MIPS: asm: checksum: Split kernel and user copy operations

In EVA mode, different instructions need to be used to read/write
from kernel and userland. In non-EVA mode, there is no functional
difference. The current address limit is checked to decide the
type of operation that will be performed.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>

1 files changed, 16 insertions, 6 deletions

diff --git a/arch/mips/include/asm/checksum.h b/arch/mips/include/asm/checksum.h
index 3c9aea55954f..f5602c6957c7 100644
--- a/arch/mips/include/asm/checksum.h
+++ b/arch/mips/include/asm/checksum.h
@@ -37,7 +37,6 @@ __wsum __csum_partial_copy_from_user(const void *src, void *dst,
                                      int len, __wsum sum, int *err_ptr);
 __wsum __csum_partial_copy_to_user(const void *src, void *dst,
                                    int len, __wsum sum, int *err_ptr);
-
 /*
  * this is a new version of the above that records errors it finds in *errp,
  * but continues and zeros the rest of the buffer.
@@ -47,8 +46,12 @@ __wsum csum_partial_copy_from_user(const void __user *src, void *dst, int len,
                                    __wsum sum, int *err_ptr)
 {
         might_fault();
-        return __csum_partial_copy_from_user((__force void *)src, dst,
-                                             len, sum, err_ptr);
+        if (segment_eq(get_fs(), get_ds()))
+                return __csum_partial_copy_kernel((__force void *)src, dst,
+                                                  len, sum, err_ptr);
+        else
+                return __csum_partial_copy_from_user((__force void *)src, dst,
+                                                     len, sum, err_ptr);
 }
 
 /*
@@ -60,9 +63,16 @@ __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len,
                              __wsum sum, int *err_ptr)
 {
         might_fault();
-        if (access_ok(VERIFY_WRITE, dst, len))
-                return __csum_partial_copy_to_user(src, (__force void *)dst,
-                                                   len, sum, err_ptr);
+        if (access_ok(VERIFY_WRITE, dst, len)) {
+                if (segment_eq(get_fs(), get_ds()))
+                        return __csum_partial_copy_kernel(src,
+                                                          (__force void *)dst,
+                                                          len, sum, err_ptr);
+                else
+                        return __csum_partial_copy_to_user(src,
+                                                           (__force void *)dst,
+                                                           len, sum, err_ptr);
+        }
         if (len)
                 *err_ptr = -EFAULT;