drivers/acpi/x86/apple.c

   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  */
  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                      val->type != ACPI_TYPE_STRING))
  76                         continue; /* skip invalid properties */
  77
  78                 __set_bit(i, valid);
  79                 newsize += key->string.length + 1;
  80                 if ( val->type == ACPI_TYPE_BUFFER)
  81                         newsize += val->buffer.length;
  82                 else if (val->type == ACPI_TYPE_STRING)
  83                         newsize += val->string.length + 1;
  84         }
  85
  86         numvalid = bitmap_weight(valid, numprops);
  87         if (numprops > numvalid)
  88                 acpi_handle_info(adev->handle, FW_INFO
  89                                  "skipped %u properties: wrong type\n",
  90                                  numprops - numvalid);
  91         if (numvalid == 0)
  92                 goto out_free;
  93
  94         /* newsize += top-level package + 3 objects for each key/value tuple */
  95         newsize += (1 + 3 * numvalid) * sizeof(union acpi_object);
  96         newprops = ACPI_ALLOCATE_ZEROED(newsize);
  97         if (!newprops)
  98                 goto out_free;
  99
 100         /* layout: top-level package | packages | key/value tuples | strings */
 101         newprops->type = ACPI_TYPE_PACKAGE;
 102         newprops->package.count = numvalid;
 103         newprops->package.elements = &newprops[1];
 104         free_space = &newprops[1 + 3 * numvalid];
 105
 106         for_each_set_bit(i, valid, numprops) {
 107                 union acpi_object *key = &props->package.elements[i * 2];
 108                 union acpi_object *val = &props->package.elements[i * 2 + 1];
 109                 unsigned int k = 1 + numvalid + j * 2; /* index into newprops */
 110                 unsigned int v = k + 1;
 111
 112                 newprops[1 + j].type = ACPI_TYPE_PACKAGE;
 113                 newprops[1 + j].package.count = 2;
 114                 newprops[1 + j].package.elements = &newprops[k];
 115
 116                 newprops[k].type = ACPI_TYPE_STRING;
 117                 newprops[k].string.length = key->string.length;
 118                 newprops[k].string.pointer = free_space;
 119                 memcpy(free_space, key->string.pointer, key->string.length);
 120                 free_space += key->string.length + 1;
 121
 122                 newprops[v].type = val->type;
 123                 if (val->type == ACPI_TYPE_INTEGER) {
 124                         newprops[v].integer.value = val->integer.value;
 125                 } else if (val->type == ACPI_TYPE_STRING) {
 126                         newprops[v].string.length = val->string.length;
 127                         newprops[v].string.pointer = free_space;
 128                         memcpy(free_space, val->string.pointer,
 129                                val->string.length);
 130                         free_space += val->string.length + 1;
 131                 } else {
 132                         newprops[v].buffer.length = val->buffer.length;
 133                         newprops[v].buffer.pointer = free_space;
 134                         memcpy(free_space, val->buffer.pointer,
 135                                val->buffer.length);
 136                         free_space += val->buffer.length;
 137                 }
 138                 j++; /* count valid properties */
 139         }
 140         WARN_ON(free_space != (void *)newprops + newsize);
 141
 142         adev->data.pointer = newprops;
 143         acpi_data_add_props(&adev->data, &apple_prp_guid, newprops);
 144
 145 out_free:
 146         ACPI_FREE(props);
 147         bitmap_free(valid);
 148 }