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545daf9091
On ChromiumOS devices, the `ecc_size` is set to 0 (check dmesg | grep ecc to see `ecc: 0`): this disables ECC for ramoops region, even when `ramoops.ecc=1` is given to kernel command line parameter. Introduce `ecc_size` module parameter to provide a method to turn on ECC for ramoops and set different values of ecc_size per devices. A large `ecc_size` value can cause a kernel panic due to a constraint in Reed-Solomon code library. The validation for this constraint should belong to the common pstore RAM layer, not in each individual driver. So this check is handled by a separate patch [1]. [1] https://lore.kernel.org/lkml/20250620054757.1006729-1-naoyatezuka@chromium.org Signed-off-by: Naoya Tezuka <naoyatezuka@chromium.org> Link: https://lore.kernel.org/r/20250620062822.1018798-1-naoyatezuka@chromium.org Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
145 lines
3.4 KiB
C
145 lines
3.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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// Driver to instantiate Chromebook ramoops device.
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//
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// Copyright (C) 2013 Google, Inc.
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#include <linux/acpi.h>
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#include <linux/dmi.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/pstore_ram.h>
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static int ecc_size;
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module_param(ecc_size, int, 0400);
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MODULE_PARM_DESC(ecc_size, "ECC parity data size in bytes. A positive value enables ECC for the ramoops region.");
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static const struct dmi_system_id chromeos_pstore_dmi_table[] __initconst = {
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{
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/*
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* Today all Chromebooks/boxes ship with Google_* as version and
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* coreboot as bios vendor. No other systems with this
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* combination are known to date.
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*/
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.matches = {
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DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
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DMI_MATCH(DMI_BIOS_VERSION, "Google_"),
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},
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},
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{
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/* x86-alex, the first Samsung Chromebook. */
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.matches = {
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DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
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DMI_MATCH(DMI_PRODUCT_NAME, "Alex"),
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},
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},
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{
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/* x86-mario, the Cr-48 pilot device from Google. */
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.matches = {
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DMI_MATCH(DMI_SYS_VENDOR, "IEC"),
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DMI_MATCH(DMI_PRODUCT_NAME, "Mario"),
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},
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},
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{
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/* x86-zgb, the first Acer Chromebook. */
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.matches = {
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DMI_MATCH(DMI_SYS_VENDOR, "ACER"),
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DMI_MATCH(DMI_PRODUCT_NAME, "ZGB"),
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},
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},
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{ }
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};
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MODULE_DEVICE_TABLE(dmi, chromeos_pstore_dmi_table);
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/*
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* On x86 chromebooks/boxes, the firmware will keep the legacy VGA memory
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* range untouched across reboots, so we use that to store our pstore
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* contents for panic logs, etc.
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*/
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static struct ramoops_platform_data chromeos_ramoops_data = {
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.mem_size = 0x100000,
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.mem_address = 0xf00000,
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.record_size = 0x40000,
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.console_size = 0x20000,
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.ftrace_size = 0x20000,
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.pmsg_size = 0x20000,
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.max_reason = KMSG_DUMP_OOPS,
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};
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static struct platform_device chromeos_ramoops = {
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.name = "ramoops",
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.dev = {
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.platform_data = &chromeos_ramoops_data,
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},
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};
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#ifdef CONFIG_ACPI
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static const struct acpi_device_id cros_ramoops_acpi_match[] = {
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{ "GOOG9999", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(acpi, cros_ramoops_acpi_match);
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static struct platform_driver chromeos_ramoops_acpi = {
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.driver = {
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.name = "chromeos_pstore",
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.acpi_match_table = ACPI_PTR(cros_ramoops_acpi_match),
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},
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};
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static int __init chromeos_probe_acpi(struct platform_device *pdev)
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{
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struct resource *res;
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resource_size_t len;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res)
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return -ENOMEM;
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len = resource_size(res);
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if (!res->start || !len)
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return -ENOMEM;
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pr_info("chromeos ramoops using acpi device.\n");
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chromeos_ramoops_data.mem_size = len;
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chromeos_ramoops_data.mem_address = res->start;
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return 0;
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}
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static bool __init chromeos_check_acpi(void)
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{
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if (!platform_driver_probe(&chromeos_ramoops_acpi, chromeos_probe_acpi))
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return true;
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return false;
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}
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#else
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static inline bool chromeos_check_acpi(void) { return false; }
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#endif
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static int __init chromeos_pstore_init(void)
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{
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bool acpi_dev_found;
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if (ecc_size > 0)
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chromeos_ramoops_data.ecc_info.ecc_size = ecc_size;
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/* First check ACPI for non-hardcoded values from firmware. */
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acpi_dev_found = chromeos_check_acpi();
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if (acpi_dev_found || dmi_check_system(chromeos_pstore_dmi_table))
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return platform_device_register(&chromeos_ramoops);
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return -ENODEV;
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}
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static void __exit chromeos_pstore_exit(void)
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{
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platform_device_unregister(&chromeos_ramoops);
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}
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module_init(chromeos_pstore_init);
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module_exit(chromeos_pstore_exit);
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MODULE_DESCRIPTION("ChromeOS pstore module");
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MODULE_LICENSE("GPL v2");
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