From 926172d46038d7610b6b8d84e40db727cefb482d Mon Sep 17 00:00:00 2001 From: Dave Young Date: Fri, 20 Dec 2013 18:02:18 +0800 Subject: efi: Export EFI runtime memory mapping to sysfs kexec kernel will need exactly same mapping for EFI runtime memory ranges. Thus here export the runtime ranges mapping to sysfs, kexec-tools will assemble them and pass to 2nd kernel via setup_data. Introducing a new directory /sys/firmware/efi/runtime-map just like /sys/firmware/memmap. Containing below attribute in each file of that directory: attribute num_pages phys_addr type virt_addr Signed-off-by: Dave Young Tested-by: Toshi Kani Signed-off-by: Matt Fleming --- drivers/firmware/efi/Kconfig | 11 +++ drivers/firmware/efi/Makefile | 1 + drivers/firmware/efi/efi.c | 4 + drivers/firmware/efi/runtime-map.c | 181 +++++++++++++++++++++++++++++++++++++ 4 files changed, 197 insertions(+) create mode 100644 drivers/firmware/efi/runtime-map.c (limited to 'drivers/firmware') diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index 3150aa4..730f5f2 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -39,4 +39,15 @@ config EFI_VARS_PSTORE_DEFAULT_DISABLE config UEFI_CPER def_bool n +config EFI_RUNTIME_MAP + bool "Export efi runtime maps to sysfs" + depends on X86 && EFI && KEXEC + default y + help + Export efi runtime memory maps to /sys/firmware/efi/runtime-map. + That memory map is used for example by kexec to set up efi virtual + mapping the 2nd kernel, but can also be used for debugging purposes. + + See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map. + endmenu diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile index 9ba156d..a58e0f1 100644 --- a/drivers/firmware/efi/Makefile +++ b/drivers/firmware/efi/Makefile @@ -5,3 +5,4 @@ obj-y += efi.o vars.o obj-$(CONFIG_EFI_VARS) += efivars.o obj-$(CONFIG_EFI_VARS_PSTORE) += efi-pstore.o obj-$(CONFIG_UEFI_CPER) += cper.o +obj-$(CONFIG_EFI_RUNTIME_MAP) += runtime-map.o diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 72533af..4753bac 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -167,6 +167,10 @@ static int __init efisubsys_init(void) goto err_unregister; } + error = efi_runtime_map_init(efi_kobj); + if (error) + goto err_remove_group; + /* and the standard mountpoint for efivarfs */ efivars_kobj = kobject_create_and_add("efivars", efi_kobj); if (!efivars_kobj) { diff --git a/drivers/firmware/efi/runtime-map.c b/drivers/firmware/efi/runtime-map.c new file mode 100644 index 0000000..97cdd16 --- /dev/null +++ b/drivers/firmware/efi/runtime-map.c @@ -0,0 +1,181 @@ +/* + * linux/drivers/efi/runtime-map.c + * Copyright (C) 2013 Red Hat, Inc., Dave Young + * + * This file is released under the GPLv2. + */ + +#include +#include +#include +#include +#include +#include + +#include + +static void *efi_runtime_map; +static int nr_efi_runtime_map; +static u32 efi_memdesc_size; + +struct efi_runtime_map_entry { + efi_memory_desc_t md; + struct kobject kobj; /* kobject for each entry */ +}; + +static struct efi_runtime_map_entry **map_entries; + +struct map_attribute { + struct attribute attr; + ssize_t (*show)(struct efi_runtime_map_entry *entry, char *buf); +}; + +static inline struct map_attribute *to_map_attr(struct attribute *attr) +{ + return container_of(attr, struct map_attribute, attr); +} + +static ssize_t type_show(struct efi_runtime_map_entry *entry, char *buf) +{ + return snprintf(buf, PAGE_SIZE, "0x%x\n", entry->md.type); +} + +#define EFI_RUNTIME_FIELD(var) entry->md.var + +#define EFI_RUNTIME_U64_ATTR_SHOW(name) \ +static ssize_t name##_show(struct efi_runtime_map_entry *entry, char *buf) \ +{ \ + return snprintf(buf, PAGE_SIZE, "0x%llx\n", EFI_RUNTIME_FIELD(name)); \ +} + +EFI_RUNTIME_U64_ATTR_SHOW(phys_addr); +EFI_RUNTIME_U64_ATTR_SHOW(virt_addr); +EFI_RUNTIME_U64_ATTR_SHOW(num_pages); +EFI_RUNTIME_U64_ATTR_SHOW(attribute); + +static inline struct efi_runtime_map_entry *to_map_entry(struct kobject *kobj) +{ + return container_of(kobj, struct efi_runtime_map_entry, kobj); +} + +static ssize_t map_attr_show(struct kobject *kobj, struct attribute *attr, + char *buf) +{ + struct efi_runtime_map_entry *entry = to_map_entry(kobj); + struct map_attribute *map_attr = to_map_attr(attr); + + return map_attr->show(entry, buf); +} + +static struct map_attribute map_type_attr = __ATTR_RO(type); +static struct map_attribute map_phys_addr_attr = __ATTR_RO(phys_addr); +static struct map_attribute map_virt_addr_attr = __ATTR_RO(virt_addr); +static struct map_attribute map_num_pages_attr = __ATTR_RO(num_pages); +static struct map_attribute map_attribute_attr = __ATTR_RO(attribute); + +/* + * These are default attributes that are added for every memmap entry. + */ +static struct attribute *def_attrs[] = { + &map_type_attr.attr, + &map_phys_addr_attr.attr, + &map_virt_addr_attr.attr, + &map_num_pages_attr.attr, + &map_attribute_attr.attr, + NULL +}; + +static const struct sysfs_ops map_attr_ops = { + .show = map_attr_show, +}; + +static void map_release(struct kobject *kobj) +{ + struct efi_runtime_map_entry *entry; + + entry = to_map_entry(kobj); + kfree(entry); +} + +static struct kobj_type __refdata map_ktype = { + .sysfs_ops = &map_attr_ops, + .default_attrs = def_attrs, + .release = map_release, +}; + +static struct kset *map_kset; + +static struct efi_runtime_map_entry * +add_sysfs_runtime_map_entry(struct kobject *kobj, int nr) +{ + int ret; + struct efi_runtime_map_entry *entry; + + if (!map_kset) { + map_kset = kset_create_and_add("runtime-map", NULL, kobj); + if (!map_kset) + return ERR_PTR(-ENOMEM); + } + + entry = kzalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) { + kset_unregister(map_kset); + return entry; + } + + memcpy(&entry->md, efi_runtime_map + nr * efi_memdesc_size, + sizeof(efi_memory_desc_t)); + + kobject_init(&entry->kobj, &map_ktype); + entry->kobj.kset = map_kset; + ret = kobject_add(&entry->kobj, NULL, "%d", nr); + if (ret) { + kobject_put(&entry->kobj); + kset_unregister(map_kset); + return ERR_PTR(ret); + } + + return entry; +} + +void efi_runtime_map_setup(void *map, int nr_entries, u32 desc_size) +{ + efi_runtime_map = map; + nr_efi_runtime_map = nr_entries; + efi_memdesc_size = desc_size; +} + +int __init efi_runtime_map_init(struct kobject *efi_kobj) +{ + int i, j, ret = 0; + struct efi_runtime_map_entry *entry; + + if (!efi_runtime_map) + return 0; + + map_entries = kzalloc(nr_efi_runtime_map * sizeof(entry), GFP_KERNEL); + if (!map_entries) { + ret = -ENOMEM; + goto out; + } + + for (i = 0; i < nr_efi_runtime_map; i++) { + entry = add_sysfs_runtime_map_entry(efi_kobj, i); + if (IS_ERR(entry)) { + ret = PTR_ERR(entry); + goto out_add_entry; + } + *(map_entries + i) = entry; + } + + return 0; +out_add_entry: + for (j = i - 1; j > 0; j--) { + entry = *(map_entries + j); + kobject_put(&entry->kobj); + } + if (map_kset) + kset_unregister(map_kset); +out: + return ret; +} -- cgit v1.1