cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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resource.c (24339B)


      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * drivers/acpi/resource.c - ACPI device resources interpretation.
      4 *
      5 * Copyright (C) 2012, Intel Corp.
      6 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
      7 *
      8 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      9 *
     10 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     11 */
     12
     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>
     19#include <linux/dmi.h>
     20
     21#ifdef CONFIG_X86
     22#define valid_IRQ(i) (((i) != 0) && ((i) != 2))
     23static inline bool acpi_iospace_resource_valid(struct resource *res)
     24{
     25	/* On X86 IO space is limited to the [0 - 64K] IO port range */
     26	return res->end < 0x10003;
     27}
     28#else
     29#define valid_IRQ(i) (true)
     30/*
     31 * ACPI IO descriptors on arches other than X86 contain MMIO CPU physical
     32 * addresses mapping IO space in CPU physical address space, IO space
     33 * resources can be placed anywhere in the 64-bit physical address space.
     34 */
     35static inline bool
     36acpi_iospace_resource_valid(struct resource *res) { return true; }
     37#endif
     38
     39#if IS_ENABLED(CONFIG_ACPI_GENERIC_GSI)
     40static inline bool is_gsi(struct acpi_resource_extended_irq *ext_irq)
     41{
     42	return ext_irq->resource_source.string_length == 0 &&
     43	       ext_irq->producer_consumer == ACPI_CONSUMER;
     44}
     45#else
     46static inline bool is_gsi(struct acpi_resource_extended_irq *ext_irq)
     47{
     48	return true;
     49}
     50#endif
     51
     52static bool acpi_dev_resource_len_valid(u64 start, u64 end, u64 len, bool io)
     53{
     54	u64 reslen = end - start + 1;
     55
     56	/*
     57	 * CHECKME: len might be required to check versus a minimum
     58	 * length as well. 1 for io is fine, but for memory it does
     59	 * not make any sense at all.
     60	 * Note: some BIOSes report incorrect length for ACPI address space
     61	 * descriptor, so remove check of 'reslen == len' to avoid regression.
     62	 */
     63	if (len && reslen && start <= end)
     64		return true;
     65
     66	pr_debug("ACPI: invalid or unassigned resource %s [%016llx - %016llx] length [%016llx]\n",
     67		io ? "io" : "mem", start, end, len);
     68
     69	return false;
     70}
     71
     72static void acpi_dev_memresource_flags(struct resource *res, u64 len,
     73				       u8 write_protect)
     74{
     75	res->flags = IORESOURCE_MEM;
     76
     77	if (!acpi_dev_resource_len_valid(res->start, res->end, len, false))
     78		res->flags |= IORESOURCE_DISABLED | IORESOURCE_UNSET;
     79
     80	if (write_protect == ACPI_READ_WRITE_MEMORY)
     81		res->flags |= IORESOURCE_MEM_WRITEABLE;
     82}
     83
     84static void acpi_dev_get_memresource(struct resource *res, u64 start, u64 len,
     85				     u8 write_protect)
     86{
     87	res->start = start;
     88	res->end = start + len - 1;
     89	acpi_dev_memresource_flags(res, len, write_protect);
     90}
     91
     92/**
     93 * acpi_dev_resource_memory - Extract ACPI memory resource information.
     94 * @ares: Input ACPI resource object.
     95 * @res: Output generic resource object.
     96 *
     97 * Check if the given ACPI resource object represents a memory resource and
     98 * if that's the case, use the information in it to populate the generic
     99 * resource object pointed to by @res.
    100 *
    101 * Return:
    102 * 1) false with res->flags setting to zero: not the expected resource type
    103 * 2) false with IORESOURCE_DISABLED in res->flags: valid unassigned resource
    104 * 3) true: valid assigned resource
    105 */
    106bool acpi_dev_resource_memory(struct acpi_resource *ares, struct resource *res)
    107{
    108	struct acpi_resource_memory24 *memory24;
    109	struct acpi_resource_memory32 *memory32;
    110	struct acpi_resource_fixed_memory32 *fixed_memory32;
    111
    112	switch (ares->type) {
    113	case ACPI_RESOURCE_TYPE_MEMORY24:
    114		memory24 = &ares->data.memory24;
    115		acpi_dev_get_memresource(res, memory24->minimum << 8,
    116					 memory24->address_length << 8,
    117					 memory24->write_protect);
    118		break;
    119	case ACPI_RESOURCE_TYPE_MEMORY32:
    120		memory32 = &ares->data.memory32;
    121		acpi_dev_get_memresource(res, memory32->minimum,
    122					 memory32->address_length,
    123					 memory32->write_protect);
    124		break;
    125	case ACPI_RESOURCE_TYPE_FIXED_MEMORY32:
    126		fixed_memory32 = &ares->data.fixed_memory32;
    127		acpi_dev_get_memresource(res, fixed_memory32->address,
    128					 fixed_memory32->address_length,
    129					 fixed_memory32->write_protect);
    130		break;
    131	default:
    132		res->flags = 0;
    133		return false;
    134	}
    135
    136	return !(res->flags & IORESOURCE_DISABLED);
    137}
    138EXPORT_SYMBOL_GPL(acpi_dev_resource_memory);
    139
    140static void acpi_dev_ioresource_flags(struct resource *res, u64 len,
    141				      u8 io_decode, u8 translation_type)
    142{
    143	res->flags = IORESOURCE_IO;
    144
    145	if (!acpi_dev_resource_len_valid(res->start, res->end, len, true))
    146		res->flags |= IORESOURCE_DISABLED | IORESOURCE_UNSET;
    147
    148	if (!acpi_iospace_resource_valid(res))
    149		res->flags |= IORESOURCE_DISABLED | IORESOURCE_UNSET;
    150
    151	if (io_decode == ACPI_DECODE_16)
    152		res->flags |= IORESOURCE_IO_16BIT_ADDR;
    153	if (translation_type == ACPI_SPARSE_TRANSLATION)
    154		res->flags |= IORESOURCE_IO_SPARSE;
    155}
    156
    157static void acpi_dev_get_ioresource(struct resource *res, u64 start, u64 len,
    158				    u8 io_decode)
    159{
    160	res->start = start;
    161	res->end = start + len - 1;
    162	acpi_dev_ioresource_flags(res, len, io_decode, 0);
    163}
    164
    165/**
    166 * acpi_dev_resource_io - Extract ACPI I/O resource information.
    167 * @ares: Input ACPI resource object.
    168 * @res: Output generic resource object.
    169 *
    170 * Check if the given ACPI resource object represents an I/O resource and
    171 * if that's the case, use the information in it to populate the generic
    172 * resource object pointed to by @res.
    173 *
    174 * Return:
    175 * 1) false with res->flags setting to zero: not the expected resource type
    176 * 2) false with IORESOURCE_DISABLED in res->flags: valid unassigned resource
    177 * 3) true: valid assigned resource
    178 */
    179bool acpi_dev_resource_io(struct acpi_resource *ares, struct resource *res)
    180{
    181	struct acpi_resource_io *io;
    182	struct acpi_resource_fixed_io *fixed_io;
    183
    184	switch (ares->type) {
    185	case ACPI_RESOURCE_TYPE_IO:
    186		io = &ares->data.io;
    187		acpi_dev_get_ioresource(res, io->minimum,
    188					io->address_length,
    189					io->io_decode);
    190		break;
    191	case ACPI_RESOURCE_TYPE_FIXED_IO:
    192		fixed_io = &ares->data.fixed_io;
    193		acpi_dev_get_ioresource(res, fixed_io->address,
    194					fixed_io->address_length,
    195					ACPI_DECODE_10);
    196		break;
    197	default:
    198		res->flags = 0;
    199		return false;
    200	}
    201
    202	return !(res->flags & IORESOURCE_DISABLED);
    203}
    204EXPORT_SYMBOL_GPL(acpi_dev_resource_io);
    205
    206static bool acpi_decode_space(struct resource_win *win,
    207			      struct acpi_resource_address *addr,
    208			      struct acpi_address64_attribute *attr)
    209{
    210	u8 iodec = attr->granularity == 0xfff ? ACPI_DECODE_10 : ACPI_DECODE_16;
    211	bool wp = addr->info.mem.write_protect;
    212	u64 len = attr->address_length;
    213	u64 start, end, offset = 0;
    214	struct resource *res = &win->res;
    215
    216	/*
    217	 * Filter out invalid descriptor according to ACPI Spec 5.0, section
    218	 * 6.4.3.5 Address Space Resource Descriptors.
    219	 */
    220	if ((addr->min_address_fixed != addr->max_address_fixed && len) ||
    221	    (addr->min_address_fixed && addr->max_address_fixed && !len))
    222		pr_debug("ACPI: Invalid address space min_addr_fix %d, max_addr_fix %d, len %llx\n",
    223			 addr->min_address_fixed, addr->max_address_fixed, len);
    224
    225	/*
    226	 * For bridges that translate addresses across the bridge,
    227	 * translation_offset is the offset that must be added to the
    228	 * address on the secondary side to obtain the address on the
    229	 * primary side. Non-bridge devices must list 0 for all Address
    230	 * Translation offset bits.
    231	 */
    232	if (addr->producer_consumer == ACPI_PRODUCER)
    233		offset = attr->translation_offset;
    234	else if (attr->translation_offset)
    235		pr_debug("ACPI: translation_offset(%lld) is invalid for non-bridge device.\n",
    236			 attr->translation_offset);
    237	start = attr->minimum + offset;
    238	end = attr->maximum + offset;
    239
    240	win->offset = offset;
    241	res->start = start;
    242	res->end = end;
    243	if (sizeof(resource_size_t) < sizeof(u64) &&
    244	    (offset != win->offset || start != res->start || end != res->end)) {
    245		pr_warn("acpi resource window ([%#llx-%#llx] ignored, not CPU addressable)\n",
    246			attr->minimum, attr->maximum);
    247		return false;
    248	}
    249
    250	switch (addr->resource_type) {
    251	case ACPI_MEMORY_RANGE:
    252		acpi_dev_memresource_flags(res, len, wp);
    253		break;
    254	case ACPI_IO_RANGE:
    255		acpi_dev_ioresource_flags(res, len, iodec,
    256					  addr->info.io.translation_type);
    257		break;
    258	case ACPI_BUS_NUMBER_RANGE:
    259		res->flags = IORESOURCE_BUS;
    260		break;
    261	default:
    262		return false;
    263	}
    264
    265	if (addr->producer_consumer == ACPI_PRODUCER)
    266		res->flags |= IORESOURCE_WINDOW;
    267
    268	if (addr->info.mem.caching == ACPI_PREFETCHABLE_MEMORY)
    269		res->flags |= IORESOURCE_PREFETCH;
    270
    271	return !(res->flags & IORESOURCE_DISABLED);
    272}
    273
    274/**
    275 * acpi_dev_resource_address_space - Extract ACPI address space information.
    276 * @ares: Input ACPI resource object.
    277 * @win: Output generic resource object.
    278 *
    279 * Check if the given ACPI resource object represents an address space resource
    280 * and if that's the case, use the information in it to populate the generic
    281 * resource object pointed to by @win.
    282 *
    283 * Return:
    284 * 1) false with win->res.flags setting to zero: not the expected resource type
    285 * 2) false with IORESOURCE_DISABLED in win->res.flags: valid unassigned
    286 *    resource
    287 * 3) true: valid assigned resource
    288 */
    289bool acpi_dev_resource_address_space(struct acpi_resource *ares,
    290				     struct resource_win *win)
    291{
    292	struct acpi_resource_address64 addr;
    293
    294	win->res.flags = 0;
    295	if (ACPI_FAILURE(acpi_resource_to_address64(ares, &addr)))
    296		return false;
    297
    298	return acpi_decode_space(win, (struct acpi_resource_address *)&addr,
    299				 &addr.address);
    300}
    301EXPORT_SYMBOL_GPL(acpi_dev_resource_address_space);
    302
    303/**
    304 * acpi_dev_resource_ext_address_space - Extract ACPI address space information.
    305 * @ares: Input ACPI resource object.
    306 * @win: Output generic resource object.
    307 *
    308 * Check if the given ACPI resource object represents an extended address space
    309 * resource and if that's the case, use the information in it to populate the
    310 * generic resource object pointed to by @win.
    311 *
    312 * Return:
    313 * 1) false with win->res.flags setting to zero: not the expected resource type
    314 * 2) false with IORESOURCE_DISABLED in win->res.flags: valid unassigned
    315 *    resource
    316 * 3) true: valid assigned resource
    317 */
    318bool acpi_dev_resource_ext_address_space(struct acpi_resource *ares,
    319					 struct resource_win *win)
    320{
    321	struct acpi_resource_extended_address64 *ext_addr;
    322
    323	win->res.flags = 0;
    324	if (ares->type != ACPI_RESOURCE_TYPE_EXTENDED_ADDRESS64)
    325		return false;
    326
    327	ext_addr = &ares->data.ext_address64;
    328
    329	return acpi_decode_space(win, (struct acpi_resource_address *)ext_addr,
    330				 &ext_addr->address);
    331}
    332EXPORT_SYMBOL_GPL(acpi_dev_resource_ext_address_space);
    333
    334/**
    335 * acpi_dev_irq_flags - Determine IRQ resource flags.
    336 * @triggering: Triggering type as provided by ACPI.
    337 * @polarity: Interrupt polarity as provided by ACPI.
    338 * @shareable: Whether or not the interrupt is shareable.
    339 */
    340unsigned long acpi_dev_irq_flags(u8 triggering, u8 polarity, u8 shareable)
    341{
    342	unsigned long flags;
    343
    344	if (triggering == ACPI_LEVEL_SENSITIVE)
    345		flags = polarity == ACPI_ACTIVE_LOW ?
    346			IORESOURCE_IRQ_LOWLEVEL : IORESOURCE_IRQ_HIGHLEVEL;
    347	else
    348		flags = polarity == ACPI_ACTIVE_LOW ?
    349			IORESOURCE_IRQ_LOWEDGE : IORESOURCE_IRQ_HIGHEDGE;
    350
    351	if (shareable == ACPI_SHARED)
    352		flags |= IORESOURCE_IRQ_SHAREABLE;
    353
    354	return flags | IORESOURCE_IRQ;
    355}
    356EXPORT_SYMBOL_GPL(acpi_dev_irq_flags);
    357
    358/**
    359 * acpi_dev_get_irq_type - Determine irq type.
    360 * @triggering: Triggering type as provided by ACPI.
    361 * @polarity: Interrupt polarity as provided by ACPI.
    362 */
    363unsigned int acpi_dev_get_irq_type(int triggering, int polarity)
    364{
    365	switch (polarity) {
    366	case ACPI_ACTIVE_LOW:
    367		return triggering == ACPI_EDGE_SENSITIVE ?
    368		       IRQ_TYPE_EDGE_FALLING :
    369		       IRQ_TYPE_LEVEL_LOW;
    370	case ACPI_ACTIVE_HIGH:
    371		return triggering == ACPI_EDGE_SENSITIVE ?
    372		       IRQ_TYPE_EDGE_RISING :
    373		       IRQ_TYPE_LEVEL_HIGH;
    374	case ACPI_ACTIVE_BOTH:
    375		if (triggering == ACPI_EDGE_SENSITIVE)
    376			return IRQ_TYPE_EDGE_BOTH;
    377		fallthrough;
    378	default:
    379		return IRQ_TYPE_NONE;
    380	}
    381}
    382EXPORT_SYMBOL_GPL(acpi_dev_get_irq_type);
    383
    384static const struct dmi_system_id medion_laptop[] = {
    385	{
    386		.ident = "MEDION P15651",
    387		.matches = {
    388			DMI_MATCH(DMI_SYS_VENDOR, "MEDION"),
    389			DMI_MATCH(DMI_BOARD_NAME, "M15T"),
    390		},
    391	},
    392	{
    393		.ident = "MEDION S17405",
    394		.matches = {
    395			DMI_MATCH(DMI_SYS_VENDOR, "MEDION"),
    396			DMI_MATCH(DMI_BOARD_NAME, "M17T"),
    397		},
    398	},
    399	{ }
    400};
    401
    402struct irq_override_cmp {
    403	const struct dmi_system_id *system;
    404	unsigned char irq;
    405	unsigned char triggering;
    406	unsigned char polarity;
    407	unsigned char shareable;
    408};
    409
    410static const struct irq_override_cmp skip_override_table[] = {
    411	{ medion_laptop, 1, ACPI_LEVEL_SENSITIVE, ACPI_ACTIVE_LOW, 0 },
    412};
    413
    414static bool acpi_dev_irq_override(u32 gsi, u8 triggering, u8 polarity,
    415				  u8 shareable)
    416{
    417	int i;
    418
    419	for (i = 0; i < ARRAY_SIZE(skip_override_table); i++) {
    420		const struct irq_override_cmp *entry = &skip_override_table[i];
    421
    422		if (dmi_check_system(entry->system) &&
    423		    entry->irq == gsi &&
    424		    entry->triggering == triggering &&
    425		    entry->polarity == polarity &&
    426		    entry->shareable == shareable)
    427			return false;
    428	}
    429
    430	return true;
    431}
    432
    433static void acpi_dev_get_irqresource(struct resource *res, u32 gsi,
    434				     u8 triggering, u8 polarity, u8 shareable,
    435				     bool check_override)
    436{
    437	int irq, p, t;
    438
    439	if (!valid_IRQ(gsi)) {
    440		irqresource_disabled(res, gsi);
    441		return;
    442	}
    443
    444	/*
    445	 * In IO-APIC mode, use overridden attribute. Two reasons:
    446	 * 1. BIOS bug in DSDT
    447	 * 2. BIOS uses IO-APIC mode Interrupt Source Override
    448	 *
    449	 * We do this only if we are dealing with IRQ() or IRQNoFlags()
    450	 * resource (the legacy ISA resources). With modern ACPI 5 devices
    451	 * using extended IRQ descriptors we take the IRQ configuration
    452	 * from _CRS directly.
    453	 */
    454	if (check_override &&
    455	    acpi_dev_irq_override(gsi, triggering, polarity, shareable) &&
    456	    !acpi_get_override_irq(gsi, &t, &p)) {
    457		u8 trig = t ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
    458		u8 pol = p ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH;
    459
    460		if (triggering != trig || polarity != pol) {
    461			pr_warn("ACPI: IRQ %d override to %s, %s\n", gsi,
    462				t ? "level" : "edge", p ? "low" : "high");
    463			triggering = trig;
    464			polarity = pol;
    465		}
    466	}
    467
    468	res->flags = acpi_dev_irq_flags(triggering, polarity, shareable);
    469	irq = acpi_register_gsi(NULL, gsi, triggering, polarity);
    470	if (irq >= 0) {
    471		res->start = irq;
    472		res->end = irq;
    473	} else {
    474		irqresource_disabled(res, gsi);
    475	}
    476}
    477
    478/**
    479 * acpi_dev_resource_interrupt - Extract ACPI interrupt resource information.
    480 * @ares: Input ACPI resource object.
    481 * @index: Index into the array of GSIs represented by the resource.
    482 * @res: Output generic resource object.
    483 *
    484 * Check if the given ACPI resource object represents an interrupt resource
    485 * and @index does not exceed the resource's interrupt count (true is returned
    486 * in that case regardless of the results of the other checks)).  If that's the
    487 * case, register the GSI corresponding to @index from the array of interrupts
    488 * represented by the resource and populate the generic resource object pointed
    489 * to by @res accordingly.  If the registration of the GSI is not successful,
    490 * IORESOURCE_DISABLED will be set it that object's flags.
    491 *
    492 * Return:
    493 * 1) false with res->flags setting to zero: not the expected resource type
    494 * 2) false with IORESOURCE_DISABLED in res->flags: valid unassigned resource
    495 * 3) true: valid assigned resource
    496 */
    497bool acpi_dev_resource_interrupt(struct acpi_resource *ares, int index,
    498				 struct resource *res)
    499{
    500	struct acpi_resource_irq *irq;
    501	struct acpi_resource_extended_irq *ext_irq;
    502
    503	switch (ares->type) {
    504	case ACPI_RESOURCE_TYPE_IRQ:
    505		/*
    506		 * Per spec, only one interrupt per descriptor is allowed in
    507		 * _CRS, but some firmware violates this, so parse them all.
    508		 */
    509		irq = &ares->data.irq;
    510		if (index >= irq->interrupt_count) {
    511			irqresource_disabled(res, 0);
    512			return false;
    513		}
    514		acpi_dev_get_irqresource(res, irq->interrupts[index],
    515					 irq->triggering, irq->polarity,
    516					 irq->shareable, true);
    517		break;
    518	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
    519		ext_irq = &ares->data.extended_irq;
    520		if (index >= ext_irq->interrupt_count) {
    521			irqresource_disabled(res, 0);
    522			return false;
    523		}
    524		if (is_gsi(ext_irq))
    525			acpi_dev_get_irqresource(res, ext_irq->interrupts[index],
    526					 ext_irq->triggering, ext_irq->polarity,
    527					 ext_irq->shareable, false);
    528		else
    529			irqresource_disabled(res, 0);
    530		break;
    531	default:
    532		res->flags = 0;
    533		return false;
    534	}
    535
    536	return true;
    537}
    538EXPORT_SYMBOL_GPL(acpi_dev_resource_interrupt);
    539
    540/**
    541 * acpi_dev_free_resource_list - Free resource from %acpi_dev_get_resources().
    542 * @list: The head of the resource list to free.
    543 */
    544void acpi_dev_free_resource_list(struct list_head *list)
    545{
    546	resource_list_free(list);
    547}
    548EXPORT_SYMBOL_GPL(acpi_dev_free_resource_list);
    549
    550struct res_proc_context {
    551	struct list_head *list;
    552	int (*preproc)(struct acpi_resource *, void *);
    553	void *preproc_data;
    554	int count;
    555	int error;
    556};
    557
    558static acpi_status acpi_dev_new_resource_entry(struct resource_win *win,
    559					       struct res_proc_context *c)
    560{
    561	struct resource_entry *rentry;
    562
    563	rentry = resource_list_create_entry(NULL, 0);
    564	if (!rentry) {
    565		c->error = -ENOMEM;
    566		return AE_NO_MEMORY;
    567	}
    568	*rentry->res = win->res;
    569	rentry->offset = win->offset;
    570	resource_list_add_tail(rentry, c->list);
    571	c->count++;
    572	return AE_OK;
    573}
    574
    575static acpi_status acpi_dev_process_resource(struct acpi_resource *ares,
    576					     void *context)
    577{
    578	struct res_proc_context *c = context;
    579	struct resource_win win;
    580	struct resource *res = &win.res;
    581	int i;
    582
    583	if (c->preproc) {
    584		int ret;
    585
    586		ret = c->preproc(ares, c->preproc_data);
    587		if (ret < 0) {
    588			c->error = ret;
    589			return AE_ABORT_METHOD;
    590		} else if (ret > 0) {
    591			return AE_OK;
    592		}
    593	}
    594
    595	memset(&win, 0, sizeof(win));
    596
    597	if (acpi_dev_resource_memory(ares, res)
    598	    || acpi_dev_resource_io(ares, res)
    599	    || acpi_dev_resource_address_space(ares, &win)
    600	    || acpi_dev_resource_ext_address_space(ares, &win))
    601		return acpi_dev_new_resource_entry(&win, c);
    602
    603	for (i = 0; acpi_dev_resource_interrupt(ares, i, res); i++) {
    604		acpi_status status;
    605
    606		status = acpi_dev_new_resource_entry(&win, c);
    607		if (ACPI_FAILURE(status))
    608			return status;
    609	}
    610
    611	return AE_OK;
    612}
    613
    614static int __acpi_dev_get_resources(struct acpi_device *adev,
    615				    struct list_head *list,
    616				    int (*preproc)(struct acpi_resource *, void *),
    617				    void *preproc_data, char *method)
    618{
    619	struct res_proc_context c;
    620	acpi_status status;
    621
    622	if (!adev || !adev->handle || !list_empty(list))
    623		return -EINVAL;
    624
    625	if (!acpi_has_method(adev->handle, method))
    626		return 0;
    627
    628	c.list = list;
    629	c.preproc = preproc;
    630	c.preproc_data = preproc_data;
    631	c.count = 0;
    632	c.error = 0;
    633	status = acpi_walk_resources(adev->handle, method,
    634				     acpi_dev_process_resource, &c);
    635	if (ACPI_FAILURE(status)) {
    636		acpi_dev_free_resource_list(list);
    637		return c.error ? c.error : -EIO;
    638	}
    639
    640	return c.count;
    641}
    642
    643/**
    644 * acpi_dev_get_resources - Get current 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).
    647 * @preproc: The caller's preprocessing routine.
    648 * @preproc_data: Pointer passed to the caller's preprocessing routine.
    649 *
    650 * Evaluate the _CRS method for the given device node and process its output by
    651 * (1) executing the @preproc() routine provided by the caller, passing the
    652 * resource pointer and @preproc_data to it as arguments, for each ACPI resource
    653 * returned and (2) converting all of the returned ACPI resources into struct
    654 * resource objects if possible.  If the return value of @preproc() in step (1)
    655 * is different from 0, step (2) is not applied to the given ACPI resource and
    656 * if that value is negative, the whole processing is aborted and that value is
    657 * returned as the final error code.
    658 *
    659 * The resultant struct resource objects are put on the list pointed to by
    660 * @list, that must be empty initially, as members of struct resource_entry
    661 * objects.  Callers of this routine should use %acpi_dev_free_resource_list() to
    662 * free that list.
    663 *
    664 * The number of resources in the output list is returned on success, an error
    665 * code reflecting the error condition is returned otherwise.
    666 */
    667int acpi_dev_get_resources(struct acpi_device *adev, struct list_head *list,
    668			   int (*preproc)(struct acpi_resource *, void *),
    669			   void *preproc_data)
    670{
    671	return __acpi_dev_get_resources(adev, list, preproc, preproc_data,
    672					METHOD_NAME__CRS);
    673}
    674EXPORT_SYMBOL_GPL(acpi_dev_get_resources);
    675
    676static int is_memory(struct acpi_resource *ares, void *not_used)
    677{
    678	struct resource_win win;
    679	struct resource *res = &win.res;
    680
    681	memset(&win, 0, sizeof(win));
    682
    683	return !(acpi_dev_resource_memory(ares, res)
    684	       || acpi_dev_resource_address_space(ares, &win)
    685	       || acpi_dev_resource_ext_address_space(ares, &win));
    686}
    687
    688/**
    689 * acpi_dev_get_dma_resources - Get current DMA resources of a device.
    690 * @adev: ACPI device node to get the resources for.
    691 * @list: Head of the resultant list of resources (must be empty).
    692 *
    693 * Evaluate the _DMA method for the given device node and process its
    694 * output.
    695 *
    696 * The resultant struct resource objects are put on the list pointed to
    697 * by @list, that must be empty initially, as members of struct
    698 * resource_entry objects.  Callers of this routine should use
    699 * %acpi_dev_free_resource_list() to free that list.
    700 *
    701 * The number of resources in the output list is returned on success,
    702 * an error code reflecting the error condition is returned otherwise.
    703 */
    704int acpi_dev_get_dma_resources(struct acpi_device *adev, struct list_head *list)
    705{
    706	return __acpi_dev_get_resources(adev, list, is_memory, NULL,
    707					METHOD_NAME__DMA);
    708}
    709EXPORT_SYMBOL_GPL(acpi_dev_get_dma_resources);
    710
    711/**
    712 * acpi_dev_filter_resource_type - Filter ACPI resource according to resource
    713 *				   types
    714 * @ares: Input ACPI resource object.
    715 * @types: Valid resource types of IORESOURCE_XXX
    716 *
    717 * This is a helper function to support acpi_dev_get_resources(), which filters
    718 * ACPI resource objects according to resource types.
    719 */
    720int acpi_dev_filter_resource_type(struct acpi_resource *ares,
    721				  unsigned long types)
    722{
    723	unsigned long type = 0;
    724
    725	switch (ares->type) {
    726	case ACPI_RESOURCE_TYPE_MEMORY24:
    727	case ACPI_RESOURCE_TYPE_MEMORY32:
    728	case ACPI_RESOURCE_TYPE_FIXED_MEMORY32:
    729		type = IORESOURCE_MEM;
    730		break;
    731	case ACPI_RESOURCE_TYPE_IO:
    732	case ACPI_RESOURCE_TYPE_FIXED_IO:
    733		type = IORESOURCE_IO;
    734		break;
    735	case ACPI_RESOURCE_TYPE_IRQ:
    736	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
    737		type = IORESOURCE_IRQ;
    738		break;
    739	case ACPI_RESOURCE_TYPE_DMA:
    740	case ACPI_RESOURCE_TYPE_FIXED_DMA:
    741		type = IORESOURCE_DMA;
    742		break;
    743	case ACPI_RESOURCE_TYPE_GENERIC_REGISTER:
    744		type = IORESOURCE_REG;
    745		break;
    746	case ACPI_RESOURCE_TYPE_ADDRESS16:
    747	case ACPI_RESOURCE_TYPE_ADDRESS32:
    748	case ACPI_RESOURCE_TYPE_ADDRESS64:
    749	case ACPI_RESOURCE_TYPE_EXTENDED_ADDRESS64:
    750		if (ares->data.address.resource_type == ACPI_MEMORY_RANGE)
    751			type = IORESOURCE_MEM;
    752		else if (ares->data.address.resource_type == ACPI_IO_RANGE)
    753			type = IORESOURCE_IO;
    754		else if (ares->data.address.resource_type ==
    755			 ACPI_BUS_NUMBER_RANGE)
    756			type = IORESOURCE_BUS;
    757		break;
    758	default:
    759		break;
    760	}
    761
    762	return (type & types) ? 0 : 1;
    763}
    764EXPORT_SYMBOL_GPL(acpi_dev_filter_resource_type);
    765
    766static int acpi_dev_consumes_res(struct acpi_device *adev, struct resource *res)
    767{
    768	struct list_head resource_list;
    769	struct resource_entry *rentry;
    770	int ret, found = 0;
    771
    772	INIT_LIST_HEAD(&resource_list);
    773	ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
    774	if (ret < 0)
    775		return 0;
    776
    777	list_for_each_entry(rentry, &resource_list, node) {
    778		if (resource_contains(rentry->res, res)) {
    779			found = 1;
    780			break;
    781		}
    782
    783	}
    784
    785	acpi_dev_free_resource_list(&resource_list);
    786	return found;
    787}
    788
    789static acpi_status acpi_res_consumer_cb(acpi_handle handle, u32 depth,
    790					 void *context, void **ret)
    791{
    792	struct resource *res = context;
    793	struct acpi_device **consumer = (struct acpi_device **) ret;
    794	struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
    795
    796	if (!adev)
    797		return AE_OK;
    798
    799	if (acpi_dev_consumes_res(adev, res)) {
    800		*consumer = adev;
    801		return AE_CTRL_TERMINATE;
    802	}
    803
    804	return AE_OK;
    805}
    806
    807/**
    808 * acpi_resource_consumer - Find the ACPI device that consumes @res.
    809 * @res: Resource to search for.
    810 *
    811 * Search the current resource settings (_CRS) of every ACPI device node
    812 * for @res.  If we find an ACPI device whose _CRS includes @res, return
    813 * it.  Otherwise, return NULL.
    814 */
    815struct acpi_device *acpi_resource_consumer(struct resource *res)
    816{
    817	struct acpi_device *consumer = NULL;
    818
    819	acpi_get_devices(NULL, acpi_res_consumer_cb, res, (void **) &consumer);
    820	return consumer;
    821}