sh: Partially unroll the SH-4 __flush_xxx_region() flushers.

This does a bit of unrolling for the SH-4 region flushers.

Based on an earlier patch by SUGIOKA Toshinobu.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

diff --git a/arch/sh/mm/flush-sh4.c b/arch/sh/mm/flush-sh4.c
index e6d918f..edefc53 100644 (file)
--- a/arch/sh/mm/flush-sh4.c
+++ b/arch/sh/mm/flush-sh4.c
@@ -10,16 +10,37 @@
  */
 void __weak __flush_wback_region(void *start, int size)
 {
-       unsigned long v;
-       unsigned long begin, end;
+       unsigned long v, cnt, end;
 
-       begin = (unsigned long)start & ~(L1_CACHE_BYTES-1);
+       v = (unsigned long)start & ~(L1_CACHE_BYTES-1);
        end = ((unsigned long)start + size + L1_CACHE_BYTES-1)
                & ~(L1_CACHE_BYTES-1);
-       for (v = begin; v < end; v+=L1_CACHE_BYTES) {
-               asm volatile("ocbwb     %0"
-                            : /* no output */
-                            : "m" (__m(v)));
+       cnt = (end - v) / L1_CACHE_BYTES;
+
+       while (cnt >= 8) {
+               asm volatile("ocbwb     @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               asm volatile("ocbwb     @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               asm volatile("ocbwb     @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               asm volatile("ocbwb     @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               asm volatile("ocbwb     @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               asm volatile("ocbwb     @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               asm volatile("ocbwb     @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               asm volatile("ocbwb     @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               cnt -= 8;
+       }
+
+       while (cnt) {
+               asm volatile("ocbwb     @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               cnt--;
        }
 }
 
@@ -31,16 +52,36 @@ void __weak __flush_wback_region(void *start, int size)
  */
 void __weak __flush_purge_region(void *start, int size)
 {
-       unsigned long v;
-       unsigned long begin, end;
+       unsigned long v, cnt, end;
 
-       begin = (unsigned long)start & ~(L1_CACHE_BYTES-1);
+       v = (unsigned long)start & ~(L1_CACHE_BYTES-1);
        end = ((unsigned long)start + size + L1_CACHE_BYTES-1)
                & ~(L1_CACHE_BYTES-1);
-       for (v = begin; v < end; v+=L1_CACHE_BYTES) {
-               asm volatile("ocbp      %0"
-                            : /* no output */
-                            : "m" (__m(v)));
+       cnt = (end - v) / L1_CACHE_BYTES;
+
+       while (cnt >= 8) {
+               asm volatile("ocbp      @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               asm volatile("ocbp      @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               asm volatile("ocbp      @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               asm volatile("ocbp      @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               asm volatile("ocbp      @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               asm volatile("ocbp      @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               asm volatile("ocbp      @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               asm volatile("ocbp      @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               cnt -= 8;
+       }
+       while (cnt) {
+               asm volatile("ocbp      @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               cnt--;
        }
 }
 
@@ -49,15 +90,36 @@ void __weak __flush_purge_region(void *start, int size)
  */
 void __weak __flush_invalidate_region(void *start, int size)
 {
-       unsigned long v;
-       unsigned long begin, end;
+       unsigned long v, cnt, end;
 
-       begin = (unsigned long)start & ~(L1_CACHE_BYTES-1);
+       v = (unsigned long)start & ~(L1_CACHE_BYTES-1);
        end = ((unsigned long)start + size + L1_CACHE_BYTES-1)
                & ~(L1_CACHE_BYTES-1);
-       for (v = begin; v < end; v+=L1_CACHE_BYTES) {
-               asm volatile("ocbi      %0"
-                            : /* no output */
-                            : "m" (__m(v)));
+       cnt = (end - v) / L1_CACHE_BYTES;
+
+       while (cnt >= 8) {
+               asm volatile("ocbi      @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               asm volatile("ocbi      @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               asm volatile("ocbi      @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               asm volatile("ocbi      @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               asm volatile("ocbi      @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               asm volatile("ocbi      @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               asm volatile("ocbi      @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               asm volatile("ocbi      @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               cnt -= 8;
+       }
+
+       while (cnt) {
+               asm volatile("ocbi      @%0" : : "r" (v));
+               v += L1_CACHE_BYTES;
+               cnt--;
        }
 }