sh: Optimized cache handling for SH-4/SH-4A caches.

This reworks some of the SH-4 cache handling code to more easily
accomodate newer-style caches (particularly for the > direct-mapped
case), as well as optimizing some of the old code.

Signed-off-by: Richard Curnow <richard.curnow@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This commit is contained in:
Richard Curnow
2006-09-27 14:09:26 +09:00
committed by Paul Mundt
parent fdfc74f9fc
commit b638d0b921
5 changed files with 475 additions and 190 deletions

View File

@@ -4,6 +4,7 @@
* CPU init code
*
* Copyright (C) 2002, 2003 Paul Mundt
* Copyright (C) 2003 Richard Curnow
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
@@ -51,7 +52,15 @@ static void __init cache_init(void)
ccr = ctrl_inl(CCR);
/*
* If the cache is already enabled .. flush it.
* At this point we don't know whether the cache is enabled or not - a
* bootloader may have enabled it. There are at least 2 things that
* could be dirty in the cache at this point:
* 1. kernel command line set up by boot loader
* 2. spilled registers from the prolog of this function
* => before re-initialising the cache, we must do a purge of the whole
* cache out to memory for safety. As long as nothing is spilled
* during the loop to lines that have already been done, this is safe.
* - RPC
*/
if (ccr & CCR_CACHE_ENABLE) {
unsigned long ways, waysize, addrstart;
@@ -98,6 +107,8 @@ static void __init cache_init(void)
/* Force EMODE if possible */
if (cpu_data->dcache.ways > 1)
flags |= CCR_CACHE_EMODE;
else
flags &= ~CCR_CACHE_EMODE;
#endif
#ifdef CONFIG_SH_WRITETHROUGH
@@ -112,6 +123,9 @@ static void __init cache_init(void)
/* Turn on OCRAM -- halve the OC */
flags |= CCR_CACHE_ORA;
cpu_data->dcache.sets >>= 1;
cpu_data->dcache.way_size = cpu_data->dcache.sets *
cpu_data->dcache.linesz;
#endif
ctrl_outl(flags, CCR);