1 files changed, 105 insertions, 0 deletions

diff --git a/arch/mn10300/kernel/gdb-cache.S b/arch/mn10300/kernel/gdb-cache.S
new file mode 100644
index 000000000000..1108badc3d32
--- /dev/null
+++ b/arch/mn10300/kernel/gdb-cache.S
@@ -0,0 +1,105 @@
+###############################################################################
+#
+# MN10300 Low-level cache purging routines for gdbstub
+#
+# Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+# Written by David Howells (dhowells@redhat.com)
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public Licence
+# as published by the Free Software Foundation; either version
+# 2 of the Licence, or (at your option) any later version.
+#
+###############################################################################
+#include <linux/sys.h>
+#include <linux/linkage.h>
+#include <asm/smp.h>
+#include <asm/cache.h>
+#include <asm/cpu-regs.h>
+#include <asm/exceptions.h>
+#include <asm/frame.inc>
+#include <asm/serial-regs.h>
+
+        .text
+
+###############################################################################
+#
+# GDB stub cache purge
+#
+###############################################################################
+        .type   gdbstub_purge_cache,@function
+ENTRY(gdbstub_purge_cache)
+        #######################################################################
+        # read the addresses tagged in the cache's tag RAM and attempt to flush
+        # those addresses specifically
+        # - we rely on the hardware to filter out invalid tag entry addresses
+        mov     DCACHE_TAG(0,0),a0              # dcache tag RAM access address
+        mov     DCACHE_PURGE(0,0),a1            # dcache purge request address
+        mov     L1_CACHE_NWAYS*L1_CACHE_NENTRIES,d1  # total number of entries
+
+mn10300_dcache_flush_loop:
+        mov     (a0),d0
+        and     L1_CACHE_TAG_ADDRESS|L1_CACHE_TAG_ENTRY,d0
+        or      L1_CACHE_TAG_VALID,d0           # retain valid entries in the
+                                                # cache
+        mov     d0,(a1)                         # conditional purge
+
+mn10300_dcache_flush_skip:
+        add     L1_CACHE_BYTES,a0
+        add     L1_CACHE_BYTES,a1
+        add     -1,d1
+        bne     mn10300_dcache_flush_loop
+
+;;      # unconditionally flush and invalidate the dcache
+;;      mov     DCACHE_PURGE(0,0),a1            # dcache purge request address
+;;      mov     L1_CACHE_NWAYS*L1_CACHE_NENTRIES,d1     # total number of
+;;                                                      # entries
+;;
+;; gdbstub_purge_cache__dcache_loop:
+;;      mov     (a1),d0                         # unconditional purge
+;;
+;;      add     L1_CACHE_BYTES,a1
+;;      add     -1,d1
+;;      bne     gdbstub_purge_cache__dcache_loop
+
+        #######################################################################
+        # now invalidate the icache
+        mov     CHCTR,a0
+        movhu   (a0),a1
+
+        mov     epsw,d1
+        and     ~EPSW_IE,epsw
+        nop
+        nop
+
+        # disable the icache
+        and     ~CHCTR_ICEN,d0
+        movhu   d0,(a0)
+
+        # and wait for it to calm down
+        setlb
+        movhu   (a0),d0
+        btst    CHCTR_ICBUSY,d0
+        lne
+
+        # invalidate
+        or      CHCTR_ICINV,d0
+        movhu   d0,(a0)
+
+        # wait for the cache to finish
+        mov     CHCTR,a0
+        setlb
+        movhu   (a0),d0
+        btst    CHCTR_ICBUSY,d0
+        lne
+
+        # and reenable it
+        movhu   a1,(a0)
+        movhu   (a0),d0                 # read back to flush
+                                        # (SIGILLs all over without this)
+
+        mov     d1,epsw
+
+        ret     [],0
+
+        .size   gdbstub_purge_cache,.-gdbstub_purge_cache