summaryrefslogtreecommitdiffstats
path: root/drivers/acpi/x86/apple.c
blob: 45d0f16f374f44e0de121a975d4ced127a18ec49 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
// SPDX-License-Identifier: GPL-2.0-only
/*
 * apple.c - Apple ACPI quirks
 * Copyright (C) 2017 Lukas Wunner <lukas@wunner.de>
 */

#include <linux/acpi.h>
#include <linux/bitmap.h>
#include <linux/platform_data/x86/apple.h>
#include <linux/uuid.h>
#include "../internal.h"

/* Apple _DSM device properties GUID */
static const guid_t apple_prp_guid =
	GUID_INIT(0xa0b5b7c6, 0x1318, 0x441c,
		  0xb0, 0xc9, 0xfe, 0x69, 0x5e, 0xaf, 0x94, 0x9b);

/**
 * acpi_extract_apple_properties - retrieve and convert Apple _DSM properties
 * @adev: ACPI device for which to retrieve the properties
 *
 * Invoke Apple's custom _DSM once to check the protocol version and once more
 * to retrieve the properties.  They are marshalled up in a single package as
 * alternating key/value elements, unlike _DSD which stores them as a package
 * of 2-element packages.  Convert to _DSD format and make them available under
 * the primary fwnode.
 */
void acpi_extract_apple_properties(struct acpi_device *adev)
{
	unsigned int i, j = 0, newsize = 0, numprops, numvalid;
	union acpi_object *props, *newprops;
	unsigned long *valid = NULL;
	void *free_space;

	if (!x86_apple_machine)
		return;

	props = acpi_evaluate_dsm_typed(adev->handle, &apple_prp_guid, 1, 0,
					NULL, ACPI_TYPE_BUFFER);
	if (!props)
		return;

	if (!props->buffer.length)
		goto out_free;

	if (props->buffer.pointer[0] != 3) {
		acpi_handle_info(adev->handle, FW_INFO
				 "unsupported properties version %*ph\n",
				 props->buffer.length, props->buffer.pointer);
		goto out_free;
	}

	ACPI_FREE(props);
	props = acpi_evaluate_dsm_typed(adev->handle, &apple_prp_guid, 1, 1,
					NULL, ACPI_TYPE_PACKAGE);
	if (!props)
		return;

	numprops = props->package.count / 2;
	if (!numprops)
		goto out_free;

	valid = bitmap_zalloc(numprops, GFP_KERNEL);
	if (!valid)
		goto out_free;

	/* newsize = key length + value length of each tuple */
	for (i = 0; i < numprops; i++) {
		union acpi_object *key = &props->package.elements[i * 2];
		union acpi_object *val = &props->package.elements[i * 2 + 1];

		if ( key->type != ACPI_TYPE_STRING ||
		    (val->type != ACPI_TYPE_INTEGER &&
		     val->type != ACPI_TYPE_BUFFER &&
		     val->type != ACPI_TYPE_STRING))
			continue; /* skip invalid properties */

		__set_bit(i, valid);
		newsize += key->string.length + 1;
		if ( val->type == ACPI_TYPE_BUFFER)
			newsize += val->buffer.length;
		else if (val->type == ACPI_TYPE_STRING)
			newsize += val->string.length + 1;
	}

	numvalid = bitmap_weight(valid, numprops);
	if (numprops > numvalid)
		acpi_handle_info(adev->handle, FW_INFO
				 "skipped %u properties: wrong type\n",
				 numprops - numvalid);
	if (numvalid == 0)
		goto out_free;

	/* newsize += top-level package + 3 objects for each key/value tuple */
	newsize	+= (1 + 3 * numvalid) * sizeof(union acpi_object);
	newprops = ACPI_ALLOCATE_ZEROED(newsize);
	if (!newprops)
		goto out_free;

	/* layout: top-level package | packages | key/value tuples | strings */
	newprops->type = ACPI_TYPE_PACKAGE;
	newprops->package.count = numvalid;
	newprops->package.elements = &newprops[1];
	free_space = &newprops[1 + 3 * numvalid];

	for_each_set_bit(i, valid, numprops) {
		union acpi_object *key = &props->package.elements[i * 2];
		union acpi_object *val = &props->package.elements[i * 2 + 1];
		unsigned int k = 1 + numvalid + j * 2; /* index into newprops */
		unsigned int v = k + 1;

		newprops[1 + j].type = ACPI_TYPE_PACKAGE;
		newprops[1 + j].package.count = 2;
		newprops[1 + j].package.elements = &newprops[k];

		newprops[k].type = ACPI_TYPE_STRING;
		newprops[k].string.length = key->string.length;
		newprops[k].string.pointer = free_space;
		memcpy(free_space, key->string.pointer, key->string.length);
		free_space += key->string.length + 1;

		newprops[v].type = val->type;
		if (val->type == ACPI_TYPE_INTEGER) {
			newprops[v].integer.value = val->integer.value;
		} else if (val->type == ACPI_TYPE_STRING) {
			newprops[v].string.length = val->string.length;
			newprops[v].string.pointer = free_space;
			memcpy(free_space, val->string.pointer,
			       val->string.length);
			free_space += val->string.length + 1;
		} else {
			newprops[v].buffer.length = val->buffer.length;
			newprops[v].buffer.pointer = free_space;
			memcpy(free_space, val->buffer.pointer,
			       val->buffer.length);
			free_space += val->buffer.length;
		}
		j++; /* count valid properties */
	}
	WARN_ON(free_space != (void *)newprops + newsize);

	adev->data.pointer = newprops;
	acpi_data_add_props(&adev->data, &apple_prp_guid, newprops);

out_free:
	ACPI_FREE(props);
	bitmap_free(valid);
}