// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2015 Miao Yan <yanmiaobest@gmail.com>
 */

#include <common.h>
#include <command.h>
#include <errno.h>
#include <log.h>
#include <malloc.h>
#include <qfw.h>
#include <asm/io.h>
#ifdef CONFIG_GENERATE_ACPI_TABLE
#include <asm/tables.h>
#endif
#include <linux/list.h>

static bool fwcfg_present;
static bool fwcfg_dma_present;
static struct fw_cfg_arch_ops *fwcfg_arch_ops;

static LIST_HEAD(fw_list);

#ifdef CONFIG_GENERATE_ACPI_TABLE
/*
 * This function allocates memory for ACPI tables
 *
 * @entry : BIOS linker command entry which tells where to allocate memory
 *          (either high memory or low memory)
 * @addr  : The address that should be used for low memory allcation. If the
 *          memory allocation request is 'ZONE_HIGH' then this parameter will
 *          be ignored.
 * @return: 0 on success, or negative value on failure
 */
static int bios_linker_allocate(struct bios_linker_entry *entry, ulong *addr)
{
        uint32_t size, align;
        struct fw_file *file;
        unsigned long aligned_addr;

        align = le32_to_cpu(entry->alloc.align);
        /* align must be power of 2 */
        if (align & (align - 1)) {
                printf("error: wrong alignment %u\n", align);
                return -EINVAL;
        }

        file = qemu_fwcfg_find_file(entry->alloc.file);
        if (!file) {
                printf("error: can't find file %s\n", entry->alloc.file);
                return -ENOENT;
        }

        size = be32_to_cpu(file->cfg.size);

        /*
         * ZONE_HIGH means we need to allocate from high memory, since
         * malloc space is already at the end of RAM, so we directly use it.
         * If allocation zone is ZONE_FSEG, then we use the 'addr' passed
         * in which is low memory
         */
        if (entry->alloc.zone == BIOS_LINKER_LOADER_ALLOC_ZONE_HIGH) {
                aligned_addr = (unsigned long)memalign(align, size);
                if (!aligned_addr) {
                        printf("error: allocating resource\n");
                        return -ENOMEM;
                }
        } else if (entry->alloc.zone == BIOS_LINKER_LOADER_ALLOC_ZONE_FSEG) {
                aligned_addr = ALIGN(*addr, align);
        } else {
                printf("error: invalid allocation zone\n");
                return -EINVAL;
        }

        debug("bios_linker_allocate: allocate file %s, size %u, zone %d, align %u, addr 0x%lx\n",
              file->cfg.name, size, entry->alloc.zone, align, aligned_addr);

        qemu_fwcfg_read_entry(be16_to_cpu(file->cfg.select),
                              size, (void *)aligned_addr);
        file->addr = aligned_addr;

        /* adjust address for low memory allocation */
        if (entry->alloc.zone == BIOS_LINKER_LOADER_ALLOC_ZONE_FSEG)
                *addr = (aligned_addr + size);

        return 0;
}

/*
 * This function patches ACPI tables previously loaded
 * by bios_linker_allocate()
 *
 * @entry : BIOS linker command entry which tells how to patch
 *          ACPI tables
 * @return: 0 on success, or negative value on failure
 */
static int bios_linker_add_pointer(struct bios_linker_entry *entry)
{
        struct fw_file *dest, *src;
        uint32_t offset = le32_to_cpu(entry->pointer.offset);
        uint64_t pointer = 0;

        dest = qemu_fwcfg_find_file(entry->pointer.dest_file);
        if (!dest || !dest->addr)
                return -ENOENT;
        src = qemu_fwcfg_find_file(entry->pointer.src_file);
        if (!src || !src->addr)
                return -ENOENT;

        debug("bios_linker_add_pointer: dest->addr 0x%lx, src->addr 0x%lx, offset 0x%x size %u, 0x%llx\n",
              dest->addr, src->addr, offset, entry->pointer.size, pointer);

        memcpy(&pointer, (char *)dest->addr + offset, entry->pointer.size);
        pointer = le64_to_cpu(pointer);
        pointer += (unsigned long)src->addr;
        pointer = cpu_to_le64(pointer);
        memcpy((char *)dest->addr + offset, &pointer, entry->pointer.size);

        return 0;
}

/*
 * This function updates checksum fields of ACPI tables previously loaded
 * by bios_linker_allocate()
 *
 * @entry : BIOS linker command entry which tells where to update ACPI table
 *          checksums
 * @return: 0 on success, or negative value on failure
 */
static int bios_linker_add_checksum(struct bios_linker_entry *entry)
{
        struct fw_file *file;
        uint8_t *data, cksum = 0;
        uint8_t *cksum_start;

        file = qemu_fwcfg_find_file(entry->cksum.file);
        if (!file || !file->addr)
                return -ENOENT;

        data = (uint8_t *)(file->addr + le32_to_cpu(entry->cksum.offset));
        cksum_start = (uint8_t *)(file->addr + le32_to_cpu(entry->cksum.start));
        cksum = table_compute_checksum(cksum_start,
                                       le32_to_cpu(entry->cksum.length));
        *data = cksum;

        return 0;
}

/* This function loads and patches ACPI tables provided by QEMU */
ulong write_acpi_tables(ulong addr)
{
        int i, ret = 0;
        struct fw_file *file;
        struct bios_linker_entry *table_loader;
        struct bios_linker_entry *entry;
        uint32_t size;

        /* make sure fw_list is loaded */
        ret = qemu_fwcfg_read_firmware_list();
        if (ret) {
                printf("error: can't read firmware file list\n");
                return addr;
        }

        file = qemu_fwcfg_find_file("etc/table-loader");
        if (!file) {
                printf("error: can't find etc/table-loader\n");
                return addr;
        }

        size = be32_to_cpu(file->cfg.size);
        if ((size % sizeof(*entry)) != 0) {
                printf("error: table-loader maybe corrupted\n");
                return addr;
        }

        table_loader = malloc(size);
        if (!table_loader) {
                printf("error: no memory for table-loader\n");
                return addr;
        }

        qemu_fwcfg_read_entry(be16_to_cpu(file->cfg.select),
                              size, table_loader);

        for (i = 0; i < (size / sizeof(*entry)); i++) {
                entry = table_loader + i;
                switch (le32_to_cpu(entry->command)) {
                case BIOS_LINKER_LOADER_COMMAND_ALLOCATE:
                        ret = bios_linker_allocate(entry, &addr);
                        if (ret)
                                goto out;
                        break;
                case BIOS_LINKER_LOADER_COMMAND_ADD_POINTER:
                        ret = bios_linker_add_pointer(entry);
                        if (ret)
                                goto out;
                        break;
                case BIOS_LINKER_LOADER_COMMAND_ADD_CHECKSUM:
                        ret = bios_linker_add_checksum(entry);
                        if (ret)
                                goto out;
                        break;
                default:
                        break;
                }
        }

out:
        if (ret) {
                struct fw_cfg_file_iter iter;
                for (file = qemu_fwcfg_file_iter_init(&iter);
                     !qemu_fwcfg_file_iter_end(&iter);
                     file = qemu_fwcfg_file_iter_next(&iter)) {
                        if (file->addr) {
                                free((void *)file->addr);
                                file->addr = 0;
                        }
                }
        }

        free(table_loader);
        return addr;
}

ulong acpi_get_rsdp_addr(void)
{
        struct fw_file *file;

        file = qemu_fwcfg_find_file("etc/acpi/rsdp");
        return file->addr;
}
#endif

/* Read configuration item using fw_cfg PIO interface */
static void qemu_fwcfg_read_entry_pio(uint16_t entry,
                uint32_t size, void *address)
{
        debug("qemu_fwcfg_read_entry_pio: entry 0x%x, size %u address %p\n",
              entry, size, address);

        return fwcfg_arch_ops->arch_read_pio(entry, size, address);
}

/* Read configuration item using fw_cfg DMA interface */
static void qemu_fwcfg_read_entry_dma(uint16_t entry,
                uint32_t size, void *address)
{
        struct fw_cfg_dma_access dma;

        dma.length = cpu_to_be32(size);
        dma.address = cpu_to_be64((uintptr_t)address);
        dma.control = cpu_to_be32(FW_CFG_DMA_READ);

        /*
         * writting FW_CFG_INVALID will cause read operation to resume at
         * last offset, otherwise read will start at offset 0
         */
        if (entry != FW_CFG_INVALID)
                dma.control |= cpu_to_be32(FW_CFG_DMA_SELECT | (entry << 16));

        barrier();

        debug("qemu_fwcfg_read_entry_dma: entry 0x%x, size %u address %p, control 0x%x\n",
              entry, size, address, be32_to_cpu(dma.control));

        fwcfg_arch_ops->arch_read_dma(&dma);
}

bool qemu_fwcfg_present(void)
{
        return fwcfg_present;
}

bool qemu_fwcfg_dma_present(void)
{
        return fwcfg_dma_present;
}

void qemu_fwcfg_read_entry(uint16_t entry, uint32_t length, void *address)
{
        if (fwcfg_dma_present)
                qemu_fwcfg_read_entry_dma(entry, length, address);
        else
                qemu_fwcfg_read_entry_pio(entry, length, address);
}

int qemu_fwcfg_online_cpus(void)
{
        uint16_t nb_cpus;

        if (!fwcfg_present)
                return -ENODEV;

        qemu_fwcfg_read_entry(FW_CFG_NB_CPUS, 2, &nb_cpus);

        return le16_to_cpu(nb_cpus);
}

int qemu_fwcfg_read_firmware_list(void)
{
        int i;
        uint32_t count;
        struct fw_file *file;
        struct list_head *entry;

        /* don't read it twice */
        if (!list_empty(&fw_list))
                return 0;

        qemu_fwcfg_read_entry(FW_CFG_FILE_DIR, 4, &count);
        if (!count)
                return 0;

        count = be32_to_cpu(count);
        for (i = 0; i < count; i++) {
                file = malloc(sizeof(*file));
                if (!file) {
                        printf("error: allocating resource\n");
                        goto err;
                }
                qemu_fwcfg_read_entry(FW_CFG_INVALID,
                                      sizeof(struct fw_cfg_file), &file->cfg);
                file->addr = 0;
                list_add_tail(&file->list, &fw_list);
        }

        return 0;

err:
        list_for_each(entry, &fw_list) {
                file = list_entry(entry, struct fw_file, list);
                free(file);
        }

        return -ENOMEM;
}

struct fw_file *qemu_fwcfg_find_file(const char *name)
{
        struct list_head *entry;
        struct fw_file *file;

        list_for_each(entry, &fw_list) {
                file = list_entry(entry, struct fw_file, list);
                if (!strcmp(file->cfg.name, name))
                        return file;
        }

        return NULL;
}

struct fw_file *qemu_fwcfg_file_iter_init(struct fw_cfg_file_iter *iter)
{
        iter->entry = fw_list.next;
        return list_entry((struct list_head *)iter->entry,
                          struct fw_file, list);
}

struct fw_file *qemu_fwcfg_file_iter_next(struct fw_cfg_file_iter *iter)
{
        iter->entry = ((struct list_head *)iter->entry)->next;
        return list_entry((struct list_head *)iter->entry,
                          struct fw_file, list);
}

bool qemu_fwcfg_file_iter_end(struct fw_cfg_file_iter *iter)
{
        return iter->entry == &fw_list;
}

void qemu_fwcfg_init(struct fw_cfg_arch_ops *ops)
{
        uint32_t qemu;
        uint32_t dma_enabled;

        fwcfg_present = false;
        fwcfg_dma_present = false;
        fwcfg_arch_ops = NULL;

        if (!ops || !ops->arch_read_pio || !ops->arch_read_dma)
                return;
        fwcfg_arch_ops = ops;

        qemu_fwcfg_read_entry_pio(FW_CFG_SIGNATURE, 4, &qemu);
        if (be32_to_cpu(qemu) == QEMU_FW_CFG_SIGNATURE)
                fwcfg_present = true;

        if (fwcfg_present) {
                qemu_fwcfg_read_entry_pio(FW_CFG_ID, 1, &dma_enabled);
                if (dma_enabled & FW_CFG_DMA_ENABLED)
                        fwcfg_dma_present = true;
        }
}