From: John Hubbard <jhubbard@nvidia.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Walls <awalls@md.metrocast.net>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
<linux-media@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>,
John Hubbard <jhubbard@nvidia.com>
Subject: [PATCH 1/2] mm/gup: introduce pin_user_pages_unlocked
Date: Sun, 17 May 2020 18:21:56 -0700 [thread overview]
Message-ID: <20200518012157.1178336-2-jhubbard@nvidia.com> (raw)
In-Reply-To: <20200518012157.1178336-1-jhubbard@nvidia.com>
Introduce pin_user_pages_unlocked(), which is nearly identical to the
get_user_pages_unlocked() that it wraps, except that it sets FOLL_PIN
and rejects FOLL_GET.
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---
include/linux/mm.h | 2 ++
mm/gup.c | 17 +++++++++++++++++
2 files changed, 19 insertions(+)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5a323422d783..a5594ac9ebe3 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1702,6 +1702,8 @@ long get_user_pages_locked(unsigned long start, unsigned long nr_pages,
unsigned int gup_flags, struct page **pages, int *locked);
long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages,
struct page **pages, unsigned int gup_flags);
+long pin_user_pages_unlocked(unsigned long start, unsigned long nr_pages,
+ struct page **pages, unsigned int gup_flags);
int get_user_pages_fast(unsigned long start, int nr_pages,
unsigned int gup_flags, struct page **pages);
diff --git a/mm/gup.c b/mm/gup.c
index 87a6a59fe667..50cd9323efff 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -2939,3 +2939,20 @@ long pin_user_pages(unsigned long start, unsigned long nr_pages,
pages, vmas, gup_flags);
}
EXPORT_SYMBOL(pin_user_pages);
+
+/*
+ * pin_user_pages_unlocked() is the FOLL_PIN variant of
+ * get_user_pages_unlocked(). Behavior is the same, except that this one sets
+ * FOLL_PIN and rejects FOLL_GET.
+ */
+long pin_user_pages_unlocked(unsigned long start, unsigned long nr_pages,
+ struct page **pages, unsigned int gup_flags)
+{
+ /* FOLL_GET and FOLL_PIN are mutually exclusive. */
+ if (WARN_ON_ONCE(gup_flags & FOLL_GET))
+ return -EINVAL;
+
+ gup_flags |= FOLL_PIN;
+ return get_user_pages_unlocked(start, nr_pages, pages, gup_flags);
+}
+EXPORT_SYMBOL(pin_user_pages_unlocked);
base-commit: b9bbe6ed63b2b9f2c9ee5cbd0f2c946a2723f4ce
prerequisite-patch-id: 0496235d2f0b29f75b9835e63a6923ddad6d0260
prerequisite-patch-id: 2711b9393a74cd0e1fcf48befea3618f7bb1ca9e
prerequisite-patch-id: 95e2521748b3058710fb2a161b2c76389644665b
prerequisite-patch-id: eeae300399f69db2cd61535b40c1f1ee1929195a
prerequisite-patch-id: 9ed26cdb071ab084a204c85a08986806d6bae877
--
2.26.2
next prev parent reply other threads:[~2020-05-18 1:22 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-18 1:21 [PATCH 0/2] mm/gup, media/ivtv: introduce pin_user_pages_unlocked John Hubbard
2020-05-18 1:21 ` John Hubbard [this message]
2020-05-18 1:21 ` [PATCH 2/2] ivtv: convert get_user_pages() --> pin_user_pages() John Hubbard
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