LXR linux/drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowacpi.c

   1/*
   2 * Copyright 2012 Red Hat Inc.
   3 *
   4 * Permission is hereby granted, free of charge, to any person obtaining a
   5 * copy of this software and associated documentation files (the "Software"),
   6 * to deal in the Software without restriction, including without limitation
   7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8 * and/or sell copies of the Software, and to permit persons to whom the
   9 * Software is furnished to do so, subject to the following conditions:
  10 *
  11 * The above copyright notice and this permission notice shall be included in
  12 * all copies or substantial portions of the Software.
  13 *
  14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
  18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  20 * OTHER DEALINGS IN THE SOFTWARE.
  21 *
  22 */
  23#include "priv.h"
  24
  25static int
  26acpi_read_bios(acpi_handle rom_handle, u8 *bios, u32 offset, u32 length)
  27{
  28#if defined(CONFIG_ACPI) && defined(CONFIG_X86)
  29        acpi_status status;
  30        union acpi_object rom_arg_elements[2], *obj;
  31        struct acpi_object_list rom_arg;
  32        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL};
  33
  34        rom_arg.count = 2;
  35        rom_arg.pointer = &rom_arg_elements[0];
  36
  37        rom_arg_elements[0].type = ACPI_TYPE_INTEGER;
  38        rom_arg_elements[0].integer.value = offset;
  39
  40        rom_arg_elements[1].type = ACPI_TYPE_INTEGER;
  41        rom_arg_elements[1].integer.value = length;
  42
  43        status = acpi_evaluate_object(rom_handle, NULL, &rom_arg, &buffer);
  44        if (ACPI_FAILURE(status)) {
  45                pr_info("failed to evaluate ROM got %s\n",
  46                        acpi_format_exception(status));
  47                return -ENODEV;
  48        }
  49        obj = (union acpi_object *)buffer.pointer;
  50        length = min(length, obj->buffer.length);
  51        memcpy(bios+offset, obj->buffer.pointer, length);
  52        kfree(buffer.pointer);
  53        return length;
  54#else
  55        return -EINVAL;
  56#endif
  57}
  58
  59/* This version of the shadow function disobeys the ACPI spec and tries
  60 * to fetch in units of more than 4KiB at a time.  This is a LOT faster
  61 * on some systems, such as Lenovo W530.
  62 */
  63static u32
  64acpi_read_fast(void *data, u32 offset, u32 length, struct nvkm_bios *bios)
  65{
  66        u32 limit = (offset + length + 0xfff) & ~0xfff;
  67        u32 start = offset & ~0x00000fff;
  68        u32 fetch = limit - start;
  69
  70        if (nvbios_extend(bios, limit) >= 0) {
  71                int ret = acpi_read_bios(data, bios->data, start, fetch);
  72                if (ret == fetch)
  73                        return fetch;
  74        }
  75
  76        return 0;
  77}
  78
  79/* Other systems, such as the one in fdo#55948, will report a success
  80 * but only return 4KiB of data.  The common bios fetching logic will
  81 * detect an invalid image, and fall back to this version of the read
  82 * function.
  83 */
  84static u32
  85acpi_read_slow(void *data, u32 offset, u32 length, struct nvkm_bios *bios)
  86{
  87        u32 limit = (offset + length + 0xfff) & ~0xfff;
  88        u32 start = offset & ~0xfff;
  89        u32 fetch = 0;
  90
  91        if (nvbios_extend(bios, limit) >= 0) {
  92                while (start + fetch < limit) {
  93                        int ret = acpi_read_bios(data, bios->data,
  94                                                 start + fetch, 0x1000);
  95                        if (ret != 0x1000)
  96                                break;
  97                        fetch += 0x1000;
  98                }
  99        }
 100
 101        return fetch;
 102}
 103
 104static void *
 105acpi_init(struct nvkm_bios *bios, const char *name)
 106{
 107#if defined(CONFIG_ACPI) && defined(CONFIG_X86)
 108        acpi_status status;
 109        acpi_handle dhandle, rom_handle;
 110
 111        dhandle = ACPI_HANDLE(bios->subdev.device->dev);
 112        if (!dhandle)
 113                return ERR_PTR(-ENODEV);
 114
 115        status = acpi_get_handle(dhandle, "_ROM", &rom_handle);
 116        if (ACPI_FAILURE(status))
 117                return ERR_PTR(-ENODEV);
 118
 119        return rom_handle;
 120#else
 121        return ERR_PTR(-ENODEV);
 122#endif
 123}
 124
 125const struct nvbios_source
 126nvbios_acpi_fast = {
 127        .name = "ACPI",
 128        .init = acpi_init,
 129        .read = acpi_read_fast,
 130        .rw = false,
 131        .require_checksum = true,
 132};
 133
 134const struct nvbios_source
 135nvbios_acpi_slow = {
 136        .name = "ACPI",
 137        .init = acpi_init,
 138        .read = acpi_read_slow,
 139        .rw = false,
 140};
 141