MN10300: Create general kernel debugger cache flushing

Create general kernel debugger cache flushing for MN10300 and get rid of the
old stuff that gdbstub was using.

Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 114 insertions, 0 deletions

diff --git a/arch/mn10300/mm/cache-dbg-flush-by-tag.S b/arch/mn10300/mm/cache-dbg-flush-by-tag.S
new file mode 100644
index 000000000000..bf56930e6e70
--- /dev/null
+++ b/arch/mn10300/mm/cache-dbg-flush-by-tag.S
@@ -0,0 +1,114 @@
+/* MN10300 CPU cache invalidation routines, using direct tag flushing
+ *
+ * Copyright (C) 2011 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/page.h>
+#include <asm/cache.h>
+#include <asm/irqflags.h>
+#include <asm/cacheflush.h>
+#include "cache.inc"
+
+	.am33_2
+
+###############################################################################
+#
+# void debugger_local_cache_flushinv(void)
+#
+# Flush the entire data cache back to RAM and invalidate the icache
+#
+###############################################################################
+	ALIGN
+	.globl	debugger_local_cache_flushinv
+        .type	debugger_local_cache_flushinv,@function
+debugger_local_cache_flushinv:
+	#
+	# firstly flush the dcache
+	#
+	movhu	(CHCTR),d0
+	btst	CHCTR_DCEN|CHCTR_ICEN,d0
+	beq	debugger_local_cache_flushinv_end
+
+	btst	CHCTR_DCEN,d0
+	beq	debugger_local_cache_flushinv_no_dcache
+
+	# 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,e0  # total number of entries
+
+mn10300_local_dcache_flush_loop:
+	mov	(a0),d0
+	and	L1_CACHE_TAG_MASK,d0
+	or	L1_CACHE_TAG_VALID,d0		# retain valid entries in the
+						# cache
+	mov	d0,(a1)				# conditional purge
+
+	add	L1_CACHE_BYTES,a0
+	add	L1_CACHE_BYTES,a1
+	add	-1,e0
+	bne	mn10300_local_dcache_flush_loop
+
+debugger_local_cache_flushinv_no_dcache:
+	#
+	# secondly, invalidate the icache if it is enabled
+	#
+	mov	CHCTR,a0
+	movhu	(a0),d0
+	btst	CHCTR_ICEN,d0
+	beq	debugger_local_cache_flushinv_end
+
+	invalidate_icache 1
+
+debugger_local_cache_flushinv_end:
+	ret	[],0
+	.size	debugger_local_cache_flushinv,.-debugger_local_cache_flushinv
+
+###############################################################################
+#
+# void debugger_local_cache_flushinv_one(u8 *addr)
+#
+# Invalidate one particular cacheline if it's in the icache
+#
+###############################################################################
+	ALIGN
+	.globl	debugger_local_cache_flushinv_one
+	.type	debugger_local_cache_flushinv_one,@function
+debugger_local_cache_flushinv_one:
+	movhu	(CHCTR),d1
+	btst	CHCTR_DCEN|CHCTR_ICEN,d1
+	beq	debugger_local_cache_flushinv_one_end
+	btst	CHCTR_DCEN,d1
+	beq	debugger_local_cache_flushinv_one_icache
+
+	# round cacheline addr down
+	and	L1_CACHE_TAG_MASK,d0
+	mov	d0,a1
+
+	# determine the dcache purge control reg address
+	mov	DCACHE_PURGE(0,0),a0
+	and	L1_CACHE_TAG_ENTRY,d0
+	add	d0,a0
+
+	# retain valid entries in the cache
+	or	L1_CACHE_TAG_VALID,a1
+
+	# conditionally purge this line in all ways
+	mov	a1,(L1_CACHE_WAYDISP*0,a0)
+
+	# now go and do the icache
+	bra	debugger_local_cache_flushinv_one_icache
+
+debugger_local_cache_flushinv_one_end:
+	ret	[],0
+	.size	debugger_local_cache_flushinv_one,.-debugger_local_cache_flushinv_one