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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307// 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/ioport.h>#include <linux/kernel.h>#include <linux/device-id/coreboot.h>#include <linux/mm.h>#include <linux/module.h>#include <linux/of.h>#include <linux/platform_device.h>#include <linux/slab.h>
#include "coreboot_table.h"
/* Coreboot table header structure */struct coreboot_table_header { char signature[4]; u32 header_bytes; u32 header_checksum; u32 table_bytes; u32 table_checksum; u32 table_entries;};
#define CB_DEV(d) container_of(d, struct coreboot_device, dev)#define CB_DRV(d) container_of_const(d, struct coreboot_driver, drv)
static int coreboot_bus_match(struct device *dev, const struct device_driver *drv){ struct coreboot_device *device = CB_DEV(dev); const struct coreboot_driver *driver = CB_DRV(drv); const struct coreboot_device_id *id;
if (!driver->id_table) return 0;
for (id = driver->id_table; id->tag; id++) { if (device->entry.tag == id->tag) return 1; }
return 0;}
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 void 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);}
static int coreboot_bus_uevent(const struct device *dev, struct kobj_uevent_env *env){ struct coreboot_device *device = CB_DEV(dev); u32 tag = device->entry.tag;
return add_uevent_var(env, "MODALIAS=coreboot:t%08X", tag);}
static const struct bus_type coreboot_bus_type = { .name = "coreboot", .match = coreboot_bus_match, .probe = coreboot_bus_probe, .remove = coreboot_bus_remove, .uevent = coreboot_bus_uevent,};
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, struct module *owner){ driver->drv.bus = &coreboot_bus_type; driver->drv.owner = owner;
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, resource_size_t len){ int i, ret; void *ptr_entry; struct coreboot_device *device; struct coreboot_table_entry *entry; struct coreboot_table_header *header = ptr; void *ptr_end;
ptr_end = ptr + len; ptr_entry = ptr + header->header_bytes; for (i = 0; i < header->table_entries; i++, ptr_entry += entry->size) { if (ptr_entry + sizeof(*entry) > ptr_end) return -EINVAL; entry = ptr_entry;
if (entry->size < sizeof(*entry)) { dev_warn(dev, "coreboot table entry too small!\n"); return -EINVAL; }
if (ptr_entry + entry->size > ptr_end) return -EINVAL;
device = kzalloc(sizeof(device->dev) + entry->size, GFP_KERNEL); if (!device) return -ENOMEM;
device->dev.parent = dev; device->dev.bus = &coreboot_bus_type; device->dev.release = coreboot_device_release; memcpy(device->raw, ptr_entry, entry->size);
switch (device->entry.tag) { case LB_TAG_CBMEM_ENTRY: /* * Skip entries that are not exclusively System RAM or * Reserved memory. * On ARM64, no-map regions are filtered out as they are * IORESOURCE_MEM (see request_standard_resources() in * arch/arm64/kernel/setup.c). * On x86, CBMEM often resides in standard reserved regions * (IORES_DESC_RESERVED). */ if (region_intersects(device->cbmem_entry.address, device->cbmem_entry.entry_size, IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE) != REGION_INTERSECTS && region_intersects(device->cbmem_entry.address, device->cbmem_entry.entry_size, IORESOURCE_MEM, IORES_DESC_RESERVED) != REGION_INTERSECTS) { kfree(device); continue; } dev_set_name(&device->dev, "cbmem-%08x", device->cbmem_entry.id); break; default: dev_set_name(&device->dev, "coreboot%d", i); break; }
ret = device_register(&device->dev); if (ret) { dev_warn(dev, "failed to register coreboot device: %d\n", ret); put_device(&device->dev); } }
return 0;}
static int coreboot_table_probe(struct platform_device *pdev){ resource_size_t len; resource_size_t table_span; 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 < sizeof(*header)) 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;
ret = strncmp(header->signature, "LBIO", sizeof(header->signature));
if (!ret && (header->header_bytes < sizeof(*header) || check_add_overflow((resource_size_t)header->header_bytes, (resource_size_t)header->table_bytes, &table_span) || table_span > len)) ret = -EINVAL;
memunmap(header); if (ret) { dev_warn(dev, "coreboot table missing or corrupt!\n"); return -ENODEV; }
ptr = memremap(res->start, table_span, MEMREMAP_WB); if (!ptr) return -ENOMEM;
ret = coreboot_table_populate(dev, ptr, table_span);
memunmap(ptr);
return ret;}
static int __cb_dev_unregister(struct device *dev, void *dummy){ device_unregister(dev); return 0;}
static void coreboot_table_remove(struct platform_device *pdev){ bus_for_each_dev(&coreboot_bus_type, NULL, NULL, __cb_dev_unregister);}
#ifdef CONFIG_ACPIstatic const struct acpi_device_id cros_coreboot_acpi_match[] = { { .id = "GOOGCB00" }, { .id = "BOOT0000" }, { }};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), },};
static int __init coreboot_table_driver_init(void){ int ret;
ret = bus_register(&coreboot_bus_type); if (ret) return ret;
ret = platform_driver_register(&coreboot_table_driver); if (ret) { bus_unregister(&coreboot_bus_type); return ret; }
return 0;}
static void __exit coreboot_table_driver_exit(void){ platform_driver_unregister(&coreboot_table_driver); bus_unregister(&coreboot_bus_type);}
subsys_initcall(coreboot_table_driver_init);module_exit(coreboot_table_driver_exit);
MODULE_AUTHOR("Google, Inc.");MODULE_DESCRIPTION("Module providing coreboot table access");MODULE_LICENSE("GPL");