1 // SPDX-License-Identifier: GPL-2.0-only
3 * drivers/acpi/resource.c - ACPI device resources interpretation.
5 * Copyright (C) 2012, Intel Corp.
6 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
8 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
10 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
13 #include <linux/acpi.h>
14 #include <linux/device.h>
15 #include <linux/export.h>
16 #include <linux/ioport.h>
17 #include <linux/slab.h>
18 #include <linux/irq.h>
21 #define valid_IRQ(i) (((i) != 0) && ((i) != 2))
22 static inline bool acpi_iospace_resource_valid(struct resource *res)
24 /* On X86 IO space is limited to the [0 - 64K] IO port range */
25 return res->end < 0x10003;
28 #define valid_IRQ(i) (true)
30 * ACPI IO descriptors on arches other than X86 contain MMIO CPU physical
31 * addresses mapping IO space in CPU physical address space, IO space
32 * resources can be placed anywhere in the 64-bit physical address space.
35 acpi_iospace_resource_valid(struct resource *res) { return true; }
38 #if IS_ENABLED(CONFIG_ACPI_GENERIC_GSI)
39 static inline bool is_gsi(struct acpi_resource_extended_irq *ext_irq)
41 return ext_irq->resource_source.string_length == 0 &&
42 ext_irq->producer_consumer == ACPI_CONSUMER;
45 static inline bool is_gsi(struct acpi_resource_extended_irq *ext_irq)
51 static bool acpi_dev_resource_len_valid(u64 start, u64 end, u64 len, bool io)
53 u64 reslen = end - start + 1;
56 * CHECKME: len might be required to check versus a minimum
57 * length as well. 1 for io is fine, but for memory it does
58 * not make any sense at all.
59 * Note: some BIOSes report incorrect length for ACPI address space
60 * descriptor, so remove check of 'reslen == len' to avoid regression.
62 if (len && reslen && start <= end)
65 pr_debug("ACPI: invalid or unassigned resource %s [%016llx - %016llx] length [%016llx]\n",
66 io ? "io" : "mem", start, end, len);
71 static void acpi_dev_memresource_flags(struct resource *res, u64 len,
74 res->flags = IORESOURCE_MEM;
76 if (!acpi_dev_resource_len_valid(res->start, res->end, len, false))
77 res->flags |= IORESOURCE_DISABLED | IORESOURCE_UNSET;
79 if (write_protect == ACPI_READ_WRITE_MEMORY)
80 res->flags |= IORESOURCE_MEM_WRITEABLE;
83 static void acpi_dev_get_memresource(struct resource *res, u64 start, u64 len,
87 res->end = start + len - 1;
88 acpi_dev_memresource_flags(res, len, write_protect);
92 * acpi_dev_resource_memory - Extract ACPI memory resource information.
93 * @ares: Input ACPI resource object.
94 * @res: Output generic resource object.
96 * Check if the given ACPI resource object represents a memory resource and
97 * if that's the case, use the information in it to populate the generic
98 * resource object pointed to by @res.
101 * 1) false with res->flags setting to zero: not the expected resource type
102 * 2) false with IORESOURCE_DISABLED in res->flags: valid unassigned resource
103 * 3) true: valid assigned resource
105 bool acpi_dev_resource_memory(struct acpi_resource *ares, struct resource *res)
107 struct acpi_resource_memory24 *memory24;
108 struct acpi_resource_memory32 *memory32;
109 struct acpi_resource_fixed_memory32 *fixed_memory32;
111 switch (ares->type) {
112 case ACPI_RESOURCE_TYPE_MEMORY24:
113 memory24 = &ares->data.memory24;
114 acpi_dev_get_memresource(res, memory24->minimum << 8,
115 memory24->address_length << 8,
116 memory24->write_protect);
118 case ACPI_RESOURCE_TYPE_MEMORY32:
119 memory32 = &ares->data.memory32;
120 acpi_dev_get_memresource(res, memory32->minimum,
121 memory32->address_length,
122 memory32->write_protect);
124 case ACPI_RESOURCE_TYPE_FIXED_MEMORY32:
125 fixed_memory32 = &ares->data.fixed_memory32;
126 acpi_dev_get_memresource(res, fixed_memory32->address,
127 fixed_memory32->address_length,
128 fixed_memory32->write_protect);
135 return !(res->flags & IORESOURCE_DISABLED);
137 EXPORT_SYMBOL_GPL(acpi_dev_resource_memory);
139 static void acpi_dev_ioresource_flags(struct resource *res, u64 len,
140 u8 io_decode, u8 translation_type)
142 res->flags = IORESOURCE_IO;
144 if (!acpi_dev_resource_len_valid(res->start, res->end, len, true))
145 res->flags |= IORESOURCE_DISABLED | IORESOURCE_UNSET;
147 if (!acpi_iospace_resource_valid(res))
148 res->flags |= IORESOURCE_DISABLED | IORESOURCE_UNSET;
150 if (io_decode == ACPI_DECODE_16)
151 res->flags |= IORESOURCE_IO_16BIT_ADDR;
152 if (translation_type == ACPI_SPARSE_TRANSLATION)
153 res->flags |= IORESOURCE_IO_SPARSE;
156 static void acpi_dev_get_ioresource(struct resource *res, u64 start, u64 len,
160 res->end = start + len - 1;
161 acpi_dev_ioresource_flags(res, len, io_decode, 0);
165 * acpi_dev_resource_io - Extract ACPI I/O resource information.
166 * @ares: Input ACPI resource object.
167 * @res: Output generic resource object.
169 * Check if the given ACPI resource object represents an I/O resource and
170 * if that's the case, use the information in it to populate the generic
171 * resource object pointed to by @res.
174 * 1) false with res->flags setting to zero: not the expected resource type
175 * 2) false with IORESOURCE_DISABLED in res->flags: valid unassigned resource
176 * 3) true: valid assigned resource
178 bool acpi_dev_resource_io(struct acpi_resource *ares, struct resource *res)
180 struct acpi_resource_io *io;
181 struct acpi_resource_fixed_io *fixed_io;
183 switch (ares->type) {
184 case ACPI_RESOURCE_TYPE_IO:
186 acpi_dev_get_ioresource(res, io->minimum,
190 case ACPI_RESOURCE_TYPE_FIXED_IO:
191 fixed_io = &ares->data.fixed_io;
192 acpi_dev_get_ioresource(res, fixed_io->address,
193 fixed_io->address_length,
201 return !(res->flags & IORESOURCE_DISABLED);
203 EXPORT_SYMBOL_GPL(acpi_dev_resource_io);
205 static bool acpi_decode_space(struct resource_win *win,
206 struct acpi_resource_address *addr,
207 struct acpi_address64_attribute *attr)
209 u8 iodec = attr->granularity == 0xfff ? ACPI_DECODE_10 : ACPI_DECODE_16;
210 bool wp = addr->info.mem.write_protect;
211 u64 len = attr->address_length;
212 u64 start, end, offset = 0;
213 struct resource *res = &win->res;
216 * Filter out invalid descriptor according to ACPI Spec 5.0, section
217 * 6.4.3.5 Address Space Resource Descriptors.
219 if ((addr->min_address_fixed != addr->max_address_fixed && len) ||
220 (addr->min_address_fixed && addr->max_address_fixed && !len))
221 pr_debug("ACPI: Invalid address space min_addr_fix %d, max_addr_fix %d, len %llx\n",
222 addr->min_address_fixed, addr->max_address_fixed, len);
225 * For bridges that translate addresses across the bridge,
226 * translation_offset is the offset that must be added to the
227 * address on the secondary side to obtain the address on the
228 * primary side. Non-bridge devices must list 0 for all Address
229 * Translation offset bits.
231 if (addr->producer_consumer == ACPI_PRODUCER)
232 offset = attr->translation_offset;
233 else if (attr->translation_offset)
234 pr_debug("ACPI: translation_offset(%lld) is invalid for non-bridge device.\n",
235 attr->translation_offset);
236 start = attr->minimum + offset;
237 end = attr->maximum + offset;
239 win->offset = offset;
242 if (sizeof(resource_size_t) < sizeof(u64) &&
243 (offset != win->offset || start != res->start || end != res->end)) {
244 pr_warn("acpi resource window ([%#llx-%#llx] ignored, not CPU addressable)\n",
245 attr->minimum, attr->maximum);
249 switch (addr->resource_type) {
250 case ACPI_MEMORY_RANGE:
251 acpi_dev_memresource_flags(res, len, wp);
254 acpi_dev_ioresource_flags(res, len, iodec,
255 addr->info.io.translation_type);
257 case ACPI_BUS_NUMBER_RANGE:
258 res->flags = IORESOURCE_BUS;
264 if (addr->producer_consumer == ACPI_PRODUCER)
265 res->flags |= IORESOURCE_WINDOW;
267 if (addr->info.mem.caching == ACPI_PREFETCHABLE_MEMORY)
268 res->flags |= IORESOURCE_PREFETCH;
270 return !(res->flags & IORESOURCE_DISABLED);
274 * acpi_dev_resource_address_space - Extract ACPI address space information.
275 * @ares: Input ACPI resource object.
276 * @win: Output generic resource object.
278 * Check if the given ACPI resource object represents an address space resource
279 * and if that's the case, use the information in it to populate the generic
280 * resource object pointed to by @win.
283 * 1) false with win->res.flags setting to zero: not the expected resource type
284 * 2) false with IORESOURCE_DISABLED in win->res.flags: valid unassigned
286 * 3) true: valid assigned resource
288 bool acpi_dev_resource_address_space(struct acpi_resource *ares,
289 struct resource_win *win)
291 struct acpi_resource_address64 addr;
294 if (ACPI_FAILURE(acpi_resource_to_address64(ares, &addr)))
297 return acpi_decode_space(win, (struct acpi_resource_address *)&addr,
300 EXPORT_SYMBOL_GPL(acpi_dev_resource_address_space);
303 * acpi_dev_resource_ext_address_space - Extract ACPI address space information.
304 * @ares: Input ACPI resource object.
305 * @win: Output generic resource object.
307 * Check if the given ACPI resource object represents an extended address space
308 * resource and if that's the case, use the information in it to populate the
309 * generic resource object pointed to by @win.
312 * 1) false with win->res.flags setting to zero: not the expected resource type
313 * 2) false with IORESOURCE_DISABLED in win->res.flags: valid unassigned
315 * 3) true: valid assigned resource
317 bool acpi_dev_resource_ext_address_space(struct acpi_resource *ares,
318 struct resource_win *win)
320 struct acpi_resource_extended_address64 *ext_addr;
323 if (ares->type != ACPI_RESOURCE_TYPE_EXTENDED_ADDRESS64)
326 ext_addr = &ares->data.ext_address64;
328 return acpi_decode_space(win, (struct acpi_resource_address *)ext_addr,
331 EXPORT_SYMBOL_GPL(acpi_dev_resource_ext_address_space);
334 * acpi_dev_irq_flags - Determine IRQ resource flags.
335 * @triggering: Triggering type as provided by ACPI.
336 * @polarity: Interrupt polarity as provided by ACPI.
337 * @shareable: Whether or not the interrupt is shareable.
339 unsigned long acpi_dev_irq_flags(u8 triggering, u8 polarity, u8 shareable)
343 if (triggering == ACPI_LEVEL_SENSITIVE)
344 flags = polarity == ACPI_ACTIVE_LOW ?
345 IORESOURCE_IRQ_LOWLEVEL : IORESOURCE_IRQ_HIGHLEVEL;
347 flags = polarity == ACPI_ACTIVE_LOW ?
348 IORESOURCE_IRQ_LOWEDGE : IORESOURCE_IRQ_HIGHEDGE;
350 if (shareable == ACPI_SHARED)
351 flags |= IORESOURCE_IRQ_SHAREABLE;
353 return flags | IORESOURCE_IRQ;
355 EXPORT_SYMBOL_GPL(acpi_dev_irq_flags);
358 * acpi_dev_get_irq_type - Determine irq type.
359 * @triggering: Triggering type as provided by ACPI.
360 * @polarity: Interrupt polarity as provided by ACPI.
362 unsigned int acpi_dev_get_irq_type(int triggering, int polarity)
365 case ACPI_ACTIVE_LOW:
366 return triggering == ACPI_EDGE_SENSITIVE ?
367 IRQ_TYPE_EDGE_FALLING :
369 case ACPI_ACTIVE_HIGH:
370 return triggering == ACPI_EDGE_SENSITIVE ?
371 IRQ_TYPE_EDGE_RISING :
373 case ACPI_ACTIVE_BOTH:
374 if (triggering == ACPI_EDGE_SENSITIVE)
375 return IRQ_TYPE_EDGE_BOTH;
378 return IRQ_TYPE_NONE;
381 EXPORT_SYMBOL_GPL(acpi_dev_get_irq_type);
383 static void acpi_dev_get_irqresource(struct resource *res, u32 gsi,
384 u8 triggering, u8 polarity, u8 shareable,
389 if (!valid_IRQ(gsi)) {
390 irqresource_disabled(res, gsi);
395 * In IO-APIC mode, use overridden attribute. Two reasons:
396 * 1. BIOS bug in DSDT
397 * 2. BIOS uses IO-APIC mode Interrupt Source Override
399 * We do this only if we are dealing with IRQ() or IRQNoFlags()
400 * resource (the legacy ISA resources). With modern ACPI 5 devices
401 * using extended IRQ descriptors we take the IRQ configuration
402 * from _CRS directly.
404 if (legacy && !acpi_get_override_irq(gsi, &t, &p)) {
405 u8 trig = t ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
406 u8 pol = p ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH;
408 if (triggering != trig || polarity != pol) {
409 pr_warn("ACPI: IRQ %d override to %s, %s\n", gsi,
410 t ? "level" : "edge", p ? "low" : "high");
416 res->flags = acpi_dev_irq_flags(triggering, polarity, shareable);
417 irq = acpi_register_gsi(NULL, gsi, triggering, polarity);
422 irqresource_disabled(res, gsi);
426 static bool irq_is_legacy(struct acpi_resource_irq *irq)
428 return irq->triggering == ACPI_EDGE_SENSITIVE &&
429 irq->polarity == ACPI_ACTIVE_HIGH &&
430 irq->shareable == ACPI_EXCLUSIVE;
434 * acpi_dev_resource_interrupt - Extract ACPI interrupt resource information.
435 * @ares: Input ACPI resource object.
436 * @index: Index into the array of GSIs represented by the resource.
437 * @res: Output generic resource object.
439 * Check if the given ACPI resource object represents an interrupt resource
440 * and @index does not exceed the resource's interrupt count (true is returned
441 * in that case regardless of the results of the other checks)). If that's the
442 * case, register the GSI corresponding to @index from the array of interrupts
443 * represented by the resource and populate the generic resource object pointed
444 * to by @res accordingly. If the registration of the GSI is not successful,
445 * IORESOURCE_DISABLED will be set it that object's flags.
448 * 1) false with res->flags setting to zero: not the expected resource type
449 * 2) false with IORESOURCE_DISABLED in res->flags: valid unassigned resource
450 * 3) true: valid assigned resource
452 bool acpi_dev_resource_interrupt(struct acpi_resource *ares, int index,
453 struct resource *res)
455 struct acpi_resource_irq *irq;
456 struct acpi_resource_extended_irq *ext_irq;
458 switch (ares->type) {
459 case ACPI_RESOURCE_TYPE_IRQ:
461 * Per spec, only one interrupt per descriptor is allowed in
462 * _CRS, but some firmware violates this, so parse them all.
464 irq = &ares->data.irq;
465 if (index >= irq->interrupt_count) {
466 irqresource_disabled(res, 0);
469 acpi_dev_get_irqresource(res, irq->interrupts[index],
470 irq->triggering, irq->polarity,
471 irq->shareable, irq_is_legacy(irq));
473 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
474 ext_irq = &ares->data.extended_irq;
475 if (index >= ext_irq->interrupt_count) {
476 irqresource_disabled(res, 0);
480 acpi_dev_get_irqresource(res, ext_irq->interrupts[index],
481 ext_irq->triggering, ext_irq->polarity,
482 ext_irq->shareable, false);
484 irqresource_disabled(res, 0);
493 EXPORT_SYMBOL_GPL(acpi_dev_resource_interrupt);
496 * acpi_dev_free_resource_list - Free resource from %acpi_dev_get_resources().
497 * @list: The head of the resource list to free.
499 void acpi_dev_free_resource_list(struct list_head *list)
501 resource_list_free(list);
503 EXPORT_SYMBOL_GPL(acpi_dev_free_resource_list);
505 struct res_proc_context {
506 struct list_head *list;
507 int (*preproc)(struct acpi_resource *, void *);
513 static acpi_status acpi_dev_new_resource_entry(struct resource_win *win,
514 struct res_proc_context *c)
516 struct resource_entry *rentry;
518 rentry = resource_list_create_entry(NULL, 0);
523 *rentry->res = win->res;
524 rentry->offset = win->offset;
525 resource_list_add_tail(rentry, c->list);
530 static acpi_status acpi_dev_process_resource(struct acpi_resource *ares,
533 struct res_proc_context *c = context;
534 struct resource_win win;
535 struct resource *res = &win.res;
541 ret = c->preproc(ares, c->preproc_data);
544 return AE_ABORT_METHOD;
545 } else if (ret > 0) {
550 memset(&win, 0, sizeof(win));
552 if (acpi_dev_resource_memory(ares, res)
553 || acpi_dev_resource_io(ares, res)
554 || acpi_dev_resource_address_space(ares, &win)
555 || acpi_dev_resource_ext_address_space(ares, &win))
556 return acpi_dev_new_resource_entry(&win, c);
558 for (i = 0; acpi_dev_resource_interrupt(ares, i, res); i++) {
561 status = acpi_dev_new_resource_entry(&win, c);
562 if (ACPI_FAILURE(status))
569 static int __acpi_dev_get_resources(struct acpi_device *adev,
570 struct list_head *list,
571 int (*preproc)(struct acpi_resource *, void *),
572 void *preproc_data, char *method)
574 struct res_proc_context c;
577 if (!adev || !adev->handle || !list_empty(list))
580 if (!acpi_has_method(adev->handle, method))
585 c.preproc_data = preproc_data;
588 status = acpi_walk_resources(adev->handle, method,
589 acpi_dev_process_resource, &c);
590 if (ACPI_FAILURE(status)) {
591 acpi_dev_free_resource_list(list);
592 return c.error ? c.error : -EIO;
599 * acpi_dev_get_resources - Get current resources of a device.
600 * @adev: ACPI device node to get the resources for.
601 * @list: Head of the resultant list of resources (must be empty).
602 * @preproc: The caller's preprocessing routine.
603 * @preproc_data: Pointer passed to the caller's preprocessing routine.
605 * Evaluate the _CRS method for the given device node and process its output by
606 * (1) executing the @preproc() routine provided by the caller, passing the
607 * resource pointer and @preproc_data to it as arguments, for each ACPI resource
608 * returned and (2) converting all of the returned ACPI resources into struct
609 * resource objects if possible. If the return value of @preproc() in step (1)
610 * is different from 0, step (2) is not applied to the given ACPI resource and
611 * if that value is negative, the whole processing is aborted and that value is
612 * returned as the final error code.
614 * The resultant struct resource objects are put on the list pointed to by
615 * @list, that must be empty initially, as members of struct resource_entry
616 * objects. Callers of this routine should use %acpi_dev_free_resource_list() to
619 * The number of resources in the output list is returned on success, an error
620 * code reflecting the error condition is returned otherwise.
622 int acpi_dev_get_resources(struct acpi_device *adev, struct list_head *list,
623 int (*preproc)(struct acpi_resource *, void *),
626 return __acpi_dev_get_resources(adev, list, preproc, preproc_data,
629 EXPORT_SYMBOL_GPL(acpi_dev_get_resources);
631 static int is_memory(struct acpi_resource *ares, void *not_used)
633 struct resource_win win;
634 struct resource *res = &win.res;
636 memset(&win, 0, sizeof(win));
638 return !(acpi_dev_resource_memory(ares, res)
639 || acpi_dev_resource_address_space(ares, &win)
640 || acpi_dev_resource_ext_address_space(ares, &win));
644 * acpi_dev_get_dma_resources - Get current DMA resources of a device.
645 * @adev: ACPI device node to get the resources for.
646 * @list: Head of the resultant list of resources (must be empty).
648 * Evaluate the _DMA method for the given device node and process its
651 * The resultant struct resource objects are put on the list pointed to
652 * by @list, that must be empty initially, as members of struct
653 * resource_entry objects. Callers of this routine should use
654 * %acpi_dev_free_resource_list() to free that list.
656 * The number of resources in the output list is returned on success,
657 * an error code reflecting the error condition is returned otherwise.
659 int acpi_dev_get_dma_resources(struct acpi_device *adev, struct list_head *list)
661 return __acpi_dev_get_resources(adev, list, is_memory, NULL,
664 EXPORT_SYMBOL_GPL(acpi_dev_get_dma_resources);
667 * acpi_dev_filter_resource_type - Filter ACPI resource according to resource
669 * @ares: Input ACPI resource object.
670 * @types: Valid resource types of IORESOURCE_XXX
672 * This is a helper function to support acpi_dev_get_resources(), which filters
673 * ACPI resource objects according to resource types.
675 int acpi_dev_filter_resource_type(struct acpi_resource *ares,
678 unsigned long type = 0;
680 switch (ares->type) {
681 case ACPI_RESOURCE_TYPE_MEMORY24:
682 case ACPI_RESOURCE_TYPE_MEMORY32:
683 case ACPI_RESOURCE_TYPE_FIXED_MEMORY32:
684 type = IORESOURCE_MEM;
686 case ACPI_RESOURCE_TYPE_IO:
687 case ACPI_RESOURCE_TYPE_FIXED_IO:
688 type = IORESOURCE_IO;
690 case ACPI_RESOURCE_TYPE_IRQ:
691 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
692 type = IORESOURCE_IRQ;
694 case ACPI_RESOURCE_TYPE_DMA:
695 case ACPI_RESOURCE_TYPE_FIXED_DMA:
696 type = IORESOURCE_DMA;
698 case ACPI_RESOURCE_TYPE_GENERIC_REGISTER:
699 type = IORESOURCE_REG;
701 case ACPI_RESOURCE_TYPE_ADDRESS16:
702 case ACPI_RESOURCE_TYPE_ADDRESS32:
703 case ACPI_RESOURCE_TYPE_ADDRESS64:
704 case ACPI_RESOURCE_TYPE_EXTENDED_ADDRESS64:
705 if (ares->data.address.resource_type == ACPI_MEMORY_RANGE)
706 type = IORESOURCE_MEM;
707 else if (ares->data.address.resource_type == ACPI_IO_RANGE)
708 type = IORESOURCE_IO;
709 else if (ares->data.address.resource_type ==
710 ACPI_BUS_NUMBER_RANGE)
711 type = IORESOURCE_BUS;
717 return (type & types) ? 0 : 1;
719 EXPORT_SYMBOL_GPL(acpi_dev_filter_resource_type);
721 static int acpi_dev_consumes_res(struct acpi_device *adev, struct resource *res)
723 struct list_head resource_list;
724 struct resource_entry *rentry;
727 INIT_LIST_HEAD(&resource_list);
728 ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
732 list_for_each_entry(rentry, &resource_list, node) {
733 if (resource_contains(rentry->res, res)) {
740 acpi_dev_free_resource_list(&resource_list);
744 static acpi_status acpi_res_consumer_cb(acpi_handle handle, u32 depth,
745 void *context, void **ret)
747 struct resource *res = context;
748 struct acpi_device **consumer = (struct acpi_device **) ret;
749 struct acpi_device *adev;
751 if (acpi_bus_get_device(handle, &adev))
754 if (acpi_dev_consumes_res(adev, res)) {
756 return AE_CTRL_TERMINATE;
763 * acpi_resource_consumer - Find the ACPI device that consumes @res.
764 * @res: Resource to search for.
766 * Search the current resource settings (_CRS) of every ACPI device node
767 * for @res. If we find an ACPI device whose _CRS includes @res, return
768 * it. Otherwise, return NULL.
770 struct acpi_device *acpi_resource_consumer(struct resource *res)
772 struct acpi_device *consumer = NULL;
774 acpi_get_devices(NULL, acpi_res_consumer_cb, res, (void **) &consumer);