Merge tag 'omap-for-v4.1/wl12xx-dt' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into next/dt

Merge "wireless wl12xx and omap device tree changes for v4.1" from Tony
Lindgren:

Wireless and omap changes to make wl12xx driver to use device tree
data instead of platform data from Eliad Peller <eliad@wizery.com>:

- Add device-tree support to the wlcore (wl12xx/wl18xx) driver.

- Update the current users to use the bindings instead of pdata-quirks.

- Finally, remove the deprecated wl12xx_platform_data struct

Note that da850 board file code that still uses the platform data,
but we have da850.dtsi that can be used instead. So it was decided
that we should try to remove the wl12xx support from the da850
board file as suggested by Sekhar Nori <nsekhar@ti.com>. As it's
the last patch in the series, the last patch can be simply reverted
if needed.

As this series touches quite a bit of arch code, it was suggested
by Kalle Valo <kvalo@codeaurora.org> that the whole series should
be merged via the arm-soc tree.

* tag 'omap-for-v4.1/wl12xx-dt' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
  wlcore: remove wl12xx_platform_data
  ARM: dts: add wl12xx/wl18xx bindings
  wlcore: add device-tree support
  dt: bindings: add TI's wilink wireless device
  wl12xx: use frequency instead of enumerations for pdata clocks
  wlcore: set irq_trigger in board files instead of hiding behind a quirk
  + Linux 4.0-rc4

Signed-off-by: Olof Johansson <olof@lixom.net>

1 files changed, 768 insertions, 0 deletions

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
new file mode 100644
index 000000000000..9d96e283520c
--- /dev/null
+++ b/lib/iov_iter.c
@@ -0,0 +1,768 @@
+#include <linux/export.h>
+#include <linux/uio.h>
+#include <linux/pagemap.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <net/checksum.h>
+
+#define iterate_iovec(i, n, __v, __p, skip, STEP) {	\
+	size_t left;					\
+	size_t wanted = n;				\
+	__p = i->iov;					\
+	__v.iov_len = min(n, __p->iov_len - skip);	\
+	if (likely(__v.iov_len)) {			\
+		__v.iov_base = __p->iov_base + skip;	\
+		left = (STEP);				\
+		__v.iov_len -= left;			\
+		skip += __v.iov_len;			\
+		n -= __v.iov_len;			\
+	} else {					\
+		left = 0;				\
+	}						\
+	while (unlikely(!left && n)) {			\
+		__p++;					\
+		__v.iov_len = min(n, __p->iov_len);	\
+		if (unlikely(!__v.iov_len))		\
+			continue;			\
+		__v.iov_base = __p->iov_base;		\
+		left = (STEP);				\
+		__v.iov_len -= left;			\
+		skip = __v.iov_len;			\
+		n -= __v.iov_len;			\
+	}						\
+	n = wanted - n;					\
+}
+
+#define iterate_kvec(i, n, __v, __p, skip, STEP) {	\
+	size_t wanted = n;				\
+	__p = i->kvec;					\
+	__v.iov_len = min(n, __p->iov_len - skip);	\
+	if (likely(__v.iov_len)) {			\
+		__v.iov_base = __p->iov_base + skip;	\
+		(void)(STEP);				\
+		skip += __v.iov_len;			\
+		n -= __v.iov_len;			\
+	}						\
+	while (unlikely(n)) {				\
+		__p++;					\
+		__v.iov_len = min(n, __p->iov_len);	\
+		if (unlikely(!__v.iov_len))		\
+			continue;			\
+		__v.iov_base = __p->iov_base;		\
+		(void)(STEP);				\
+		skip = __v.iov_len;			\
+		n -= __v.iov_len;			\
+	}						\
+	n = wanted;					\
+}
+
+#define iterate_bvec(i, n, __v, __p, skip, STEP) {	\
+	size_t wanted = n;				\
+	__p = i->bvec;					\
+	__v.bv_len = min_t(size_t, n, __p->bv_len - skip);	\
+	if (likely(__v.bv_len)) {			\
+		__v.bv_page = __p->bv_page;		\
+		__v.bv_offset = __p->bv_offset + skip; 	\
+		(void)(STEP);				\
+		skip += __v.bv_len;			\
+		n -= __v.bv_len;			\
+	}						\
+	while (unlikely(n)) {				\
+		__p++;					\
+		__v.bv_len = min_t(size_t, n, __p->bv_len);	\
+		if (unlikely(!__v.bv_len))		\
+			continue;			\
+		__v.bv_page = __p->bv_page;		\
+		__v.bv_offset = __p->bv_offset;		\
+		(void)(STEP);				\
+		skip = __v.bv_len;			\
+		n -= __v.bv_len;			\
+	}						\
+	n = wanted;					\
+}
+
+#define iterate_all_kinds(i, n, v, I, B, K) {			\
+	size_t skip = i->iov_offset;				\
+	if (unlikely(i->type & ITER_BVEC)) {			\
+		const struct bio_vec *bvec;			\
+		struct bio_vec v;				\
+		iterate_bvec(i, n, v, bvec, skip, (B))		\
+	} else if (unlikely(i->type & ITER_KVEC)) {		\
+		const struct kvec *kvec;			\
+		struct kvec v;					\
+		iterate_kvec(i, n, v, kvec, skip, (K))		\
+	} else {						\
+		const struct iovec *iov;			\
+		struct iovec v;					\
+		iterate_iovec(i, n, v, iov, skip, (I))		\
+	}							\
+}
+
+#define iterate_and_advance(i, n, v, I, B, K) {			\
+	size_t skip = i->iov_offset;				\
+	if (unlikely(i->type & ITER_BVEC)) {			\
+		const struct bio_vec *bvec;			\
+		struct bio_vec v;				\
+		iterate_bvec(i, n, v, bvec, skip, (B))		\
+		if (skip == bvec->bv_len) {			\
+			bvec++;					\
+			skip = 0;				\
+		}						\
+		i->nr_segs -= bvec - i->bvec;			\
+		i->bvec = bvec;					\
+	} else if (unlikely(i->type & ITER_KVEC)) {		\
+		const struct kvec *kvec;			\
+		struct kvec v;					\
+		iterate_kvec(i, n, v, kvec, skip, (K))		\
+		if (skip == kvec->iov_len) {			\
+			kvec++;					\
+			skip = 0;				\
+		}						\
+		i->nr_segs -= kvec - i->kvec;			\
+		i->kvec = kvec;					\
+	} else {						\
+		const struct iovec *iov;			\
+		struct iovec v;					\
+		iterate_iovec(i, n, v, iov, skip, (I))		\
+		if (skip == iov->iov_len) {			\
+			iov++;					\
+			skip = 0;				\
+		}						\
+		i->nr_segs -= iov - i->iov;			\
+		i->iov = iov;					\
+	}							\
+	i->count -= n;						\
+	i->iov_offset = skip;					\
+}
+
+static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes,
+			 struct iov_iter *i)
+{
+	size_t skip, copy, left, wanted;
+	const struct iovec *iov;
+	char __user *buf;
+	void *kaddr, *from;
+
+	if (unlikely(bytes > i->count))
+		bytes = i->count;
+
+	if (unlikely(!bytes))
+		return 0;
+
+	wanted = bytes;
+	iov = i->iov;
+	skip = i->iov_offset;
+	buf = iov->iov_base + skip;
+	copy = min(bytes, iov->iov_len - skip);
+
+	if (!fault_in_pages_writeable(buf, copy)) {
+		kaddr = kmap_atomic(page);
+		from = kaddr + offset;
+
+		/* first chunk, usually the only one */
+		left = __copy_to_user_inatomic(buf, from, copy);
+		copy -= left;
+		skip += copy;
+		from += copy;
+		bytes -= copy;
+
+		while (unlikely(!left && bytes)) {
+			iov++;
+			buf = iov->iov_base;
+			copy = min(bytes, iov->iov_len);
+			left = __copy_to_user_inatomic(buf, from, copy);
+			copy -= left;
+			skip = copy;
+			from += copy;
+			bytes -= copy;
+		}
+		if (likely(!bytes)) {
+			kunmap_atomic(kaddr);
+			goto done;
+		}
+		offset = from - kaddr;
+		buf += copy;
+		kunmap_atomic(kaddr);
+		copy = min(bytes, iov->iov_len - skip);
+	}
+	/* Too bad - revert to non-atomic kmap */
+	kaddr = kmap(page);
+	from = kaddr + offset;
+	left = __copy_to_user(buf, from, copy);
+	copy -= left;
+	skip += copy;
+	from += copy;
+	bytes -= copy;
+	while (unlikely(!left && bytes)) {
+		iov++;
+		buf = iov->iov_base;
+		copy = min(bytes, iov->iov_len);
+		left = __copy_to_user(buf, from, copy);
+		copy -= left;
+		skip = copy;
+		from += copy;
+		bytes -= copy;
+	}
+	kunmap(page);
+done:
+	if (skip == iov->iov_len) {
+		iov++;
+		skip = 0;
+	}
+	i->count -= wanted - bytes;
+	i->nr_segs -= iov - i->iov;
+	i->iov = iov;
+	i->iov_offset = skip;
+	return wanted - bytes;
+}
+
+static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes,
+			 struct iov_iter *i)
+{
+	size_t skip, copy, left, wanted;
+	const struct iovec *iov;
+	char __user *buf;
+	void *kaddr, *to;
+
+	if (unlikely(bytes > i->count))
+		bytes = i->count;
+
+	if (unlikely(!bytes))
+		return 0;
+
+	wanted = bytes;
+	iov = i->iov;
+	skip = i->iov_offset;
+	buf = iov->iov_base + skip;
+	copy = min(bytes, iov->iov_len - skip);
+
+	if (!fault_in_pages_readable(buf, copy)) {
+		kaddr = kmap_atomic(page);
+		to = kaddr + offset;
+
+		/* first chunk, usually the only one */
+		left = __copy_from_user_inatomic(to, buf, copy);
+		copy -= left;
+		skip += copy;
+		to += copy;
+		bytes -= copy;
+
+		while (unlikely(!left && bytes)) {
+			iov++;
+			buf = iov->iov_base;
+			copy = min(bytes, iov->iov_len);
+			left = __copy_from_user_inatomic(to, buf, copy);
+			copy -= left;
+			skip = copy;
+			to += copy;
+			bytes -= copy;
+		}
+		if (likely(!bytes)) {
+			kunmap_atomic(kaddr);
+			goto done;
+		}
+		offset = to - kaddr;
+		buf += copy;
+		kunmap_atomic(kaddr);
+		copy = min(bytes, iov->iov_len - skip);
+	}
+	/* Too bad - revert to non-atomic kmap */
+	kaddr = kmap(page);
+	to = kaddr + offset;
+	left = __copy_from_user(to, buf, copy);
+	copy -= left;
+	skip += copy;
+	to += copy;
+	bytes -= copy;
+	while (unlikely(!left && bytes)) {
+		iov++;
+		buf = iov->iov_base;
+		copy = min(bytes, iov->iov_len);
+		left = __copy_from_user(to, buf, copy);
+		copy -= left;
+		skip = copy;
+		to += copy;
+		bytes -= copy;
+	}
+	kunmap(page);
+done:
+	if (skip == iov->iov_len) {
+		iov++;
+		skip = 0;
+	}
+	i->count -= wanted - bytes;
+	i->nr_segs -= iov - i->iov;
+	i->iov = iov;
+	i->iov_offset = skip;
+	return wanted - bytes;
+}
+
+/*
+ * Fault in the first iovec of the given iov_iter, to a maximum length
+ * of bytes. Returns 0 on success, or non-zero if the memory could not be
+ * accessed (ie. because it is an invalid address).
+ *
+ * writev-intensive code may want this to prefault several iovecs -- that
+ * would be possible (callers must not rely on the fact that _only_ the
+ * first iovec will be faulted with the current implementation).
+ */
+int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes)
+{
+	if (!(i->type & (ITER_BVEC|ITER_KVEC))) {
+		char __user *buf = i->iov->iov_base + i->iov_offset;
+		bytes = min(bytes, i->iov->iov_len - i->iov_offset);
+		return fault_in_pages_readable(buf, bytes);
+	}
+	return 0;
+}
+EXPORT_SYMBOL(iov_iter_fault_in_readable);
+
+void iov_iter_init(struct iov_iter *i, int direction,
+			const struct iovec *iov, unsigned long nr_segs,
+			size_t count)
+{
+	/* It will get better.  Eventually... */
+	if (segment_eq(get_fs(), KERNEL_DS)) {
+		direction |= ITER_KVEC;
+		i->type = direction;
+		i->kvec = (struct kvec *)iov;
+	} else {
+		i->type = direction;
+		i->iov = iov;
+	}
+	i->nr_segs = nr_segs;
+	i->iov_offset = 0;
+	i->count = count;
+}
+EXPORT_SYMBOL(iov_iter_init);
+
+static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len)
+{
+	char *from = kmap_atomic(page);
+	memcpy(to, from + offset, len);
+	kunmap_atomic(from);
+}
+
+static void memcpy_to_page(struct page *page, size_t offset, char *from, size_t len)
+{
+	char *to = kmap_atomic(page);
+	memcpy(to + offset, from, len);
+	kunmap_atomic(to);
+}
+
+static void memzero_page(struct page *page, size_t offset, size_t len)
+{
+	char *addr = kmap_atomic(page);
+	memset(addr + offset, 0, len);
+	kunmap_atomic(addr);
+}
+
+size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i)
+{
+	char *from = addr;
+	if (unlikely(bytes > i->count))
+		bytes = i->count;
+
+	if (unlikely(!bytes))
+		return 0;
+
+	iterate_and_advance(i, bytes, v,
+		__copy_to_user(v.iov_base, (from += v.iov_len) - v.iov_len,
+			       v.iov_len),
+		memcpy_to_page(v.bv_page, v.bv_offset,
+			       (from += v.bv_len) - v.bv_len, v.bv_len),
+		memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len)
+	)
+
+	return bytes;
+}
+EXPORT_SYMBOL(copy_to_iter);
+
+size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
+{
+	char *to = addr;
+	if (unlikely(bytes > i->count))
+		bytes = i->count;
+
+	if (unlikely(!bytes))
+		return 0;
+
+	iterate_and_advance(i, bytes, v,
+		__copy_from_user((to += v.iov_len) - v.iov_len, v.iov_base,
+				 v.iov_len),
+		memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
+				 v.bv_offset, v.bv_len),
+		memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
+	)
+
+	return bytes;
+}
+EXPORT_SYMBOL(copy_from_iter);
+
+size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
+{
+	char *to = addr;
+	if (unlikely(bytes > i->count))
+		bytes = i->count;
+
+	if (unlikely(!bytes))
+		return 0;
+
+	iterate_and_advance(i, bytes, v,
+		__copy_from_user_nocache((to += v.iov_len) - v.iov_len,
+					 v.iov_base, v.iov_len),
+		memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
+				 v.bv_offset, v.bv_len),
+		memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
+	)
+
+	return bytes;
+}
+EXPORT_SYMBOL(copy_from_iter_nocache);
+
+size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
+			 struct iov_iter *i)
+{
+	if (i->type & (ITER_BVEC|ITER_KVEC)) {
+		void *kaddr = kmap_atomic(page);
+		size_t wanted = copy_to_iter(kaddr + offset, bytes, i);
+		kunmap_atomic(kaddr);
+		return wanted;
+	} else
+		return copy_page_to_iter_iovec(page, offset, bytes, i);
+}
+EXPORT_SYMBOL(copy_page_to_iter);
+
+size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
+			 struct iov_iter *i)
+{
+	if (i->type & (ITER_BVEC|ITER_KVEC)) {
+		void *kaddr = kmap_atomic(page);
+		size_t wanted = copy_from_iter(kaddr + offset, bytes, i);
+		kunmap_atomic(kaddr);
+		return wanted;
+	} else
+		return copy_page_from_iter_iovec(page, offset, bytes, i);
+}
+EXPORT_SYMBOL(copy_page_from_iter);
+
+size_t iov_iter_zero(size_t bytes, struct iov_iter *i)
+{
+	if (unlikely(bytes > i->count))
+		bytes = i->count;
+
+	if (unlikely(!bytes))
+		return 0;
+
+	iterate_and_advance(i, bytes, v,
+		__clear_user(v.iov_base, v.iov_len),
+		memzero_page(v.bv_page, v.bv_offset, v.bv_len),
+		memset(v.iov_base, 0, v.iov_len)
+	)
+
+	return bytes;
+}
+EXPORT_SYMBOL(iov_iter_zero);
+
+size_t iov_iter_copy_from_user_atomic(struct page *page,
+		struct iov_iter *i, unsigned long offset, size_t bytes)
+{
+	char *kaddr = kmap_atomic(page), *p = kaddr + offset;
+	iterate_all_kinds(i, bytes, v,
+		__copy_from_user_inatomic((p += v.iov_len) - v.iov_len,
+					  v.iov_base, v.iov_len),
+		memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page,
+				 v.bv_offset, v.bv_len),
+		memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
+	)
+	kunmap_atomic(kaddr);
+	return bytes;
+}
+EXPORT_SYMBOL(iov_iter_copy_from_user_atomic);
+
+void iov_iter_advance(struct iov_iter *i, size_t size)
+{
+	iterate_and_advance(i, size, v, 0, 0, 0)
+}
+EXPORT_SYMBOL(iov_iter_advance);
+
+/*
+ * Return the count of just the current iov_iter segment.
+ */
+size_t iov_iter_single_seg_count(const struct iov_iter *i)
+{
+	if (i->nr_segs == 1)
+		return i->count;
+	else if (i->type & ITER_BVEC)
+		return min(i->count, i->bvec->bv_len - i->iov_offset);
+	else
+		return min(i->count, i->iov->iov_len - i->iov_offset);
+}
+EXPORT_SYMBOL(iov_iter_single_seg_count);
+
+void iov_iter_kvec(struct iov_iter *i, int direction,
+			const struct kvec *kvec, unsigned long nr_segs,
+			size_t count)
+{
+	BUG_ON(!(direction & ITER_KVEC));
+	i->type = direction;
+	i->kvec = kvec;
+	i->nr_segs = nr_segs;
+	i->iov_offset = 0;
+	i->count = count;
+}
+EXPORT_SYMBOL(iov_iter_kvec);
+
+void iov_iter_bvec(struct iov_iter *i, int direction,
+			const struct bio_vec *bvec, unsigned long nr_segs,
+			size_t count)
+{
+	BUG_ON(!(direction & ITER_BVEC));
+	i->type = direction;
+	i->bvec = bvec;
+	i->nr_segs = nr_segs;
+	i->iov_offset = 0;
+	i->count = count;
+}
+EXPORT_SYMBOL(iov_iter_bvec);
+
+unsigned long iov_iter_alignment(const struct iov_iter *i)
+{
+	unsigned long res = 0;
+	size_t size = i->count;
+
+	if (!size)
+		return 0;
+
+	iterate_all_kinds(i, size, v,
+		(res |= (unsigned long)v.iov_base | v.iov_len, 0),
+		res |= v.bv_offset | v.bv_len,
+		res |= (unsigned long)v.iov_base | v.iov_len
+	)
+	return res;
+}
+EXPORT_SYMBOL(iov_iter_alignment);
+
+ssize_t iov_iter_get_pages(struct iov_iter *i,
+		   struct page **pages, size_t maxsize, unsigned maxpages,
+		   size_t *start)
+{
+	if (maxsize > i->count)
+		maxsize = i->count;
+
+	if (!maxsize)
+		return 0;
+
+	iterate_all_kinds(i, maxsize, v, ({
+		unsigned long addr = (unsigned long)v.iov_base;
+		size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1));
+		int n;
+		int res;
+
+		if (len > maxpages * PAGE_SIZE)
+			len = maxpages * PAGE_SIZE;
+		addr &= ~(PAGE_SIZE - 1);
+		n = DIV_ROUND_UP(len, PAGE_SIZE);
+		res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages);
+		if (unlikely(res < 0))
+			return res;
+		return (res == n ? len : res * PAGE_SIZE) - *start;
+	0;}),({
+		/* can't be more than PAGE_SIZE */
+		*start = v.bv_offset;
+		get_page(*pages = v.bv_page);
+		return v.bv_len;
+	}),({
+		return -EFAULT;
+	})
+	)
+	return 0;
+}
+EXPORT_SYMBOL(iov_iter_get_pages);
+
+static struct page **get_pages_array(size_t n)
+{
+	struct page **p = kmalloc(n * sizeof(struct page *), GFP_KERNEL);
+	if (!p)
+		p = vmalloc(n * sizeof(struct page *));
+	return p;
+}
+
+ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
+		   struct page ***pages, size_t maxsize,
+		   size_t *start)
+{
+	struct page **p;
+
+	if (maxsize > i->count)
+		maxsize = i->count;
+
+	if (!maxsize)
+		return 0;
+
+	iterate_all_kinds(i, maxsize, v, ({
+		unsigned long addr = (unsigned long)v.iov_base;
+		size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1));
+		int n;
+		int res;
+
+		addr &= ~(PAGE_SIZE - 1);
+		n = DIV_ROUND_UP(len, PAGE_SIZE);
+		p = get_pages_array(n);
+		if (!p)
+			return -ENOMEM;
+		res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p);
+		if (unlikely(res < 0)) {
+			kvfree(p);
+			return res;
+		}
+		*pages = p;
+		return (res == n ? len : res * PAGE_SIZE) - *start;
+	0;}),({
+		/* can't be more than PAGE_SIZE */
+		*start = v.bv_offset;
+		*pages = p = get_pages_array(1);
+		if (!p)
+			return -ENOMEM;
+		get_page(*p = v.bv_page);
+		return v.bv_len;
+	}),({
+		return -EFAULT;
+	})
+	)
+	return 0;
+}
+EXPORT_SYMBOL(iov_iter_get_pages_alloc);
+
+size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
+			       struct iov_iter *i)
+{
+	char *to = addr;
+	__wsum sum, next;
+	size_t off = 0;
+	if (unlikely(bytes > i->count))
+		bytes = i->count;
+
+	if (unlikely(!bytes))
+		return 0;
+
+	sum = *csum;
+	iterate_and_advance(i, bytes, v, ({
+		int err = 0;
+		next = csum_and_copy_from_user(v.iov_base, 
+					       (to += v.iov_len) - v.iov_len,
+					       v.iov_len, 0, &err);
+		if (!err) {
+			sum = csum_block_add(sum, next, off);
+			off += v.iov_len;
+		}
+		err ? v.iov_len : 0;
+	}), ({
+		char *p = kmap_atomic(v.bv_page);
+		next = csum_partial_copy_nocheck(p + v.bv_offset,
+						 (to += v.bv_len) - v.bv_len,
+						 v.bv_len, 0);
+		kunmap_atomic(p);
+		sum = csum_block_add(sum, next, off);
+		off += v.bv_len;
+	}),({
+		next = csum_partial_copy_nocheck(v.iov_base,
+						 (to += v.iov_len) - v.iov_len,
+						 v.iov_len, 0);
+		sum = csum_block_add(sum, next, off);
+		off += v.iov_len;
+	})
+	)
+	*csum = sum;
+	return bytes;
+}
+EXPORT_SYMBOL(csum_and_copy_from_iter);
+
+size_t csum_and_copy_to_iter(void *addr, size_t bytes, __wsum *csum,
+			     struct iov_iter *i)
+{
+	char *from = addr;
+	__wsum sum, next;
+	size_t off = 0;
+	if (unlikely(bytes > i->count))
+		bytes = i->count;
+
+	if (unlikely(!bytes))
+		return 0;
+
+	sum = *csum;
+	iterate_and_advance(i, bytes, v, ({
+		int err = 0;
+		next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len,
+					     v.iov_base, 
+					     v.iov_len, 0, &err);
+		if (!err) {
+			sum = csum_block_add(sum, next, off);
+			off += v.iov_len;
+		}
+		err ? v.iov_len : 0;
+	}), ({
+		char *p = kmap_atomic(v.bv_page);
+		next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len,
+						 p + v.bv_offset,
+						 v.bv_len, 0);
+		kunmap_atomic(p);
+		sum = csum_block_add(sum, next, off);
+		off += v.bv_len;
+	}),({
+		next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len,
+						 v.iov_base,
+						 v.iov_len, 0);
+		sum = csum_block_add(sum, next, off);
+		off += v.iov_len;
+	})
+	)
+	*csum = sum;
+	return bytes;
+}
+EXPORT_SYMBOL(csum_and_copy_to_iter);
+
+int iov_iter_npages(const struct iov_iter *i, int maxpages)
+{
+	size_t size = i->count;
+	int npages = 0;
+
+	if (!size)
+		return 0;
+
+	iterate_all_kinds(i, size, v, ({
+		unsigned long p = (unsigned long)v.iov_base;
+		npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE)
+			- p / PAGE_SIZE;
+		if (npages >= maxpages)
+			return maxpages;
+	0;}),({
+		npages++;
+		if (npages >= maxpages)
+			return maxpages;
+	}),({
+		unsigned long p = (unsigned long)v.iov_base;
+		npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE)
+			- p / PAGE_SIZE;
+		if (npages >= maxpages)
+			return maxpages;
+	})
+	)
+	return npages;
+}
+EXPORT_SYMBOL(iov_iter_npages);
+
+const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags)
+{
+	*new = *old;
+	if (new->type & ITER_BVEC)
+		return new->bvec = kmemdup(new->bvec,
+				    new->nr_segs * sizeof(struct bio_vec),
+				    flags);
+	else
+		/* iovec and kvec have identical layout */
+		return new->iov = kmemdup(new->iov,
+				   new->nr_segs * sizeof(struct iovec),
+				   flags);
+}
+EXPORT_SYMBOL(dup_iter);