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, 120 insertions, 0 deletions

diff --git a/arch/mn10300/mm/cache-dbg-inv-by-tag.S b/arch/mn10300/mm/cache-dbg-inv-by-tag.S
new file mode 100644
index 000000000000..d8ec821e5f88
--- /dev/null
+++ b/arch/mn10300/mm/cache-dbg-inv-by-tag.S
@@ -0,0 +1,120 @@
+/* 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
+
+	.globl	debugger_local_cache_flushinv_one_icache
+
+###############################################################################
+#
+# 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_icache
+	.type	debugger_local_cache_flushinv_one_icache,@function
+debugger_local_cache_flushinv_one_icache:
+	movm	[d3,a2],(sp)
+
+	mov	CHCTR,a2
+	movhu	(a2),d0
+	btst	CHCTR_ICEN,d0
+	beq	debugger_local_cache_flushinv_one_icache_end
+
+	mov	d0,a1
+	and	L1_CACHE_TAG_MASK,a1
+
+	# read the tags from the tag RAM, and if they indicate a matching valid
+	# cache line then we invalidate that line
+	mov	ICACHE_TAG(0,0),a0
+	mov	a1,d0
+	and	L1_CACHE_TAG_ENTRY,d0
+	add	d0,a0				# starting icache tag RAM
+						# access address
+
+	and	~(L1_CACHE_DISPARITY-1),a1	# determine comparator base
+	or	L1_CACHE_TAG_VALID,a1
+	mov	L1_CACHE_TAG_ADDRESS|L1_CACHE_TAG_VALID,d1
+
+	LOCAL_CLI_SAVE(d3)
+
+	# disable the icache
+	movhu	(a2),d0
+	and	~CHCTR_ICEN,d0
+	movhu	d0,(a2)
+
+	# and wait for it to calm down
+	setlb
+	movhu	(a2),d0
+	btst	CHCTR_ICBUSY,d0
+	lne
+
+	# check all the way tags for this cache entry
+	mov	(a0),d0				# read the tag in the way 0 slot
+	xor	a1,d0
+	and	d1,d0
+	beq	debugger_local_icache_kill	# jump if matched
+
+	add	L1_CACHE_WAYDISP,a0
+	mov	(a0),d0				# read the tag in the way 1 slot
+	xor	a1,d0
+	and	d1,d0
+	beq	debugger_local_icache_kill	# jump if matched
+
+	add	L1_CACHE_WAYDISP,a0
+	mov	(a0),d0				# read the tag in the way 2 slot
+	xor	a1,d0
+	and	d1,d0
+	beq	debugger_local_icache_kill	# jump if matched
+
+	add	L1_CACHE_WAYDISP,a0
+	mov	(a0),d0				# read the tag in the way 3 slot
+	xor	a1,d0
+	and	d1,d0
+	bne	debugger_local_icache_finish	# jump if not matched
+
+debugger_local_icache_kill:
+	mov	d0,(a0)				# kill the tag (D0 is 0 at this point)
+
+debugger_local_icache_finish:
+	# wait for the cache to finish what it's doing
+	setlb
+	movhu	(a2),d0
+	btst	CHCTR_ICBUSY,d0
+	lne
+
+	# and reenable it
+	or	CHCTR_ICEN,d0
+	movhu	d0,(a2)
+	movhu	(a2),d0
+
+	# re-enable interrupts
+	LOCAL_IRQ_RESTORE(d3)
+
+debugger_local_cache_flushinv_one_icache_end:
+	ret	[d3,a2],8
+	.size	debugger_local_cache_flushinv_one_icache,.-debugger_local_cache_flushinv_one_icache
+
+#ifdef CONFIG_MN10300_DEBUGGER_CACHE_INV_BY_TAG
+	.globl	debugger_local_cache_flushinv_one
+	.type	debugger_local_cache_flushinv_one,@function
+debugger_local_cache_flushinv_one = debugger_local_cache_flushinv_one_icache
+#endif