_notifier *exclude)

{
struct mmu_notifier *mn;
@@ -205,6 +206,8 @@ void __mmu_notifier_invalidate_range_start(struct mm_struct *mm,

id = srcu_read_lock(&srcu);
hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
+ if (mn == exclude)
+ continue;
if (mn->ops->invalidate_range_start)
mn->ops->invalidate_range_start(mn, mm, range);
}
@@ -213,13 +216,16 @@ void __mmu_notifier_invalidate_range_start(struct mm_struct *mm,
EXPORT_SYMBOL_GPL(__mmu_notifier_invalidate_range_start);

void __mmu_notifier_invalidate_range_end(struct mm_struct *mm,
- struct mmu_notifier_range *range)
+ struct mmu_notifier_range *range,
+ const struct mmu_notifier *exclude)
{
struct mmu_notifier *mn;
int id;

id = srcu_read_lock(&srcu);
hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
+ if (mn == exclude)
+ continue;
/*
* Call invalidate_range here too to avoid the need for the
* subsystem of having to register an invalidate_range_end
@@ -250,13 +256,17 @@ void __mmu_notifier_invalidate_range_end(struct mm_struct *mm,
EXPORT_SYMBOL_GPL(__mmu_notifier_invalidate_range_end);

void __mmu_notifier_invalidate_range(struct mm_struct *mm,
- unsigned long start, unsigned long end)
+ unsigned long start,
+ unsigned long end,
+ const struct mmu_notifier *exclude)
{
struct mmu_notifier *mn;
int id;

id = srcu_read_lock(&srcu);
hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
+ if (mn == exclude)
+ continue;
if (mn->ops->invalidate_range)
mn->ops->invalidate_range(mn, mm, start, end);
}
--
2.4.3