/*-
 * Copyright (c) 2014 The FreeBSD Foundation
 *
 * This software was developed by Semihalf under
 * the sponsorship of the FreeBSD Foundation.
 * 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 AUTHOR 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 AUTHOR 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.
 */

#include <sys/param.h>

#include <machine/armreg.h>
#include <machine/atomic.h>

#include <stand.h>

#include "bootstrap.h"
#include "cache.h"

static long cache_flags;
#define CACHE_FLAG_DIC_OFF      (1<<0)
#define CACHE_FLAG_IDC_OFF      (1<<1)

static bool
get_cache_dic(uint64_t ctr)
{
        if ((cache_flags & CACHE_FLAG_DIC_OFF) != 0) {
                return (false);
        }

        return (CTR_DIC_VAL(ctr) != 0);
}

static bool
get_cache_idc(uint64_t ctr)
{
        if ((cache_flags & CACHE_FLAG_IDC_OFF) != 0) {
                return (false);
        }

        return (CTR_IDC_VAL(ctr) != 0);
}

static unsigned int
get_dcache_line_size(uint64_t ctr)
{
        unsigned int dcl_size;

        /*
         * Relevant field [19:16] is LOG2
         * of the number of words in DCache line
         */
        dcl_size = CTR_DLINE_SIZE(ctr);

        /* Size of word shifted by cache line size */
        return (sizeof(int) << dcl_size);
}

void
cpu_flush_dcache(const void *ptr, size_t len)
{
        uint64_t cl_size, ctr;
        vm_offset_t addr, end;

        /* Accessible from all security levels */
        ctr = READ_SPECIALREG(ctr_el0);

        if (get_cache_idc(ctr)) {
                dsb(ishst);
        } else {
                cl_size = get_dcache_line_size(ctr);

                /* Calculate end address to clean */
                end = (vm_offset_t)ptr + (vm_offset_t)len;
                /* Align start address to cache line */
                addr = (vm_offset_t)ptr;
                addr = rounddown2(addr, cl_size);

                for (; addr < end; addr += cl_size)
                        __asm __volatile("dc    civac, %0" : : "r" (addr) :
                            "memory");
                /* Full system DSB */
                dsb(ish);
        }
}

void
cpu_inval_icache(void)
{
        uint64_t ctr;

        /* Accessible from all security levels */
        ctr = READ_SPECIALREG(ctr_el0);

        if (get_cache_dic(ctr)) {
                isb();
        } else {
                __asm __volatile(
                    "ic         ialluis \n"
                    "dsb        ish     \n"
                    "isb                \n"
                    : : : "memory");
        }
}

static int
command_cache_flags(int argc, char *argv[])
{
        char *cp;
        long new_flags;

        if (argc == 3) {
                if (strcmp(argv[1], "set") == 0) {
                        new_flags = strtol(argv[2], &cp, 0);
                        if (cp[0] != '\0') {
                                printf("Invalid flags\n");
                        } else {
                                printf("Setting cache flags to %#lx\n",
                                    new_flags);
                                cache_flags = new_flags;
                                return (CMD_OK);
                        }
                }
        }

        printf("usage: cache_flags set <value>\n");
        return (CMD_ERROR);
}
COMMAND_SET(cache_flags, "cache_flags", "Set cache flags", command_cache_flags);