Re: [RFC PATCH] Add esrt support.

[Peter Jones <pjones-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

On Wed, Dec 10, 2014 at 04:12:33PM +0530, Parmeshwr_Prasad-8PEkshWhKlo@public.gmane.org wrote:
> Peter I have checked you patch with linux-3.18-rc2 got few compilation error.
> 
> drivers/firmware/efi/esrt.c:196:83: error: stray '##' in program
>  static struct kobj_attribute esrt_attr_##name = __ATTR(name, 0400,esrt_attr_##name##_show, NULL);

What gcc version are you using?  This builds without this problem with
gcc-4.9.2-1.fc21.x86_64 .  But I don't offhand see any reason it
/shouldn't/ work, and we use this construct elsewhere in the kernel.

Is this the first error you get?  I.e. you don't get the same error from
the esre_ versions of that same thing around line 123?

>                                                                                    ^
> include/linux/sysfs.h:76:10: note: in definition of macro '__ATTR'
>   .show = _show,      \
>           ^
> drivers/firmware/efi/esrt.c:203:3: error: 'esrt_attr_fw_resource_count' undeclared here (not in a function)
>   &esrt_attr_fw_resource_count.attr,
>    ^
> drivers/firmware/efi/esrt.c:204:3: error: 'esrt_attr_fw_resource_count_max' undeclared here (not in a function)
>   &esrt_attr_fw_resource_count_max.attr,
>    ^
> drivers/firmware/efi/esrt.c:205:3: error: 'esrt_attr_fw_resource_version' undeclared here (not in a function)
>   &esrt_attr_fw_resource_version.attr,

These are pretty clearly the result of the first thing going wrong.

> 
> Is these are really error or I am making mistake.
> 
> I will be happy to test you patch.
> 
> -Param
> 
> -----Original Message-----
> From: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org [mailto:linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org] On Behalf Of Peter Jones
> Sent: Wednesday, December 10, 2014 3:58 AM
> To: linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> Cc: Peter Jones
> Subject: [RFC PATCH] Add esrt support.
> 
> 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.
> 
> Signed-off-by: Peter Jones <pjones-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> ---
>  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-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>");
> +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);
> --
> 2.1.0
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at  http://vger.kernel.org/majordomo-info.html

-- 
        Peter