blob: ee78a210c6068645574b8a5954e14578efd7e564 [file] [log] [blame]
// 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]\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)
{
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\n",
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.\n",
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)\n",
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_get_irqresource(struct resource *res, u32 gsi,
u8 triggering, u8 polarity, u8 shareable,
bool legacy)
{
int irq, p, t;
if (!valid_IRQ(gsi)) {
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\n", 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 {
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) {
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) {
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
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() routine 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;
}