1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * apple.c - Apple ACPI quirks
4 * Copyright (C) 2017 Lukas Wunner <lukas@wunner.de>
5 */
6
7 #include <linux/acpi.h>
8 #include <linux/bitmap.h>
9 #include <linux/platform_data/x86/apple.h>
10 #include <linux/uuid.h>
11 #include "../internal.h"
12
13 /* Apple _DSM device properties GUID */
14 static const guid_t apple_prp_guid =
15 GUID_INIT(0xa0b5b7c6, 0x1318, 0x441c,
16 0xb0, 0xc9, 0xfe, 0x69, 0x5e, 0xaf, 0x94, 0x9b);
17
18 /**
19 * acpi_extract_apple_properties - retrieve and convert Apple _DSM properties
20 * @adev: ACPI device for which to retrieve the properties
21 *
22 * Invoke Apple's custom _DSM once to check the protocol version and once more
23 * to retrieve the properties. They are marshalled up in a single package as
24 * alternating key/value elements, unlike _DSD which stores them as a package
25 * of 2-element packages. Convert to _DSD format and make them available under
26 * the primary fwnode.
27 */
acpi_extract_apple_properties(struct acpi_device * adev)28 void acpi_extract_apple_properties(struct acpi_device *adev)
29 {
30 unsigned int i, j = 0, newsize = 0, numprops, numvalid;
31 union acpi_object *props, *newprops;
32 unsigned long *valid = NULL;
33 void *free_space;
34
35 if (!x86_apple_machine)
36 return;
37
38 props = acpi_evaluate_dsm_typed(adev->handle, &apple_prp_guid, 1, 0,
39 NULL, ACPI_TYPE_BUFFER);
40 if (!props)
41 return;
42
43 if (!props->buffer.length)
44 goto out_free;
45
46 if (props->buffer.pointer[0] != 3) {
47 acpi_handle_info(adev->handle, FW_INFO
48 "unsupported properties version %*ph\n",
49 props->buffer.length, props->buffer.pointer);
50 goto out_free;
51 }
52
53 ACPI_FREE(props);
54 props = acpi_evaluate_dsm_typed(adev->handle, &apple_prp_guid, 1, 1,
55 NULL, ACPI_TYPE_PACKAGE);
56 if (!props)
57 return;
58
59 numprops = props->package.count / 2;
60 if (!numprops)
61 goto out_free;
62
63 valid = bitmap_zalloc(numprops, GFP_KERNEL);
64 if (!valid)
65 goto out_free;
66
67 /* newsize = key length + value length of each tuple */
68 for (i = 0; i < numprops; i++) {
69 union acpi_object *key = &props->package.elements[i * 2];
70 union acpi_object *val = &props->package.elements[i * 2 + 1];
71
72 if ( key->type != ACPI_TYPE_STRING ||
73 (val->type != ACPI_TYPE_INTEGER &&
74 val->type != ACPI_TYPE_BUFFER))
75 continue; /* skip invalid properties */
76
77 __set_bit(i, valid);
78 newsize += key->string.length + 1;
79 if ( val->type == ACPI_TYPE_BUFFER)
80 newsize += val->buffer.length;
81 }
82
83 numvalid = bitmap_weight(valid, numprops);
84 if (numprops > numvalid)
85 acpi_handle_info(adev->handle, FW_INFO
86 "skipped %u properties: wrong type\n",
87 numprops - numvalid);
88 if (numvalid == 0)
89 goto out_free;
90
91 /* newsize += top-level package + 3 objects for each key/value tuple */
92 newsize += (1 + 3 * numvalid) * sizeof(union acpi_object);
93 newprops = ACPI_ALLOCATE_ZEROED(newsize);
94 if (!newprops)
95 goto out_free;
96
97 /* layout: top-level package | packages | key/value tuples | strings */
98 newprops->type = ACPI_TYPE_PACKAGE;
99 newprops->package.count = numvalid;
100 newprops->package.elements = &newprops[1];
101 free_space = &newprops[1 + 3 * numvalid];
102
103 for_each_set_bit(i, valid, numprops) {
104 union acpi_object *key = &props->package.elements[i * 2];
105 union acpi_object *val = &props->package.elements[i * 2 + 1];
106 unsigned int k = 1 + numvalid + j * 2; /* index into newprops */
107 unsigned int v = k + 1;
108
109 newprops[1 + j].type = ACPI_TYPE_PACKAGE;
110 newprops[1 + j].package.count = 2;
111 newprops[1 + j].package.elements = &newprops[k];
112
113 newprops[k].type = ACPI_TYPE_STRING;
114 newprops[k].string.length = key->string.length;
115 newprops[k].string.pointer = free_space;
116 memcpy(free_space, key->string.pointer, key->string.length);
117 free_space += key->string.length + 1;
118
119 newprops[v].type = val->type;
120 if (val->type == ACPI_TYPE_INTEGER) {
121 newprops[v].integer.value = val->integer.value;
122 } else {
123 newprops[v].buffer.length = val->buffer.length;
124 newprops[v].buffer.pointer = free_space;
125 memcpy(free_space, val->buffer.pointer,
126 val->buffer.length);
127 free_space += val->buffer.length;
128 }
129 j++; /* count valid properties */
130 }
131 WARN_ON(free_space != (void *)newprops + newsize);
132
133 adev->data.pointer = newprops;
134 acpi_data_add_props(&adev->data, &apple_prp_guid, newprops);
135
136 out_free:
137 ACPI_FREE(props);
138 bitmap_free(valid);
139 }
140
