microblaze: uaccess: Fix put_user for noMMU

Here is small regression on dhrystone tests and I think
that on all benchmarking tests. It is due to better checking
mechanism in put_user macro

Signed-off-by: Michal Simek <monstr@monstr.eu>

1 files changed, 56 insertions, 22 deletions

diff --git a/arch/microblaze/include/asm/uaccess.h b/arch/microblaze/include/asm/uaccess.h
index b079ac31a671..4f17950d0a0e 100644
--- a/arch/microblaze/include/asm/uaccess.h
+++ b/arch/microblaze/include/asm/uaccess.h
@@ -213,32 +213,66 @@ extern long __user_bad(void);
                 ? __get_user((x), (ptr)) : -EFAULT;                     \
 })
 
-/* Undefined function to trigger linker error */
-extern int bad_user_access_length(void);
+#define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err)      \
+({                                                              \
+        __asm__ __volatile__ (                                  \
+                        "1:"    insn    " %1, %2, r0;"          \
+                        "       addk    %0, r0, r0;"            \
+                        "2:                     "               \
+                        __FIXUP_SECTION                         \
+                        "3:     brid    2b;"                    \
+                        "       addik   %0, r0, %3;"            \
+                        ".previous;"                            \
+                        __EX_TABLE_SECTION                      \
+                        ".word  1b,3b;"                         \
+                        ".previous;"                            \
+                : "=&r"(__gu_err)                               \
+                : "r"(__gu_val), "r"(__gu_ptr), "i"(-EFAULT)    \
+        );                                                      \
+})
 
-/* FIXME is not there defined __pu_val */
-#define __put_user(var, ptr)                                    \
+#define __put_user_asm_8(__gu_ptr, __gu_val, __gu_err)          \
 ({                                                              \
-        int __pu_err = 0;                                       \
-        switch (sizeof(*(ptr))) {                               \
-        case 1:                                                 \
-        case 2:                                                 \
-        case 4:                                                 \
-                *(ptr) = (var);                                 \
-                break;                                          \
-        case 8: {                                               \
-                typeof(*(ptr)) __pu_val = (var);                \
-                memcpy(ptr, &__pu_val, sizeof(__pu_val));       \
-                }                                               \
-                break;                                          \
-        default:                                                \
-                __pu_err = __put_user_bad();                    \
-                break;                                          \
-        }                                                       \
-        __pu_err;                                               \
+        __asm__ __volatile__ (" lwi     %0, %1, 0;"             \
+                        "1:     swi     %0, %2, 0;"             \
+                        "       lwi     %0, %1, 4;"             \
+                        "2:     swi     %0, %2, 4;"             \
+                        "       addk    %0, r0, r0;"            \
+                        "3:                     "               \
+                        __FIXUP_SECTION                         \
+                        "4:     brid    3b;"                    \
+                        "       addik   %0, r0, %3;"            \
+                        ".previous;"                            \
+                        __EX_TABLE_SECTION                      \
+                        ".word  1b,4b,2b,4b;"                   \
+                        ".previous;"                            \
+                : "=&r"(__gu_err)                               \
+                : "r"(&__gu_val), "r"(__gu_ptr), "i"(-EFAULT)   \
+                );                                              \
 })
 
-#define __put_user_bad()        (bad_user_access_length(), (-EFAULT))
+#define __put_user(x, ptr)                                              \
+({                                                                      \
+        __typeof__(*(ptr)) volatile __gu_val = (x);                     \
+        long __gu_err = 0;                                              \
+        switch (sizeof(__gu_val)) {                                     \
+        case 1:                                                         \
+                __put_user_asm("sb", (ptr), __gu_val, __gu_err);        \
+                break;                                                  \
+        case 2:                                                         \
+                __put_user_asm("sh", (ptr), __gu_val, __gu_err);        \
+                break;                                                  \
+        case 4:                                                         \
+                __put_user_asm("sw", (ptr), __gu_val, __gu_err);        \
+                break;                                                  \
+        case 8:                                                         \
+                __put_user_asm_8((ptr), __gu_val, __gu_err);            \
+                break;                                                  \
+        default:                                                        \
+                /*__gu_err = -EINVAL;*/ __gu_err = __user_bad();        \
+        }                                                               \
+        __gu_err;                                                       \
+})
 
 #define put_user(x, ptr)        __put_user((x), (ptr))