1 files changed, 424 insertions, 0 deletions

diff --git a/kernel/drivers/firmware/memmap.c b/kernel/drivers/firmware/memmap.c
new file mode 100644
index 000000000..cc016c615
--- /dev/null
+++ b/kernel/drivers/firmware/memmap.c
@@ -0,0 +1,424 @@
+/*
+ * linux/drivers/firmware/memmap.c
+ *  Copyright (C) 2008 SUSE LINUX Products GmbH
+ *  by Bernhard Walle <bernhard.walle@gmx.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License v2.0 as published by
+ * the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/string.h>
+#include <linux/firmware-map.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/bootmem.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+
+/*
+ * Data types ------------------------------------------------------------------
+ */
+
+/*
+ * Firmware map entry. Because firmware memory maps are flat and not
+ * hierarchical, it's ok to organise them in a linked list. No parent
+ * information is necessary as for the resource tree.
+ */
+struct firmware_map_entry {
+	/*
+	 * start and end must be u64 rather than resource_size_t, because e820
+	 * resources can lie at addresses above 4G.
+	 */
+	u64			start;	/* start of the memory range */
+	u64			end;	/* end of the memory range (incl.) */
+	const char		*type;	/* type of the memory range */
+	struct list_head	list;	/* entry for the linked list */
+	struct kobject		kobj;   /* kobject for each entry */
+};
+
+/*
+ * Forward declarations --------------------------------------------------------
+ */
+static ssize_t memmap_attr_show(struct kobject *kobj,
+				struct attribute *attr, char *buf);
+static ssize_t start_show(struct firmware_map_entry *entry, char *buf);
+static ssize_t end_show(struct firmware_map_entry *entry, char *buf);
+static ssize_t type_show(struct firmware_map_entry *entry, char *buf);
+
+static struct firmware_map_entry * __meminit
+firmware_map_find_entry(u64 start, u64 end, const char *type);
+
+/*
+ * Static data -----------------------------------------------------------------
+ */
+
+struct memmap_attribute {
+	struct attribute attr;
+	ssize_t (*show)(struct firmware_map_entry *entry, char *buf);
+};
+
+static struct memmap_attribute memmap_start_attr = __ATTR_RO(start);
+static struct memmap_attribute memmap_end_attr   = __ATTR_RO(end);
+static struct memmap_attribute memmap_type_attr  = __ATTR_RO(type);
+
+/*
+ * These are default attributes that are added for every memmap entry.
+ */
+static struct attribute *def_attrs[] = {
+	&memmap_start_attr.attr,
+	&memmap_end_attr.attr,
+	&memmap_type_attr.attr,
+	NULL
+};
+
+static const struct sysfs_ops memmap_attr_ops = {
+	.show = memmap_attr_show,
+};
+
+/* Firmware memory map entries. */
+static LIST_HEAD(map_entries);
+static DEFINE_SPINLOCK(map_entries_lock);
+
+/*
+ * For memory hotplug, there is no way to free memory map entries allocated
+ * by boot mem after the system is up. So when we hot-remove memory whose
+ * map entry is allocated by bootmem, we need to remember the storage and
+ * reuse it when the memory is hot-added again.
+ */
+static LIST_HEAD(map_entries_bootmem);
+static DEFINE_SPINLOCK(map_entries_bootmem_lock);
+
+
+static inline struct firmware_map_entry *
+to_memmap_entry(struct kobject *kobj)
+{
+	return container_of(kobj, struct firmware_map_entry, kobj);
+}
+
+static void __meminit release_firmware_map_entry(struct kobject *kobj)
+{
+	struct firmware_map_entry *entry = to_memmap_entry(kobj);
+
+	if (PageReserved(virt_to_page(entry))) {
+		/*
+		 * Remember the storage allocated by bootmem, and reuse it when
+		 * the memory is hot-added again. The entry will be added to
+		 * map_entries_bootmem here, and deleted from &map_entries in
+		 * firmware_map_remove_entry().
+		 */
+		spin_lock(&map_entries_bootmem_lock);
+		list_add(&entry->list, &map_entries_bootmem);
+		spin_unlock(&map_entries_bootmem_lock);
+
+		return;
+	}
+
+	kfree(entry);
+}
+
+static struct kobj_type __refdata memmap_ktype = {
+	.release	= release_firmware_map_entry,
+	.sysfs_ops	= &memmap_attr_ops,
+	.default_attrs	= def_attrs,
+};
+
+/*
+ * Registration functions ------------------------------------------------------
+ */
+
+/**
+ * firmware_map_add_entry() - Does the real work to add a firmware memmap entry.
+ * @start: Start of the memory range.
+ * @end:   End of the memory range (exclusive).
+ * @type:  Type of the memory range.
+ * @entry: Pre-allocated (either kmalloc() or bootmem allocator), uninitialised
+ *         entry.
+ *
+ * Common implementation of firmware_map_add() and firmware_map_add_early()
+ * which expects a pre-allocated struct firmware_map_entry.
+ **/
+static int firmware_map_add_entry(u64 start, u64 end,
+				  const char *type,
+				  struct firmware_map_entry *entry)
+{
+	BUG_ON(start > end);
+
+	entry->start = start;
+	entry->end = end - 1;
+	entry->type = type;
+	INIT_LIST_HEAD(&entry->list);
+	kobject_init(&entry->kobj, &memmap_ktype);
+
+	spin_lock(&map_entries_lock);
+	list_add_tail(&entry->list, &map_entries);
+	spin_unlock(&map_entries_lock);
+
+	return 0;
+}
+
+/**
+ * firmware_map_remove_entry() - Does the real work to remove a firmware
+ * memmap entry.
+ * @entry: removed entry.
+ *
+ * The caller must hold map_entries_lock, and release it properly.
+ **/
+static inline void firmware_map_remove_entry(struct firmware_map_entry *entry)
+{
+	list_del(&entry->list);
+}
+
+/*
+ * Add memmap entry on sysfs
+ */
+static int add_sysfs_fw_map_entry(struct firmware_map_entry *entry)
+{
+	static int map_entries_nr;
+	static struct kset *mmap_kset;
+
+	if (entry->kobj.state_in_sysfs)
+		return -EEXIST;
+
+	if (!mmap_kset) {
+		mmap_kset = kset_create_and_add("memmap", NULL, firmware_kobj);
+		if (!mmap_kset)
+			return -ENOMEM;
+	}
+
+	entry->kobj.kset = mmap_kset;
+	if (kobject_add(&entry->kobj, NULL, "%d", map_entries_nr++))
+		kobject_put(&entry->kobj);
+
+	return 0;
+}
+
+/*
+ * Remove memmap entry on sysfs
+ */
+static inline void remove_sysfs_fw_map_entry(struct firmware_map_entry *entry)
+{
+	kobject_put(&entry->kobj);
+}
+
+/*
+ * firmware_map_find_entry_in_list() - Search memmap entry in a given list.
+ * @start: Start of the memory range.
+ * @end:   End of the memory range (exclusive).
+ * @type:  Type of the memory range.
+ * @list:  In which to find the entry.
+ *
+ * This function is to find the memmap entey of a given memory range in a
+ * given list. The caller must hold map_entries_lock, and must not release
+ * the lock until the processing of the returned entry has completed.
+ *
+ * Return: Pointer to the entry to be found on success, or NULL on failure.
+ */
+static struct firmware_map_entry * __meminit
+firmware_map_find_entry_in_list(u64 start, u64 end, const char *type,
+				struct list_head *list)
+{
+	struct firmware_map_entry *entry;
+
+	list_for_each_entry(entry, list, list)
+		if ((entry->start == start) && (entry->end == end) &&
+		    (!strcmp(entry->type, type))) {
+			return entry;
+		}
+
+	return NULL;
+}
+
+/*
+ * firmware_map_find_entry() - Search memmap entry in map_entries.
+ * @start: Start of the memory range.
+ * @end:   End of the memory range (exclusive).
+ * @type:  Type of the memory range.
+ *
+ * This function is to find the memmap entey of a given memory range.
+ * The caller must hold map_entries_lock, and must not release the lock
+ * until the processing of the returned entry has completed.
+ *
+ * Return: Pointer to the entry to be found on success, or NULL on failure.
+ */
+static struct firmware_map_entry * __meminit
+firmware_map_find_entry(u64 start, u64 end, const char *type)
+{
+	return firmware_map_find_entry_in_list(start, end, type, &map_entries);
+}
+
+/*
+ * firmware_map_find_entry_bootmem() - Search memmap entry in map_entries_bootmem.
+ * @start: Start of the memory range.
+ * @end:   End of the memory range (exclusive).
+ * @type:  Type of the memory range.
+ *
+ * This function is similar to firmware_map_find_entry except that it find the
+ * given entry in map_entries_bootmem.
+ *
+ * Return: Pointer to the entry to be found on success, or NULL on failure.
+ */
+static struct firmware_map_entry * __meminit
+firmware_map_find_entry_bootmem(u64 start, u64 end, const char *type)
+{
+	return firmware_map_find_entry_in_list(start, end, type,
+					       &map_entries_bootmem);
+}
+
+/**
+ * firmware_map_add_hotplug() - Adds a firmware mapping entry when we do
+ * memory hotplug.
+ * @start: Start of the memory range.
+ * @end:   End of the memory range (exclusive)
+ * @type:  Type of the memory range.
+ *
+ * Adds a firmware mapping entry. This function is for memory hotplug, it is
+ * similar to function firmware_map_add_early(). The only difference is that
+ * it will create the syfs entry dynamically.
+ *
+ * Returns 0 on success, or -ENOMEM if no memory could be allocated.
+ **/
+int __meminit firmware_map_add_hotplug(u64 start, u64 end, const char *type)
+{
+	struct firmware_map_entry *entry;
+
+	entry = firmware_map_find_entry(start, end - 1, type);
+	if (entry)
+		return 0;
+
+	entry = firmware_map_find_entry_bootmem(start, end - 1, type);
+	if (!entry) {
+		entry = kzalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC);
+		if (!entry)
+			return -ENOMEM;
+	} else {
+		/* Reuse storage allocated by bootmem. */
+		spin_lock(&map_entries_bootmem_lock);
+		list_del(&entry->list);
+		spin_unlock(&map_entries_bootmem_lock);
+
+		memset(entry, 0, sizeof(*entry));
+	}
+
+	firmware_map_add_entry(start, end, type, entry);
+	/* create the memmap entry */
+	add_sysfs_fw_map_entry(entry);
+
+	return 0;
+}
+
+/**
+ * firmware_map_add_early() - Adds a firmware mapping entry.
+ * @start: Start of the memory range.
+ * @end:   End of the memory range.
+ * @type:  Type of the memory range.
+ *
+ * Adds a firmware mapping entry. This function uses the bootmem allocator
+ * for memory allocation.
+ *
+ * That function must be called before late_initcall.
+ *
+ * Returns 0 on success, or -ENOMEM if no memory could be allocated.
+ **/
+int __init firmware_map_add_early(u64 start, u64 end, const char *type)
+{
+	struct firmware_map_entry *entry;
+
+	entry = memblock_virt_alloc(sizeof(struct firmware_map_entry), 0);
+	if (WARN_ON(!entry))
+		return -ENOMEM;
+
+	return firmware_map_add_entry(start, end, type, entry);
+}
+
+/**
+ * firmware_map_remove() - remove a firmware mapping entry
+ * @start: Start of the memory range.
+ * @end:   End of the memory range.
+ * @type:  Type of the memory range.
+ *
+ * removes a firmware mapping entry.
+ *
+ * Returns 0 on success, or -EINVAL if no entry.
+ **/
+int __meminit firmware_map_remove(u64 start, u64 end, const char *type)
+{
+	struct firmware_map_entry *entry;
+
+	spin_lock(&map_entries_lock);
+	entry = firmware_map_find_entry(start, end - 1, type);
+	if (!entry) {
+		spin_unlock(&map_entries_lock);
+		return -EINVAL;
+	}
+
+	firmware_map_remove_entry(entry);
+	spin_unlock(&map_entries_lock);
+
+	/* remove the memmap entry */
+	remove_sysfs_fw_map_entry(entry);
+
+	return 0;
+}
+
+/*
+ * Sysfs functions -------------------------------------------------------------
+ */
+
+static ssize_t start_show(struct firmware_map_entry *entry, char *buf)
+{
+	return snprintf(buf, PAGE_SIZE, "0x%llx\n",
+		(unsigned long long)entry->start);
+}
+
+static ssize_t end_show(struct firmware_map_entry *entry, char *buf)
+{
+	return snprintf(buf, PAGE_SIZE, "0x%llx\n",
+		(unsigned long long)entry->end);
+}
+
+static ssize_t type_show(struct firmware_map_entry *entry, char *buf)
+{
+	return snprintf(buf, PAGE_SIZE, "%s\n", entry->type);
+}
+
+static inline struct memmap_attribute *to_memmap_attr(struct attribute *attr)
+{
+	return container_of(attr, struct memmap_attribute, attr);
+}
+
+static ssize_t memmap_attr_show(struct kobject *kobj,
+				struct attribute *attr, char *buf)
+{
+	struct firmware_map_entry *entry = to_memmap_entry(kobj);
+	struct memmap_attribute *memmap_attr = to_memmap_attr(attr);
+
+	return memmap_attr->show(entry, buf);
+}
+
+/*
+ * Initialises stuff and adds the entries in the map_entries list to
+ * sysfs. Important is that firmware_map_add() and firmware_map_add_early()
+ * must be called before late_initcall. That's just because that function
+ * is called as late_initcall() function, which means that if you call
+ * firmware_map_add() or firmware_map_add_early() afterwards, the entries
+ * are not added to sysfs.
+ */
+static int __init firmware_memmap_init(void)
+{
+	struct firmware_map_entry *entry;
+
+	list_for_each_entry(entry, &map_entries, list)
+		add_sysfs_fw_map_entry(entry);
+
+	return 0;
+}
+late_initcall(firmware_memmap_init);
+