MN10300: AM34: Add cacheflushing by using the AM34 purge registers

The AM34 CPU core provides an automated way of purging the cache rather than
manually iterating over all the tags in the cache.  Make it possible to use
these.

Signed-off-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com>
Signed-off-by: Kiyoshi Owada <owada.kiyoshi@jp.panasonic.com>
Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/arch/mn10300/mm/cache-inv-by-reg.S b/arch/mn10300/mm/cache-inv-by-reg.S
new file mode 100644
index 0000000..c895086
--- /dev/null
+++ b/arch/mn10300/mm/cache-inv-by-reg.S
@@ -0,0 +1,356 @@
+/* MN10300 CPU cache invalidation routines, using automatic purge registers
+ *
+ * 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/page.h>
+#include <asm/cache.h>
+#include <asm/irqflags.h>
+#include <asm/cacheflush.h>
+
+#define mn10300_local_dcache_inv_range_intr_interval \
+	+((1 << MN10300_DCACHE_INV_RANGE_INTR_LOG2_INTERVAL) - 1)
+
+#if mn10300_local_dcache_inv_range_intr_interval > 0xff
+#error MN10300_DCACHE_INV_RANGE_INTR_LOG2_INTERVAL must be 8 or less
+#endif
+
+	.am33_2
+
+#ifndef CONFIG_SMP
+	.globl	mn10300_icache_inv
+	.globl	mn10300_icache_inv_page
+	.globl	mn10300_icache_inv_range
+	.globl	mn10300_icache_inv_range2
+	.globl	mn10300_dcache_inv
+	.globl	mn10300_dcache_inv_page
+	.globl	mn10300_dcache_inv_range
+	.globl	mn10300_dcache_inv_range2
+
+mn10300_icache_inv		= mn10300_local_icache_inv
+mn10300_icache_inv_page		= mn10300_local_icache_inv_page
+mn10300_icache_inv_range	= mn10300_local_icache_inv_range
+mn10300_icache_inv_range2	= mn10300_local_icache_inv_range2
+mn10300_dcache_inv		= mn10300_local_dcache_inv
+mn10300_dcache_inv_page		= mn10300_local_dcache_inv_page
+mn10300_dcache_inv_range	= mn10300_local_dcache_inv_range
+mn10300_dcache_inv_range2	= mn10300_local_dcache_inv_range2
+
+#endif /* !CONFIG_SMP */
+
+###############################################################################
+#
+# void mn10300_local_icache_inv(void)
+# Invalidate the entire icache
+#
+###############################################################################
+	ALIGN
+	.globl	mn10300_local_icache_inv
+        .type	mn10300_local_icache_inv,@function
+mn10300_local_icache_inv:
+	mov	CHCTR,a0
+
+	movhu	(a0),d0
+	btst	CHCTR_ICEN,d0
+	beq	mn10300_local_icache_inv_end
+
+	# invalidate
+	or	CHCTR_ICINV,d0
+	movhu	d0,(a0)
+	movhu	(a0),d0
+
+mn10300_local_icache_inv_end:
+	ret	[],0
+	.size	mn10300_local_icache_inv,.-mn10300_local_icache_inv
+
+###############################################################################
+#
+# void mn10300_local_dcache_inv(void)
+# Invalidate the entire dcache
+#
+###############################################################################
+	ALIGN
+	.globl	mn10300_local_dcache_inv
+	.type	mn10300_local_dcache_inv,@function
+mn10300_local_dcache_inv:
+	mov	CHCTR,a0
+
+	movhu	(a0),d0
+	btst	CHCTR_DCEN,d0
+	beq	mn10300_local_dcache_inv_end
+
+	# invalidate
+	or	CHCTR_DCINV,d0
+	movhu	d0,(a0)
+	movhu	(a0),d0
+
+mn10300_local_dcache_inv_end:
+	ret	[],0
+	.size	mn10300_local_dcache_inv,.-mn10300_local_dcache_inv
+
+###############################################################################
+#
+# void mn10300_local_dcache_inv_range(unsigned long start, unsigned long end)
+# void mn10300_local_dcache_inv_range2(unsigned long start, unsigned long size)
+# void mn10300_local_dcache_inv_page(unsigned long start)
+# Invalidate a range of addresses on a page in the dcache
+#
+###############################################################################
+	ALIGN
+	.globl	mn10300_local_dcache_inv_page
+	.globl	mn10300_local_dcache_inv_range
+	.globl	mn10300_local_dcache_inv_range2
+	.type	mn10300_local_dcache_inv_page,@function
+	.type	mn10300_local_dcache_inv_range,@function
+	.type	mn10300_local_dcache_inv_range2,@function
+mn10300_local_dcache_inv_page:
+	and	~(PAGE_SIZE-1),d0
+	mov	PAGE_SIZE,d1
+mn10300_local_dcache_inv_range2:
+	add	d0,d1
+mn10300_local_dcache_inv_range:
+	# If we are in writeback mode we check the start and end alignments,
+	# and if they're not cacheline-aligned, we must flush any bits outside
+	# the range that share cachelines with stuff inside the range
+#ifdef CONFIG_MN10300_CACHE_WBACK
+	btst	~(L1_CACHE_BYTES-1),d0
+	bne	1f
+	btst	~(L1_CACHE_BYTES-1),d1
+	beq	2f
+1:
+	bra	mn10300_local_dcache_flush_inv_range
+2:
+#endif /* CONFIG_MN10300_CACHE_WBACK */
+
+	movm	[d2,d3,a2],(sp)
+
+	mov	CHCTR,a0
+	movhu	(a0),d2
+	btst	CHCTR_DCEN,d2
+	beq	mn10300_local_dcache_inv_range_end
+
+	# round the addresses out to be full cachelines, unless we're in
+	# writeback mode, in which case we would be in flush and invalidate by
+	# now
+#ifndef CONFIG_MN10300_CACHE_WBACK
+	and	L1_CACHE_TAG_ADDRESS|L1_CACHE_TAG_ENTRY,d0	# round start
+								# addr down
+
+	mov	L1_CACHE_BYTES-1,d2
+	add	d2,d1
+	and	L1_CACHE_TAG_ADDRESS|L1_CACHE_TAG_ENTRY,d1	# round end addr up
+#endif /* !CONFIG_MN10300_CACHE_WBACK */
+
+	sub	d0,d1,d2		# calculate the total size
+	mov	d0,a2			# A2 = start address
+	mov	d1,a1			# A1 = end address
+
+	LOCAL_CLI_SAVE(d3)
+
+	mov	DCPGCR,a0		# make sure the purger isn't busy
+	setlb
+	mov	(a0),d0
+	btst	DCPGCR_DCPGBSY,d0
+	lne
+
+	# skip initial address alignment calculation if address is zero
+	mov	d2,d1
+	cmp	0,a2
+	beq	1f
+
+dcivloop:
+	/* calculate alignsize
+	 *
+	 * alignsize = L1_CACHE_BYTES;
+	 * while (! start & alignsize) {
+	 *	alignsize <<=1;
+	 * }
+	 * d1 = alignsize;
+	 */
+	mov	L1_CACHE_BYTES,d1
+	lsr	1,d1
+	setlb
+	add	d1,d1
+	mov	d1,d0
+	and	a2,d0
+	leq
+
+1:
+	/* calculate invsize
+	 *
+	 * if (totalsize > alignsize) {
+	 *	invsize = alignsize;
+	 * } else {
+	 *	invsize = totalsize;
+	 *	tmp = 0x80000000;
+	 *	while (! invsize & tmp) {
+	 *		tmp >>= 1;
+	 *	}
+	 *	invsize = tmp;
+	 * }
+	 * d1 = invsize
+	 */
+	cmp	d2,d1
+	bns	2f
+	mov	d2,d1
+
+	mov	0x80000000,d0		# start from 31bit=1
+	setlb
+	lsr	1,d0
+	mov	d0,e0
+	and	d1,e0
+	leq
+	mov	d0,d1
+
+2:
+	/* set mask
+	 *
+	 * mask = ~(invsize-1);
+	 * DCPGMR = mask;
+	 */
+	mov	d1,d0
+	add	-1,d0
+	not	d0
+	mov	d0,(DCPGMR)
+
+	# invalidate area
+	mov	a2,d0
+	or	DCPGCR_DCI,d0
+	mov	d0,(a0)			# DCPGCR = (mask & start) | DCPGCR_DCI
+
+	setlb				# wait for the purge to complete
+	mov	(a0),d0
+	btst	DCPGCR_DCPGBSY,d0
+	lne
+
+	sub	d1,d2			# decrease size remaining
+	add	d1,a2			# increase next start address
+
+	/* check invalidating of end address
+	 *
+	 * a2 = a2 + invsize
+	 * if (a2 < end) {
+	 *     goto dcivloop;
+	 * } */
+	cmp	a1,a2
+	bns	dcivloop
+
+	LOCAL_IRQ_RESTORE(d3)
+
+mn10300_local_dcache_inv_range_end:
+	ret	[d2,d3,a2],12
+	.size	mn10300_local_dcache_inv_page,.-mn10300_local_dcache_inv_page
+	.size	mn10300_local_dcache_inv_range,.-mn10300_local_dcache_inv_range
+	.size	mn10300_local_dcache_inv_range2,.-mn10300_local_dcache_inv_range2
+
+###############################################################################
+#
+# void mn10300_local_icache_inv_page(unsigned long start)
+# void mn10300_local_icache_inv_range2(unsigned long start, unsigned long size)
+# void mn10300_local_icache_inv_range(unsigned long start, unsigned long end)
+# Invalidate a range of addresses on a page in the icache
+#
+###############################################################################
+	ALIGN
+	.globl	mn10300_local_icache_inv_page
+	.globl	mn10300_local_icache_inv_range
+	.globl	mn10300_local_icache_inv_range2
+	.type	mn10300_local_icache_inv_page,@function
+	.type	mn10300_local_icache_inv_range,@function
+	.type	mn10300_local_icache_inv_range2,@function
+mn10300_local_icache_inv_page:
+	and	~(PAGE_SIZE-1),d0
+	mov	PAGE_SIZE,d1
+mn10300_local_icache_inv_range2:
+	add	d0,d1
+mn10300_local_icache_inv_range:
+	movm	[d2,d3,a2],(sp)
+
+	mov	CHCTR,a0
+	movhu	(a0),d2
+	btst	CHCTR_ICEN,d2
+	beq	mn10300_local_icache_inv_range_reg_end
+
+	/* calculate alignsize
+	 *
+	 * alignsize = L1_CACHE_BYTES;
+	 * for (i = (end - start - 1) / L1_CACHE_BYTES ;  i > 0; i >>= 1) {
+	 *     alignsize <<= 1;
+	 * }
+	 * d2 = alignsize;
+	 */
+	mov	L1_CACHE_BYTES,d2
+	sub	d0,d1,d3
+	add	-1,d3
+	lsr	L1_CACHE_SHIFT,d3
+	beq	2f
+1:
+	add	d2,d2
+	lsr	1,d3
+	bne	1b
+2:
+
+	/* a1 = end */
+	mov	d1,a1
+
+	LOCAL_CLI_SAVE(d3)
+
+	mov	ICIVCR,a0
+	/* wait for busy bit of area invalidation */
+	setlb
+	mov	(a0),d1
+	btst	ICIVCR_ICIVBSY,d1
+	lne
+
+	/* set mask
+	 *
+	 * mask = ~(alignsize-1);
+	 * ICIVMR = mask;
+	 */
+	mov	d2,d1
+	add	-1,d1
+	not	d1
+	mov	d1,(ICIVMR)
+	/* a2 = mask & start */
+	and	d1,d0,a2
+
+icivloop:
+	/* area invalidate
+	 *
+	 * ICIVCR = (mask & start) | ICIVCR_ICI
+	 */
+	mov	a2,d0
+	or	ICIVCR_ICI,d0
+	mov	d0,(a0)
+
+	/* wait for busy bit of area invalidation */
+	setlb
+	mov	(a0),d1
+	btst	ICIVCR_ICIVBSY,d1
+	lne
+
+	/* check invalidating of end address
+	 *
+	 * a2 = a2 + alignsize
+	 * if (a2 < end) {
+	 *     goto icivloop;
+	 * } */
+	add	d2,a2
+	cmp	a1,a2
+	bns	icivloop
+
+	LOCAL_IRQ_RESTORE(d3)
+
+mn10300_local_icache_inv_range_reg_end:
+	ret	[d2,d3,a2],12
+	.size	mn10300_local_icache_inv_page,.-mn10300_local_icache_inv_page
+	.size	mn10300_local_icache_inv_range,.-mn10300_local_icache_inv_range
+	.size	mn10300_local_icache_inv_range2,.-mn10300_local_icache_inv_range2