Add iov_iter_get_pages_flags() and iov_iter_get_pages_alloc_flags()
which take a flags argument that is passed to get_user_pages_fast().
This is so that FOLL_PCI_P2PDMA can be passed when appropriate.
Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
---
include/linux/uio.h | 21 +++++++++++++++++----
lib/iov_iter.c | 28 ++++++++++++++++------------
2 files changed, 33 insertions(+), 16 deletions(-)
diff --git a/include/linux/uio.h b/include/linux/uio.h
index 5265024e8b90..d4ce252db728 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -228,10 +228,23 @@ void iov_iter_pipe(struct iov_iter *i, unsigned int direction, struct pipe_inode
void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count);
void iov_iter_xarray(struct iov_iter *i, unsigned int direction, struct xarray *xarray,
loff_t start, size_t count);
-ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages,
- size_t maxsize, unsigned maxpages, size_t *start);
-ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages,
- size_t maxsize, size_t *start);
+ssize_t iov_iter_get_pages_flags(struct iov_iter *i, struct page **pages,
+ size_t maxsize, unsigned maxpages, size_t *start,
+ unsigned int gup_flags);
+ssize_t iov_iter_get_pages_alloc_flags(struct iov_iter *i,
+ struct page ***pages, size_t maxsize, size_t *start,
+ unsigned int gup_flags);
+static inline ssize_t iov_iter_get_pages(struct iov_iter *i,
+ struct page **pages, size_t maxsize, unsigned maxpages,
+ size_t *start)
+{
+ return iov_iter_get_pages_flags(i, pages, maxsize, maxpages, start, 0);
+}
+static inline ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
+ struct page ***pages, size_t maxsize, size_t *start)
+{
+ return iov_iter_get_pages_alloc_flags(i, pages, maxsize, start, 0);
+}
int iov_iter_npages(const struct iov_iter *i, int maxpages);
const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags);
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index f2d50d69a6c3..bbf0fb6736a9 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1468,9 +1468,9 @@ static struct page *first_bvec_segment(const struct iov_iter *i,
return page;
}
-ssize_t iov_iter_get_pages(struct iov_iter *i,
+ssize_t iov_iter_get_pages_flags(struct iov_iter *i,
struct page **pages, size_t maxsize, unsigned maxpages,
- size_t *start)
+ size_t *start, unsigned int gup_flags)
{
size_t len;
int n, res;
@@ -1485,9 +1485,11 @@ ssize_t iov_iter_get_pages(struct iov_iter *i,
addr = first_iovec_segment(i, &len, start, maxsize, maxpages);
n = DIV_ROUND_UP(len, PAGE_SIZE);
- res = get_user_pages_fast(addr, n,
- iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0,
- pages);
+
+ if (iov_iter_rw(i) != WRITE)
+ gup_flags |= FOLL_WRITE;
+
+ res = get_user_pages_fast(addr, n, gup_flags, pages);
if (unlikely(res < 0))
return res;
return (res == n ? len : res * PAGE_SIZE) - *start;
@@ -1507,7 +1509,7 @@ ssize_t iov_iter_get_pages(struct iov_iter *i,
return iter_xarray_get_pages(i, pages, maxsize, maxpages, start);
return -EFAULT;
}
-EXPORT_SYMBOL(iov_iter_get_pages);
+EXPORT_SYMBOL(iov_iter_get_pages_flags);
static struct page **get_pages_array(size_t n)
{
@@ -1589,9 +1591,9 @@ static ssize_t iter_xarray_get_pages_alloc(struct iov_iter *i,
return actual;
}
-ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
+ssize_t iov_iter_get_pages_alloc_flags(struct iov_iter *i,
struct page ***pages, size_t maxsize,
- size_t *start)
+ size_t *start, unsigned int gup_flags)
{
struct page **p;
size_t len;
@@ -1604,14 +1606,16 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
if (likely(iter_is_iovec(i))) {
unsigned long addr;
-
addr = first_iovec_segment(i, &len, start, maxsize, ~0U);
n = DIV_ROUND_UP(len, PAGE_SIZE);
p = get_pages_array(n);
if (!p)
return -ENOMEM;
- res = get_user_pages_fast(addr, n,
- iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, p);
+
+ if (iov_iter_rw(i) != WRITE)
+ gup_flags |= FOLL_WRITE;
+
+ res = get_user_pages_fast(addr, n, gup_flags, p);
if (unlikely(res < 0)) {
kvfree(p);
return res;
@@ -1637,7 +1641,7 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
return iter_xarray_get_pages_alloc(i, pages, maxsize, start);
return -EFAULT;
}
-EXPORT_SYMBOL(iov_iter_get_pages_alloc);
+EXPORT_SYMBOL(iov_iter_get_pages_alloc_flags);
size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
struct iov_iter *i)
--
2.30.2
