1 // SPDX-License-Identifier: GPL-2.0 2 // 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 12 static const struct dmi_system_id chromeos_pstore_dmi_table[] __initconst = { 13 { 14 /* 15 * Today all Chromebooks/boxes ship with Google_* as version and 16 * coreboot as bios vendor. No other systems with this 17 * 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 }; 47 MODULE_DEVICE_TABLE(dmi, chromeos_pstore_dmi_table); 48 49 /* 50 * On x86 chromebooks/boxes, the firmware will keep the legacy VGA memory 51 * range untouched across reboots, so we use that to store our pstore 52 * contents for panic logs, etc. 53 */ 54 static 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 64 static struct platform_device chromeos_ramoops = { 65 .name = "ramoops", 66 .dev = { 67 .platform_data = &chromeos_ramoops_data, 68 }, 69 }; 70 71 #ifdef CONFIG_ACPI 72 static const struct acpi_device_id cros_ramoops_acpi_match[] = { 73 { "GOOG9999", 0 }, 74 { } 75 }; 76 MODULE_DEVICE_TABLE(acpi, cros_ramoops_acpi_match); 77 78 static 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 85 static 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 } 105 106 static 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 #else 113 static inline bool chromeos_check_acpi(void) { return false; } 114 #endif 115 116 static 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 } 128 129 static void __exit chromeos_pstore_exit(void) 130 { 131 platform_device_unregister(&chromeos_ramoops); 132 } 133 134 module_init(chromeos_pstore_init); 135 module_exit(chromeos_pstore_exit); 136 137 MODULE_DESCRIPTION("ChromeOS pstore module"); 138 MODULE_LICENSE("GPL v2"); 139