/*      $NetBSD: bonito_iobc.c,v 1.5 2011/07/10 23:13:22 matt Exp $     */

/*-
 * Copyright (c) 2002 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jason R. Thorpe.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``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 THE FOUNDATION OR CONTRIBUTORS
 * 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.
 */

/*
 * Code to manipulate the I/O Buffer Cache on the BONITO.
 *
 * The BONITO snoops uncached access to memory (e.g. via KSEG1); we only
 * need to deal with the IOBC for DMA to cached memory.
 *
 * Note: This only applies to the 32-bit BONITO; BONITO64's IOBC
 * is coherent.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: bonito_iobc.c,v 1.5 2011/07/10 23:13:22 matt Exp $");

#include <sys/param.h>
#include <sys/intr.h>

#include <mips/locore.h>

#include <mips/bonito/bonitoreg.h>
#include <mips/bonito/bonitovar.h>

#define CACHECMD_INVAL          0
#define CACHECMD_WBINV          1
#define CACHECMD_RDTAG          2
#define CACHECMD_WQFLUSH        3

#define IOBC_LINESIZE           32
#define IOBC_LINESHIFT          5
#define IOBC_NLINES             4

#define TAG_LOCK                0x80000000
#define TAG_WBACK               0x40000000
#define TAG_PFPEND              0x20000000
#define TAG_PEND                0x10000000
#define TAG_MOD                 0x08000000
#define TAG_PFDVAL              0x04000000
#define TAG_DVAL                0x02000000
#define TAG_AVAL                0x01000000
#define TAG_ADDR                0x00ffffff

#define IOBC_LOCK(s)            (s) = splhigh()
#define IOBC_UNLOCK(s)          splx((s))

static void
bonito_iobc_cmd(uint32_t cmd, uint32_t line)
{
        uint32_t ctrl;

        ctrl = (cmd << BONITO_PCICACHECTRL_CACHECMD_SHIFT) |
               (line << BONITO_PCICACHECTRL_CACHECMDLINE_SHIFT);

        REGVAL(BONITO_PCICACHECTRL) = ctrl;
        wbflush();

        REGVAL(BONITO_PCICACHECTRL) = ctrl | BONITO_PCICACHECTRL_CMDEXEC;
        wbflush();

        while (REGVAL(BONITO_PCICACHECTRL) & BONITO_PCICACHECTRL_CMDEXEC)
                /* spin */ ;

        REGVAL(BONITO_PCICACHECTRL) = ctrl;
        wbflush();
}

/*
 * bonito_iobc_wbinv_range:
 *
 *      Write-back and invalidate the specified range in
 *      the BONITO IOBC.
 */
void
bonito_iobc_wbinv_range(paddr_t pa, psize_t size)
{
        uint32_t line, tag;
        paddr_t tagaddr;
        int s;

        IOBC_LOCK(s);

        for (line = 0; line < IOBC_NLINES; line++) {
                bonito_iobc_cmd(CACHECMD_RDTAG, line);
                tag = REGVAL(BONITO_PCICACHETAG);
                if (tag & TAG_AVAL) {
                        tagaddr = (tag & TAG_ADDR) << IOBC_LINESHIFT;
                        if (tagaddr < (pa + size) &&
                            (tagaddr + IOBC_LINESIZE) > pa)
                                bonito_iobc_cmd(CACHECMD_WBINV, line);
                }
        }
        bonito_iobc_cmd(CACHECMD_WQFLUSH, 0);

        IOBC_UNLOCK(s);
}

/*
 * bonito_iobc_inv_range:
 *
 *      Invalidate the specified range in the BONITO IOBC.
 */
void
bonito_iobc_inv_range(paddr_t pa, psize_t size)
{
        uint32_t line, tag;
        paddr_t tagaddr;
        int s;

        IOBC_LOCK(s);

        for (line = 0; line < IOBC_NLINES; line++) {
                bonito_iobc_cmd(CACHECMD_RDTAG, line);
                tag = REGVAL(BONITO_PCICACHETAG);
                if (tag & TAG_AVAL) {
                        tagaddr = (tag & TAG_ADDR) << IOBC_LINESHIFT; 
                        if (tagaddr < (pa + size) &&
                            (tagaddr + IOBC_LINESIZE) > pa) 
                                bonito_iobc_cmd(CACHECMD_INVAL, line);
                }
        }
        bonito_iobc_cmd(CACHECMD_WQFLUSH, 0);  

        IOBC_UNLOCK(s);
}