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 */ 13static 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 */ 27void 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 135out_free: 136 ACPI_FREE(props); 137 bitmap_free(valid); 138} 139