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authorGravatar Ard Biesheuvel <ardb@kernel.org> 2022-11-07 09:17:16 +0100
committerGravatar Ard Biesheuvel <ardb@kernel.org> 2022-11-18 09:14:09 +0100
commit1fff234de2b6047ee311c6bf88f31ad5008f2889 (patch)
tree730cbd65af945e6ef4ac46f8bda9e72e341ff4fe /arch/x86/platform
parentefi: runtime-maps: Clarify purpose and enable by default for kexec (diff)
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efi: x86: Move EFI runtime map sysfs code to arch/x86
The EFI runtime map code is only wired up on x86, which is the only architecture that has a need for it in its implementation of kexec. So let's move this code under arch/x86 and drop all references to it from generic code. To ensure that the efi_runtime_map_init() is invoked at the appropriate time use a 'sync' subsys_initcall() that will be called right after the EFI initcall made from generic code where the original invocation of efi_runtime_map_init() resided. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Dave Young <dyoung@redhat.com>
Diffstat (limited to 'arch/x86/platform')
-rw-r--r--arch/x86/platform/efi/Makefile1
-rw-r--r--arch/x86/platform/efi/runtime-map.c194
2 files changed, 195 insertions, 0 deletions
diff --git a/arch/x86/platform/efi/Makefile b/arch/x86/platform/efi/Makefile
index ed5502a5185d..543df9a1379d 100644
--- a/arch/x86/platform/efi/Makefile
+++ b/arch/x86/platform/efi/Makefile
@@ -6,3 +6,4 @@ obj-$(CONFIG_EFI) += memmap.o quirks.o efi.o efi_$(BITS).o \
efi_stub_$(BITS).o
obj-$(CONFIG_EFI_MIXED) += efi_thunk_$(BITS).o
obj-$(CONFIG_EFI_FAKE_MEMMAP) += fake_mem.o
+obj-$(CONFIG_EFI_RUNTIME_MAP) += runtime-map.o
diff --git a/arch/x86/platform/efi/runtime-map.c b/arch/x86/platform/efi/runtime-map.c
new file mode 100644
index 000000000000..bbee682ef8cd
--- /dev/null
+++ b/arch/x86/platform/efi/runtime-map.c
@@ -0,0 +1,194 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2013 Red Hat, Inc., Dave Young <dyoung@redhat.com>
+ */
+
+#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/efi.h>
+#include <asm/setup.h>
+
+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_MODE(type, 0400);
+static struct map_attribute map_phys_addr_attr = __ATTR_RO_MODE(phys_addr, 0400);
+static struct map_attribute map_virt_addr_attr = __ATTR_RO_MODE(virt_addr, 0400);
+static struct map_attribute map_num_pages_attr = __ATTR_RO_MODE(num_pages, 0400);
+static struct map_attribute map_attribute_attr = __ATTR_RO_MODE(attribute, 0400);
+
+/*
+ * 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
+};
+ATTRIBUTE_GROUPS(def);
+
+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_groups = def_groups,
+ .release = map_release,
+};
+
+static struct kset *map_kset;
+
+static struct efi_runtime_map_entry *
+add_sysfs_runtime_map_entry(struct kobject *kobj, int nr,
+ efi_memory_desc_t *md)
+{
+ 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);
+ map_kset = NULL;
+ return ERR_PTR(-ENOMEM);
+ }
+
+ memcpy(&entry->md, md, 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);
+ map_kset = NULL;
+ return ERR_PTR(ret);
+ }
+
+ return entry;
+}
+
+int efi_get_runtime_map_size(void)
+{
+ return efi.memmap.nr_map * efi.memmap.desc_size;
+}
+
+int efi_get_runtime_map_desc_size(void)
+{
+ return efi.memmap.desc_size;
+}
+
+int efi_runtime_map_copy(void *buf, size_t bufsz)
+{
+ size_t sz = efi_get_runtime_map_size();
+
+ if (sz > bufsz)
+ sz = bufsz;
+
+ memcpy(buf, efi.memmap.map, sz);
+ return 0;
+}
+
+static int __init efi_runtime_map_init(void)
+{
+ int i, j, ret = 0;
+ struct efi_runtime_map_entry *entry;
+ efi_memory_desc_t *md;
+
+ if (!efi_enabled(EFI_MEMMAP) || !efi_kobj)
+ return 0;
+
+ map_entries = kcalloc(efi.memmap.nr_map, sizeof(entry), GFP_KERNEL);
+ if (!map_entries) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ i = 0;
+ for_each_efi_memory_desc(md) {
+ entry = add_sysfs_runtime_map_entry(efi_kobj, i, md);
+ 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);
+ }
+out:
+ return ret;
+}
+subsys_initcall_sync(efi_runtime_map_init);