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>

4 files changed, 1 insertions, 209 deletions

diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig
index 552512f211a1..08ed88e49ea3 100644
--- a/drivers/firmware/efi/Kconfig
+++ b/drivers/firmware/efi/Kconfig
@@ -26,17 +26,6 @@ config EFI_VARS_PSTORE_DEFAULT_DISABLE
 	  backend for pstore by default. This setting can be overridden
 	  using the efivars module's pstore_disable parameter.
 
-config EFI_RUNTIME_MAP
-	bool "Export EFI runtime maps to sysfs" if EXPERT
-	depends on X86 && EFI
-	default KEXEC_CORE
-	help
-	  Export EFI runtime memory regions to /sys/firmware/efi/runtime-map.
-	  That memory map is required by the 2nd kernel to set up EFI virtual
-	  mappings after kexec, but can also be used for debugging purposes.
-
-	  See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map.
-
 config EFI_SOFT_RESERVE
 	bool "Reserve EFI Specific Purpose Memory"
 	depends on EFI && EFI_STUB && ACPI_HMAT
diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile
index 8e4f0d5b26e5..7d3b08cc8c5a 100644
--- a/drivers/firmware/efi/Makefile
+++ b/drivers/firmware/efi/Makefile
@@ -20,7 +20,6 @@ obj-$(CONFIG_EFI_PARAMS_FROM_FDT)	+= fdtparams.o
 obj-$(CONFIG_EFI_ESRT)			+= esrt.o
 obj-$(CONFIG_EFI_VARS_PSTORE)		+= efi-pstore.o
 obj-$(CONFIG_UEFI_CPER)			+= cper.o
-obj-$(CONFIG_EFI_RUNTIME_MAP)		+= runtime-map.o
 obj-$(CONFIG_EFI_RUNTIME_WRAPPERS)	+= runtime-wrappers.o
 subdir-$(CONFIG_EFI_STUB)		+= libstub
 obj-$(CONFIG_EFI_BOOTLOADER_CONTROL)	+= efibc.o
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 951a42d27cf4..dfdbbc702da0 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -396,10 +396,6 @@ 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 */
 	error = sysfs_create_mount_point(efi_kobj, "efivars");
 	if (error) {
@@ -425,6 +421,7 @@ err_unregister:
 		generic_ops_unregister();
 err_put:
 	kobject_put(efi_kobj);
+	efi_kobj = NULL;
 	destroy_workqueue(efi_rts_wq);
 	return error;
 }
diff --git a/drivers/firmware/efi/runtime-map.c b/drivers/firmware/efi/runtime-map.c
deleted file mode 100644
index 92a3d45a795c..000000000000
--- a/drivers/firmware/efi/runtime-map.c
+++ /dev/null
@@ -1,193 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * linux/drivers/efi/runtime-map.c
- * 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/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;
-}
-
-int __init efi_runtime_map_init(struct kobject *efi_kobj)
-{
-	int i, j, ret = 0;
-	struct efi_runtime_map_entry *entry;
-	efi_memory_desc_t *md;
-
-	if (!efi_enabled(EFI_MEMMAP))
-		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;
-}