diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-firmware-efi-runtime-map | 34 | ||||
| -rw-r--r-- | arch/x86/platform/efi/efi.c | 46 | ||||
| -rw-r--r-- | drivers/firmware/efi/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/firmware/efi/Makefile | 1 | ||||
| -rw-r--r-- | drivers/firmware/efi/efi.c | 4 | ||||
| -rw-r--r-- | drivers/firmware/efi/runtime-map.c | 181 | ||||
| -rw-r--r-- | include/linux/efi.h | 13 |
7 files changed, 287 insertions, 3 deletions
diff --git a/Documentation/ABI/testing/sysfs-firmware-efi-runtime-map b/Documentation/ABI/testing/sysfs-firmware-efi-runtime-map new file mode 100644 index 000000000000..c61b9b348e99 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-firmware-efi-runtime-map @@ -0,0 +1,34 @@ +What: /sys/firmware/efi/runtime-map/ +Date: December 2013 +Contact: Dave Young <dyoung@redhat.com> +Description: Switching efi runtime services to virtual mode requires + that all efi memory ranges which have the runtime attribute + bit set to be mapped to virtual addresses. + + The efi runtime services can only be switched to virtual + mode once without rebooting. The kexec kernel must maintain + the same physical to virtual address mappings as the first + kernel. The mappings are exported to sysfs so userspace tools + can reassemble them and pass them into the kexec kernel. + + /sys/firmware/efi/runtime-map/ is the directory the kernel + exports that information in. + + subdirectories are named with the number of the memory range: + + /sys/firmware/efi/runtime-map/0 + /sys/firmware/efi/runtime-map/1 + /sys/firmware/efi/runtime-map/2 + /sys/firmware/efi/runtime-map/3 + ... + + Each subdirectory contains five files: + + attribute : The attributes of the memory range. + num_pages : The size of the memory range in pages. + phys_addr : The physical address of the memory range. + type : The type of the memory range. + virt_addr : The virtual address of the memory range. + + Above values are all hexadecimal numbers with the '0x' prefix. +Users: Kexec diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index 28591072fbb7..74fe7a719508 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -76,6 +76,9 @@ static __initdata efi_config_table_type_t arch_tables[] = { {NULL_GUID, NULL, NULL}, }; +static void *efi_runtime_map; +static int nr_efi_runtime_map; + /* * Returns 1 if 'facility' is enabled, 0 otherwise. */ @@ -824,6 +827,39 @@ static void __init get_systab_virt_addr(efi_memory_desc_t *md) } } +static int __init save_runtime_map(void) +{ + efi_memory_desc_t *md; + void *tmp, *p, *q = NULL; + int count = 0; + + for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { + md = p; + + if (!(md->attribute & EFI_MEMORY_RUNTIME) || + (md->type == EFI_BOOT_SERVICES_CODE) || + (md->type == EFI_BOOT_SERVICES_DATA)) + continue; + tmp = krealloc(q, (count + 1) * memmap.desc_size, GFP_KERNEL); + if (!tmp) + goto out; + q = tmp; + + memcpy(q + count * memmap.desc_size, md, memmap.desc_size); + count++; + } + + efi_runtime_map = q; + nr_efi_runtime_map = count; + efi_runtime_map_setup(efi_runtime_map, nr_efi_runtime_map, + boot_params.efi_info.efi_memdesc_size); + + return 0; +out: + kfree(q); + return -ENOMEM; +} + /* * Map efi memory ranges for runtime serivce and update new_memmap with virtual * addresses. @@ -849,7 +885,7 @@ static void * __init efi_map_regions(int *count) tmp = krealloc(new_memmap, (*count + 1) * memmap.desc_size, GFP_KERNEL); if (!tmp) - goto out_krealloc; + goto out; new_memmap = tmp; memcpy(new_memmap + (*count * memmap.desc_size), md, memmap.desc_size); @@ -857,7 +893,7 @@ static void * __init efi_map_regions(int *count) } return new_memmap; -out_krealloc: +out: kfree(new_memmap); return NULL; } @@ -883,7 +919,7 @@ void __init efi_enter_virtual_mode(void) { efi_status_t status; void *new_memmap = NULL; - int count = 0; + int err, count = 0; efi.systab = NULL; @@ -904,6 +940,10 @@ void __init efi_enter_virtual_mode(void) return; } + err = save_runtime_map(); + if (err) + pr_err("Error saving runtime map, efi runtime on kexec non-functional!!\n"); + BUG_ON(!efi.systab); efi_setup_page_tables(); diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index 3150aa4874e8..730f5f2e8b7f 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 9ba156d3c775..a58e0f183a08 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 72533af72b98..4753bac65279 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 000000000000..97cdd16a2169 --- /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 <dyoung@redhat.com> + * + * This file is released under the GPLv2. + */ + +#include <linux/string.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/efi.h> +#include <linux/slab.h> + +#include <asm/setup.h> + +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; +} diff --git a/include/linux/efi.h b/include/linux/efi.h index fb60b10b7bd9..e64540746c63 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -872,4 +872,17 @@ int efivars_sysfs_init(void); #endif /* CONFIG_EFI_VARS */ +#ifdef CONFIG_EFI_RUNTIME_MAP +int efi_runtime_map_init(struct kobject *); +void efi_runtime_map_setup(void *, int, u32); +#else +static inline int efi_runtime_map_init(struct kobject *kobj) +{ + return 0; +} + +static inline void +efi_runtime_map_setup(void *map, int nr_entries, u32 desc_size) {} +#endif + #endif /* _LINUX_EFI_H */ |