From ded963a486e08eb89a2c861c3323fe33abf2c6c8 Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Thu, 16 Oct 2008 23:01:24 +0800 Subject: Blackfin arch: unify/cleanup cache code - to be correct wrt to end ranges - to be optimal with a one-instruction hardware loop Signed-off-by: Mike Frysinger Signed-off-by: Bryan Wu --- arch/blackfin/mach-common/cache.S | 173 +++++++++++++------------------------- 1 file changed, 58 insertions(+), 115 deletions(-) (limited to 'arch/blackfin') diff --git a/arch/blackfin/mach-common/cache.S b/arch/blackfin/mach-common/cache.S index 85f8c79b3c3..db532181fbd 100644 --- a/arch/blackfin/mach-common/cache.S +++ b/arch/blackfin/mach-common/cache.S @@ -1,148 +1,91 @@ /* - * File: arch/blackfin/mach-common/cache.S - * Based on: - * Author: LG Soft India + * Blackfin cache control code * - * Created: - * Description: cache control support + * Copyright 2004-2008 Analog Devices Inc. * - * Modified: - * Copyright 2004-2006 Analog Devices Inc. + * Enter bugs at http://blackfin.uclinux.org/ * - * Bugs: Enter bugs at http://blackfin.uclinux.org/ - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, see the file COPYING, or write - * to the Free Software Foundation, Inc., - * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * Licensed under the GPL-2 or later. */ #include -#include -#include #include #include +#include .text -/* - * blackfin_cache_flush_range(start, end) - * Invalidate all cache lines assocoiated with this - * area of memory. +/* Since all L1 caches work the same way, we use the same method for flushing + * them. Only the actual flush instruction differs. We write this in asm as + * GCC can be hard to coax into writing nice hardware loops. * - * start: Start address - * end: End address + * Also, we assume the following register setup: + * R0 = start address + * R1 = end address */ -ENTRY(_blackfin_icache_flush_range) +.macro do_flush flushins:req optflushins optnopins label + + /* end = ((end - 1) & -L1_CACHE_BYTES) + L1_CACHE_BYTES; */ + R1 += -1; R2 = -L1_CACHE_BYTES; - R2 = R0 & R2; - P0 = R2; - P1 = R1; - CSYNC(R3); - IFLUSH [P0]; + R1 = R1 & R2; + R1 += L1_CACHE_BYTES; + + /* count = (end - start) >> L1_CACHE_SHIFT */ + R2 = R1 - R0; + R2 >>= L1_CACHE_SHIFT; + P1 = R2; + +.ifnb \label +\label : +.endif + P0 = R0; + LSETUP (1f, 2f) LC1 = P1; 1: - IFLUSH [P0++]; - CC = P0 < P1 (iu); - IF CC JUMP 1b (bp); - IFLUSH [P0]; - SSYNC(R3); +.ifnb \optflushins + \optflushins [P0]; +.endif +.ifb \optnopins +2: +.endif + \flushins [P0++]; +.ifnb \optnopins +2: \optnopins; +.endif + RTS; -ENDPROC(_blackfin_icache_flush_range) +.endm -/* - * blackfin_icache_dcache_flush_range(start, end) - * FLUSH all cache lines assocoiated with this - * area of memory. - * - * start: Start address - * end: End address - */ +/* Invalidate all instruction cache lines assocoiated with this memory area */ +ENTRY(_blackfin_icache_flush_range) + do_flush IFLUSH, , nop +ENDPROC(_blackfin_icache_flush_range) +/* Flush all cache lines assocoiated with this area of memory. */ ENTRY(_blackfin_icache_dcache_flush_range) - R2 = -L1_CACHE_BYTES; - R2 = R0 & R2; - P0 = R2; - P1 = R1; - CSYNC(R3); - IFLUSH [P0]; -1: - FLUSH [P0]; - IFLUSH [P0++]; - CC = P0 < P1 (iu); - IF CC JUMP 1b (bp); - IFLUSH [P0]; - FLUSH [P0]; - SSYNC(R3); - RTS; + do_flush IFLUSH, FLUSH ENDPROC(_blackfin_icache_dcache_flush_range) /* Throw away all D-cached data in specified region without any obligation to - * write them back. However, we must clean the D-cached entries around the - * boundaries of the start and/or end address is not cache aligned. - * - * Start: start address, - * end : end address. + * write them back. Since the Blackfin ISA does not have an "invalidate" + * instruction, we use flush/invalidate. Perhaps as a speed optimization we + * could bang on the DTEST MMRs ... */ - ENTRY(_blackfin_dcache_invalidate_range) - R2 = -L1_CACHE_BYTES; - R2 = R0 & R2; - P0 = R2; - P1 = R1; - CSYNC(R3); - FLUSHINV[P0]; -1: - FLUSHINV[P0++]; - CC = P0 < P1 (iu); - IF CC JUMP 1b (bp); - - /* If the data crosses a cache line, then we'll be pointing to - * the last cache line, but won't have flushed/invalidated it yet, - * so do one more. - */ - FLUSHINV[P0]; - SSYNC(R3); - RTS; + do_flush FLUSHINV ENDPROC(_blackfin_dcache_invalidate_range) +/* Flush all data cache lines assocoiated with this memory area */ ENTRY(_blackfin_dcache_flush_range) - R2 = -L1_CACHE_BYTES; - R2 = R0 & R2; - P0 = R2; - P1 = R1; - CSYNC(R3); - FLUSH[P0]; -1: - FLUSH[P0++]; - CC = P0 < P1 (iu); - IF CC JUMP 1b (bp); - - /* If the data crosses a cache line, then we'll be pointing to - * the last cache line, but won't have flushed it yet, so do - * one more. - */ - FLUSH[P0]; - SSYNC(R3); - RTS; + do_flush FLUSH, , , .Ldfr ENDPROC(_blackfin_dcache_flush_range) +/* Our headers convert the page structure to an address, so just need to flush + * its contents like normal. We know the start address is page aligned (which + * greater than our cache alignment), as is the end address. So just jump into + * the middle of the dcache flush function. + */ ENTRY(_blackfin_dflush_page) P1 = 1 << (PAGE_SHIFT - L1_CACHE_SHIFT); - P0 = R0; - CSYNC(R3); - FLUSH[P0]; - LSETUP (.Lfl1, .Lfl1) LC0 = P1; -.Lfl1: FLUSH [P0++]; - SSYNC(R3); - RTS; + jump .Ldfr; ENDPROC(_blackfin_dflush_page) -- cgit v1.2.3