/*      $NetBSD: syncicache.c,v 1.2 2012/11/24 07:16:04 christos Exp $  */

/*
 * Copyright (C) 1995-1997, 1999 Wolfgang Solfrank.
 * Copyright (C) 1995-1997, 1999 TooLs GmbH.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by TooLs GmbH.
 * 4. The name of TooLs GmbH may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#include <sys/param.h>
#if     defined(_KERNEL) || defined(_STANDALONE)
#include <sys/time.h>
#include <sys/proc.h>
#include <uvm/uvm_extern.h>
#endif
#include <sys/sysctl.h>

#include <machine/cpu.h>


#if defined(_STANDALONE)
#ifndef CACHELINESIZE
#error "Must know the size of a cache line"
#endif
static struct cache_info _cache_info = {
        CACHELINESIZE,
        CACHELINESIZE,
        CACHELINESIZE,
        CACHELINESIZE
};
#define CACHEINFO       _cache_info
#elif defined(_KERNEL)
#define CACHEINFO       (curcpu()->ci_ci)
#else
#include <stdlib.h>

size_t __getcachelinesize (void);

static int _cachelinesize = 0;

static struct cache_info _cache_info;
#define CACHEINFO       _cache_info

size_t
__getcachelinesize(void)
{
        static int cachemib[] = { CTL_MACHDEP, CPU_CACHELINE };
        static int cacheinfomib[] = { CTL_MACHDEP, CPU_CACHEINFO };
        size_t clen = sizeof(_cache_info);

        if (_cachelinesize)
                return _cachelinesize;

        if (sysctl(cacheinfomib, (u_int)__arraycount(cacheinfomib),
            &_cache_info, &clen, NULL, 0) == 0) {
                _cachelinesize = _cache_info.dcache_line_size;
                return _cachelinesize;
        }

        /* Try older deprecated sysctl */
        clen = sizeof(_cachelinesize);
        if (sysctl(cachemib, (u_int)__arraycount(cachemib),
            &_cachelinesize, &clen, NULL, 0) < 0 || !_cachelinesize)
                abort();

        _cache_info.dcache_size = _cachelinesize;
        _cache_info.dcache_line_size = _cachelinesize;
        _cache_info.icache_size = _cachelinesize;
        _cache_info.icache_line_size = _cachelinesize;

        /* If there is no cache, indicate we have issued the sysctl. */
        if (!_cachelinesize)
                _cachelinesize = 1;

        return _cachelinesize;
}
#endif

void
__syncicache(void *from, size_t len)
{
        size_t l, off;
        size_t linesz;
        char *p;

#if     !defined(_KERNEL) && !defined(_STANDALONE)
        if (!_cachelinesize)
                __getcachelinesize();
#endif  

        if (CACHEINFO.dcache_size > 0) {
                linesz = CACHEINFO.dcache_line_size;
                off = (uintptr_t)from & (linesz - 1);
                l = (len + off + linesz - 1) & ~(linesz - 1);
                p = (char *)from - off;
                do {
                        __asm volatile ("dcbst 0,%0" :: "r"(p));
                        p += linesz;
                } while ((l -= linesz) != 0);
        }
        __asm volatile ("sync");

        if (CACHEINFO.icache_size > 0 ) {
                linesz = CACHEINFO.icache_line_size;
                off = (uintptr_t)from & (linesz - 1);
                l = (len + off + linesz - 1) & ~(linesz - 1);
                p = (char *)from - off;
                do {
                        __asm volatile ("icbi 0,%0" :: "r"(p));
                        p += linesz;
                } while ((l -= linesz) != 0);
        }
        __asm volatile ("sync; isync");
}