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

#include <common.h>
#include <env.h>
#include <fdt_support.h>
#include <fdtdec.h>
#include <hang.h>
#include <init.h>
#include <log.h>
#include <malloc.h>
#include <net.h>
#include <stdlib.h>
#include <string.h>

#include <linux/ctype.h>
#include <linux/sizes.h>

#include <asm/arch/tegra.h>
#include <asm/arch-tegra/cboot.h>
#include <asm/armv8/mmu.h>

/*
 * Size of a region that's large enough to hold the relocated U-Boot and all
 * other allocations made around it (stack, heap, page tables, etc.)
 * In practice, running "bdinfo" at the shell prompt, the stack reaches about
 * 5MB from the address selected for ram_top as of the time of writing,
 * so a 16MB region should be plenty.
 */
#define MIN_USABLE_RAM_SIZE SZ_16M
/*
 * The amount of space we expect to require for stack usage. Used to validate
 * that all reservations fit into the region selected for the relocation target
 */
#define MIN_USABLE_STACK_SIZE SZ_1M

DECLARE_GLOBAL_DATA_PTR;

extern struct mm_region tegra_mem_map[];

/*
 * These variables are written to before relocation, and hence cannot be
 * in.bss, since .bss overlaps the DTB that's appended to the U-Boot binary.
 * The section attribute forces this into .data and avoids this issue. This
 * also has the nice side-effect of the content being valid after relocation.
 */

/* The number of valid entries in ram_banks[] */
static int ram_bank_count __attribute__((section(".data")));

/*
 * The usable top-of-RAM for U-Boot. This is both:
 * a) Below 4GB to avoid issues with peripherals that use 32-bit addressing.
 * b) At the end of a region that has enough space to hold the relocated U-Boot
 *    and all other allocations made around it (stack, heap, page tables, etc.)
 */
static u64 ram_top __attribute__((section(".data")));
/* The base address of the region of RAM that ends at ram_top */
static u64 region_base __attribute__((section(".data")));

/*
 * Explicitly put this in the .data section because it is written before the
 * .bss section is zeroed out but it needs to persist.
 */
unsigned long cboot_boot_x0 __attribute__((section(".data")));

void cboot_save_boot_params(unsigned long x0, unsigned long x1,
                            unsigned long x2, unsigned long x3)
{
        cboot_boot_x0 = x0;
}

int cboot_dram_init(void)
{
        unsigned int na, ns;
        const void *cboot_blob = (void *)cboot_boot_x0;
        int node, len, i;
        const u32 *prop;

        if (!cboot_blob)
                return -EINVAL;

        na = fdtdec_get_uint(cboot_blob, 0, "#address-cells", 2);
        ns = fdtdec_get_uint(cboot_blob, 0, "#size-cells", 2);

        node = fdt_path_offset(cboot_blob, "/memory");
        if (node < 0) {
                pr_err("Can't find /memory node in cboot DTB");
                hang();
        }
        prop = fdt_getprop(cboot_blob, node, "reg", &len);
        if (!prop) {
                pr_err("Can't find /memory/reg property in cboot DTB");
                hang();
        }

        /* Calculate the true # of base/size pairs to read */
        len /= 4;               /* Convert bytes to number of cells */
        len /= (na + ns);       /* Convert cells to number of banks */
        if (len > CONFIG_NR_DRAM_BANKS)
                len = CONFIG_NR_DRAM_BANKS;

        /* Parse the /memory node, and save useful entries */
        gd->ram_size = 0;
        ram_bank_count = 0;
        for (i = 0; i < len; i++) {
                u64 bank_start, bank_end, bank_size, usable_bank_size;

                /* Extract raw memory region data from DTB */
                bank_start = fdt_read_number(prop, na);
                prop += na;
                bank_size = fdt_read_number(prop, ns);
                prop += ns;
                gd->ram_size += bank_size;
                bank_end = bank_start + bank_size;
                debug("Bank %d: %llx..%llx (+%llx)\n", i,
                      bank_start, bank_end, bank_size);

                /*
                 * Align the bank to MMU section size. This is not strictly
                 * necessary, since the translation table construction code
                 * handles page granularity without issue. However, aligning
                 * the MMU entries reduces the size and number of levels in the
                 * page table, so is worth it.
                 */
                bank_start = ROUND(bank_start, SZ_2M);
                bank_end = bank_end & ~(SZ_2M - 1);
                bank_size = bank_end - bank_start;
                debug("  aligned: %llx..%llx (+%llx)\n",
                      bank_start, bank_end, bank_size);
                if (bank_end <= bank_start)
                        continue;

                /* Record data used to create MMU translation tables */
                ram_bank_count++;
                /* Index below is deliberately 1-based to skip MMIO entry */
                tegra_mem_map[ram_bank_count].virt = bank_start;
                tegra_mem_map[ram_bank_count].phys = bank_start;
                tegra_mem_map[ram_bank_count].size = bank_size;
                tegra_mem_map[ram_bank_count].attrs =
                        PTE_BLOCK_MEMTYPE(MT_NORMAL) | PTE_BLOCK_INNER_SHARE;

                /* Determine best bank to relocate U-Boot into */
                if (bank_end > SZ_4G)
                        bank_end = SZ_4G;
                debug("  end  %llx (usable)\n", bank_end);
                usable_bank_size = bank_end - bank_start;
                debug("  size %llx (usable)\n", usable_bank_size);
                if ((usable_bank_size >= MIN_USABLE_RAM_SIZE) &&
                    (bank_end > ram_top)) {
                        ram_top = bank_end;
                        region_base = bank_start;
                        debug("ram top now %llx\n", ram_top);
                }
        }

        /* Ensure memory map contains the desired sentinel entry */
        tegra_mem_map[ram_bank_count + 1].virt = 0;
        tegra_mem_map[ram_bank_count + 1].phys = 0;
        tegra_mem_map[ram_bank_count + 1].size = 0;
        tegra_mem_map[ram_bank_count + 1].attrs = 0;

        /* Error out if a relocation target couldn't be found */
        if (!ram_top) {
                pr_err("Can't find a usable RAM top");
                hang();
        }

        return 0;
}

int cboot_dram_init_banksize(void)
{
        int i;

        if (ram_bank_count == 0)
                return -EINVAL;

        if ((gd->start_addr_sp - region_base) < MIN_USABLE_STACK_SIZE) {
                pr_err("Reservations exceed chosen region size");
                hang();
        }

        for (i = 0; i < ram_bank_count; i++) {
                gd->bd->bi_dram[i].start = tegra_mem_map[1 + i].virt;
                gd->bd->bi_dram[i].size = tegra_mem_map[1 + i].size;
        }

#ifdef CONFIG_PCI
        gd->pci_ram_top = ram_top;
#endif

        return 0;
}

ulong cboot_get_usable_ram_top(ulong total_size)
{
        return ram_top;
}

/*
 * 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.
 */

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(cboot_boot_x0, fdt_totalsize(cboot_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 after allocating %s:\n", var);
                dump_ram_banks();
#endif
        }

        free(vars);
}

static int set_fdt_addr(void)
{
        int ret;

        ret = env_set_hex("fdt_addr", cboot_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 cboot DTB to U-Boot's
 * ethaddr environment variable if possible.
 */
static int cboot_get_ethaddr_legacy(const void *fdt, uint8_t mac[ETH_ALEN])
{
        const char *const properties[] = {
                "nvidia,ethernet-mac",
                "nvidia,ether-mac",
        };
        const char *prop;
        unsigned int i;
        int node, len;

        node = fdt_path_offset(fdt, "/chosen");
        if (node < 0) {
                printf("Can't find /chosen node in cboot DTB\n");
                return node;
        }

        for (i = 0; i < ARRAY_SIZE(properties); i++) {
                prop = fdt_getprop(fdt, node, properties[i], &len);
                if (prop)
                        break;
        }

        if (!prop) {
                printf("Can't find Ethernet MAC address in cboot DTB\n");
                return -ENOENT;
        }

        string_to_enetaddr(prop, mac);

        if (!is_valid_ethaddr(mac)) {
                printf("Invalid MAC address: %s\n", prop);
                return -EINVAL;
        }

        debug("Legacy MAC address: %pM\n", mac);

        return 0;
}

int cboot_get_ethaddr(const void *fdt, uint8_t mac[ETH_ALEN])
{
        int node, len, err = 0;
        const uchar *prop;
        const char *path;

        path = fdt_get_alias(fdt, "ethernet");
        if (!path) {
                err = -ENOENT;
                goto out;
        }

        debug("ethernet alias found: %s\n", path);

        node = fdt_path_offset(fdt, path);
        if (node < 0) {
                err = -ENOENT;
                goto out;
        }

        prop = fdt_getprop(fdt, node, "local-mac-address", &len);
        if (!prop) {
                err = -ENOENT;
                goto out;
        }

        if (len != ETH_ALEN) {
                err = -EINVAL;
                goto out;
        }

        debug("MAC address: %pM\n", prop);
        memcpy(mac, prop, ETH_ALEN);

out:
        if (err < 0)
                err = cboot_get_ethaddr_legacy(fdt, mac);

        return err;
}

static char *strip(const char *ptr)
{
        const char *end;

        while (*ptr && isblank(*ptr))
                ptr++;

        /* empty string */
        if (*ptr == '\0')
                return strdup(ptr);

        end = ptr;

        while (end[1])
                end++;

        while (isblank(*end))
                end--;

        return strndup(ptr, end - ptr + 1);
}

static char *cboot_get_bootargs(const void *fdt)
{
        const char *args;
        int offset, len;

        offset = fdt_path_offset(fdt, "/chosen");
        if (offset < 0)
                return NULL;

        args = fdt_getprop(fdt, offset, "bootargs", &len);
        if (!args)
                return NULL;

        return strip(args);
}

int cboot_late_init(void)
{
        const void *fdt = (const void *)cboot_boot_x0;
        uint8_t mac[ETH_ALEN];
        char *bootargs;
        int err;

        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 */
        err = cboot_get_ethaddr(fdt, mac);
        if (!err) {
                void *blob = (void *)gd->fdt_blob;

                err = fdtdec_set_ethernet_mac_address(blob, mac, sizeof(mac));
                if (err < 0)
                        printf("failed to set MAC address %pM: %d\n", mac, err);
        }

        bootargs = cboot_get_bootargs(fdt);
        if (bootargs) {
                env_set("cbootargs", bootargs);
                free(bootargs);
        }

        return 0;
}