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
  25 #if defined(CONFIG_ACPI) && defined(CONFIG_X86)
  26 int nouveau_acpi_get_bios_chunk(uint8_t *bios, int offset, int len);
  27 bool nouveau_acpi_rom_supported(struct device *);
  28 #else
  29 static inline bool
  30 nouveau_acpi_rom_supported(struct device *dev)
  31 {
  32         return false;
  33 }
  34
  35 static inline int
  36 nouveau_acpi_get_bios_chunk(uint8_t *bios, int offset, int len)
  37 {
  38         return -EINVAL;
  39 }
  40 #endif
  41
  42 /* This version of the shadow function disobeys the ACPI spec and tries
  43  * to fetch in units of more than 4KiB at a time.  This is a LOT faster
  44  * on some systems, such as Lenovo W530.
  45  */
  46 static u32
  47 acpi_read_fast(void *data, u32 offset, u32 length, struct nvkm_bios *bios)
  48 {
  49         u32 limit = (offset + length + 0xfff) & ~0xfff;
  50         u32 start = offset & ~0x00000fff;
  51         u32 fetch = limit - start;
  52
  53         if (nvbios_extend(bios, limit) >= 0) {
  54                 int ret = nouveau_acpi_get_bios_chunk(bios->data, start, fetch);
  55                 if (ret == fetch)
  56                         return fetch;
  57         }
  58
  59         return 0;
  60 }
  61
  62 /* Other systems, such as the one in fdo#55948, will report a success
  63  * but only return 4KiB of data.  The common bios fetching logic will
  64  * detect an invalid image, and fall back to this version of the read
  65  * function.
  66  */
  67 static u32
  68 acpi_read_slow(void *data, u32 offset, u32 length, struct nvkm_bios *bios)
  69 {
  70         u32 limit = (offset + length + 0xfff) & ~0xfff;
  71         u32 start = offset & ~0xfff;
  72         u32 fetch = 0;
  73
  74         if (nvbios_extend(bios, limit) >= 0) {
  75                 while (start + fetch < limit) {
  76                         int ret = nouveau_acpi_get_bios_chunk(bios->data,
  77                                                               start + fetch,
  78                                                               0x1000);
  79                         if (ret != 0x1000)
  80                                 break;
  81                         fetch += 0x1000;
  82                 }
  83         }
  84
  85         return fetch;
  86 }
  87
  88 static void *
  89 acpi_init(struct nvkm_bios *bios, const char *name)
  90 {
  91         if (!nouveau_acpi_rom_supported(bios->subdev.device->dev))
  92                 return ERR_PTR(-ENODEV);
  93         return NULL;
  94 }
  95
  96 const struct nvbios_source
  97 nvbios_acpi_fast = {
  98         .name = "ACPI",
  99         .init = acpi_init,
 100         .read = acpi_read_fast,
 101         .rw = false,
 102         .require_checksum = true,
 103 };
 104
 105 const struct nvbios_source
 106 nvbios_acpi_slow = {
 107         .name = "ACPI",
 108         .init = acpi_init,
 109         .read = acpi_read_slow,
 110         .rw = false,
 111 };