/*
 * Copyright (c) 2016-2018, NVIDIA CORPORATION.
 *
 * SPDX-License-Identifier: GPL-2.0+
 */

#include <stdlib.h>
#include <common.h>
#include <fdt_support.h>
#include <fdtdec.h>
#include <asm/arch/tegra.h>
#include <asm/armv8/mmu.h>

DECLARE_GLOBAL_DATA_PTR;

extern unsigned long nvtboot_boot_x0;

/*
 * The following few functions run late during the boot process and dynamically
 * calculate the load address of various binaries. To keep track of multiple
 * allocations, some writable list of RAM banks must be used. tegra_mem_map[]
 * is used for this purpose to avoid making yet another copy of the list of RAM
 * banks. This is safe because tegra_mem_map[] is only used once during very
 * early boot to create U-Boot's page tables, long before this code runs. If
 * this assumption becomes invalid later, we can just fix the code to copy the
 * list of RAM banks into some private data structure before running.
 */

extern struct mm_region tegra_mem_map[];

static char *gen_varname(const char *var, const char *ext)
{
        size_t len_var = strlen(var);
        size_t len_ext = strlen(ext);
        size_t len = len_var + len_ext + 1;
        char *varext = malloc(len);

        if (!varext)
                return 0;
        strcpy(varext, var);
        strcpy(varext + len_var, ext);
        return varext;
}

static void mark_ram_allocated(int bank, u64 allocated_start, u64 allocated_end)
{
        u64 bank_start = tegra_mem_map[bank].virt;
        u64 bank_size = tegra_mem_map[bank].size;
        u64 bank_end = bank_start + bank_size;
        bool keep_front = allocated_start != bank_start;
        bool keep_tail = allocated_end != bank_end;

        if (keep_front && keep_tail) {
                /*
                 * There are CONFIG_NR_DRAM_BANKS DRAM entries in the array,
                 * starting at index 1 (index 0 is MMIO). So, we are at DRAM
                 * entry "bank" not "bank - 1" as for a typical 0-base array.
                 * The number of remaining DRAM entries is therefore
                 * "CONFIG_NR_DRAM_BANKS - bank". We want to duplicate the
                 * current entry and shift up the remaining entries, dropping
                 * the last one. Thus, we must copy one fewer entry than the
                 * number remaining.
                 */
                memmove(&tegra_mem_map[bank + 1], &tegra_mem_map[bank],
                        CONFIG_NR_DRAM_BANKS - bank - 1);
                tegra_mem_map[bank].size = allocated_start - bank_start;
                bank++;
                tegra_mem_map[bank].virt = allocated_end;
                tegra_mem_map[bank].phys = allocated_end;
                tegra_mem_map[bank].size = bank_end - allocated_end;
        } else if (keep_front) {
                tegra_mem_map[bank].size = allocated_start - bank_start;
        } else if (keep_tail) {
                tegra_mem_map[bank].virt = allocated_end;
                tegra_mem_map[bank].phys = allocated_end;
                tegra_mem_map[bank].size = bank_end - allocated_end;
        } else {
                /*
                 * We could move all subsequent banks down in the array but
                 * that's not necessary for subsequent allocations to work, so
                 * we skip doing so.
                 */
                tegra_mem_map[bank].size = 0;
        }
}

static void reserve_ram(u64 start, u64 size)
{
        int bank;
        u64 end = start + size;

        for (bank = 1; bank <= CONFIG_NR_DRAM_BANKS; bank++) {
                u64 bank_start = tegra_mem_map[bank].virt;
                u64 bank_size = tegra_mem_map[bank].size;
                u64 bank_end = bank_start + bank_size;

                if (end <= bank_start || start > bank_end)
                        continue;
                mark_ram_allocated(bank, start, end);
                break;
        }
}

static u64 alloc_ram(u64 size, u64 align, u64 offset)
{
        int bank;

        for (bank = 1; bank <= CONFIG_NR_DRAM_BANKS; bank++) {
                u64 bank_start = tegra_mem_map[bank].virt;
                u64 bank_size = tegra_mem_map[bank].size;
                u64 bank_end = bank_start + bank_size;
                u64 allocated = ROUND(bank_start, align) + offset;
                u64 allocated_end = allocated + size;

                if (allocated_end > bank_end)
                        continue;
                mark_ram_allocated(bank, allocated, allocated_end);
                return allocated;
        }
        return 0;
}

static void set_calculated_aliases(char *aliases, u64 address)
{
        char *tmp, *alias;
        int err;

        aliases = strdup(aliases);
        if (!aliases) {
                pr_err("strdup(aliases) failed");
                return;
        }

        tmp = aliases;
        while (true) {
                alias = strsep(&tmp, " ");
                if (!alias)
                        break;
                debug("%s: alias: %s\n", __func__, alias);
                err = env_set_hex(alias, address);
                if (err)
                        pr_err("Could not set %s\n", alias);
        }

        free(aliases);
}

static void set_calculated_env_var(const char *var)
{
        char *var_size;
        char *var_align;
        char *var_offset;
        char *var_aliases;
        u64 size;
        u64 align;
        u64 offset;
        char *aliases;
        u64 address;
        int err;

        var_size = gen_varname(var, "_size");
        if (!var_size)
                return;
        var_align = gen_varname(var, "_align");
        if (!var_align)
                goto out_free_var_size;
        var_offset = gen_varname(var, "_offset");
        if (!var_offset)
                goto out_free_var_align;
        var_aliases = gen_varname(var, "_aliases");
        if (!var_aliases)
                goto out_free_var_offset;

        size = env_get_hex(var_size, 0);
        if (!size) {
                pr_err("%s not set or zero\n", var_size);
                goto out_free_var_aliases;
        }
        align = env_get_hex(var_align, 1);
        /* Handle extant variables, but with a value of 0 */
        if (!align)
                align = 1;
        offset = env_get_hex(var_offset, 0);
        aliases = env_get(var_aliases);

        debug("%s: Calc var %s; size=%llx, align=%llx, offset=%llx\n",
              __func__, var, size, align, offset);
        if (aliases)
                debug("%s: Aliases: %s\n", __func__, aliases);

        address = alloc_ram(size, align, offset);
        if (!address) {
                pr_err("Could not allocate %s\n", var);
                goto out_free_var_aliases;
        }
        debug("%s: Address %llx\n", __func__, address);

        err = env_set_hex(var, address);
        if (err)
                pr_err("Could not set %s\n", var);
        if (aliases)
                set_calculated_aliases(aliases, address);

out_free_var_aliases:
        free(var_aliases);
out_free_var_offset:
        free(var_offset);
out_free_var_align:
        free(var_align);
out_free_var_size:
        free(var_size);
}

#ifdef DEBUG
static void dump_ram_banks(void)
{
        int bank;

        for (bank = 1; bank <= CONFIG_NR_DRAM_BANKS; bank++) {
                u64 bank_start = tegra_mem_map[bank].virt;
                u64 bank_size = tegra_mem_map[bank].size;
                u64 bank_end = bank_start + bank_size;

                if (!bank_size)
                        continue;
                printf("%d: %010llx..%010llx (+%010llx)\n", bank - 1,
                       bank_start, bank_end, bank_size);
        }
}
#endif

static void set_calculated_env_vars(void)
{
        char *vars, *tmp, *var;

#ifdef DEBUG
        printf("RAM banks before any calculated env. var.s:\n");
        dump_ram_banks();
#endif

        reserve_ram(nvtboot_boot_x0, fdt_totalsize(nvtboot_boot_x0));

#ifdef DEBUG
        printf("RAM after reserving cboot DTB:\n");
        dump_ram_banks();
#endif

        vars = env_get("calculated_vars");
        if (!vars) {
                debug("%s: No env var calculated_vars\n", __func__);
                return;
        }

        vars = strdup(vars);
        if (!vars) {
                pr_err("strdup(calculated_vars) failed");
                return;
        }

        tmp = vars;
        while (true) {
                var = strsep(&tmp, " ");
                if (!var)
                        break;
                debug("%s: var: %s\n", __func__, var);
                set_calculated_env_var(var);
#ifdef DEBUG
                printf("RAM banks affter allocating %s:\n", var);
                dump_ram_banks();
#endif
        }

        free(vars);
}

static int set_fdt_addr(void)
{
        int ret;

        ret = env_set_hex("fdt_addr", nvtboot_boot_x0);
        if (ret) {
                printf("Failed to set fdt_addr to point at DTB: %d\n", ret);
                return ret;
        }

        return 0;
}

/*
 * Attempt to use /chosen/nvidia,ether-mac in the nvtboot DTB to U-Boot's
 * ethaddr environment variable if possible.
 */
static int set_ethaddr_from_nvtboot(void)
{
        const void *nvtboot_blob = (void *)nvtboot_boot_x0;
        int ret, node, len;
        const u32 *prop;

        /* Already a valid address in the environment? If so, keep it */
        if (env_get("ethaddr"))
                return 0;

        node = fdt_path_offset(nvtboot_blob, "/chosen");
        if (node < 0) {
                printf("Can't find /chosen node in nvtboot DTB\n");
                return node;
        }
        prop = fdt_getprop(nvtboot_blob, node, "nvidia,ether-mac", &len);
        if (!prop) {
                printf("Can't find nvidia,ether-mac property in nvtboot DTB\n");
                return -ENOENT;
        }

        ret = env_set("ethaddr", (void *)prop);
        if (ret) {
                printf("Failed to set ethaddr from nvtboot DTB: %d\n", ret);
                return ret;
        }

        return 0;
}

int tegra_soc_board_init_late(void)
{
        set_calculated_env_vars();
        /*
         * Ignore errors here; the value may not be used depending on
         * extlinux.conf or boot script content.
         */
        set_fdt_addr();
        /* Ignore errors here; not all cases care about Ethernet addresses */
        set_ethaddr_from_nvtboot();

        return 0;
}