// 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>

  
  #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]
  ",

  		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)
  {

  	res->start = start;

  	res->end = start + len - 1;

  	acpi_dev_ioresource_flags(res, len, io_decode, 0);

  }
  
  /**
   * acpi_dev_resource_io - Extract ACPI I/O resource information.
   * @ares: Input ACPI resource object.
   * @res: Output generic resource object.
   *
   * Check if the given ACPI resource object represents an I/O 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_io(struct acpi_resource *ares, struct resource *res)
  {
  	struct acpi_resource_io *io;
  	struct acpi_resource_fixed_io *fixed_io;
  
  	switch (ares->type) {
  	case ACPI_RESOURCE_TYPE_IO:
  		io = &ares->data.io;
  		acpi_dev_get_ioresource(res, io->minimum,
  					io->address_length,
  					io->io_decode);
  		break;
  	case ACPI_RESOURCE_TYPE_FIXED_IO:
  		fixed_io = &ares->data.fixed_io;
  		acpi_dev_get_ioresource(res, fixed_io->address,
  					fixed_io->address_length,
  					ACPI_DECODE_10);
  		break;
  	default:

  		res->flags = 0;

  		return false;
  	}

  
  	return !(res->flags & IORESOURCE_DISABLED);

  }
  EXPORT_SYMBOL_GPL(acpi_dev_resource_io);

  static bool acpi_decode_space(struct resource_win *win,

  			      struct acpi_resource_address *addr,
  			      struct acpi_address64_attribute *attr)
  {
  	u8 iodec = attr->granularity == 0xfff ? ACPI_DECODE_10 : ACPI_DECODE_16;

  	bool wp = addr->info.mem.write_protect;
  	u64 len = attr->address_length;

  	u64 start, end, offset = 0;

  	struct resource *res = &win->res;

  	/*
  	 * Filter out invalid descriptor according to ACPI Spec 5.0, section
  	 * 6.4.3.5 Address Space Resource Descriptors.
  	 */
  	if ((addr->min_address_fixed != addr->max_address_fixed && len) ||
  	    (addr->min_address_fixed && addr->max_address_fixed && !len))
  		pr_debug("ACPI: Invalid address space min_addr_fix %d, max_addr_fix %d, len %llx
  ",
  			 addr->min_address_fixed, addr->max_address_fixed, len);

  	/*
  	 * For bridges that translate addresses across the bridge,
  	 * translation_offset is the offset that must be added to the
  	 * address on the secondary side to obtain the address on the
  	 * primary side. Non-bridge devices must list 0 for all Address
  	 * Translation offset bits.
  	 */

  	if (addr->producer_consumer == ACPI_PRODUCER)
  		offset = attr->translation_offset;
  	else if (attr->translation_offset)

  		pr_debug("ACPI: translation_offset(%lld) is invalid for non-bridge device.
  ",
  			 attr->translation_offset);

  	start = attr->minimum + offset;
  	end = attr->maximum + offset;
  
  	win->offset = offset;
  	res->start = start;
  	res->end = end;
  	if (sizeof(resource_size_t) < sizeof(u64) &&
  	    (offset != win->offset || start != res->start || end != res->end)) {
  		pr_warn("acpi resource window ([%#llx-%#llx] ignored, not CPU addressable)
  ",
  			attr->minimum, attr->maximum);
  		return false;

  	}

  	switch (addr->resource_type) {
  	case ACPI_MEMORY_RANGE:

  		acpi_dev_memresource_flags(res, len, wp);

  		break;
  	case ACPI_IO_RANGE:

  		acpi_dev_ioresource_flags(res, len, iodec,
  					  addr->info.io.translation_type);

  		break;
  	case ACPI_BUS_NUMBER_RANGE:
  		res->flags = IORESOURCE_BUS;
  		break;
  	default:
  		return false;
  	}

  	if (addr->producer_consumer == ACPI_PRODUCER)
  		res->flags |= IORESOURCE_WINDOW;

  
  	if (addr->info.mem.caching == ACPI_PREFETCHABLE_MEMORY)
  		res->flags |= IORESOURCE_PREFETCH;

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

  /**
   * acpi_dev_resource_address_space - Extract ACPI address space information.
   * @ares: Input ACPI resource object.

   * @win: Output generic resource object.

   *
   * Check if the given ACPI resource object represents an address space resource
   * and if that's the case, use the information in it to populate the generic

   * resource object pointed to by @win.

   *
   * Return:

   * 1) false with win->res.flags setting to zero: not the expected resource type
   * 2) false with IORESOURCE_DISABLED in win->res.flags: valid unassigned
   *    resource

   * 3) true: valid assigned resource

   */
  bool acpi_dev_resource_address_space(struct acpi_resource *ares,

  				     struct resource_win *win)

  {

  	struct acpi_resource_address64 addr;

  	win->res.flags = 0;

  	if (ACPI_FAILURE(acpi_resource_to_address64(ares, &addr)))

  		return false;

  	return acpi_decode_space(win, (struct acpi_resource_address *)&addr,

  				 &addr.address);

  }
  EXPORT_SYMBOL_GPL(acpi_dev_resource_address_space);
  
  /**
   * acpi_dev_resource_ext_address_space - Extract ACPI address space information.
   * @ares: Input ACPI resource object.

   * @win: Output generic resource object.

   *
   * Check if the given ACPI resource object represents an extended address space
   * resource and if that's the case, use the information in it to populate the

   * generic resource object pointed to by @win.

   *
   * Return:

   * 1) false with win->res.flags setting to zero: not the expected resource type
   * 2) false with IORESOURCE_DISABLED in win->res.flags: valid unassigned
   *    resource

   * 3) true: valid assigned resource

   */
  bool acpi_dev_resource_ext_address_space(struct acpi_resource *ares,

  					 struct resource_win *win)

  {
  	struct acpi_resource_extended_address64 *ext_addr;

  	win->res.flags = 0;

  	if (ares->type != ACPI_RESOURCE_TYPE_EXTENDED_ADDRESS64)
  		return false;
  
  	ext_addr = &ares->data.ext_address64;

  	return acpi_decode_space(win, (struct acpi_resource_address *)ext_addr,

  				 &ext_addr->address);

  }
  EXPORT_SYMBOL_GPL(acpi_dev_resource_ext_address_space);
  
  /**
   * acpi_dev_irq_flags - Determine IRQ resource flags.
   * @triggering: Triggering type as provided by ACPI.
   * @polarity: Interrupt polarity as provided by ACPI.
   * @shareable: Whether or not the interrupt is shareable.
   */
  unsigned long acpi_dev_irq_flags(u8 triggering, u8 polarity, u8 shareable)
  {
  	unsigned long flags;
  
  	if (triggering == ACPI_LEVEL_SENSITIVE)
  		flags = polarity == ACPI_ACTIVE_LOW ?
  			IORESOURCE_IRQ_LOWLEVEL : IORESOURCE_IRQ_HIGHLEVEL;
  	else
  		flags = polarity == ACPI_ACTIVE_LOW ?
  			IORESOURCE_IRQ_LOWEDGE : IORESOURCE_IRQ_HIGHEDGE;
  
  	if (shareable == ACPI_SHARED)
  		flags |= IORESOURCE_IRQ_SHAREABLE;
  
  	return flags | IORESOURCE_IRQ;
  }
  EXPORT_SYMBOL_GPL(acpi_dev_irq_flags);

  /**
   * acpi_dev_get_irq_type - Determine irq type.
   * @triggering: Triggering type as provided by ACPI.
   * @polarity: Interrupt polarity as provided by ACPI.
   */
  unsigned int acpi_dev_get_irq_type(int triggering, int polarity)
  {
  	switch (polarity) {
  	case ACPI_ACTIVE_LOW:
  		return triggering == ACPI_EDGE_SENSITIVE ?
  		       IRQ_TYPE_EDGE_FALLING :
  		       IRQ_TYPE_LEVEL_LOW;
  	case ACPI_ACTIVE_HIGH:
  		return triggering == ACPI_EDGE_SENSITIVE ?
  		       IRQ_TYPE_EDGE_RISING :
  		       IRQ_TYPE_LEVEL_HIGH;
  	case ACPI_ACTIVE_BOTH:
  		if (triggering == ACPI_EDGE_SENSITIVE)
  			return IRQ_TYPE_EDGE_BOTH;

  		fallthrough;

  	default:
  		return IRQ_TYPE_NONE;
  	}
  }
  EXPORT_SYMBOL_GPL(acpi_dev_get_irq_type);

  static void acpi_dev_irqresource_disabled(struct resource *res, u32 gsi)
  {
  	res->start = gsi;
  	res->end = gsi;

  	res->flags = IORESOURCE_IRQ | IORESOURCE_DISABLED | IORESOURCE_UNSET;

  }
  
  static void acpi_dev_get_irqresource(struct resource *res, u32 gsi,

  				     u8 triggering, u8 polarity, u8 shareable,
  				     bool legacy)

  {
  	int irq, p, t;
  
  	if (!valid_IRQ(gsi)) {
  		acpi_dev_irqresource_disabled(res, gsi);
  		return;
  	}
  
  	/*

  	 * In IO-APIC mode, use overridden attribute. Two reasons:

  	 * 1. BIOS bug in DSDT
  	 * 2. BIOS uses IO-APIC mode Interrupt Source Override

  	 *
  	 * We do this only if we are dealing with IRQ() or IRQNoFlags()
  	 * resource (the legacy ISA resources). With modern ACPI 5 devices
  	 * using extended IRQ descriptors we take the IRQ configuration
  	 * from _CRS directly.

  	 */

  	if (legacy && !acpi_get_override_irq(gsi, &t, &p)) {

  		u8 trig = t ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
  		u8 pol = p ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH;
  
  		if (triggering != trig || polarity != pol) {

  			pr_warn("ACPI: IRQ %d override to %s, %s
  ", gsi,
  				t ? "level" : "edge", p ? "low" : "high");

  			triggering = trig;
  			polarity = pol;
  		}
  	}
  
  	res->flags = acpi_dev_irq_flags(triggering, polarity, shareable);
  	irq = acpi_register_gsi(NULL, gsi, triggering, polarity);
  	if (irq >= 0) {
  		res->start = irq;
  		res->end = irq;
  	} else {
  		acpi_dev_irqresource_disabled(res, gsi);
  	}
  }
  
  /**
   * acpi_dev_resource_interrupt - Extract ACPI interrupt resource information.
   * @ares: Input ACPI resource object.
   * @index: Index into the array of GSIs represented by the resource.
   * @res: Output generic resource object.
   *
   * Check if the given ACPI resource object represents an interrupt resource
   * and @index does not exceed the resource's interrupt count (true is returned
   * in that case regardless of the results of the other checks)).  If that's the
   * case, register the GSI corresponding to @index from the array of interrupts
   * represented by the resource and populate the generic resource object pointed
   * to by @res accordingly.  If the registration of the GSI is not successful,
   * IORESOURCE_DISABLED will be set it that object's flags.

   *
   * 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_interrupt(struct acpi_resource *ares, int index,
  				 struct resource *res)
  {
  	struct acpi_resource_irq *irq;
  	struct acpi_resource_extended_irq *ext_irq;
  
  	switch (ares->type) {
  	case ACPI_RESOURCE_TYPE_IRQ:
  		/*
  		 * Per spec, only one interrupt per descriptor is allowed in
  		 * _CRS, but some firmware violates this, so parse them all.
  		 */
  		irq = &ares->data.irq;
  		if (index >= irq->interrupt_count) {
  			acpi_dev_irqresource_disabled(res, 0);
  			return false;
  		}
  		acpi_dev_get_irqresource(res, irq->interrupts[index],
  					 irq->triggering, irq->polarity,

  					 irq->shareable, true);

  		break;
  	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
  		ext_irq = &ares->data.extended_irq;
  		if (index >= ext_irq->interrupt_count) {
  			acpi_dev_irqresource_disabled(res, 0);
  			return false;
  		}

  		if (is_gsi(ext_irq))
  			acpi_dev_get_irqresource(res, ext_irq->interrupts[index],

  					 ext_irq->triggering, ext_irq->polarity,

  					 ext_irq->shareable, false);

  		else
  			acpi_dev_irqresource_disabled(res, 0);

  		break;
  	default:

  		res->flags = 0;

  		return false;
  	}
  
  	return true;
  }
  EXPORT_SYMBOL_GPL(acpi_dev_resource_interrupt);

  
  /**
   * acpi_dev_free_resource_list - Free resource from %acpi_dev_get_resources().
   * @list: The head of the resource list to free.
   */
  void acpi_dev_free_resource_list(struct list_head *list)
  {

  	resource_list_free(list);

  }
  EXPORT_SYMBOL_GPL(acpi_dev_free_resource_list);
  
  struct res_proc_context {
  	struct list_head *list;
  	int (*preproc)(struct acpi_resource *, void *);
  	void *preproc_data;
  	int count;
  	int error;
  };

  static acpi_status acpi_dev_new_resource_entry(struct resource_win *win,

  					       struct res_proc_context *c)
  {

  	struct resource_entry *rentry;

  	rentry = resource_list_create_entry(NULL, 0);

  	if (!rentry) {
  		c->error = -ENOMEM;
  		return AE_NO_MEMORY;
  	}

  	*rentry->res = win->res;

  	rentry->offset = win->offset;

  	resource_list_add_tail(rentry, c->list);

  	c->count++;
  	return AE_OK;
  }
  
  static acpi_status acpi_dev_process_resource(struct acpi_resource *ares,
  					     void *context)
  {
  	struct res_proc_context *c = context;

  	struct resource_win win;
  	struct resource *res = &win.res;

  	int i;
  
  	if (c->preproc) {
  		int ret;
  
  		ret = c->preproc(ares, c->preproc_data);
  		if (ret < 0) {
  			c->error = ret;

  			return AE_ABORT_METHOD;

  		} else if (ret > 0) {
  			return AE_OK;
  		}
  	}

  	memset(&win, 0, sizeof(win));

  	if (acpi_dev_resource_memory(ares, res)
  	    || acpi_dev_resource_io(ares, res)
  	    || acpi_dev_resource_address_space(ares, &win)
  	    || acpi_dev_resource_ext_address_space(ares, &win))
  		return acpi_dev_new_resource_entry(&win, c);

  	for (i = 0; acpi_dev_resource_interrupt(ares, i, res); i++) {

  		acpi_status status;

  		status = acpi_dev_new_resource_entry(&win, c);

  		if (ACPI_FAILURE(status))
  			return status;
  	}
  
  	return AE_OK;
  }

  static int __acpi_dev_get_resources(struct acpi_device *adev,
  				    struct list_head *list,
  				    int (*preproc)(struct acpi_resource *, void *),
  				    void *preproc_data, char *method)
  {
  	struct res_proc_context c;
  	acpi_status status;
  
  	if (!adev || !adev->handle || !list_empty(list))
  		return -EINVAL;
  
  	if (!acpi_has_method(adev->handle, method))
  		return 0;
  
  	c.list = list;
  	c.preproc = preproc;
  	c.preproc_data = preproc_data;
  	c.count = 0;
  	c.error = 0;
  	status = acpi_walk_resources(adev->handle, method,
  				     acpi_dev_process_resource, &c);
  	if (ACPI_FAILURE(status)) {
  		acpi_dev_free_resource_list(list);
  		return c.error ? c.error : -EIO;
  	}
  
  	return c.count;
  }

  /**
   * acpi_dev_get_resources - Get current resources of a device.
   * @adev: ACPI device node to get the resources for.
   * @list: Head of the resultant list of resources (must be empty).
   * @preproc: The caller's preprocessing routine.
   * @preproc_data: Pointer passed to the caller's preprocessing routine.
   *
   * Evaluate the _CRS method for the given device node and process its output by
   * (1) executing the @preproc() rountine provided by the caller, passing the
   * resource pointer and @preproc_data to it as arguments, for each ACPI resource
   * returned and (2) converting all of the returned ACPI resources into struct
   * resource objects if possible.  If the return value of @preproc() in step (1)
   * is different from 0, step (2) is not applied to the given ACPI resource and
   * if that value is negative, the whole processing is aborted and that value is
   * returned as the final error code.
   *
   * The resultant struct resource objects are put on the list pointed to by

   * @list, that must be empty initially, as members of struct resource_entry

   * objects.  Callers of this routine should use %acpi_dev_free_resource_list() to
   * free that list.
   *
   * The number of resources in the output list is returned on success, an error
   * code reflecting the error condition is returned otherwise.
   */
  int acpi_dev_get_resources(struct acpi_device *adev, struct list_head *list,
  			   int (*preproc)(struct acpi_resource *, void *),
  			   void *preproc_data)
  {

  	return __acpi_dev_get_resources(adev, list, preproc, preproc_data,
  					METHOD_NAME__CRS);

  }
  EXPORT_SYMBOL_GPL(acpi_dev_get_resources);

  static int is_memory(struct acpi_resource *ares, void *not_used)
  {
  	struct resource_win win;
  	struct resource *res = &win.res;
  
  	memset(&win, 0, sizeof(win));
  
  	return !(acpi_dev_resource_memory(ares, res)
  	       || acpi_dev_resource_address_space(ares, &win)
  	       || acpi_dev_resource_ext_address_space(ares, &win));
  }
  
  /**
   * acpi_dev_get_dma_resources - Get current DMA resources of a device.
   * @adev: ACPI device node to get the resources for.
   * @list: Head of the resultant list of resources (must be empty).
   *
   * Evaluate the _DMA method for the given device node and process its
   * output.
   *
   * The resultant struct resource objects are put on the list pointed to
   * by @list, that must be empty initially, as members of struct
   * resource_entry objects.  Callers of this routine should use
   * %acpi_dev_free_resource_list() to free that list.
   *
   * The number of resources in the output list is returned on success,
   * an error code reflecting the error condition is returned otherwise.
   */
  int acpi_dev_get_dma_resources(struct acpi_device *adev, struct list_head *list)
  {
  	return __acpi_dev_get_resources(adev, list, is_memory, NULL,
  					METHOD_NAME__DMA);
  }
  EXPORT_SYMBOL_GPL(acpi_dev_get_dma_resources);

  /**
   * acpi_dev_filter_resource_type - Filter ACPI resource according to resource
   *				   types
   * @ares: Input ACPI resource object.
   * @types: Valid resource types of IORESOURCE_XXX
   *

   * This is a helper function to support acpi_dev_get_resources(), which filters

   * ACPI resource objects according to resource types.
   */
  int acpi_dev_filter_resource_type(struct acpi_resource *ares,
  				  unsigned long types)
  {
  	unsigned long type = 0;
  
  	switch (ares->type) {
  	case ACPI_RESOURCE_TYPE_MEMORY24:
  	case ACPI_RESOURCE_TYPE_MEMORY32:
  	case ACPI_RESOURCE_TYPE_FIXED_MEMORY32:
  		type = IORESOURCE_MEM;
  		break;
  	case ACPI_RESOURCE_TYPE_IO:
  	case ACPI_RESOURCE_TYPE_FIXED_IO:
  		type = IORESOURCE_IO;
  		break;
  	case ACPI_RESOURCE_TYPE_IRQ:
  	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
  		type = IORESOURCE_IRQ;
  		break;
  	case ACPI_RESOURCE_TYPE_DMA:
  	case ACPI_RESOURCE_TYPE_FIXED_DMA:
  		type = IORESOURCE_DMA;
  		break;
  	case ACPI_RESOURCE_TYPE_GENERIC_REGISTER:
  		type = IORESOURCE_REG;
  		break;
  	case ACPI_RESOURCE_TYPE_ADDRESS16:
  	case ACPI_RESOURCE_TYPE_ADDRESS32:
  	case ACPI_RESOURCE_TYPE_ADDRESS64:
  	case ACPI_RESOURCE_TYPE_EXTENDED_ADDRESS64:
  		if (ares->data.address.resource_type == ACPI_MEMORY_RANGE)
  			type = IORESOURCE_MEM;
  		else if (ares->data.address.resource_type == ACPI_IO_RANGE)
  			type = IORESOURCE_IO;
  		else if (ares->data.address.resource_type ==
  			 ACPI_BUS_NUMBER_RANGE)
  			type = IORESOURCE_BUS;
  		break;
  	default:
  		break;
  	}
  
  	return (type & types) ? 0 : 1;
  }
  EXPORT_SYMBOL_GPL(acpi_dev_filter_resource_type);

  
  static int acpi_dev_consumes_res(struct acpi_device *adev, struct resource *res)
  {
  	struct list_head resource_list;
  	struct resource_entry *rentry;
  	int ret, found = 0;
  
  	INIT_LIST_HEAD(&resource_list);
  	ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
  	if (ret < 0)
  		return 0;
  
  	list_for_each_entry(rentry, &resource_list, node) {
  		if (resource_contains(rentry->res, res)) {
  			found = 1;
  			break;
  		}
  
  	}
  
  	acpi_dev_free_resource_list(&resource_list);
  	return found;
  }
  
  static acpi_status acpi_res_consumer_cb(acpi_handle handle, u32 depth,
  					 void *context, void **ret)
  {
  	struct resource *res = context;
  	struct acpi_device **consumer = (struct acpi_device **) ret;
  	struct acpi_device *adev;
  
  	if (acpi_bus_get_device(handle, &adev))
  		return AE_OK;
  
  	if (acpi_dev_consumes_res(adev, res)) {
  		*consumer = adev;
  		return AE_CTRL_TERMINATE;
  	}
  
  	return AE_OK;
  }
  
  /**
   * acpi_resource_consumer - Find the ACPI device that consumes @res.
   * @res: Resource to search for.
   *
   * Search the current resource settings (_CRS) of every ACPI device node
   * for @res.  If we find an ACPI device whose _CRS includes @res, return
   * it.  Otherwise, return NULL.
   */
  struct acpi_device *acpi_resource_consumer(struct resource *res)
  {
  	struct acpi_device *consumer = NULL;
  
  	acpi_get_devices(NULL, acpi_res_consumer_cb, res, (void **) &consumer);
  	return consumer;
  }