sh: trapped io support V2

The idea is that we want to get rid of the in/out/readb/writeb callbacks from
the machvec and replace that with simple inline read and write operations to
memory. Fast and simple for most hardware devices (think pci).

Some devices require special treatment though - like 16-bit only CF devices -
so we need to have some method to hook in callbacks.

This patch makes it possible to add a per-device trap generating filter. This
way we can get maximum performance of sane hardware - which doesn't need this
filter - and crappy hardware works but gets punished by a performance hit.

V2 changes things around a bit and replaces io access callbacks with a
simple minimum_bus_width value. In the future we can add stride as well.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/asm-sh/system.h b/include/asm-sh/system.h
index 772cd1a0a674..5145aa2a0ce9 100644
--- a/include/asm-sh/system.h
+++ b/include/asm-sh/system.h
@@ -182,6 +182,11 @@ BUILD_TRAP_HANDLER(fpu_state_restore);
 
 #define arch_align_stack(x) (x)
 
+struct mem_access {
+	unsigned long (*from)(void *dst, const void *src, unsigned long cnt);
+	unsigned long (*to)(void *dst, const void *src, unsigned long cnt);
+};
+
 #ifdef CONFIG_SUPERH32
 # include "system_32.h"
 #else