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-rw-r--r--drivers/acpi/utils.c922
1 files changed, 922 insertions, 0 deletions
diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
new file mode 100644
index 000000000..d5411a166
--- /dev/null
+++ b/drivers/acpi/utils.c
@@ -0,0 +1,922 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * acpi_utils.c - ACPI Utility Functions ($Revision: 10 $)
+ *
+ * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/hardirq.h>
+#include <linux/acpi.h>
+#include <linux/dynamic_debug.h>
+
+#include "internal.h"
+#include "sleep.h"
+
+#define _COMPONENT ACPI_BUS_COMPONENT
+ACPI_MODULE_NAME("utils");
+
+/* --------------------------------------------------------------------------
+ Object Evaluation Helpers
+ -------------------------------------------------------------------------- */
+static void
+acpi_util_eval_error(acpi_handle h, acpi_string p, acpi_status s)
+{
+#ifdef ACPI_DEBUG_OUTPUT
+ char prefix[80] = {'\0'};
+ struct acpi_buffer buffer = {sizeof(prefix), prefix};
+ acpi_get_name(h, ACPI_FULL_PATHNAME, &buffer);
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluate [%s.%s]: %s\n",
+ (char *) prefix, p, acpi_format_exception(s)));
+#else
+ return;
+#endif
+}
+
+acpi_status
+acpi_extract_package(union acpi_object *package,
+ struct acpi_buffer *format, struct acpi_buffer *buffer)
+{
+ u32 size_required = 0;
+ u32 tail_offset = 0;
+ char *format_string = NULL;
+ u32 format_count = 0;
+ u32 i = 0;
+ u8 *head = NULL;
+ u8 *tail = NULL;
+
+
+ if (!package || (package->type != ACPI_TYPE_PACKAGE)
+ || (package->package.count < 1)) {
+ printk(KERN_WARNING PREFIX "Invalid package argument\n");
+ return AE_BAD_PARAMETER;
+ }
+
+ if (!format || !format->pointer || (format->length < 1)) {
+ printk(KERN_WARNING PREFIX "Invalid format argument\n");
+ return AE_BAD_PARAMETER;
+ }
+
+ if (!buffer) {
+ printk(KERN_WARNING PREFIX "Invalid buffer argument\n");
+ return AE_BAD_PARAMETER;
+ }
+
+ format_count = (format->length / sizeof(char)) - 1;
+ if (format_count > package->package.count) {
+ printk(KERN_WARNING PREFIX "Format specifies more objects [%d]"
+ " than exist in package [%d].\n",
+ format_count, package->package.count);
+ return AE_BAD_DATA;
+ }
+
+ format_string = format->pointer;
+
+ /*
+ * Calculate size_required.
+ */
+ for (i = 0; i < format_count; i++) {
+
+ union acpi_object *element = &(package->package.elements[i]);
+
+ switch (element->type) {
+
+ case ACPI_TYPE_INTEGER:
+ switch (format_string[i]) {
+ case 'N':
+ size_required += sizeof(u64);
+ tail_offset += sizeof(u64);
+ break;
+ case 'S':
+ size_required +=
+ sizeof(char *) + sizeof(u64) +
+ sizeof(char);
+ tail_offset += sizeof(char *);
+ break;
+ default:
+ printk(KERN_WARNING PREFIX "Invalid package element"
+ " [%d]: got number, expecting"
+ " [%c]\n",
+ i, format_string[i]);
+ return AE_BAD_DATA;
+ }
+ break;
+
+ case ACPI_TYPE_STRING:
+ case ACPI_TYPE_BUFFER:
+ switch (format_string[i]) {
+ case 'S':
+ size_required +=
+ sizeof(char *) +
+ (element->string.length * sizeof(char)) +
+ sizeof(char);
+ tail_offset += sizeof(char *);
+ break;
+ case 'B':
+ size_required +=
+ sizeof(u8 *) + element->buffer.length;
+ tail_offset += sizeof(u8 *);
+ break;
+ default:
+ printk(KERN_WARNING PREFIX "Invalid package element"
+ " [%d] got string/buffer,"
+ " expecting [%c]\n",
+ i, format_string[i]);
+ return AE_BAD_DATA;
+ }
+ break;
+ case ACPI_TYPE_LOCAL_REFERENCE:
+ switch (format_string[i]) {
+ case 'R':
+ size_required += sizeof(void *);
+ tail_offset += sizeof(void *);
+ break;
+ default:
+ printk(KERN_WARNING PREFIX "Invalid package element"
+ " [%d] got reference,"
+ " expecting [%c]\n",
+ i, format_string[i]);
+ return AE_BAD_DATA;
+ }
+ break;
+
+ case ACPI_TYPE_PACKAGE:
+ default:
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+ "Found unsupported element at index=%d\n",
+ i));
+ /* TBD: handle nested packages... */
+ return AE_SUPPORT;
+ }
+ }
+
+ /*
+ * Validate output buffer.
+ */
+ if (buffer->length == ACPI_ALLOCATE_BUFFER) {
+ buffer->pointer = ACPI_ALLOCATE_ZEROED(size_required);
+ if (!buffer->pointer)
+ return AE_NO_MEMORY;
+ buffer->length = size_required;
+ } else {
+ if (buffer->length < size_required) {
+ buffer->length = size_required;
+ return AE_BUFFER_OVERFLOW;
+ } else if (buffer->length != size_required ||
+ !buffer->pointer) {
+ return AE_BAD_PARAMETER;
+ }
+ }
+
+ head = buffer->pointer;
+ tail = buffer->pointer + tail_offset;
+
+ /*
+ * Extract package data.
+ */
+ for (i = 0; i < format_count; i++) {
+
+ u8 **pointer = NULL;
+ union acpi_object *element = &(package->package.elements[i]);
+
+ switch (element->type) {
+
+ case ACPI_TYPE_INTEGER:
+ switch (format_string[i]) {
+ case 'N':
+ *((u64 *) head) =
+ element->integer.value;
+ head += sizeof(u64);
+ break;
+ case 'S':
+ pointer = (u8 **) head;
+ *pointer = tail;
+ *((u64 *) tail) =
+ element->integer.value;
+ head += sizeof(u64 *);
+ tail += sizeof(u64);
+ /* NULL terminate string */
+ *tail = (char)0;
+ tail += sizeof(char);
+ break;
+ default:
+ /* Should never get here */
+ break;
+ }
+ break;
+
+ case ACPI_TYPE_STRING:
+ case ACPI_TYPE_BUFFER:
+ switch (format_string[i]) {
+ case 'S':
+ pointer = (u8 **) head;
+ *pointer = tail;
+ memcpy(tail, element->string.pointer,
+ element->string.length);
+ head += sizeof(char *);
+ tail += element->string.length * sizeof(char);
+ /* NULL terminate string */
+ *tail = (char)0;
+ tail += sizeof(char);
+ break;
+ case 'B':
+ pointer = (u8 **) head;
+ *pointer = tail;
+ memcpy(tail, element->buffer.pointer,
+ element->buffer.length);
+ head += sizeof(u8 *);
+ tail += element->buffer.length;
+ break;
+ default:
+ /* Should never get here */
+ break;
+ }
+ break;
+ case ACPI_TYPE_LOCAL_REFERENCE:
+ switch (format_string[i]) {
+ case 'R':
+ *(void **)head =
+ (void *)element->reference.handle;
+ head += sizeof(void *);
+ break;
+ default:
+ /* Should never get here */
+ break;
+ }
+ break;
+ case ACPI_TYPE_PACKAGE:
+ /* TBD: handle nested packages... */
+ default:
+ /* Should never get here */
+ break;
+ }
+ }
+
+ return AE_OK;
+}
+
+EXPORT_SYMBOL(acpi_extract_package);
+
+acpi_status
+acpi_evaluate_integer(acpi_handle handle,
+ acpi_string pathname,
+ struct acpi_object_list *arguments, unsigned long long *data)
+{
+ acpi_status status = AE_OK;
+ union acpi_object element;
+ struct acpi_buffer buffer = { 0, NULL };
+
+ if (!data)
+ return AE_BAD_PARAMETER;
+
+ buffer.length = sizeof(union acpi_object);
+ buffer.pointer = &element;
+ status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
+ if (ACPI_FAILURE(status)) {
+ acpi_util_eval_error(handle, pathname, status);
+ return status;
+ }
+
+ if (element.type != ACPI_TYPE_INTEGER) {
+ acpi_util_eval_error(handle, pathname, AE_BAD_DATA);
+ return AE_BAD_DATA;
+ }
+
+ *data = element.integer.value;
+
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Return value [%llu]\n", *data));
+
+ return AE_OK;
+}
+
+EXPORT_SYMBOL(acpi_evaluate_integer);
+
+acpi_status
+acpi_evaluate_reference(acpi_handle handle,
+ acpi_string pathname,
+ struct acpi_object_list *arguments,
+ struct acpi_handle_list *list)
+{
+ acpi_status status = AE_OK;
+ union acpi_object *package = NULL;
+ union acpi_object *element = NULL;
+ struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+ u32 i = 0;
+
+
+ if (!list) {
+ return AE_BAD_PARAMETER;
+ }
+
+ /* Evaluate object. */
+
+ status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
+ if (ACPI_FAILURE(status))
+ goto end;
+
+ package = buffer.pointer;
+
+ if ((buffer.length == 0) || !package) {
+ status = AE_BAD_DATA;
+ acpi_util_eval_error(handle, pathname, status);
+ goto end;
+ }
+ if (package->type != ACPI_TYPE_PACKAGE) {
+ status = AE_BAD_DATA;
+ acpi_util_eval_error(handle, pathname, status);
+ goto end;
+ }
+ if (!package->package.count) {
+ status = AE_BAD_DATA;
+ acpi_util_eval_error(handle, pathname, status);
+ goto end;
+ }
+
+ if (package->package.count > ACPI_MAX_HANDLES) {
+ kfree(package);
+ return AE_NO_MEMORY;
+ }
+ list->count = package->package.count;
+
+ /* Extract package data. */
+
+ for (i = 0; i < list->count; i++) {
+
+ element = &(package->package.elements[i]);
+
+ if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
+ status = AE_BAD_DATA;
+ acpi_util_eval_error(handle, pathname, status);
+ break;
+ }
+
+ if (!element->reference.handle) {
+ status = AE_NULL_ENTRY;
+ acpi_util_eval_error(handle, pathname, status);
+ break;
+ }
+ /* Get the acpi_handle. */
+
+ list->handles[i] = element->reference.handle;
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found reference [%p]\n",
+ list->handles[i]));
+ }
+
+ end:
+ if (ACPI_FAILURE(status)) {
+ list->count = 0;
+ //kfree(list->handles);
+ }
+
+ kfree(buffer.pointer);
+
+ return status;
+}
+
+EXPORT_SYMBOL(acpi_evaluate_reference);
+
+acpi_status
+acpi_get_physical_device_location(acpi_handle handle, struct acpi_pld_info **pld)
+{
+ acpi_status status;
+ struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+ union acpi_object *output;
+
+ status = acpi_evaluate_object(handle, "_PLD", NULL, &buffer);
+
+ if (ACPI_FAILURE(status))
+ return status;
+
+ output = buffer.pointer;
+
+ if (!output || output->type != ACPI_TYPE_PACKAGE
+ || !output->package.count
+ || output->package.elements[0].type != ACPI_TYPE_BUFFER
+ || output->package.elements[0].buffer.length < ACPI_PLD_REV1_BUFFER_SIZE) {
+ status = AE_TYPE;
+ goto out;
+ }
+
+ status = acpi_decode_pld_buffer(
+ output->package.elements[0].buffer.pointer,
+ output->package.elements[0].buffer.length,
+ pld);
+
+out:
+ kfree(buffer.pointer);
+ return status;
+}
+EXPORT_SYMBOL(acpi_get_physical_device_location);
+
+/**
+ * acpi_evaluate_ost: Evaluate _OST for hotplug operations
+ * @handle: ACPI device handle
+ * @source_event: source event code
+ * @status_code: status code
+ * @status_buf: optional detailed information (NULL if none)
+ *
+ * Evaluate _OST for hotplug operations. All ACPI hotplug handlers
+ * must call this function when evaluating _OST for hotplug operations.
+ * When the platform does not support _OST, this function has no effect.
+ */
+acpi_status
+acpi_evaluate_ost(acpi_handle handle, u32 source_event, u32 status_code,
+ struct acpi_buffer *status_buf)
+{
+ union acpi_object params[3] = {
+ {.type = ACPI_TYPE_INTEGER,},
+ {.type = ACPI_TYPE_INTEGER,},
+ {.type = ACPI_TYPE_BUFFER,}
+ };
+ struct acpi_object_list arg_list = {3, params};
+
+ params[0].integer.value = source_event;
+ params[1].integer.value = status_code;
+ if (status_buf != NULL) {
+ params[2].buffer.pointer = status_buf->pointer;
+ params[2].buffer.length = status_buf->length;
+ } else {
+ params[2].buffer.pointer = NULL;
+ params[2].buffer.length = 0;
+ }
+
+ return acpi_evaluate_object(handle, "_OST", &arg_list, NULL);
+}
+EXPORT_SYMBOL(acpi_evaluate_ost);
+
+/**
+ * acpi_handle_path: Return the object path of handle
+ * @handle: ACPI device handle
+ *
+ * Caller must free the returned buffer
+ */
+static char *acpi_handle_path(acpi_handle handle)
+{
+ struct acpi_buffer buffer = {
+ .length = ACPI_ALLOCATE_BUFFER,
+ .pointer = NULL
+ };
+
+ if (in_interrupt() ||
+ acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer) != AE_OK)
+ return NULL;
+ return buffer.pointer;
+}
+
+/**
+ * acpi_handle_printk: Print message with ACPI prefix and object path
+ * @level: log level
+ * @handle: ACPI device handle
+ * @fmt: format string
+ *
+ * This function is called through acpi_handle_<level> macros and prints
+ * a message with ACPI prefix and object path. This function acquires
+ * the global namespace mutex to obtain an object path. In interrupt
+ * context, it shows the object path as <n/a>.
+ */
+void
+acpi_handle_printk(const char *level, acpi_handle handle, const char *fmt, ...)
+{
+ struct va_format vaf;
+ va_list args;
+ const char *path;
+
+ va_start(args, fmt);
+ vaf.fmt = fmt;
+ vaf.va = &args;
+
+ path = acpi_handle_path(handle);
+ printk("%sACPI: %s: %pV", level, path ? path : "<n/a>" , &vaf);
+
+ va_end(args);
+ kfree(path);
+}
+EXPORT_SYMBOL(acpi_handle_printk);
+
+#if defined(CONFIG_DYNAMIC_DEBUG)
+/**
+ * __acpi_handle_debug: pr_debug with ACPI prefix and object path
+ * @descriptor: Dynamic Debug descriptor
+ * @handle: ACPI device handle
+ * @fmt: format string
+ *
+ * This function is called through acpi_handle_debug macro and debug
+ * prints a message with ACPI prefix and object path. This function
+ * acquires the global namespace mutex to obtain an object path. In
+ * interrupt context, it shows the object path as <n/a>.
+ */
+void
+__acpi_handle_debug(struct _ddebug *descriptor, acpi_handle handle,
+ const char *fmt, ...)
+{
+ struct va_format vaf;
+ va_list args;
+ const char *path;
+
+ va_start(args, fmt);
+ vaf.fmt = fmt;
+ vaf.va = &args;
+
+ path = acpi_handle_path(handle);
+ __dynamic_pr_debug(descriptor, "ACPI: %s: %pV", path ? path : "<n/a>", &vaf);
+
+ va_end(args);
+ kfree(path);
+}
+EXPORT_SYMBOL(__acpi_handle_debug);
+#endif
+
+/**
+ * acpi_has_method: Check whether @handle has a method named @name
+ * @handle: ACPI device handle
+ * @name: name of object or method
+ *
+ * Check whether @handle has a method named @name.
+ */
+bool acpi_has_method(acpi_handle handle, char *name)
+{
+ acpi_handle tmp;
+
+ return ACPI_SUCCESS(acpi_get_handle(handle, name, &tmp));
+}
+EXPORT_SYMBOL(acpi_has_method);
+
+acpi_status acpi_execute_simple_method(acpi_handle handle, char *method,
+ u64 arg)
+{
+ union acpi_object obj = { .type = ACPI_TYPE_INTEGER };
+ struct acpi_object_list arg_list = { .count = 1, .pointer = &obj, };
+
+ obj.integer.value = arg;
+
+ return acpi_evaluate_object(handle, method, &arg_list, NULL);
+}
+EXPORT_SYMBOL(acpi_execute_simple_method);
+
+/**
+ * acpi_evaluate_ej0: Evaluate _EJ0 method for hotplug operations
+ * @handle: ACPI device handle
+ *
+ * Evaluate device's _EJ0 method for hotplug operations.
+ */
+acpi_status acpi_evaluate_ej0(acpi_handle handle)
+{
+ acpi_status status;
+
+ status = acpi_execute_simple_method(handle, "_EJ0", 1);
+ if (status == AE_NOT_FOUND)
+ acpi_handle_warn(handle, "No _EJ0 support for device\n");
+ else if (ACPI_FAILURE(status))
+ acpi_handle_warn(handle, "Eject failed (0x%x)\n", status);
+
+ return status;
+}
+
+/**
+ * acpi_evaluate_lck: Evaluate _LCK method to lock/unlock device
+ * @handle: ACPI device handle
+ * @lock: lock device if non-zero, otherwise unlock device
+ *
+ * Evaluate device's _LCK method if present to lock/unlock device
+ */
+acpi_status acpi_evaluate_lck(acpi_handle handle, int lock)
+{
+ acpi_status status;
+
+ status = acpi_execute_simple_method(handle, "_LCK", !!lock);
+ if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
+ if (lock)
+ acpi_handle_warn(handle,
+ "Locking device failed (0x%x)\n", status);
+ else
+ acpi_handle_warn(handle,
+ "Unlocking device failed (0x%x)\n", status);
+ }
+
+ return status;
+}
+
+/**
+ * acpi_evaluate_reg: Evaluate _REG method to register OpRegion presence
+ * @handle: ACPI device handle
+ * @space_id: ACPI address space id to register OpRegion presence for
+ * @function: Parameter to pass to _REG one of ACPI_REG_CONNECT or
+ * ACPI_REG_DISCONNECT
+ *
+ * Evaluate device's _REG method to register OpRegion presence.
+ */
+acpi_status acpi_evaluate_reg(acpi_handle handle, u8 space_id, u32 function)
+{
+ struct acpi_object_list arg_list;
+ union acpi_object params[2];
+
+ params[0].type = ACPI_TYPE_INTEGER;
+ params[0].integer.value = space_id;
+ params[1].type = ACPI_TYPE_INTEGER;
+ params[1].integer.value = function;
+ arg_list.count = 2;
+ arg_list.pointer = params;
+
+ return acpi_evaluate_object(handle, "_REG", &arg_list, NULL);
+}
+EXPORT_SYMBOL(acpi_evaluate_reg);
+
+/**
+ * acpi_evaluate_dsm - evaluate device's _DSM method
+ * @handle: ACPI device handle
+ * @guid: GUID of requested functions, should be 16 bytes
+ * @rev: revision number of requested function
+ * @func: requested function number
+ * @argv4: the function specific parameter
+ *
+ * Evaluate device's _DSM method with specified GUID, revision id and
+ * function number. Caller needs to free the returned object.
+ *
+ * Though ACPI defines the fourth parameter for _DSM should be a package,
+ * some old BIOSes do expect a buffer or an integer etc.
+ */
+union acpi_object *
+acpi_evaluate_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 func,
+ union acpi_object *argv4)
+{
+ acpi_status ret;
+ struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
+ union acpi_object params[4];
+ struct acpi_object_list input = {
+ .count = 4,
+ .pointer = params,
+ };
+
+ params[0].type = ACPI_TYPE_BUFFER;
+ params[0].buffer.length = 16;
+ params[0].buffer.pointer = (u8 *)guid;
+ params[1].type = ACPI_TYPE_INTEGER;
+ params[1].integer.value = rev;
+ params[2].type = ACPI_TYPE_INTEGER;
+ params[2].integer.value = func;
+ if (argv4) {
+ params[3] = *argv4;
+ } else {
+ params[3].type = ACPI_TYPE_PACKAGE;
+ params[3].package.count = 0;
+ params[3].package.elements = NULL;
+ }
+
+ ret = acpi_evaluate_object(handle, "_DSM", &input, &buf);
+ if (ACPI_SUCCESS(ret))
+ return (union acpi_object *)buf.pointer;
+
+ if (ret != AE_NOT_FOUND)
+ acpi_handle_warn(handle,
+ "failed to evaluate _DSM (0x%x)\n", ret);
+
+ return NULL;
+}
+EXPORT_SYMBOL(acpi_evaluate_dsm);
+
+/**
+ * acpi_check_dsm - check if _DSM method supports requested functions.
+ * @handle: ACPI device handle
+ * @guid: GUID of requested functions, should be 16 bytes at least
+ * @rev: revision number of requested functions
+ * @funcs: bitmap of requested functions
+ *
+ * Evaluate device's _DSM method to check whether it supports requested
+ * functions. Currently only support 64 functions at maximum, should be
+ * enough for now.
+ */
+bool acpi_check_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 funcs)
+{
+ int i;
+ u64 mask = 0;
+ union acpi_object *obj;
+
+ if (funcs == 0)
+ return false;
+
+ obj = acpi_evaluate_dsm(handle, guid, rev, 0, NULL);
+ if (!obj)
+ return false;
+
+ /* For compatibility, old BIOSes may return an integer */
+ if (obj->type == ACPI_TYPE_INTEGER)
+ mask = obj->integer.value;
+ else if (obj->type == ACPI_TYPE_BUFFER)
+ for (i = 0; i < obj->buffer.length && i < 8; i++)
+ mask |= (((u64)obj->buffer.pointer[i]) << (i * 8));
+ ACPI_FREE(obj);
+
+ /*
+ * Bit 0 indicates whether there's support for any functions other than
+ * function 0 for the specified GUID and revision.
+ */
+ if ((mask & 0x1) && (mask & funcs) == funcs)
+ return true;
+
+ return false;
+}
+EXPORT_SYMBOL(acpi_check_dsm);
+
+/**
+ * acpi_dev_hid_uid_match - Match device by supplied HID and UID
+ * @adev: ACPI device to match.
+ * @hid2: Hardware ID of the device.
+ * @uid2: Unique ID of the device, pass NULL to not check _UID.
+ *
+ * Matches HID and UID in @adev with given @hid2 and @uid2.
+ * Returns true if matches.
+ */
+bool acpi_dev_hid_uid_match(struct acpi_device *adev,
+ const char *hid2, const char *uid2)
+{
+ const char *hid1 = acpi_device_hid(adev);
+ const char *uid1 = acpi_device_uid(adev);
+
+ if (strcmp(hid1, hid2))
+ return false;
+
+ if (!uid2)
+ return true;
+
+ return uid1 && !strcmp(uid1, uid2);
+}
+EXPORT_SYMBOL(acpi_dev_hid_uid_match);
+
+/**
+ * acpi_dev_found - Detect presence of a given ACPI device in the namespace.
+ * @hid: Hardware ID of the device.
+ *
+ * Return %true if the device was present at the moment of invocation.
+ * Note that if the device is pluggable, it may since have disappeared.
+ *
+ * For this function to work, acpi_bus_scan() must have been executed
+ * which happens in the subsys_initcall() subsection. Hence, do not
+ * call from a subsys_initcall() or earlier (use acpi_get_devices()
+ * instead). Calling from module_init() is fine (which is synonymous
+ * with device_initcall()).
+ */
+bool acpi_dev_found(const char *hid)
+{
+ struct acpi_device_bus_id *acpi_device_bus_id;
+ bool found = false;
+
+ mutex_lock(&acpi_device_lock);
+ list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
+ if (!strcmp(acpi_device_bus_id->bus_id, hid)) {
+ found = true;
+ break;
+ }
+ mutex_unlock(&acpi_device_lock);
+
+ return found;
+}
+EXPORT_SYMBOL(acpi_dev_found);
+
+struct acpi_dev_match_info {
+ struct acpi_device_id hid[2];
+ const char *uid;
+ s64 hrv;
+};
+
+static int acpi_dev_match_cb(struct device *dev, const void *data)
+{
+ struct acpi_device *adev = to_acpi_device(dev);
+ const struct acpi_dev_match_info *match = data;
+ unsigned long long hrv;
+ acpi_status status;
+
+ if (acpi_match_device_ids(adev, match->hid))
+ return 0;
+
+ if (match->uid && (!adev->pnp.unique_id ||
+ strcmp(adev->pnp.unique_id, match->uid)))
+ return 0;
+
+ if (match->hrv == -1)
+ return 1;
+
+ status = acpi_evaluate_integer(adev->handle, "_HRV", NULL, &hrv);
+ if (ACPI_FAILURE(status))
+ return 0;
+
+ return hrv == match->hrv;
+}
+
+/**
+ * acpi_dev_present - Detect that a given ACPI device is present
+ * @hid: Hardware ID of the device.
+ * @uid: Unique ID of the device, pass NULL to not check _UID
+ * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
+ *
+ * Return %true if a matching device was present at the moment of invocation.
+ * Note that if the device is pluggable, it may since have disappeared.
+ *
+ * Note that unlike acpi_dev_found() this function checks the status
+ * of the device. So for devices which are present in the dsdt, but
+ * which are disabled (their _STA callback returns 0) this function
+ * will return false.
+ *
+ * For this function to work, acpi_bus_scan() must have been executed
+ * which happens in the subsys_initcall() subsection. Hence, do not
+ * call from a subsys_initcall() or earlier (use acpi_get_devices()
+ * instead). Calling from module_init() is fine (which is synonymous
+ * with device_initcall()).
+ */
+bool acpi_dev_present(const char *hid, const char *uid, s64 hrv)
+{
+ struct acpi_dev_match_info match = {};
+ struct device *dev;
+
+ strlcpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
+ match.uid = uid;
+ match.hrv = hrv;
+
+ dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb);
+ put_device(dev);
+ return !!dev;
+}
+EXPORT_SYMBOL(acpi_dev_present);
+
+/**
+ * acpi_dev_get_first_match_dev - Return the first match of ACPI device
+ * @hid: Hardware ID of the device.
+ * @uid: Unique ID of the device, pass NULL to not check _UID
+ * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
+ *
+ * Return the first match of ACPI device if a matching device was present
+ * at the moment of invocation, or NULL otherwise.
+ *
+ * The caller is responsible to call put_device() on the returned device.
+ *
+ * See additional information in acpi_dev_present() as well.
+ */
+struct acpi_device *
+acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv)
+{
+ struct acpi_dev_match_info match = {};
+ struct device *dev;
+
+ strlcpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
+ match.uid = uid;
+ match.hrv = hrv;
+
+ dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb);
+ return dev ? to_acpi_device(dev) : NULL;
+}
+EXPORT_SYMBOL(acpi_dev_get_first_match_dev);
+
+/*
+ * acpi_backlight= handling, this is done here rather then in video_detect.c
+ * because __setup cannot be used in modules.
+ */
+char acpi_video_backlight_string[16];
+EXPORT_SYMBOL(acpi_video_backlight_string);
+
+static int __init acpi_backlight(char *str)
+{
+ strlcpy(acpi_video_backlight_string, str,
+ sizeof(acpi_video_backlight_string));
+ return 1;
+}
+__setup("acpi_backlight=", acpi_backlight);
+
+/**
+ * acpi_match_platform_list - Check if the system matches with a given list
+ * @plat: pointer to acpi_platform_list table terminated by a NULL entry
+ *
+ * Return the matched index if the system is found in the platform list.
+ * Otherwise, return a negative error code.
+ */
+int acpi_match_platform_list(const struct acpi_platform_list *plat)
+{
+ struct acpi_table_header hdr;
+ int idx = 0;
+
+ if (acpi_disabled)
+ return -ENODEV;
+
+ for (; plat->oem_id[0]; plat++, idx++) {
+ if (ACPI_FAILURE(acpi_get_table_header(plat->table, 0, &hdr)))
+ continue;
+
+ if (strncmp(plat->oem_id, hdr.oem_id, ACPI_OEM_ID_SIZE))
+ continue;
+
+ if (strncmp(plat->oem_table_id, hdr.oem_table_id, ACPI_OEM_TABLE_ID_SIZE))
+ continue;
+
+ if ((plat->pred == all_versions) ||
+ (plat->pred == less_than_or_equal && hdr.oem_revision <= plat->oem_revision) ||
+ (plat->pred == greater_than_or_equal && hdr.oem_revision >= plat->oem_revision) ||
+ (plat->pred == equal && hdr.oem_revision == plat->oem_revision))
+ return idx;
+ }
+
+ return -ENODEV;
+}
+EXPORT_SYMBOL(acpi_match_platform_list);