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: Thierry Escande <thierry.escande@collabora.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/firmware/google/Kconfig b/drivers/firmware/google/Kconfig
index 840bd62e3b1c4ad8acff3bb66c8e7faa9171ec96..00000e0376b90fc0e750ef429bc2688d6a2ee450 100644 (file)
--- a/drivers/firmware/google/Kconfig
+++ b/drivers/firmware/google/Kconfig
@@ -1,6 +1,5 @@
 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

diff --git a/drivers/firmware/google/Makefile b/drivers/firmware/google/Makefile
index 662a83edb03ca0e11f0dd1a2d32864498471c2df..bb952c686d3be8e5051191c3376afa7801b61ad8 100644 (file)
--- a/drivers/firmware/google/Makefile
+++ b/drivers/firmware/google/Makefile
@@ -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

diff --git a/drivers/firmware/google/coreboot_table-of.c b/drivers/firmware/google/coreboot_table-of.c
new file mode 100644 (file)
index 0000000..727acdc
--- /dev/null
+++ b/drivers/firmware/google/coreboot_table-of.c
@@ -0,0 +1,82 @@
+/*
+ * 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");