MIPS: lib: memcpy: Add MIPS R6 support

MIPS R6 does not support the unaligned load and store instructions
so we add a special MIPS R6 case to copy one byte at a time if we
need to read/write to unaligned memory addresses.

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

diff --git a/arch/mips/lib/memcpy.S b/arch/mips/lib/memcpy.S
index 5d3238a..9245e17 100644 (file)
--- a/arch/mips/lib/memcpy.S
+++ b/arch/mips/lib/memcpy.S
@@ -293,9 +293,14 @@
         and    t0, src, ADDRMASK
        PREFS(  0, 2*32(src) )
        PREFD(  1, 2*32(dst) )
+#ifndef CONFIG_CPU_MIPSR6
        bnez    t1, .Ldst_unaligned\@
         nop
        bnez    t0, .Lsrc_unaligned_dst_aligned\@
+#else
+       or      t0, t0, t1
+       bnez    t0, .Lcopy_unaligned_bytes\@
+#endif
        /*
         * use delay slot for fall-through
         * src and dst are aligned; need to compute rem
@@ -376,6 +381,7 @@
        bne     rem, len, 1b
        .set    noreorder
 
+#ifndef CONFIG_CPU_MIPSR6
        /*
         * src and dst are aligned, need to copy rem bytes (rem < NBYTES)
         * A loop would do only a byte at a time with possible branch
@@ -477,6 +483,7 @@
        bne     len, rem, 1b
        .set    noreorder
 
+#endif /* !CONFIG_CPU_MIPSR6 */
 .Lcopy_bytes_checklen\@:
        beqz    len, .Ldone\@
         nop
@@ -504,6 +511,22 @@
 .Ldone\@:
        jr      ra
         nop
+
+#ifdef CONFIG_CPU_MIPSR6
+.Lcopy_unaligned_bytes\@:
+1:
+       COPY_BYTE(0)
+       COPY_BYTE(1)
+       COPY_BYTE(2)
+       COPY_BYTE(3)
+       COPY_BYTE(4)
+       COPY_BYTE(5)
+       COPY_BYTE(6)
+       COPY_BYTE(7)
+       ADD     src, src, 8
+       b       1b
+        ADD    dst, dst, 8
+#endif /* CONFIG_CPU_MIPSR6 */
        .if __memcpy == 1
        END(memcpy)
        .set __memcpy, 0