Merge tag 'mvebu-dt-3.17-2' of git://git.infradead.org/linux-mvebu into next/dt

[cascardo/linux.git] / lib / iovec.c

diff --git a/lib/iovec.c b/lib/iovec.c
index 454baa8..7a7c2da 100644 (file)
--- a/lib/iovec.c
+++ b/lib/iovec.c
@@ -51,3 +51,58 @@ int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len)
        return 0;
 }
 EXPORT_SYMBOL(memcpy_toiovec);
+
+/*
+ *     Copy kernel to iovec. Returns -EFAULT on error.
+ */
+
+int memcpy_toiovecend(const struct iovec *iov, unsigned char *kdata,
+                     int offset, int len)
+{
+       int copy;
+       for (; len > 0; ++iov) {
+               /* Skip over the finished iovecs */
+               if (unlikely(offset >= iov->iov_len)) {
+                       offset -= iov->iov_len;
+                       continue;
+               }
+               copy = min_t(unsigned int, iov->iov_len - offset, len);
+               if (copy_to_user(iov->iov_base + offset, kdata, copy))
+                       return -EFAULT;
+               offset = 0;
+               kdata += copy;
+               len -= copy;
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL(memcpy_toiovecend);
+
+/*
+ *     Copy iovec to kernel. Returns -EFAULT on error.
+ */
+
+int memcpy_fromiovecend(unsigned char *kdata, const struct iovec *iov,
+                       int offset, int len)
+{
+       /* Skip over the finished iovecs */
+       while (offset >= iov->iov_len) {
+               offset -= iov->iov_len;
+               iov++;
+       }
+
+       while (len > 0) {
+               u8 __user *base = iov->iov_base + offset;
+               int copy = min_t(unsigned int, len, iov->iov_len - offset);
+
+               offset = 0;
+               if (copy_from_user(kdata, base, copy))
+                       return -EFAULT;
+               len -= copy;
+               kdata += copy;
+               iov++;
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL(memcpy_fromiovecend);