###############################################################################
#
# MN10300 Low-level cache purging routines for gdbstub
#
# 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/cache.h>
#include <asm/cpu-regs.h>
#include <asm/exceptions.h>
#include <asm/frame.inc>
#include <asm/serial-regs.h>
.text
###############################################################################
#
# GDB stub cache purge
#
###############################################################################
.type gdbstub_purge_cache,@function
ENTRY(gdbstub_purge_cache)
#######################################################################
# read the addresses tagged in the cache's tag RAM and attempt to flush
# those addresses specifically
# - we rely on the hardware to filter out invalid tag entry addresses
mov DCACHE_TAG(0,0),a0 # dcache tag RAM access address
mov DCACHE_PURGE(0,0),a1 # dcache purge request address
mov L1_CACHE_NWAYS*L1_CACHE_NENTRIES,d1 # total number of entries
mn10300_dcache_flush_loop:
mov (a0),d0
and L1_CACHE_TAG_ADDRESS|L1_CACHE_TAG_ENTRY,d0
or L1_CACHE_TAG_VALID,d0 # retain valid entries in the
# cache
mov d0,(a1) # conditional purge
mn10300_dcache_flush_skip:
add L1_CACHE_BYTES,a0
add L1_CACHE_BYTES,a1
add -1,d1
bne mn10300_dcache_flush_loop
;; # unconditionally flush and invalidate the dcache
;; mov DCACHE_PURGE(0,0),a1 # dcache purge request address
;; mov L1_CACHE_NWAYS*L1_CACHE_NENTRIES,d1 # total number of
;; # entries
;;
;; gdbstub_purge_cache__dcache_loop:
;; mov (a1),d0 # unconditional purge
;;
;; add L1_CACHE_BYTES,a1
;; add -1,d1
;; bne gdbstub_purge_cache__dcache_loop
#######################################################################
# now invalidate the icache
mov CHCTR,a0
movhu (a0),a1
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
movhu a1,(a0)
movhu (a0),d0 # read back to flush
# (SIGILLs all over without this)
mov d1,epsw
ret [],0
.size gdbstub_purge_cache,.-gdbstub_purge_cache
