Commit a1d6f9cf authored by Thierry Escande's avatar Thierry Escande Committed by Greg Kroah-Hartman

firmware: google memconsole: Add ARM/ARM64 support

This patch expands the Google firmware memory console driver to also
work on certain tree based platforms running coreboot, such as ARM/ARM64
Chromebooks. This patch now adds another path to find the coreboot table
through the device tree. In order to find that, a second level
bootloader must have installed the 'coreboot' compatible device tree
node that describes its base address and size.

This patch is a rework/split/merge of patches from the chromeos v4.4
kernel tree originally authored by:
 Wei-Ning Huang <wnhuang@chromium.org>
 Julius Werner <jwerner@chromium.org>
 Brian Norris <briannorris@chromium.org>
Signed-off-by: default avatarThierry Escande <thierry.escande@collabora.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 88cfb1ee
menuconfig GOOGLE_FIRMWARE
bool "Google Firmware Drivers"
depends on X86
default n
help
These firmware drivers are used by Google's servers. They are
......@@ -11,7 +10,7 @@ if GOOGLE_FIRMWARE
config GOOGLE_SMI
tristate "SMI interface for Google platforms"
depends on ACPI && DMI && EFI
depends on X86 && ACPI && DMI && EFI
select EFI_VARS
help
Say Y here if you want to enable SMI callbacks for Google
......@@ -21,7 +20,7 @@ config GOOGLE_SMI
config GOOGLE_COREBOOT_TABLE
tristate
depends on GOOGLE_COREBOOT_TABLE_ACPI
depends on GOOGLE_COREBOOT_TABLE_ACPI || GOOGLE_COREBOOT_TABLE_OF
config GOOGLE_COREBOOT_TABLE_ACPI
tristate "Coreboot Table Access - ACPI"
......@@ -33,6 +32,16 @@ config GOOGLE_COREBOOT_TABLE_ACPI
pointer is accessed through the ACPI "GOOGCB00" object.
If unsure say N.
config GOOGLE_COREBOOT_TABLE_OF
tristate "Coreboot Table Access - Device Tree"
depends on OF
select GOOGLE_COREBOOT_TABLE
help
This option enable the coreboot_table module, which provide other
firmware modules to access coreboot table. The coreboot table pointer
is accessed through the device tree node /firmware/coreboot.
If unsure say N.
config GOOGLE_MEMCONSOLE
tristate
depends on GOOGLE_MEMCONSOLE_X86_LEGACY || GOOGLE_MEMCONSOLE_COREBOOT
......
......@@ -2,6 +2,7 @@
obj-$(CONFIG_GOOGLE_SMI) += gsmi.o
obj-$(CONFIG_GOOGLE_COREBOOT_TABLE) += coreboot_table.o
obj-$(CONFIG_GOOGLE_COREBOOT_TABLE_ACPI) += coreboot_table-acpi.o
obj-$(CONFIG_GOOGLE_COREBOOT_TABLE_OF) += coreboot_table-of.o
obj-$(CONFIG_GOOGLE_MEMCONSOLE) += memconsole.o
obj-$(CONFIG_GOOGLE_MEMCONSOLE_COREBOOT) += memconsole-coreboot.o
obj-$(CONFIG_GOOGLE_MEMCONSOLE_X86_LEGACY) += memconsole-x86-legacy.o
/*
* coreboot_table-of.c
*
* Coreboot table access through open firmware.
*
* Copyright 2017 Google Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License v2.0 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/device.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include "coreboot_table.h"
static int coreboot_table_of_probe(struct platform_device *pdev)
{
struct device_node *fw_dn = pdev->dev.of_node;
void __iomem *ptr;
ptr = of_iomap(fw_dn, 0);
of_node_put(fw_dn);
if (!ptr)
return -ENOMEM;
return coreboot_table_init(ptr);
}
static int coreboot_table_of_remove(struct platform_device *pdev)
{
return coreboot_table_exit();
}
static const struct of_device_id coreboot_of_match[] = {
{ .compatible = "coreboot" },
{},
};
static struct platform_driver coreboot_table_of_driver = {
.probe = coreboot_table_of_probe,
.remove = coreboot_table_of_remove,
.driver = {
.name = "coreboot_table_of",
.of_match_table = coreboot_of_match,
},
};
static int __init platform_coreboot_table_of_init(void)
{
struct platform_device *pdev;
struct device_node *of_node;
/* Limit device creation to the presence of /firmware/coreboot node */
of_node = of_find_node_by_path("/firmware/coreboot");
if (!of_node)
return -ENODEV;
if (!of_match_node(coreboot_of_match, of_node))
return -ENODEV;
pdev = of_platform_device_create(of_node, "coreboot_table_of", NULL);
if (!pdev)
return -ENODEV;
return platform_driver_register(&coreboot_table_of_driver);
}
module_init(platform_coreboot_table_of_init);
MODULE_AUTHOR("Google, Inc.");
MODULE_LICENSE("GPL");
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