path: root/drivers/acpi/resource.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * drivers/acpi/resource.c - ACPI device resources interpretation.
 *
 * Copyright (C) 2012, Intel Corp.
 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

#include <linux/acpi.h>
#include <linux/device.h>
#include <linux/export.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/irq.h>
#include <linux/dmi.h>

#ifdef CONFIG_X86
#define valid_IRQ(i) (((i) != 0) && ((i) != 2))
static inline bool acpi_iospace_resource_valid(struct resource *res)
{
	/* On X86 IO space is limited to the [0 - 64K] IO port range */
	return res->end < 0x10003;
}
#else
#define valid_IRQ(i) (true)
/*
 * ACPI IO descriptors on arches other than X86 contain MMIO CPU physical
 * addresses mapping IO space in CPU physical address space, IO space
 * resources can be placed anywhere in the 64-bit physical address space.
 */
static inline bool
acpi_iospace_resource_valid(struct resource *res) { return true; }
#endif

#if IS_ENABLED(CONFIG_ACPI_GENERIC_GSI)
static inline bool is_gsi(struct acpi_resource_extended_irq *ext_irq)
{
	return ext_irq->resource_source.string_length == 0 &&
	       ext_irq->producer_consumer == ACPI_CONSUMER;
}
#else
static inline bool is_gsi(struct acpi_resource_extended_irq *ext_irq)
{
	return true;
}
#endif

static bool acpi_dev_resource_len_valid(u64 start, u64 end, u64 len, bool io)
{
	u64 reslen = end - start + 1;

	/*
	 * CHECKME: len might be required to check versus a minimum
	 * length as well. 1 for io is fine, but for memory it does
	 * not make any sense at all.
	 * Note: some BIOSes report incorrect length for ACPI address space
	 * descriptor, so remove check of 'reslen == len' to avoid regression.
	 */
	if (len && reslen && start <= end)
		return true;

	pr_debug("ACPI: invalid or unassigned resource %s [%016llx - %016llx] length [%016llx]\n",
		io ? "io" : "mem", start, end, len);

	return false;
}

static void acpi_dev_memresource_flags(struct resource *res, u64 len,
				       u8 write_protect)
{
	res->flags = IORESOURCE_MEM;

	if (!acpi_dev_resource_len_valid(res->start, res->end, len, false))
		res->flags |= IORESOURCE_DISABLED | IORESOURCE_UNSET;

	if (write_protect == ACPI_READ_WRITE_MEMORY)
		res->flags |= IORESOURCE_MEM_WRITEABLE;
}

static void acpi_dev_get_memresource(struct resource *res, u64 start, u64 len,
				     u8 write_protect)
{
	res->start = start;
	res->end = start + len - 1;
	acpi_dev_memresource_flags(res, len, write_protect);
}

/**
 * acpi_dev_resource_memory - Extract ACPI memory resource information.
 * @ares: Input ACPI resource object.
 * @res: Output generic resource object.
 *
 * Check if the given ACPI resource object represents a memory resource and
 * if that's the case, use the information in it to populate the generic
 * resource object pointed to by @res.
 *
 * Return:
 * 1) false with res->flags setting to zero: not the expected resource type
 * 2) false with IORESOURCE_DISABLED in res->flags: valid unassigned resource
 * 3) true: valid assigned resource
 */
bool acpi_dev_resource_memory(struct acpi_resource *ares, struct resource *res)
{
	struct acpi_resource_memory24 *memory24;
	struct acpi_resource_memory32 *memory32;
	struct acpi_resource_fixed_memory32 *fixed_memory32;

	switch (ares->type) {
	case ACPI_RESOURCE_TYPE_MEMORY24:
		memory24 = &ares->data.memory24;
		acpi_dev_get_memresource(res, memory24->minimum << 8,
					 memory24->address_length << 8,
					 memory24->write_protect);
		break;
	case ACPI_RESOURCE_TYPE_MEMORY32:
		memory32 = &ares->data.memory32;
		acpi_dev_get_memresource(res, memory32->minimum,
					 memory32->address_length,
					 memory32->write_protect);
		break;
	case ACPI_RESOURCE_TYPE_FIXED_MEMORY32:
		fixed_memory32 = &ares->data.fixed_memory32;
		acpi_dev_get_memresource(res, fixed_memory32->address,
					 fixed_memory32->address_length,
					 fixed_memory32->write_protect);
		break;
	default:
		res->flags = 0;
		return false;
	}

	return !(res->flags & IORESOURCE_DISABLED);
}
EXPORT_SYMBOL_GPL(acpi_dev_resource_memory);

static void acpi_dev_ioresource_flags(struct resource *res, u64 len,
				      u8 io_decode, u8 translation_type)
{
	res->flags = IORESOURCE_IO;

	if (!acpi_dev_resource_len_valid(res->start, res->end, len, true))
		res->flags |= IORESOURCE_DISABLED | IORESOURCE_UNSET;

	if (!acpi_iospace_resource_valid(res))
		res->flags |= IORESOURCE_DISABLED | IORESOURCE_UNSET;

	if (io_decode == ACPI_DECODE_16)
		res->flags |= IORESOURCE_IO_16BIT_ADDR;
	if (translation_type == ACPI_SPARSE_TRANSLATION)
		res->flags |= IORESOURCE_IO_SPARSE;
}

static void acpi_dev_get_ioresource(struct resource *res, u64 start, u64 len,
				    u8 io_decode)
{