chromeos_pstore.c
/*
* chromeos_pstore.c - Driver to instantiate Chromebook ramoops device
*
* Copyright (C) 2013 Google, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 2 of the License.
*/
#include <linux/acpi.h>
#include <linux/dmi.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pstore_ram.h>
static struct dmi_system_id chromeos_pstore_dmi_table[] __initdata = {
{
/*
* Today all Chromebooks/boxes ship with Google_* as version and
* coreboot as bios vendor. No other systems with this
* combination are known to date.
*/
.matches = {
DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
DMI_MATCH(DMI_BIOS_VERSION, "Google_"),
},
},
{
/* x86-alex, the first Samsung Chromebook. */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "Alex"),
},
},
{
/* x86-mario, the Cr-48 pilot device from Google. */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "IEC"),
DMI_MATCH(DMI_PRODUCT_NAME, "Mario"),
},
},
{
/* x86-zgb, the first Acer Chromebook. */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "ACER"),
DMI_MATCH(DMI_PRODUCT_NAME, "ZGB"),
},
},
{ }
};
MODULE_DEVICE_TABLE(dmi, chromeos_pstore_dmi_table);
/*
* On x86 chromebooks/boxes, the firmware will keep the legacy VGA memory
* range untouched across reboots, so we use that to store our pstore
* contents for panic logs, etc.
*/
static struct ramoops_platform_data chromeos_ramoops_data = {
.mem_size = 0x100000,
.mem_address = 0xf00000,
.record_size = 0x40000,
.console_size = 0x20000,
.ftrace_size = 0x20000,
.dump_oops = 1,
};
static struct platform_device chromeos_ramoops = {
.name = "ramoops",
.dev = {
.platform_data = &chromeos_ramoops_data,
},
};
#ifdef CONFIG_ACPI
static const struct acpi_device_id cros_ramoops_acpi_match[] = {
{ "GOOG9999", 0 },
{ }
};
MODULE_DEVICE_TABLE(acpi, cros_ramoops_acpi_match);
static struct platform_driver chromeos_ramoops_acpi = {
.driver = {
.name = "chromeos_pstore",
.acpi_match_table = ACPI_PTR(cros_ramoops_acpi_match),
},
};
static int __init chromeos_probe_acpi(struct platform_device *pdev)
{
struct resource *res;
resource_size_t len;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -ENOMEM;
len = resource_size(res);
if (!res->start || !len)
return -ENOMEM;
pr_info("chromeos ramoops using acpi device.\n");
chromeos_ramoops_data.mem_size = len;
chromeos_ramoops_data.mem_address = res->start;
return 0;
}
static bool __init chromeos_check_acpi(void)
{
if (!platform_driver_probe(&chromeos_ramoops_acpi, chromeos_probe_acpi))
return true;
return false;
}
#else
static inline bool chromeos_check_acpi(void) { return false; }
#endif
static int __init chromeos_pstore_init(void)
{
bool acpi_dev_found;
/* First check ACPI for non-hardcoded values from firmware. */
acpi_dev_found = chromeos_check_acpi();
if (acpi_dev_found || dmi_check_system(chromeos_pstore_dmi_table))
return platform_device_register(&chromeos_ramoops);
return -ENODEV;
}
static void __exit chromeos_pstore_exit(void)
{
platform_device_unregister(&chromeos_ramoops);
}
module_init(chromeos_pstore_init);
module_exit(chromeos_pstore_exit);
MODULE_DESCRIPTION("Chrome OS pstore module");
MODULE_LICENSE("GPL");