/*
* Copyright 2012 Red Hat Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
*/
#include "priv.h"
static int
acpi_read_bios(acpi_handle rom_handle, u8 *bios, u32 offset, u32 length)
{
#if defined(CONFIG_ACPI) && defined(CONFIG_X86)
acpi_status status;
union acpi_object rom_arg_elements[2], *obj;
struct acpi_object_list rom_arg;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL};
rom_arg.count = 2;
rom_arg.pointer = &rom_arg_elements[0];
rom_arg_elements[0].type = ACPI_TYPE_INTEGER;
rom_arg_elements[0].integer.value = offset;
rom_arg_elements[1].type = ACPI_TYPE_INTEGER;
rom_arg_elements[1].integer.value = length;
status = acpi_evaluate_object(rom_handle, NULL, &rom_arg, &buffer);
if (ACPI_FAILURE(status)) {
pr_info("failed to evaluate ROM got %s\n",
acpi_format_exception(status));
return -ENODEV;
}
obj = (union acpi_object *)buffer.pointer;
length = min(length, obj->buffer.length);
memcpy(bios+offset, obj->buffer.pointer, length);
kfree(buffer.pointer);
return length;
#else
return -EINVAL;
#endif
}
/* This version of the shadow function disobeys the ACPI spec and tries
* to fetch in units of more than 4KiB at a time. This is a LOT faster
* on some systems, such as Lenovo W530.
*/
static u32
acpi_read_fast(void *data, u32 offset, u32 length, struct nvkm_bios *bios)
{
u32 limit = (offset + length + 0xfff) & ~0xfff;
u32 start = offset & ~0x00000fff;
u32 fetch = limit - start;
if (nvbios_extend(bios, limit) >= 0) {
int ret = acpi_read_bios(data, bios->data, start, fetch);
if (ret == fetch)
return fetch;
}
return 0;
}
/* Other systems, such as the one in fdo#55948, will report a success
* but only return 4KiB of data. The common bios fetching logic will
* detect an invalid image, and fall back to this version of the read
* function.
*/
static u32
acpi_read_slow(void *data, u32 offset, u32 length, struct nvkm_bios *bios)
{
u32 limit = (offset + length + 0xfff) & ~0xfff;
u32 start = offset & ~0xfff;
u32 fetch = 0;
if (nvbios_extend(bios, limit) >= 0) {
while (start + fetch < limit) {
int ret = acpi_read_bios(data, bios->data,
start + fetch, 0x1000);
if (ret != 0x1000)
break;
fetch += 0x1000;
}
}
return fetch;
}
static void *
acpi_init(struct nvkm_bios *bios, const char *name)
{
#if defined(CONFIG_ACPI) && defined(CONFIG_X86)
acpi_status status;
acpi_handle dhandle, rom_handle;
dhandle = ACPI_HANDLE(bios->subdev.device->dev);
if (!dhandle)
return ERR_PTR(-ENODEV);
status = acpi_get_handle(dhandle, "_ROM", &rom_handle);
if (ACPI_FAILURE(status))
return ERR_PTR(-ENODEV);
return rom_handle;
#else
return ERR_PTR(-ENODEV);
#endif
}
const struct nvbios_source
nvbios_acpi_fast = {
.name = "ACPI",
.init = acpi_init,
.read = acpi_read_fast,
.rw = false,
.require_checksum = true,
};
const struct nvbios_source
nvbios_acpi_slow = {
.name = "ACPI",
.init = acpi_init,
.read = acpi_read_slow,
.rw = false,
};
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