From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= <jglisse@redhat.com>
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        =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= <jglisse@redhat.com>
Subject: [PATCH v12 24/29] HMM: allow to get pointer to spinlock protecting a directory.
Date: Tue,  8 Mar 2016 15:43:17 -0500
Message-Id: <1457469802-11850-25-git-send-email-jglisse@redhat.com>
In-Reply-To: <1457469802-11850-1-git-send-email-jglisse@redhat.com>
References: <1457469802-11850-1-git-send-email-jglisse@redhat.com>
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Several use case for getting pointer to spinlock protecting a directory.

Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
---
 include/linux/hmm_pt.h | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/include/linux/hmm_pt.h b/include/linux/hmm_pt.h
index f745d6c..22100a6 100644
--- a/include/linux/hmm_pt.h
+++ b/include/linux/hmm_pt.h
@@ -255,6 +255,16 @@ static inline void hmm_pt_directory_lock(struct hmm_pt *pt,
 		spin_lock(&pt->lock);
 }
 
+static inline spinlock_t *hmm_pt_directory_lock_ptr(struct hmm_pt *pt,
+						    struct page *ptd,
+						    unsigned level)
+{
+	if (level)
+		return &ptd->ptl;
+	else
+		return &pt->lock;
+}
+
 static inline void hmm_pt_directory_unlock(struct hmm_pt *pt,
 					   struct page *ptd,
 					   unsigned level)
@@ -272,6 +282,13 @@ static inline void hmm_pt_directory_lock(struct hmm_pt *pt,
 	spin_lock(&pt->lock);
 }
 
+static inline spinlock_t *hmm_pt_directory_lock_ptr(struct hmm_pt *pt,
+						    struct page *ptd,
+						    unsigned level)
+{
+	return &pt->lock;
+}
+
 static inline void hmm_pt_directory_unlock(struct hmm_pt *pt,
 					   struct page *ptd,
 					   unsigned level)
@@ -358,6 +375,14 @@ static inline void hmm_pt_iter_directory_lock(struct hmm_pt_iter *iter)
 	hmm_pt_directory_lock(pt, iter->ptd[pt->llevel - 1], pt->llevel);
 }
 
+static inline spinlock_t *hmm_pt_iter_directory_lock_ptr(struct hmm_pt_iter *i)
+{
+	struct hmm_pt *pt = i->pt;
+
+	return hmm_pt_directory_lock_ptr(pt, i->ptd[pt->llevel - 1],
+					 pt->llevel);
+}
+
 static inline void hmm_pt_iter_directory_unlock(struct hmm_pt_iter *iter)
 {
 	struct hmm_pt *pt = iter->pt;
-- 
2.4.3