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1// SPDX-License-Identifier: GPL-2.02// Driver to instantiate Chromebook ramoops device.3//4// Copyright (C) 2013 Google, Inc.5 6#include <linux/acpi.h>7#include <linux/dmi.h>8#include <linux/module.h>9#include <linux/platform_device.h>10#include <linux/pstore_ram.h>11 12static const struct dmi_system_id chromeos_pstore_dmi_table[] __initconst = {13 {14 /*15 * Today all Chromebooks/boxes ship with Google_* as version and16 * coreboot as bios vendor. No other systems with this17 * combination are known to date.18 */19 .matches = {20 DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),21 DMI_MATCH(DMI_BIOS_VERSION, "Google_"),22 },23 },24 {25 /* x86-alex, the first Samsung Chromebook. */26 .matches = {27 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),28 DMI_MATCH(DMI_PRODUCT_NAME, "Alex"),29 },30 },31 {32 /* x86-mario, the Cr-48 pilot device from Google. */33 .matches = {34 DMI_MATCH(DMI_SYS_VENDOR, "IEC"),35 DMI_MATCH(DMI_PRODUCT_NAME, "Mario"),36 },37 },38 {39 /* x86-zgb, the first Acer Chromebook. */40 .matches = {41 DMI_MATCH(DMI_SYS_VENDOR, "ACER"),42 DMI_MATCH(DMI_PRODUCT_NAME, "ZGB"),43 },44 },45 { }46};47MODULE_DEVICE_TABLE(dmi, chromeos_pstore_dmi_table);48 49/*50 * On x86 chromebooks/boxes, the firmware will keep the legacy VGA memory51 * range untouched across reboots, so we use that to store our pstore52 * contents for panic logs, etc.53 */54static struct ramoops_platform_data chromeos_ramoops_data = {55 .mem_size = 0x100000,56 .mem_address = 0xf00000,57 .record_size = 0x40000,58 .console_size = 0x20000,59 .ftrace_size = 0x20000,60 .pmsg_size = 0x20000,61 .max_reason = KMSG_DUMP_OOPS,62};63 64static struct platform_device chromeos_ramoops = {65 .name = "ramoops",66 .dev = {67 .platform_data = &chromeos_ramoops_data,68 },69};70 71#ifdef CONFIG_ACPI72static const struct acpi_device_id cros_ramoops_acpi_match[] = {73 { "GOOG9999", 0 },74 { }75};76MODULE_DEVICE_TABLE(acpi, cros_ramoops_acpi_match);77 78static struct platform_driver chromeos_ramoops_acpi = {79 .driver = {80 .name = "chromeos_pstore",81 .acpi_match_table = ACPI_PTR(cros_ramoops_acpi_match),82 },83};84 85static int __init chromeos_probe_acpi(struct platform_device *pdev)86{87 struct resource *res;88 resource_size_t len;89 90 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);91 if (!res)92 return -ENOMEM;93 94 len = resource_size(res);95 if (!res->start || !len)96 return -ENOMEM;97 98 pr_info("chromeos ramoops using acpi device.\n");99 100 chromeos_ramoops_data.mem_size = len;101 chromeos_ramoops_data.mem_address = res->start;102 103 return 0;104}105 106static bool __init chromeos_check_acpi(void)107{108 if (!platform_driver_probe(&chromeos_ramoops_acpi, chromeos_probe_acpi))109 return true;110 return false;111}112#else113static inline bool chromeos_check_acpi(void) { return false; }114#endif115 116static int __init chromeos_pstore_init(void)117{118 bool acpi_dev_found;119 120 /* First check ACPI for non-hardcoded values from firmware. */121 acpi_dev_found = chromeos_check_acpi();122 123 if (acpi_dev_found || dmi_check_system(chromeos_pstore_dmi_table))124 return platform_device_register(&chromeos_ramoops);125 126 return -ENODEV;127}128 129static void __exit chromeos_pstore_exit(void)130{131 platform_device_unregister(&chromeos_ramoops);132}133 134module_init(chromeos_pstore_init);135module_exit(chromeos_pstore_exit);136 137MODULE_DESCRIPTION("ChromeOS pstore module");138MODULE_LICENSE("GPL v2");139