/*      $OpenBSD: exec.c,v 1.18 2024/03/10 15:37:54 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 <arm/armreg.h>

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

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

#define CLIDR_LOC(x)            ((x >> 24) & 0x7)
#define CLIDR_CTYPE(x, n)       ((x >> (n * 3)) & 0x7)
#define CLIDR_CTYPE_NOCACHE     0x0
#define CLIDR_CTYPE_ICACHE      0x1
#define CLIDR_CTYPE_DCACHE      0x2
#define CLIDR_CTYPE_SEP_CACHE   0x3
#define CLIDR_CTYPE_UNI_CACHE   0x4
#define CCSIDR_NUMSETS(x)       ((x >> 13) & 0x7fff)
#define CCSIDR_ASSOCIATIVITY(x) ((x >> 3) & 0x3ff)
#define CCSIDR_LINESZ(x)        (x & 0x7)

void
dcache_wbinv_all(void)
{
        uint32_t clidr;
        uint32_t ccsidr;
        uint32_t val;
        int nways, nsets;
        int wshift, sshift;
        int way, set;
        int level;
        
        __asm volatile("mrc p15, 1, %0, c0, c0, 1" : "=r"(clidr));
        for (level = 0; level < CLIDR_LOC(clidr); level++) {
                if (CLIDR_CTYPE(clidr, level) == CLIDR_CTYPE_NOCACHE)
                        break;
                if (CLIDR_CTYPE(clidr, level) == CLIDR_CTYPE_ICACHE)
                        continue;

                __asm volatile("mcr p15, 2, %0, c0, c0, 0" :: "r"(level << 1));
                __asm volatile("isb");
                __asm volatile("mrc p15, 1, %0, c0, c0, 0" : "=r"(ccsidr));

                nways = CCSIDR_ASSOCIATIVITY(ccsidr) + 1;
                nsets = CCSIDR_NUMSETS(ccsidr) + 1;

                sshift = CCSIDR_LINESZ(ccsidr) + 4;
                wshift = __builtin_clz(CCSIDR_ASSOCIATIVITY(ccsidr));

                for (way = 0; way < nways; way++) {
                        for (set = 0; set < nsets; set++) {
                                val = (way << wshift) | (set << sshift) |
                                    (level << 1);
                                __asm volatile("mcr p15, 0, %0, c7, c14, 2"
                                    :: "r"(val));
                        }
                }
        }

        __asm volatile("dsb");
}

void
icache_inv_all(void)
{
        __asm volatile("mcr p15, 0, r0, c7, c5, 0"); /* ICIALLU */
        __asm volatile("dsb");
        __asm volatile("isb");
}

void
dcache_disable(void)
{
        uint32_t sctlr;

        __asm volatile("mrc p15, 0, %0, c1, c0, 0" : "=r"(sctlr));
        sctlr &= ~CPU_CONTROL_DC_ENABLE;
        __asm volatile("mcr p15, 0, %0, c1, c0, 0" :: "r"(sctlr));
        __asm volatile("dsb");
        __asm volatile("isb");
}

void
icache_disable(void)
{
        uint32_t sctlr;

        __asm volatile("mrc p15, 0, %0, c1, c0, 0" : "=r"(sctlr));
        sctlr &= ~CPU_CONTROL_IC_ENABLE;
        __asm volatile("mcr p15, 0, %0, c1, c0, 0" :: "r"(sctlr));
        __asm volatile("dsb");
        __asm volatile("isb");
}

void
mmu_disable(void)
{
        uint32_t sctlr;

        __asm volatile("mrc p15, 0, %0, c1, c0, 0" : "=r"(sctlr));
        sctlr &= ~CPU_CONTROL_MMU_ENABLE;
        __asm volatile("mcr p15, 0, %0, c1, c0, 0" :: "r"(sctlr));

        __asm volatile("mcr p15, 0, r0, c8, c7, 0"); /* TLBIALL */
        __asm volatile("mcr p15, 0, r0, c7, c5, 6"); /* BPIALL */
        __asm volatile("dsb");
        __asm volatile("isb");
}

void
run_loadfile(uint64_t *marks, int howto)
{
        Elf_Ehdr *elf = (Elf_Ehdr *)marks[MARK_SYM];
        Elf_Shdr *shp = (Elf_Shdr *)(marks[MARK_SYM] + elf->e_shoff);
        u_long esym = marks[MARK_END] & 0x0fffffff;
        u_long offset = 0;
        char args[256];
        char *cp;
        void *fdt;
        int i;

        /*
         * Tell locore.S where the symbol table ends by setting
         * 'esym', which should be the first word in the .data
         * section.
         */
        for (i = 0; i < elf->e_shnum; i++) {
                /* XXX Assume .data is the first writable segment. */
                if (shp[i].sh_flags & SHF_WRITE) {
                        /* XXX We have to store the virtual address. */
                        esym |= shp[i].sh_addr & 0xf0000000;
                        *(u_long *)(LOADADDR(shp[i].sh_addr)) = esym;
                        break;
                }
        }

        snprintf(args, sizeof(args) - 8, "%s:%s", cmd.bootdev, cmd.image);
        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();

        dcache_wbinv_all();
        dcache_disable();
        icache_inv_all();
        icache_disable();
        mmu_disable();

        (*(startfuncp)(marks[MARK_ENTRY]))((void *)esym, NULL, fdt);

        /* NOTREACHED */
}