// SPDX-License-Identifier: GPL-2.0-only/* * coreboot_table.c * * Module providing coreboot table access. * * Copyright 2017 Google Inc. * Copyright 2017 Samuel Holland <samuel@sholland.org> */ #include <linux/acpi.h>#include <linux/device.h>#include <linux/err.h>#include <linux/init.h>#include <linux/io.h>#include <linux/kernel.h>#include <linux/module.h>#include <linux/of.h>#include <linux/platform_device.h>#include <linux/slab.h> #include "coreboot_table.h" #define CB_DEV(d) container_of(d, struct coreboot_device, dev)#define CB_DRV(d) container_of(d, struct coreboot_driver, drv) static int coreboot_bus_match(struct device *dev, struct device_driver *drv){	struct coreboot_device *device = CB_DEV(dev);	struct coreboot_driver *driver = CB_DRV(drv); 	return device->entry.tag == driver->tag;} static int coreboot_bus_probe(struct device *dev){	int ret = -ENODEV;	struct coreboot_device *device = CB_DEV(dev);	struct coreboot_driver *driver = CB_DRV(dev->driver); 	if (driver->probe)		ret = driver->probe(device); 	return ret;} static int coreboot_bus_remove(struct device *dev){	struct coreboot_device *device = CB_DEV(dev);	struct coreboot_driver *driver = CB_DRV(dev->driver); 	if (driver->remove)		driver->remove(device); 	return 0;} static struct bus_type coreboot_bus_type = {	.name		= "coreboot",	.match		= coreboot_bus_match,	.probe		= coreboot_bus_probe,	.remove		= coreboot_bus_remove,}; static void coreboot_device_release(struct device *dev){	struct coreboot_device *device = CB_DEV(dev); 	kfree(device);} int coreboot_driver_register(struct coreboot_driver *driver){	driver->drv.bus = &coreboot_bus_type; 	return driver_register(&driver->drv);}EXPORT_SYMBOL(coreboot_driver_register); void coreboot_driver_unregister(struct coreboot_driver *driver){	driver_unregister(&driver->drv);}EXPORT_SYMBOL(coreboot_driver_unregister); static int coreboot_table_populate(struct device *dev, void *ptr){	int i, ret;	void *ptr_entry;	struct coreboot_device *device;	struct coreboot_table_entry *entry;	struct coreboot_table_header *header = ptr; 	ptr_entry = ptr + header->header_bytes;	for (i = 0; i < header->table_entries; i++) {		entry = ptr_entry; 		device = kzalloc(sizeof(struct device) + entry->size, GFP_KERNEL);		if (!device)			return -ENOMEM; 		dev_set_name(&device->dev, "coreboot%d", i);		device->dev.parent = dev;		device->dev.bus = &coreboot_bus_type;		device->dev.release = coreboot_device_release;		memcpy(&device->entry, ptr_entry, entry->size); 		ret = device_register(&device->dev);		if (ret) {			put_device(&device->dev);			return ret;		} 		ptr_entry += entry->size;	} 	return 0;} static int coreboot_table_probe(struct platform_device *pdev){	resource_size_t len;	struct coreboot_table_header *header;	struct resource *res;	struct device *dev = &pdev->dev;	void *ptr;	int ret; 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);	if (!res)		return -EINVAL; 	len = resource_size(res);	if (!res->start || !len)		return -EINVAL; 	/* Check just the header first to make sure things are sane */	header = memremap(res->start, sizeof(*header), MEMREMAP_WB);	if (!header)		return -ENOMEM; 	len = header->header_bytes + header->table_bytes;	ret = strncmp(header->signature, "LBIO", sizeof(header->signature));	memunmap(header);	if (ret) {		dev_warn(dev, "coreboot table missing or corrupt!\n");		return -ENODEV;	} 	ptr = memremap(res->start, len, MEMREMAP_WB);	if (!ptr)		return -ENOMEM; 	ret = bus_register(&coreboot_bus_type);	if (!ret) {		ret = coreboot_table_populate(dev, ptr);		if (ret)			bus_unregister(&coreboot_bus_type);	}	memunmap(ptr); 	return ret;} static int __cb_dev_unregister(struct device *dev, void *dummy){	device_unregister(dev);	return 0;} static int coreboot_table_remove(struct platform_device *pdev){	bus_for_each_dev(&coreboot_bus_type, NULL, NULL, __cb_dev_unregister);	bus_unregister(&coreboot_bus_type);	return 0;} #ifdef CONFIG_ACPIstatic const struct acpi_device_id cros_coreboot_acpi_match[] = {	{ "GOOGCB00", 0 },	{ "BOOT0000", 0 },	{ }};MODULE_DEVICE_TABLE(acpi, cros_coreboot_acpi_match);#endif #ifdef CONFIG_OFstatic const struct of_device_id coreboot_of_match[] = {	{ .compatible = "coreboot" },	{}};MODULE_DEVICE_TABLE(of, coreboot_of_match);#endif static struct platform_driver coreboot_table_driver = {	.probe = coreboot_table_probe,	.remove = coreboot_table_remove,	.driver = {		.name = "coreboot_table",		.acpi_match_table = ACPI_PTR(cros_coreboot_acpi_match),		.of_match_table = of_match_ptr(coreboot_of_match),	},};module_platform_driver(coreboot_table_driver);MODULE_AUTHOR("Google, Inc.");MODULE_LICENSE("GPL");