v4.19.13 snapshot.
diff --git a/drivers/firmware/efi/esrt.c b/drivers/firmware/efi/esrt.c
new file mode 100644
index 0000000..5d06bd2
--- /dev/null
+++ b/drivers/firmware/efi/esrt.c
@@ -0,0 +1,436 @@
+/*
+ * 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/io.h>
+#include <linux/kernel.h>
+#include <linux/kobject.h>
+#include <linux/list.h>
+#include <linux/memblock.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include <asm/io.h>
+#include <asm/early_ioremap.h>
+
+struct efi_system_resource_entry_v1 {
+ 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;
+};
+
+/*
+ * _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 efi_system_resource_table {
+ u32 fw_resource_count;
+ u32 fw_resource_count_max;
+ u64 fw_resource_version;
+ u8 entries[];
+};
+
+static phys_addr_t esrt_data;
+static size_t esrt_data_size;
+
+static struct efi_system_resource_table *esrt;
+
+struct esre_entry {
+ union {
+ struct efi_system_resource_entry_v1 *esre1;
+ } 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 fw_class_show(struct esre_entry *entry, char *buf)
+{
+ char *str = buf;
+
+ efi_guid_to_str(&entry->esre.esre1->fw_class, str);
+ str += strlen(str);
+ str += sprintf(str, "\n");
+
+ return str - buf;
+}
+
+static struct esre_attribute esre_fw_class = __ATTR_RO_MODE(fw_class, 0400);
+
+#define esre_attr_decl(name, size, fmt) \
+static ssize_t name##_show(struct esre_entry *entry, char *buf) \
+{ \
+ return sprintf(buf, fmt "\n", \
+ le##size##_to_cpu(entry->esre.esre1->name)); \
+} \
+\
+static struct esre_attribute esre_##name = __ATTR_RO_MODE(name, 0400)
+
+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 *esre1_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 esre1_ktype = {
+ .release = esre_release,
+ .sysfs_ops = &esre_attr_ops,
+ .default_attrs = esre1_attrs,
+};
+
+
+static struct kobject *esrt_kobj;
+static struct kset *esrt_kset;
+
+static int esre_create_sysfs_entry(void *esre, int entry_num)
+{
+ struct esre_entry *entry;
+
+ entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+ if (!entry)
+ return -ENOMEM;
+
+ entry->kobj.kset = esrt_kset;
+
+ if (esrt->fw_resource_version == 1) {
+ int rc = 0;
+
+ entry->esre.esre1 = esre;
+ rc = kobject_init_and_add(&entry->kobj, &esre1_ktype, NULL,
+ "entry%d", entry_num);
+ 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 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_RO_MODE(name, 0400)
+
+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 const struct attribute_group esrt_attr_group = {
+ .attrs = esrt_attrs,
+ .is_visible = esrt_attr_is_visible,
+};
+
+/*
+ * remap the table, validate it, mark it reserved and unmap it.
+ */
+void __init efi_esrt_init(void)
+{
+ void *va;
+ struct efi_system_resource_table tmpesrt;
+ struct efi_system_resource_entry_v1 *v1_entries;
+ size_t size, max, entry_size, entries_size;
+ efi_memory_desc_t md;
+ int rc;
+ phys_addr_t end;
+
+ pr_debug("esrt-init: loading.\n");
+ if (!esrt_table_exists())
+ return;
+
+ rc = efi_mem_desc_lookup(efi.esrt, &md);
+ if (rc < 0 ||
+ (!(md.attribute & EFI_MEMORY_RUNTIME) &&
+ md.type != EFI_BOOT_SERVICES_DATA &&
+ md.type != EFI_RUNTIME_SERVICES_DATA)) {
+ pr_warn("ESRT header is not in the memory map.\n");
+ return;
+ }
+
+ max = efi_mem_desc_end(&md);
+ if (max < efi.esrt) {
+ pr_err("EFI memory descriptor is invalid. (esrt: %p max: %p)\n",
+ (void *)efi.esrt, (void *)max);
+ return;
+ }
+
+ size = sizeof(*esrt);
+ max -= efi.esrt;
+
+ if (max < size) {
+ pr_err("ESRT header doesn't fit on single memory map entry. (size: %zu max: %zu)\n",
+ size, max);
+ return;
+ }
+
+ va = early_memremap(efi.esrt, size);
+ if (!va) {
+ pr_err("early_memremap(%p, %zu) failed.\n", (void *)efi.esrt,
+ size);
+ return;
+ }
+
+ memcpy(&tmpesrt, va, sizeof(tmpesrt));
+ early_memunmap(va, size);
+
+ if (tmpesrt.fw_resource_version == 1) {
+ entry_size = sizeof (*v1_entries);
+ } else {
+ pr_err("Unsupported ESRT version %lld.\n",
+ tmpesrt.fw_resource_version);
+ return;
+ }
+
+ if (tmpesrt.fw_resource_count > 0 && max - size < entry_size) {
+ pr_err("ESRT memory map entry can only hold the header. (max: %zu size: %zu)\n",
+ max - size, entry_size);
+ return;
+ }
+
+ /*
+ * 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);
+ return;
+ }
+
+ /*
+ * 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.
+ */
+ entries_size = tmpesrt.fw_resource_count * entry_size;
+ if (max < size + entries_size) {
+ pr_err("ESRT does not fit on single memory map entry (size: %zu max: %zu)\n",
+ size, max);
+ return;
+ }
+
+ size += entries_size;
+
+ esrt_data = (phys_addr_t)efi.esrt;
+ esrt_data_size = size;
+
+ end = esrt_data + size;
+ pr_info("Reserving ESRT space from %pa to %pa.\n", &esrt_data, &end);
+ if (md.type == EFI_BOOT_SERVICES_DATA)
+ efi_mem_reserve(esrt_data, esrt_data_size);
+
+ pr_debug("esrt-init: loaded.\n");
+}
+
+static int __init register_entries(void)
+{
+ struct efi_system_resource_entry_v1 *v1_entries = (void *)esrt->entries;
+ int i, rc;
+
+ if (!esrt_table_exists())
+ return 0;
+
+ for (i = 0; i < le32_to_cpu(esrt->fw_resource_count); i++) {
+ void *esre = NULL;
+ if (esrt->fw_resource_version == 1) {
+ esre = &v1_entries[i];
+ } else {
+ pr_err("Unsupported ESRT version %lld.\n",
+ esrt->fw_resource_version);
+ return -EINVAL;
+ }
+
+ rc = esre_create_sysfs_entry(esre, 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;
+
+ pr_debug("esrt-sysfs: loading.\n");
+ if (!esrt_data || !esrt_data_size)
+ return -ENOSYS;
+
+ esrt = memremap(esrt_data, esrt_data_size, MEMREMAP_WB);
+ if (!esrt) {
+ pr_err("memremap(%pa, %zu) failed.\n", &esrt_data,
+ esrt_data_size);
+ return -ENOMEM;
+ }
+
+ 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:
+ memunmap(esrt);
+ esrt = NULL;
+ return error;
+}
+device_initcall(esrt_sysfs_init);
+
+/*
+MODULE_AUTHOR("Peter Jones <pjones@redhat.com>");
+MODULE_DESCRIPTION("EFI System Resource Table support");
+MODULE_LICENSE("GPL");
+*/