diff options
| author | Vineet Gupta <vgupta@synopsys.com> | 2013-10-07 18:10:08 +0530 |
|---|---|---|
| committer | Vineet Gupta <vgupta@synopsys.com> | 2015-06-22 14:06:56 +0530 |
| commit | 8922bc3058abbe5deaf887147e26531750ce7513 (patch) | |
| tree | 647f15f01077a23afd047e3d01b125a93e2ac9b1 /arch/arc/include/asm/uaccess.h | |
| parent | 1f7e3dc0baaa41217dc06d3370e1efd1aecbc1f0 (diff) | |
ARCv2: Adhere to Zero Delay loop restriction
Branch insn can't be scheduled as last insn of Zero Overhead loop
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc/include/asm/uaccess.h')
| -rw-r--r-- | arch/arc/include/asm/uaccess.h | 17 |
1 files changed, 8 insertions, 9 deletions
diff --git a/arch/arc/include/asm/uaccess.h b/arch/arc/include/asm/uaccess.h index 30c9baffa96f..d1da6032b715 100644 --- a/arch/arc/include/asm/uaccess.h +++ b/arch/arc/include/asm/uaccess.h @@ -659,31 +659,30 @@ static inline unsigned long __arc_clear_user(void __user *to, unsigned long n) static inline long __arc_strncpy_from_user(char *dst, const char __user *src, long count) { - long res = count; + long res = 0; char val; - unsigned int hw_count; if (count == 0) return 0; __asm__ __volatile__( - " lp 2f \n" + " lp 3f \n" "1: ldb.ab %3, [%2, 1] \n" - " breq.d %3, 0, 2f \n" + " breq.d %3, 0, 3f \n" " stb.ab %3, [%1, 1] \n" - "2: sub %0, %6, %4 \n" - "3: ;nop \n" + " add %0, %0, 1 # Num of NON NULL bytes copied \n" + "3: \n" " .section .fixup, \"ax\" \n" " .align 4 \n" - "4: mov %0, %5 \n" + "4: mov %0, %4 # sets @res as -EFAULT \n" " j 3b \n" " .previous \n" " .section __ex_table, \"a\" \n" " .align 4 \n" " .word 1b, 4b \n" " .previous \n" - : "=r"(res), "+r"(dst), "+r"(src), "=&r"(val), "=l"(hw_count) - : "g"(-EFAULT), "ir"(count), "4"(count) /* this "4" seeds lp_count */ + : "+r"(res), "+r"(dst), "+r"(src), "=r"(val) + : "g"(-EFAULT), "l"(count) : "memory"); return res; |