v4.19.13 snapshot.
diff --git a/arch/x86/lib/csum-wrappers_64.c b/arch/x86/lib/csum-wrappers_64.c
new file mode 100644
index 0000000..8bd5358
--- /dev/null
+++ b/arch/x86/lib/csum-wrappers_64.c
@@ -0,0 +1,158 @@
+/*
+ * Copyright 2002, 2003 Andi Kleen, SuSE Labs.
+ * Subject to the GNU Public License v.2
+ *
+ * Wrappers of assembly checksum functions for x86-64.
+ */
+#include <asm/checksum.h>
+#include <linux/export.h>
+#include <linux/uaccess.h>
+#include <asm/smap.h>
+
+/**
+ * csum_partial_copy_from_user - Copy and checksum from user space.
+ * @src: source address (user space)
+ * @dst: destination address
+ * @len: number of bytes to be copied.
+ * @isum: initial sum that is added into the result (32bit unfolded)
+ * @errp: set to -EFAULT for an bad source address.
+ *
+ * Returns an 32bit unfolded checksum of the buffer.
+ * src and dst are best aligned to 64bits.
+ */
+__wsum
+csum_partial_copy_from_user(const void __user *src, void *dst,
+ int len, __wsum isum, int *errp)
+{
+ might_sleep();
+ *errp = 0;
+
+ if (!likely(access_ok(VERIFY_READ, src, len)))
+ goto out_err;
+
+ /*
+ * Why 6, not 7? To handle odd addresses aligned we
+ * would need to do considerable complications to fix the
+ * checksum which is defined as an 16bit accumulator. The
+ * fix alignment code is primarily for performance
+ * compatibility with 32bit and that will handle odd
+ * addresses slowly too.
+ */
+ if (unlikely((unsigned long)src & 6)) {
+ while (((unsigned long)src & 6) && len >= 2) {
+ __u16 val16;
+
+ if (__get_user(val16, (const __u16 __user *)src))
+ goto out_err;
+
+ *(__u16 *)dst = val16;
+ isum = (__force __wsum)add32_with_carry(
+ (__force unsigned)isum, val16);
+ src += 2;
+ dst += 2;
+ len -= 2;
+ }
+ }
+ stac();
+ isum = csum_partial_copy_generic((__force const void *)src,
+ dst, len, isum, errp, NULL);
+ clac();
+ if (unlikely(*errp))
+ goto out_err;
+
+ return isum;
+
+out_err:
+ *errp = -EFAULT;
+ memset(dst, 0, len);
+
+ return isum;
+}
+EXPORT_SYMBOL(csum_partial_copy_from_user);
+
+/**
+ * csum_partial_copy_to_user - Copy and checksum to user space.
+ * @src: source address
+ * @dst: destination address (user space)
+ * @len: number of bytes to be copied.
+ * @isum: initial sum that is added into the result (32bit unfolded)
+ * @errp: set to -EFAULT for an bad destination address.
+ *
+ * Returns an 32bit unfolded checksum of the buffer.
+ * src and dst are best aligned to 64bits.
+ */
+__wsum
+csum_partial_copy_to_user(const void *src, void __user *dst,
+ int len, __wsum isum, int *errp)
+{
+ __wsum ret;
+
+ might_sleep();
+
+ if (unlikely(!access_ok(VERIFY_WRITE, dst, len))) {
+ *errp = -EFAULT;
+ return 0;
+ }
+
+ if (unlikely((unsigned long)dst & 6)) {
+ while (((unsigned long)dst & 6) && len >= 2) {
+ __u16 val16 = *(__u16 *)src;
+
+ isum = (__force __wsum)add32_with_carry(
+ (__force unsigned)isum, val16);
+ *errp = __put_user(val16, (__u16 __user *)dst);
+ if (*errp)
+ return isum;
+ src += 2;
+ dst += 2;
+ len -= 2;
+ }
+ }
+
+ *errp = 0;
+ stac();
+ ret = csum_partial_copy_generic(src, (void __force *)dst,
+ len, isum, NULL, errp);
+ clac();
+ return ret;
+}
+EXPORT_SYMBOL(csum_partial_copy_to_user);
+
+/**
+ * csum_partial_copy_nocheck - Copy and checksum.
+ * @src: source address
+ * @dst: destination address
+ * @len: number of bytes to be copied.
+ * @sum: initial sum that is added into the result (32bit unfolded)
+ *
+ * Returns an 32bit unfolded checksum of the buffer.
+ */
+__wsum
+csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
+{
+ return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL);
+}
+EXPORT_SYMBOL(csum_partial_copy_nocheck);
+
+__sum16 csum_ipv6_magic(const struct in6_addr *saddr,
+ const struct in6_addr *daddr,
+ __u32 len, __u8 proto, __wsum sum)
+{
+ __u64 rest, sum64;
+
+ rest = (__force __u64)htonl(len) + (__force __u64)htons(proto) +
+ (__force __u64)sum;
+
+ asm(" addq (%[saddr]),%[sum]\n"
+ " adcq 8(%[saddr]),%[sum]\n"
+ " adcq (%[daddr]),%[sum]\n"
+ " adcq 8(%[daddr]),%[sum]\n"
+ " adcq $0,%[sum]\n"
+
+ : [sum] "=r" (sum64)
+ : "[sum]" (rest), [saddr] "r" (saddr), [daddr] "r" (daddr));
+
+ return csum_fold(
+ (__force __wsum)add32_with_carry(sum64 & 0xffffffff, sum64>>32));
+}
+EXPORT_SYMBOL(csum_ipv6_magic);