/*      $OpenBSD: exec.c,v 1.8 2020/05/10 11:55:42 kettenis Exp $       */

/*
 * Copyright (c) 2006, 2016 Mark Kettenis
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/param.h>
#include <sys/reboot.h>
#include <dev/cons.h>

#include <lib/libkern/libkern.h>
#include <lib/libsa/loadfile.h>
#include <sys/exec_elf.h>

#include <efi.h>
#include <stand/boot/cmd.h>

#include <machine/armreg.h>

#include "efiboot.h"
#include "libsa.h"
#include "fdt.h"

typedef void (*startfuncp)(void *, void *, void *) __attribute__ ((noreturn));

unsigned int cpu_get_dcache_line_size(void);
void cpu_flush_dcache(vaddr_t, vsize_t);
void cpu_inval_icache(void);

unsigned int
cpu_get_dcache_line_size(void)
{
        uint64_t ctr;
        unsigned int dcl_size;

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

        /*
         * 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(vaddr_t addr, vsize_t len)
{
        uint64_t cl_size;
        vaddr_t end;

        cl_size = cpu_get_dcache_line_size();

        /* Calculate end address to clean */
        end = addr + len;
        /* Align start address to cache line */
        addr = addr & ~(cl_size - 1);

        for (; addr < end; addr += cl_size)
                __asm volatile("dc civac, %0" :: "r" (addr) : "memory");

        /* Full system DSB */
        __asm volatile("dsb sy" ::: "memory");
}

void
cpu_inval_icache(void)
{
        __asm volatile(
            "ic         ialluis \n"
            "dsb        ish     \n"
            : : : "memory");
}

void
run_loadfile(uint64_t *marks, int howto)
{
        char args[256];
        char *cp;
        void *fdt;

        strlcpy(args, cmd.path, sizeof(args));
        cp = args + strlen(args);

        *cp++ = ' ';
        *cp = '-';
        if (howto & RB_ASKNAME)
                *++cp = 'a';
        if (howto & RB_CONFIG)
                *++cp = 'c';
        if (howto & RB_SINGLE)
                *++cp = 's';
        if (howto & RB_KDB)
                *++cp = 'd';
        if (*cp == '-')
                *--cp = 0;
        else
                *++cp = 0;

        fdt = efi_makebootargs(args, howto);

        efi_cleanup();

        cpu_flush_dcache(marks[MARK_ENTRY], marks[MARK_END] - marks[MARK_ENTRY]);
        cpu_inval_icache();

        cpu_flush_dcache((vaddr_t)fdt, fdt_get_size(fdt));

        (*(startfuncp)(marks[MARK_ENTRY]))((void *)marks[MARK_END], 0, fdt);

        /* NOTREACHED */
}