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 <dyoung@redhat.com>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
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 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-$(CONFIG_EFI_VARS) += efivars.o
obj-$(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 @@
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 <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;
+}