drivers/misc/qfw.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2015 Miao Yan <yanmiaobest@gmail.com>
 * (C) Copyright 2021 Asherah Connor <ashe@kivikakk.ee>
 */

#define LOG_CATEGORY UCLASS_QFW

#include <common.h>
#include <command.h>
#include <errno.h>
#include <log.h>
#include <malloc.h>
#include <qfw.h>
#include <dm.h>
#include <misc.h>
#include <tables_csum.h>
#ifdef CONFIG_GENERATE_ACPI_TABLE
#include <asm/tables.h>
#endif

#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 udevice *dev,
				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 = qfw_find_file(dev, 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);

	qfw_read_entry(dev, 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 udevice *dev,
				   struct bios_linker_entry *entry)
{
	struct fw_file *dest, *src;
	uint32_t offset = le32_to_cpu(entry->pointer.offset);
	uint64_t pointer = 0;

	dest = qfw_find_file(dev, entry->pointer.dest_file);
	if (!dest || !dest->addr)
		return -ENOENT;
	src = qfw_find_file(dev, 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 udevice *dev,
				    struct bios_linker_entry *entry)
{
	struct fw_file *file;
	uint8_t *data, cksum = 0;
	uint8_t *cksum_start;

	file = qfw_find_file(dev, 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;
	struct fw_file *file;
	struct bios_linker_entry *table_loader;
	struct bios_linker_entry *entry;
	uint32_t size;
	struct udevice *dev;

	ret = qfw_get_dev(&dev);
	if (ret) {
		printf("error: no qfw\n");
		return addr;
	}

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

	file = qfw_find_file(dev, "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;
	}

	qfw_read_entry(dev, 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(dev, entry, &addr);
			if (ret)
				goto out;
			break;
		case BIOS_LINKER_LOADER_COMMAND_ADD_POINTER:
			ret = bios_linker_add_pointer(dev, entry);
			if (ret)
				goto out;
			break;
		case BIOS_LINKER_LOADER_COMMAND_ADD_CHECKSUM:
			ret = bios_linker_add_checksum(dev, entry);
			if (ret)
				goto out;
			break;
		default:
			break;
		}
	}

out:
	if (ret) {
		struct fw_cfg_file_iter iter;
		for (file = qfw_file_iter_init(dev, &iter);
		     !qfw_file_iter_end(&iter);
		     file = qfw_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)
{
	int ret;
	struct fw_file *file;
	struct udevice *dev;

	ret = qfw_get_dev(&dev);
	if (ret) {
		printf("error: no qfw\n");
		return 0;
	}

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

static void qfw_read_entry_io(struct qfw_dev *qdev, u16 entry, u32 size,
			      void *address)
{
	struct dm_qfw_ops *ops = dm_qfw_get_ops(qdev->dev);

	debug("%s: entry 0x%x, size %u address %p\n", __func__, entry, size,
	      address);

	ops->read_entry_io(qdev->dev, entry, size, address);
}

static void qfw_read_entry_dma(struct qfw_dev *qdev, u16 entry, u32 size,
			       void *address)
{
	struct dm_qfw_ops *ops = dm_qfw_get_ops(qdev->dev);

	struct qfw_dma dma = {
		.length = cpu_to_be32(size),
		.address = cpu_to_be64((uintptr_t)address),
		.control = cpu_to_be32(FW_CFG_DMA_READ),
	};

	/*
	 * writing 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));

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

	barrier();

	ops->read_entry_dma(qdev->dev, &dma);
}

void qfw_read_entry(struct udevice *dev, u16 entry, u32 size, void *address)
{
	struct qfw_dev *qdev = dev_get_uclass_priv(dev);

	if (qdev->dma_present)
		qfw_read_entry_dma(qdev, entry, size, address);
	else
		qfw_read_entry_io(qdev, entry, size, address);
}

int qfw_register(struct udevice *dev)
{
	struct qfw_dev *qdev = dev_get_uclass_priv(dev);
	u32 qemu, dma_enabled;

	qdev->dev = dev;
	INIT_LIST_HEAD(&qdev->fw_list);

	qfw_read_entry_io(qdev, FW_CFG_SIGNATURE, 4, &qemu);
	if (be32_to_cpu(qemu) != QEMU_FW_CFG_SIGNATURE)
		return -ENODEV;

	qfw_read_entry_io(qdev, FW_CFG_ID, 1, &dma_enabled);
	if (dma_enabled & FW_CFG_DMA_ENABLED)
		qdev->dma_present = true;

	return 0;
}

UCLASS_DRIVER(qfw) = {
	.id		= UCLASS_QFW,
	.name		= "qfw",
	.per_device_auto	= sizeof(struct qfw_dev),
};