On Tue, 2014-12-09 at 17:28 -0500, Peter Jones wrote:
> Add sysfs files for EFI System Resource Table under
> /sys/firmware/efi/esrt and for each EFI System Resource Entry under
> entries/ as a subdir.
>
> v2 with suggestions from bpetkov.
> v3 with me remembering checkpatch.
Hi Peter,
I also see compilations errors after applying this patch to v3.18. I am
using gcc ver gcc version 4.9.2 (Ubuntu 4.9.2-0ubuntu1~14.04) and doing
make x86_64_defconfig && make:
drivers/firmware/efi/esrt.c:49:35: error: array type has incomplete
element type
struct efi_system_resource_entry entries[];
^
drivers/firmware/efi/esrt.c: In function ‘esre_fw_class_show’:
drivers/firmware/efi/esrt.c:104:31: error: dereferencing pointer to
incomplete type
efi_guid_unparse(&entry->esre->fw_class, str);
^
In file included from include/linux/byteorder/little_endian.h:4:0,
from ./arch/x86/include/uapi/asm/byteorder.h:4,
from include/asm-generic/bitops/le.h:5,
from ./arch/x86/include/asm/bitops.h:504,
from include/linux/bitops.h:36,
from include/linux/kernel.h:10,
from include/linux/list.h:8,
from include/linux/kobject.h:20,
from include/linux/device.h:17,
from drivers/firmware/efi/esrt.c:16:
drivers/firmware/efi/esrt.c: In function ‘esre_fw_type_show’:
drivers/firmware/efi/esrt.c:117:61: error: dereferencing pointer to
incomplete type
return sprintf(buf, fmt "\n", le##size##_to_cpu(entry->esre->name)); \
^
include/uapi/linux/byteorder/little_endian.h:33:51: note: in definition
of macro ‘__le32_to_cpu’
#define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
^
drivers/firmware/efi/esrt.c:123:1: note: in expansion of macro
‘esre_attr_decl’
esre_attr_decl(fw_type, 32, "%u");
^
drivers/firmware/efi/esrt.c: In function ‘esre_fw_version_show’:
drivers/firmware/efi/esrt.c:117:61: error: dereferencing pointer to
incomplete type
return sprintf(buf, fmt "\n", le##size##_to_cpu(entry->esre->name)); \
^
include/uapi/linux/byteorder/little_endian.h:33:51: note: in definition
of macro ‘__le32_to_cpu’
#define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
^
drivers/firmware/efi/esrt.c:124:1: note: in expansion of macro
‘esre_attr_decl’
esre_attr_decl(fw_version, 32, "%u");
^
drivers/firmware/efi/esrt.c: In function
‘esre_lowest_supported_fw_version_show’:
drivers/firmware/efi/esrt.c:117:61: error: dereferencing pointer to
incomplete type
return sprintf(buf, fmt "\n", le##size##_to_cpu(entry->esre->name)); \
^
include/uapi/linux/byteorder/little_endian.h:33:51: note: in definition
of macro ‘__le32_to_cpu’
#define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
^
drivers/firmware/efi/esrt.c:125:1: note: in expansion of macro
‘esre_attr_decl’
esre_attr_decl(lowest_supported_fw_version, 32, "%u");
^
drivers/firmware/efi/esrt.c: In function ‘esre_capsule_flags_show’:
drivers/firmware/efi/esrt.c:117:61: error: dereferencing pointer to
incomplete type
return sprintf(buf, fmt "\n", le##size##_to_cpu(entry->esre->name)); \
^
include/uapi/linux/byteorder/little_endian.h:33:51: note: in definition
of macro ‘__le32_to_cpu’
#define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
^
drivers/firmware/efi/esrt.c:126:1: note: in expansion of macro
‘esre_attr_decl’
esre_attr_decl(capsule_flags, 32, "0x%x");
^
drivers/firmware/efi/esrt.c: In function
‘esre_last_attempt_version_show’:
drivers/firmware/efi/esrt.c:117:61: error: dereferencing pointer to
incomplete type
return sprintf(buf, fmt "\n", le##size##_to_cpu(entry->esre->name)); \
^
include/uapi/linux/byteorder/little_endian.h:33:51: note: in definition
of macro ‘__le32_to_cpu’
#define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
^
drivers/firmware/efi/esrt.c:127:1: note: in expansion of macro
‘esre_attr_decl’
esre_attr_decl(last_attempt_version, 32, "%u");
^
drivers/firmware/efi/esrt.c: In function
‘esre_last_attempt_status_show’:
drivers/firmware/efi/esrt.c:117:61: error: dereferencing pointer to
incomplete type
return sprintf(buf, fmt "\n", le##size##_to_cpu(entry->esre->name)); \
^
include/uapi/linux/byteorder/little_endian.h:33:51: note: in definition
of macro ‘__le32_to_cpu’
#define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
^
drivers/firmware/efi/esrt.c:128:1: note: in expansion of macro
‘esre_attr_decl’
esre_attr_decl(last_attempt_status, 32, "%u");
^
drivers/firmware/efi/esrt.c: In function ‘esre_create_sysfs_entry’:
drivers/firmware/efi/esrt.c:168:24: error: dereferencing pointer to
incomplete type
efi_guid_unparse(&esre->fw_class, name);
^
In file included from include/linux/byteorder/little_endian.h:4:0,
from ./arch/x86/include/uapi/asm/byteorder.h:4,
from include/asm-generic/bitops/le.h:5,
from ./arch/x86/include/asm/bitops.h:504,
from include/linux/bitops.h:36,
from include/linux/kernel.h:10,
from include/linux/list.h:8,
from include/linux/kobject.h:20,
from include/linux/device.h:17,
from drivers/firmware/efi/esrt.c:16:
drivers/firmware/efi/esrt.c: In function ‘esrt_fw_resource_count_show’:
drivers/firmware/efi/esrt.c:188:54: error: dereferencing pointer to
incomplete type
return sprintf(buf, fmt "\n", le##size##_to_cpu(esrt->name)); \
^
include/uapi/linux/byteorder/little_endian.h:33:51: note: in definition
of macro ‘__le32_to_cpu’
#define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
^
drivers/firmware/efi/esrt.c:194:1: note: in expansion of macro
‘esrt_attr_decl’
esrt_attr_decl(fw_resource_count, 32, "%u");
^
drivers/firmware/efi/esrt.c: In function
‘esrt_fw_resource_count_max_show’:
drivers/firmware/efi/esrt.c:188:54: error: dereferencing pointer to
incomplete type
return sprintf(buf, fmt "\n", le##size##_to_cpu(esrt->name)); \
^
include/uapi/linux/byteorder/little_endian.h:33:51: note: in definition
of macro ‘__le32_to_cpu’
#define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
^
drivers/firmware/efi/esrt.c:195:1: note: in expansion of macro
‘esrt_attr_decl’
esrt_attr_decl(fw_resource_count_max, 32, "%u");
^
drivers/firmware/efi/esrt.c: In function
‘esrt_fw_resource_version_show’:
drivers/firmware/efi/esrt.c:188:54: error: dereferencing pointer to
incomplete type
return sprintf(buf, fmt "\n", le##size##_to_cpu(esrt->name)); \
^
include/uapi/linux/byteorder/little_endian.h:31:51: note: in definition
of macro ‘__le64_to_cpu’
#define __le64_to_cpu(x) ((__force __u64)(__le64)(x))
^
drivers/firmware/efi/esrt.c:196:1: note: in expansion of macro
‘esrt_attr_decl’
esrt_attr_decl(fw_resource_version, 64, "%llu");
^
drivers/firmware/efi/esrt.c: In function ‘esrt_duplicate_pages’:
drivers/firmware/efi/esrt.c:245:16: error: dereferencing pointer to
incomplete type
size = sizeof(*esrt);
^
drivers/firmware/efi/esrt.c:258:13: error: dereferencing pointer to
incomplete type
if (tmpesrt->fw_resource_count > 0 && max - size < sizeof(*entries)) {
^
drivers/firmware/efi/esrt.c:258:60: error: dereferencing pointer to
incomplete type
if (tmpesrt->fw_resource_count > 0 && max - size < sizeof(*entries)) {
^
drivers/firmware/efi/esrt.c:270:13: error: dereferencing pointer to
incomplete type
if (tmpesrt->fw_resource_count > 128) {
^
In file included from include/linux/kernel.h:13:0,
from include/linux/list.h:8,
from include/linux/kobject.h:20,
from include/linux/device.h:17,
from drivers/firmware/efi/esrt.c:16:
drivers/firmware/efi/esrt.c:272:17: error: dereferencing pointer to
incomplete type
tmpesrt->fw_resource_count);
^
include/linux/printk.h:240:33: note: in definition of macro ‘pr_err’
printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
^
drivers/firmware/efi/esrt.c:280:17: error: dereferencing pointer to
incomplete type
size += tmpesrt->fw_resource_count * sizeof(*entries);
^
drivers/firmware/efi/esrt.c:280:46: error: dereferencing pointer to
incomplete type
size += tmpesrt->fw_resource_count * sizeof(*entries);
^
drivers/firmware/efi/esrt.c: In function ‘register_entries’:
drivers/firmware/efi/esrt.c:301:50: error: dereferencing pointer to
incomplete type
struct efi_system_resource_entry *entries = esrt->entries;
^
In file included from include/linux/byteorder/little_endian.h:4:0,
from ./arch/x86/include/uapi/asm/byteorder.h:4,
from include/asm-generic/bitops/le.h:5,
from ./arch/x86/include/asm/bitops.h:504,
from include/linux/bitops.h:36,
from include/linux/kernel.h:10,
from include/linux/list.h:8,
from include/linux/kobject.h:20,
from include/linux/device.h:17,
from drivers/firmware/efi/esrt.c:16:
drivers/firmware/efi/esrt.c:307:34: error: dereferencing pointer to
incomplete type
for (i = 0; i < le32_to_cpu(esrt->fw_resource_count); i++) {
^
include/uapi/linux/byteorder/little_endian.h:33:51: note: in definition
of macro ‘__le32_to_cpu’
#define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
^
drivers/firmware/efi/esrt.c:307:18: note: in expansion of macro
‘le32_to_cpu’
for (i = 0; i < le32_to_cpu(esrt->fw_resource_count); i++) {
^
drivers/firmware/efi/esrt.c:308:3: error: invalid use of undefined type
‘struct efi_system_resource_entry’
rc = esre_create_sysfs_entry(&entries[i]);
^
drivers/firmware/efi/esrt.c:308:40: error: dereferencing pointer to
incomplete type
rc = esre_create_sysfs_entry(&entries[i]);
^
drivers/firmware/efi/esrt.c: In function
‘esrt_fw_resource_version_show’:
drivers/firmware/efi/esrt.c:186:14: warning: control reaches end of
non-void function [-Wreturn-type]
struct kobj_attribute *attr, char *buf)\
^
drivers/firmware/efi/esrt.c:196:1: note: in expansion of macro
‘esrt_attr_decl’
esrt_attr_decl(fw_resource_version, 64, "%llu");
^
drivers/firmware/efi/esrt.c: In function
‘esrt_fw_resource_count_max_show’:
drivers/firmware/efi/esrt.c:186:14: warning: control reaches end of
non-void function [-Wreturn-type]
struct kobj_attribute *attr, char *buf)\
^
drivers/firmware/efi/esrt.c:195:1: note: in expansion of macro
‘esrt_attr_decl’
esrt_attr_decl(fw_resource_count_max, 32, "%u");
^
drivers/firmware/efi/esrt.c: In function ‘esrt_fw_resource_count_show’:
drivers/firmware/efi/esrt.c:186:14: warning: control reaches end of
non-void function [-Wreturn-type]
struct kobj_attribute *attr, char *buf)\
^
drivers/firmware/efi/esrt.c:194:1: note: in expansion of macro
‘esrt_attr_decl’
esrt_attr_decl(fw_resource_count, 32, "%u");
^
>
> Signed-off-by: Peter Jones <pjones@xxxxxxxxxx>
> ---
> drivers/firmware/efi/Makefile | 2 +-
> drivers/firmware/efi/efi.c | 46 ++++-
> drivers/firmware/efi/esrt.c | 393 ++++++++++++++++++++++++++++++++++++++++++
> include/linux/efi.h | 6 +
> 4 files changed, 445 insertions(+), 2 deletions(-)
> create mode 100644 drivers/firmware/efi/esrt.c
>
> diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile
> index aef6a95..0d61089 100644
> --- a/drivers/firmware/efi/Makefile
> +++ b/drivers/firmware/efi/Makefile
> @@ -1,7 +1,7 @@
> #
> # Makefile for linux kernel
> #
> -obj-$(CONFIG_EFI) += efi.o vars.o reboot.o
> +obj-$(CONFIG_EFI) += efi.o esrt.o vars.o reboot.o
> obj-$(CONFIG_EFI_VARS) += efivars.o
> obj-$(CONFIG_EFI_VARS_PSTORE) += efi-pstore.o
> obj-$(CONFIG_UEFI_CPER) += cper.o
> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> index 8590099..68002d8 100644
> --- a/drivers/firmware/efi/efi.c
> +++ b/drivers/firmware/efi/efi.c
> @@ -38,6 +38,7 @@ struct efi __read_mostly efi = {
> .fw_vendor = EFI_INVALID_TABLE_ADDR,
> .runtime = EFI_INVALID_TABLE_ADDR,
> .config_table = EFI_INVALID_TABLE_ADDR,
> + .esrt = EFI_INVALID_TABLE_ADDR,
> };
> EXPORT_SYMBOL(efi);
>
> @@ -63,7 +64,7 @@ static int __init parse_efi_cmdline(char *str)
> }
> early_param("efi", parse_efi_cmdline);
>
> -static struct kobject *efi_kobj;
> +struct kobject *efi_kobj;
> static struct kobject *efivars_kobj;
>
> /*
> @@ -92,6 +93,8 @@ static ssize_t systab_show(struct kobject *kobj,
> str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
> if (efi.uga != EFI_INVALID_TABLE_ADDR)
> str += sprintf(str, "UGA=0x%lx\n", efi.uga);
> + if (efi.esrt != EFI_INVALID_TABLE_ADDR)
> + str += sprintf(str, "ESRT=0x%lx\n", efi.esrt);
>
> return str - buf;
> }
> @@ -220,6 +223,46 @@ err_put:
>
> subsys_initcall(efisubsys_init);
>
> +/*
> + * Given a physicall address, determine if it exists within an EFI Memory Map
> + * entry, and if so, how much of that map exists at a higher address. That
> + * is, if this is the address of something in an EFI map, what's the highest
> + * address at which it's likely to end.
> + */
> +u64 efi_mem_max_reasonable_size(u64 phys_addr)
> +{
> + struct efi_memory_map *map = efi.memmap;
> + void *p, *e;
> +
> + if (!map)
> + return -1;
> + if (WARN_ON(!map->phys_map))
> + return -1;
> + if (WARN_ON(map->nr_map == 0) || WARN_ON(map->desc_size == 0))
> + return -1;
> +
> + e = map->phys_map + map->nr_map * map->desc_size;
> + for (p = map->phys_map; p < e; p += map->desc_size) {
> + /*
> + * If a driver calls this after efi_free_boot_services,
> + * ->map will be NULL.
> + * So just always get our own virtual map on the CPU.
> + */
> + efi_memory_desc_t *md = phys_to_virt((phys_addr_t)p);
> + u64 size = md->num_pages << EFI_PAGE_SHIFT;
> + u64 end = md->phys_addr + size;
> +
> + if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
> + md->type != EFI_BOOT_SERVICES_CODE &&
> + md->type != EFI_BOOT_SERVICES_DATA)
> + continue;
> + if (!md->virt_addr)
> + continue;
> + if (phys_addr >= md->phys_addr && phys_addr < end)
> + return end - phys_addr;
> + }
> + return -1;
> +}
>
> /*
> * We can't ioremap data in EFI boot services RAM, because we've already mapped
> @@ -261,6 +304,7 @@ static __initdata efi_config_table_type_t common_tables[] = {
> {SAL_SYSTEM_TABLE_GUID, "SALsystab", &efi.sal_systab},
> {SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios},
> {UGA_IO_PROTOCOL_GUID, "UGA", &efi.uga},
> + {EFI_SYSTEM_RESOURCE_TABLE_GUID, "ESRT", &efi.esrt},
> {NULL_GUID, NULL, NULL},
> };
>
> diff --git a/drivers/firmware/efi/esrt.c b/drivers/firmware/efi/esrt.c
> new file mode 100644
> index 0000000..71eb77c
> --- /dev/null
> +++ b/drivers/firmware/efi/esrt.c
> @@ -0,0 +1,393 @@
> +/*
> + * esrt.c
> + *
> + * This module exports EFI System Resource Table (ESRT) entries into userspace
> + * through the sysfs file system. The ESRT provides a read-only catalog of
> + * system components for which the system accepts firmware upgrades via UEFI's
> + * "Capsule Update" feature. This module allows userland utilities to evaluate
> + * what firmware updates can be applied to this system, and potentially arrange
> + * for those updates to occur.
> + *
> + * Data is currently found below /sys/firmware/efi/esrt/...
> + */
> +#define pr_fmt(fmt) "esrt: " fmt
> +
> +#include <linux/capability.h>
> +#include <linux/device.h>
> +#include <linux/efi.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/kobject.h>
> +#include <linux/list.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/types.h>
> +
> +struct {
> + efi_guid_t fw_class;
> + u32 fw_type;
> + u32 fw_version;
> + u32 lowest_supported_fw_version;
> + u32 capsule_flags;
> + u32 last_attempt_version;
> + u32 last_attempt_status;
> +} efi_system_resource_entry;
> +
> +/*
> + * _count and _version are what they seem like. _max is actually just
> + * accounting info for the firmware when creating the table; it should never
> + * have been exposed to us. To wit, the spec says:
> + * The maximum number of resource array entries that can be within the
> + * table without reallocating the table, must not be zero.
> + * Since there's no guidance about what that means in terms of memory layout,
> + * it means nothing to us.
> + */
> +struct {
> + u32 fw_resource_count;
> + u32 fw_resource_count_max;
> + u64 fw_resource_version;
> + struct efi_system_resource_entry entries[];
> +} efi_system_resource_table;
> +
> +static struct efi_system_resource_table *esrt;
> +
> +struct esre_entry {
> + struct efi_system_resource_entry *esre;
> +
> + struct kobject kobj;
> + struct list_head list;
> +};
> +
> +/* global list of esre_entry. */
> +static LIST_HEAD(entry_list);
> +
> +/* entry attribute */
> +struct esre_attribute {
> + struct attribute attr;
> + ssize_t (*show)(struct esre_entry *entry, char *buf);
> + ssize_t (*store)(struct esre_entry *entry,
> + const char *buf, size_t count);
> +};
> +
> +static struct esre_entry *to_entry(struct kobject *kobj)
> +{
> + return container_of(kobj, struct esre_entry, kobj);
> +}
> +
> +static struct esre_attribute *to_attr(struct attribute *attr)
> +{
> + return container_of(attr, struct esre_attribute, attr);
> +}
> +
> +static ssize_t esre_attr_show(struct kobject *kobj,
> + struct attribute *_attr, char *buf)
> +{
> + struct esre_entry *entry = to_entry(kobj);
> + struct esre_attribute *attr = to_attr(_attr);
> +
> + /* Don't tell normal users what firmware versions we've got... */
> + if (!capable(CAP_SYS_ADMIN))
> + return -EACCES;
> +
> + return attr->show(entry, buf);
> +}
> +
> +static const struct sysfs_ops esre_attr_ops = {
> + .show = esre_attr_show,
> +};
> +
> +/* Generic ESRT Entry ("ESRE") support. */
> +static ssize_t esre_fw_class_show(struct esre_entry *entry, char *buf)
> +{
> + char *str = buf;
> +
> + efi_guid_unparse(&entry->esre->fw_class, str);
> + str += strlen(str);
> + str += sprintf(str, "\n");
> +
> + return str - buf;
> +}
> +
> +static struct esre_attribute esre_fw_class = __ATTR(fw_class, 0400,
> + esre_fw_class_show, NULL);
> +
> +#define esre_attr_decl(name, size, fmt) \
> +static ssize_t esre_##name##_show(struct esre_entry *entry, char *buf)\
> +{ \
> + return sprintf(buf, fmt "\n", le##size##_to_cpu(entry->esre->name)); \
> +} \
> +\
> +static struct esre_attribute esre_##name = __ATTR(name, 0400, \
> + esre_##name##_show, NULL)
> +
> +esre_attr_decl(fw_type, 32, "%u");
> +esre_attr_decl(fw_version, 32, "%u");
> +esre_attr_decl(lowest_supported_fw_version, 32, "%u");
> +esre_attr_decl(capsule_flags, 32, "0x%x");
> +esre_attr_decl(last_attempt_version, 32, "%u");
> +esre_attr_decl(last_attempt_status, 32, "%u");
> +
> +static struct attribute *esre_attrs[] = {
> + &esre_fw_class.attr,
> + &esre_fw_type.attr,
> + &esre_fw_version.attr,
> + &esre_lowest_supported_fw_version.attr,
> + &esre_capsule_flags.attr,
> + &esre_last_attempt_version.attr,
> + &esre_last_attempt_status.attr,
> + NULL
> +};
> +
> +static void esre_release(struct kobject *kobj)
> +{
> + struct esre_entry *entry = to_entry(kobj);
> +
> + list_del(&entry->list);
> + kfree(entry);
> +}
> +
> +static struct kobj_type esre_ktype = {
> + .release = esre_release,
> + .sysfs_ops = &esre_attr_ops,
> + .default_attrs = esre_attrs,
> +};
> +
> +static struct kobject *esrt_kobj;
> +static struct kset *esrt_kset;
> +
> +static int esre_create_sysfs_entry(struct efi_system_resource_entry *esre)
> +{
> + int rc;
> + struct esre_entry *entry;
> + char name[EFI_VARIABLE_GUID_LEN + 1];
> +
> + entry = kzalloc(sizeof(*entry), GFP_KERNEL);
> + if (!entry)
> + return -ENOMEM;
> +
> + efi_guid_unparse(&esre->fw_class, name);
> +
> + entry->esre = esre;
> + entry->kobj.kset = esrt_kset;
> + rc = kobject_init_and_add(&entry->kobj, &esre_ktype, NULL,
> + "%s", name);
> + if (rc) {
> + kfree(entry);
> + return rc;
> + }
> +
> + list_add_tail(&entry->list, &entry_list);
> + return 0;
> +}
> +
> +/* support for displaying ESRT fields at the top level */
> +#define esrt_attr_decl(name, size, fmt) \
> +static ssize_t esrt_##name##_show(struct kobject *kobj, \
> + struct kobj_attribute *attr, char *buf)\
> +{ \
> + return sprintf(buf, fmt "\n", le##size##_to_cpu(esrt->name)); \
> +} \
> +\
> +static struct kobj_attribute esrt_##name = __ATTR(name, 0400, \
> + esrt_##name##_show, NULL)
> +
> +esrt_attr_decl(fw_resource_count, 32, "%u");
> +esrt_attr_decl(fw_resource_count_max, 32, "%u");
> +esrt_attr_decl(fw_resource_version, 64, "%llu");
> +
> +static struct attribute *esrt_attrs[] = {
> + &esrt_fw_resource_count.attr,
> + &esrt_fw_resource_count_max.attr,
> + &esrt_fw_resource_version.attr,
> + NULL,
> +};
> +
> +static inline int esrt_table_exists(void)
> +{
> + if (!efi_enabled(EFI_CONFIG_TABLES))
> + return 0;
> + if (efi.esrt == EFI_INVALID_TABLE_ADDR)
> + return 0;
> + return 1;
> +}
> +
> +static umode_t esrt_attr_is_visible(struct kobject *kobj,
> + struct attribute *attr, int n)
> +{
> + if (!esrt_table_exists())
> + return 0;
> + return attr->mode;
> +}
> +
> +static struct attribute_group esrt_attr_group = {
> + .attrs = esrt_attrs,
> + .is_visible = esrt_attr_is_visible,
> +};
> +
> +/*
> + * ioremap the table, copy it to kmalloced pages, and unmap it.
> + */
> +static int esrt_duplicate_pages(void)
> +{
> + struct efi_system_resource_table *tmpesrt;
> + struct efi_system_resource_entry *entries;
> + size_t size, max;
> + int err = -EINVAL;
> +
> + if (!esrt_table_exists())
> + return err;
> +
> + max = efi_mem_max_reasonable_size(efi.esrt);
> + if (max < 0) {
> + pr_err("ESRT header is not in the memory map.\n");
> + return err;
> + }
> + size = sizeof(*esrt);
> +
> + if (max < size) {
> + pr_err("ESRT header doen't fit on single memory map entry.\n");
> + return err;
> + }
> +
> + tmpesrt = ioremap(efi.esrt, size);
> + if (!tmpesrt) {
> + pr_err("ioremap failed.\n");
> + return -ENOMEM;
> + }
> +
> + if (tmpesrt->fw_resource_count > 0 && max - size < sizeof(*entries)) {
> + pr_err("ESRT memory map entry can only hold the header.\n");
> + goto err_iounmap;
> + }
> +
> + /*
> + * The format doesn't really give us any boundary to test here,
> + * so I'm making up 128 as the max number of individually updatable
> + * components we support.
> + * 128 should be pretty excessive, but there's still some chance
> + * somebody will do that someday and we'll need to raise this.
> + */
> + if (tmpesrt->fw_resource_count > 128) {
> + pr_err("ESRT says fw_resource_count has very large value %d.\n",
> + tmpesrt->fw_resource_count);
> + goto err_iounmap;
> + }
> +
> + /*
> + * We know it can't be larger than N * sizeof() here, and N is limited
> + * by the previous test to a small number, so there's no overflow.
> + */
> + size += tmpesrt->fw_resource_count * sizeof(*entries);
> + if (max < size) {
> + pr_err("ESRT does not fit on single memory map entry.\n");
> + goto err_iounmap;
> + }
> +
> + esrt = kmalloc(size, GFP_KERNEL);
> + if (!esrt) {
> + err = -ENOMEM;
> + goto err_iounmap;
> + }
> +
> + memcpy(esrt, tmpesrt, size);
> + err = 0;
> +err_iounmap:
> + iounmap(tmpesrt);
> + return err;
> +}
> +
> +static int register_entries(void)
> +{
> + struct efi_system_resource_entry *entries = esrt->entries;
> + int i, rc;
> +
> + if (!esrt_table_exists())
> + return 0;
> +
> + for (i = 0; i < le32_to_cpu(esrt->fw_resource_count); i++) {
> + rc = esre_create_sysfs_entry(&entries[i]);
> + if (rc < 0) {
> + pr_err("ESRT entry creation failed with error %d.\n",
> + rc);
> + return rc;
> + }
> + }
> + return 0;
> +}
> +
> +static void cleanup_entry_list(void)
> +{
> + struct esre_entry *entry, *next;
> +
> + list_for_each_entry_safe(entry, next, &entry_list, list) {
> + kobject_put(&entry->kobj);
> + }
> +}
> +
> +static int __init esrt_sysfs_init(void)
> +{
> + int error;
> +
> + error = esrt_duplicate_pages();
> + if (error)
> + return error;
> +
> + esrt_kobj = kobject_create_and_add("esrt", efi_kobj);
> + if (!esrt_kobj) {
> + pr_err("Firmware table registration failed.\n");
> + error = -ENOMEM;
> + goto err;
> + }
> +
> + error = sysfs_create_group(esrt_kobj, &esrt_attr_group);
> + if (error) {
> + pr_err("Sysfs attribute export failed with error %d.\n",
> + error);
> + goto err_remove_esrt;
> + }
> +
> + esrt_kset = kset_create_and_add("entries", NULL, esrt_kobj);
> + if (!esrt_kset) {
> + pr_err("kset creation failed.\n");
> + error = -ENOMEM;
> + goto err_remove_group;
> + }
> +
> + error = register_entries();
> + if (error)
> + goto err_cleanup_list;
> +
> + pr_debug("esrt-sysfs: loaded.\n");
> +
> + return 0;
> +err_cleanup_list:
> + cleanup_entry_list();
> + kset_unregister(esrt_kset);
> +err_remove_group:
> + sysfs_remove_group(esrt_kobj, &esrt_attr_group);
> +err_remove_esrt:
> + kobject_put(esrt_kobj);
> +err:
> + kfree(esrt);
> + esrt = NULL;
> + return error;
> +}
> +
> +static void __exit esrt_sysfs_exit(void)
> +{
> + pr_debug("esrt-sysfs: unloading.\n");
> + cleanup_entry_list();
> + kset_unregister(esrt_kset);
> + sysfs_remove_group(esrt_kobj, &esrt_attr_group);
> + kfree(esrt);
> + esrt = NULL;
> + kobject_del(esrt_kobj);
> + kobject_put(esrt_kobj);
> +}
> +
> +module_init(esrt_sysfs_init);
> +module_exit(esrt_sysfs_exit);
> +
> +MODULE_AUTHOR("Peter Jones <pjones@xxxxxxxxxx>");
> +MODULE_DESCRIPTION("EFI System Resource Table support");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/efi.h b/include/linux/efi.h
> index 0949f9c..5b663a7 100644
> --- a/include/linux/efi.h
> +++ b/include/linux/efi.h
> @@ -562,6 +562,9 @@ void efi_native_runtime_setup(void);
> #define UV_SYSTEM_TABLE_GUID \
> EFI_GUID( 0x3b13a7d4, 0x633e, 0x11dd, 0x93, 0xec, 0xda, 0x25, 0x56, 0xd8, 0x95, 0x93 )
>
> +#define EFI_SYSTEM_RESOURCE_TABLE_GUID \
> + EFI_GUID( 0xb122a263, 0x3661, 0x4f68, 0x99, 0x29, 0x78, 0xf8, 0xb0, 0xd6, 0x21, 0x80 )
> +
> #define LINUX_EFI_CRASH_GUID \
> EFI_GUID( 0xcfc8fc79, 0xbe2e, 0x4ddc, 0x97, 0xf0, 0x9f, 0x98, 0xbf, 0xe2, 0x98, 0xa0 )
>
> @@ -819,6 +822,7 @@ extern struct efi {
> unsigned long fw_vendor; /* fw_vendor */
> unsigned long runtime; /* runtime table */
> unsigned long config_table; /* config tables */
> + unsigned long esrt; /* EFI System Resource Table */
> efi_get_time_t *get_time;
> efi_set_time_t *set_time;
> efi_get_wakeup_time_t *get_wakeup_time;
> @@ -875,6 +879,7 @@ extern u64 efi_get_iobase (void);
> extern u32 efi_mem_type (unsigned long phys_addr);
> extern u64 efi_mem_attributes (unsigned long phys_addr);
> extern u64 efi_mem_attribute (unsigned long phys_addr, unsigned long size);
> +extern u64 efi_mem_max_reasonable_size(u64 phys_addr);
> extern int __init efi_uart_console_only (void);
> extern void efi_initialize_iomem_resources(struct resource *code_resource,
> struct resource *data_resource, struct resource *bss_resource);
> @@ -882,6 +887,7 @@ extern void efi_get_time(struct timespec *now);
> extern void efi_reserve_boot_services(void);
> extern int efi_get_fdt_params(struct efi_fdt_params *params, int verbose);
> extern struct efi_memory_map memmap;
> +extern struct kobject *efi_kobj;
>
> extern int efi_reboot_quirk_mode;
> extern bool efi_poweroff_required(void);
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