MN10300: AM34: The current cacheflush routines operate by controlling tag regs

The current cache flush and invalidate routines operate by controlling the
cache tag registers.  Rename the files and add config items to select them.

This makes it easier to support the use of other cache flush methods instead,
such as the use of AM34's area purge registers, if available.

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

1 files changed, 289 insertions, 0 deletions

diff --git a/arch/mn10300/mm/cache-inv-by-tag.S b/arch/mn10300/mm/cache-inv-by-tag.S
new file mode 100644
index 00000000000..e839d0aedd6
--- /dev/null
+++ b/arch/mn10300/mm/cache-inv-by-tag.S
@@ -0,0 +1,289 @@
+/* MN10300 CPU core caching routines
+ *
+ * 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>
+
+#define mn10300_dcache_inv_range_intr_interval \
+	+((1 << MN10300_DCACHE_INV_RANGE_INTR_LOG2_INTERVAL) - 1)
+
+#if mn10300_dcache_inv_range_intr_interval > 0xff
+#error MN10300_DCACHE_INV_RANGE_INTR_LOG2_INTERVAL must be 8 or less
+#endif
+
+	.am33_2
+
+	.globl mn10300_icache_inv
+	.globl mn10300_dcache_inv
+	.globl mn10300_dcache_inv_range
+	.globl mn10300_dcache_inv_range2
+	.globl mn10300_dcache_inv_page
+
+###############################################################################
+#
+# void mn10300_icache_inv(void)
+# Invalidate the entire icache
+#
+###############################################################################
+	ALIGN
+mn10300_icache_inv:
+	mov	CHCTR,a0
+
+	movhu	(a0),d0
+	btst	CHCTR_ICEN,d0
+	beq	mn10300_icache_inv_end
+
+	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
+	and	~CHCTR_ICINV,d0
+	or	CHCTR_ICEN,d0
+	movhu	d0,(a0)
+	movhu	(a0),d0
+
+	mov	d1,epsw
+
+mn10300_icache_inv_end:
+	ret	[],0
+
+###############################################################################
+#
+# void mn10300_dcache_inv(void)
+# Invalidate the entire dcache
+#
+###############################################################################
+	ALIGN
+mn10300_dcache_inv:
+	mov	CHCTR,a0
+
+	movhu	(a0),d0
+	btst	CHCTR_DCEN,d0
+	beq	mn10300_dcache_inv_end
+
+	mov	epsw,d1
+	and	~EPSW_IE,epsw
+	nop
+	nop
+
+	# disable the dcache
+	and	~CHCTR_DCEN,d0
+	movhu	d0,(a0)
+
+	# and wait for it to calm down
+	setlb
+	movhu	(a0),d0
+	btst	CHCTR_DCBUSY,d0
+	lne
+
+	# invalidate
+	or	CHCTR_DCINV,d0
+	movhu	d0,(a0)
+
+	# wait for the cache to finish
+	mov	CHCTR,a0
+	setlb
+	movhu	(a0),d0
+	btst	CHCTR_DCBUSY,d0
+	lne
+
+	# and reenable it
+	and	~CHCTR_DCINV,d0
+	or	CHCTR_DCEN,d0
+	movhu	d0,(a0)
+	movhu	(a0),d0
+
+	mov	d1,epsw
+
+mn10300_dcache_inv_end:
+	ret	[],0
+
+###############################################################################
+#
+# void mn10300_dcache_inv_range(unsigned start, unsigned end)
+# void mn10300_dcache_inv_range2(unsigned start, unsigned size)
+# void mn10300_dcache_inv_page(unsigned start)
+# Invalidate a range of addresses on a page in the dcache
+#
+###############################################################################
+	ALIGN
+mn10300_dcache_inv_page:
+	mov	PAGE_SIZE,d1
+mn10300_dcache_inv_range2:
+	add	d0,d1
+mn10300_dcache_inv_range:
+	movm	[d2,d3,a2],(sp)
+	mov	CHCTR,a2
+
+	movhu	(a2),d2
+	btst	CHCTR_DCEN,d2
+	beq	mn10300_dcache_inv_range_end
+
+	and	L1_CACHE_TAG_ADDRESS|L1_CACHE_TAG_ENTRY,d0	# round start
+								# addr down
+	mov	d0,a1
+
+	add	L1_CACHE_BYTES,d1			# round end addr up
+	and	L1_CACHE_TAG_ADDRESS|L1_CACHE_TAG_ENTRY,d1
+
+	clr	d2				# we're going to clear tag ram
+						# entries
+
+	# read the tags from the tag RAM, and if they indicate a valid dirty
+	# cache line then invalidate that line
+	mov	DCACHE_TAG(0,0),a0
+	mov	a1,d0
+	and	L1_CACHE_TAG_ENTRY,d0
+	add	d0,a0				# starting dcache tag RAM
+						# access address
+
+	sub	a1,d1
+	lsr	L1_CACHE_SHIFT,d1		# total number of entries to
+						# examine
+
+	and	~(L1_CACHE_DISPARITY-1),a1	# determine comparator base
+
+mn10300_dcache_inv_range_outer_loop:
+	# disable interrupts
+	mov	epsw,d3
+	and	~EPSW_IE,epsw
+	nop					# note that reading CHCTR and
+						# AND'ing D0 occupy two delay
+						# slots after disabling
+						# interrupts
+
+	# disable the dcache
+	movhu	(a2),d0
+	and	~CHCTR_DCEN,d0
+	movhu	d0,(a2)
+
+	# and wait for it to calm down
+	setlb
+	movhu	(a2),d0
+	btst	CHCTR_DCBUSY,d0
+	lne
+
+mn10300_dcache_inv_range_loop:
+
+	# process the way 0 slot
+	mov	(L1_CACHE_WAYDISP*0,a0),d0	# read the tag in the way 0 slot
+	btst	L1_CACHE_TAG_VALID,d0
+	beq	mn10300_dcache_inv_range_skip_0	# jump if this cacheline is not
+						# valid
+
+	xor	a1,d0
+	lsr	12,d0
+	bne	mn10300_dcache_inv_range_skip_0	# jump if not this cacheline
+
+	mov	d2,(a0)				# kill the tag
+
+mn10300_dcache_inv_range_skip_0:
+
+	# process the way 1 slot
+	mov	(L1_CACHE_WAYDISP*1,a0),d0	# read the tag in the way 1 slot
+	btst	L1_CACHE_TAG_VALID,d0
+	beq	mn10300_dcache_inv_range_skip_1	# jump if this cacheline is not
+						# valid
+
+	xor	a1,d0
+	lsr	12,d0
+	bne	mn10300_dcache_inv_range_skip_1	# jump if not this cacheline
+
+	mov	d2,(a0)				# kill the tag
+
+mn10300_dcache_inv_range_skip_1:
+
+	# process the way 2 slot
+	mov	(L1_CACHE_WAYDISP*2,a0),d0	# read the tag in the way 2 slot
+	btst	L1_CACHE_TAG_VALID,d0
+	beq	mn10300_dcache_inv_range_skip_2	# jump if this cacheline is not
+						# valid
+
+	xor	a1,d0
+	lsr	12,d0
+	bne	mn10300_dcache_inv_range_skip_2	# jump if not this cacheline
+
+	mov	d2,(a0)				# kill the tag
+
+mn10300_dcache_inv_range_skip_2:
+
+	# process the way 3 slot
+	mov	(L1_CACHE_WAYDISP*3,a0),d0	# read the tag in the way 3 slot
+	btst	L1_CACHE_TAG_VALID,d0
+	beq	mn10300_dcache_inv_range_skip_3	# jump if this cacheline is not
+						# valid
+
+	xor	a1,d0
+	lsr	12,d0
+	bne	mn10300_dcache_inv_range_skip_3	# jump if not this cacheline
+
+	mov	d2,(a0)				# kill the tag
+
+mn10300_dcache_inv_range_skip_3:
+
+	# approx every N steps we re-enable the cache and see if there are any
+	# interrupts to be processed
+	# we also break out if we've reached the end of the loop
+	# (the bottom nibble of the count is zero in both cases)
+	add	L1_CACHE_BYTES,a0
+	add	L1_CACHE_BYTES,a1
+	add	-1,d1
+	btst	mn10300_dcache_inv_range_intr_interval,d1
+	bne	mn10300_dcache_inv_range_loop
+
+	# wait for the cache to finish what it's doing
+	setlb
+	movhu	(a2),d0
+	btst	CHCTR_DCBUSY,d0
+	lne
+
+	# and reenable it
+	or	CHCTR_DCEN,d0
+	movhu	d0,(a2)
+	movhu	(a2),d0
+
+	# re-enable interrupts
+	# - we don't bother with delay NOPs as we'll have enough instructions
+	#   before we disable interrupts again to give the interrupts a chance
+	#   to happen
+	mov	d3,epsw
+
+	# go around again if the counter hasn't yet reached zero
+	add	0,d1
+	bne	mn10300_dcache_inv_range_outer_loop
+
+mn10300_dcache_inv_range_end:
+	ret	[d2,d3,a2],12