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