Merge tag 'disintegrate-mtd-20121009' of git://git.infradead.org/users/dhowells/linux-headers

UAPI Disintegration 2012-10-09

Conflicts:
	MAINTAINERS
	arch/arm/configs/bcmring_defconfig
	arch/arm/mach-imx/clk-imx51-imx53.c
	drivers/mtd/nand/Kconfig
	drivers/mtd/nand/bcm_umi_nand.c
	drivers/mtd/nand/nand_bcm_umi.h
	drivers/mtd/nand/orion_nand.c

1 files changed, 807 insertions, 103 deletions

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 803cfc1597a..81541452887 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -21,11 +21,83 @@
 #include <linux/firmware.h>
 #include <linux/slab.h>
 #include <linux/sched.h>
+#include <linux/file.h>
+#include <linux/list.h>
+#include <linux/async.h>
+#include <linux/pm.h>
+#include <linux/suspend.h>
+#include <linux/syscore_ops.h>
+
+#include <generated/utsrelease.h>
+
+#include "base.h"
 
 MODULE_AUTHOR("Manuel Estrada Sainz");
 MODULE_DESCRIPTION("Multi purpose firmware loading support");
 MODULE_LICENSE("GPL");
 
+static const char *fw_path[] = {
+	"/lib/firmware/updates/" UTS_RELEASE,
+	"/lib/firmware/updates",
+	"/lib/firmware/" UTS_RELEASE,
+	"/lib/firmware"
+};
+
+/* Don't inline this: 'struct kstat' is biggish */
+static noinline long fw_file_size(struct file *file)
+{
+	struct kstat st;
+	if (vfs_getattr(file->f_path.mnt, file->f_path.dentry, &st))
+		return -1;
+	if (!S_ISREG(st.mode))
+		return -1;
+	if (st.size != (long)st.size)
+		return -1;
+	return st.size;
+}
+
+static bool fw_read_file_contents(struct file *file, struct firmware *fw)
+{
+	long size;
+	char *buf;
+
+	size = fw_file_size(file);
+	if (size < 0)
+		return false;
+	buf = vmalloc(size);
+	if (!buf)
+		return false;
+	if (kernel_read(file, 0, buf, size) != size) {
+		vfree(buf);
+		return false;
+	}
+	fw->data = buf;
+	fw->size = size;
+	return true;
+}
+
+static bool fw_get_filesystem_firmware(struct firmware *fw, const char *name)
+{
+	int i;
+	bool success = false;
+	char *path = __getname();
+
+	for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
+		struct file *file;
+		snprintf(path, PATH_MAX, "%s/%s", fw_path[i], name);
+
+		file = filp_open(path, O_RDONLY, 0);
+		if (IS_ERR(file))
+			continue;
+		success = fw_read_file_contents(file, fw);
+		fput(file);
+		if (success)
+			break;
+	}
+	__putname(path);
+	return success;
+}
+
 /* Builtin firmware support */
 
 #ifdef CONFIG_FW_LOADER
@@ -85,23 +157,168 @@ static inline long firmware_loading_timeout(void)
 	return loading_timeout > 0 ? loading_timeout * HZ : MAX_SCHEDULE_TIMEOUT;
 }
 
-/* fw_lock could be moved to 'struct firmware_priv' but since it is just
- * guarding for corner cases a global lock should be OK */
-static DEFINE_MUTEX(fw_lock);
+struct firmware_cache {
+	/* firmware_buf instance will be added into the below list */
+	spinlock_t lock;
+	struct list_head head;
+	int state;
+
+#ifdef CONFIG_PM_SLEEP
+	/*
+	 * Names of firmware images which have been cached successfully
+	 * will be added into the below list so that device uncache
+	 * helper can trace which firmware images have been cached
+	 * before.
+	 */
+	spinlock_t name_lock;
+	struct list_head fw_names;
+
+	wait_queue_head_t wait_queue;
+	int cnt;
+	struct delayed_work work;
+
+	struct notifier_block   pm_notify;
+#endif
+};
 
-struct firmware_priv {
+struct firmware_buf {
+	struct kref ref;
+	struct list_head list;
 	struct completion completion;
-	struct firmware *fw;
+	struct firmware_cache *fwc;
 	unsigned long status;
+	void *data;
+	size_t size;
 	struct page **pages;
 	int nr_pages;
 	int page_array_size;
+	char fw_id[];
+};
+
+struct fw_cache_entry {
+	struct list_head list;
+	char name[];
+};
+
+struct firmware_priv {
 	struct timer_list timeout;
-	struct device dev;
 	bool nowait;
-	char fw_id[];
+	struct device dev;
+	struct firmware_buf *buf;
+	struct firmware *fw;
+};
+
+struct fw_name_devm {
+	unsigned long magic;
+	char name[];
 };
 
+#define to_fwbuf(d) container_of(d, struct firmware_buf, ref)
+
+#define	FW_LOADER_NO_CACHE	0
+#define	FW_LOADER_START_CACHE	1
+
+static int fw_cache_piggyback_on_request(const char *name);
+
+/* fw_lock could be moved to 'struct firmware_priv' but since it is just
+ * guarding for corner cases a global lock should be OK */
+static DEFINE_MUTEX(fw_lock);
+
+static struct firmware_cache fw_cache;
+
+static struct firmware_buf *__allocate_fw_buf(const char *fw_name,
+					      struct firmware_cache *fwc)
+{
+	struct firmware_buf *buf;
+
+	buf = kzalloc(sizeof(*buf) + strlen(fw_name) + 1 , GFP_ATOMIC);
+
+	if (!buf)
+		return buf;
+
+	kref_init(&buf->ref);
+	strcpy(buf->fw_id, fw_name);
+	buf->fwc = fwc;
+	init_completion(&buf->completion);
+
+	pr_debug("%s: fw-%s buf=%p\n", __func__, fw_name, buf);
+
+	return buf;
+}
+
+static struct firmware_buf *__fw_lookup_buf(const char *fw_name)
+{
+	struct firmware_buf *tmp;
+	struct firmware_cache *fwc = &fw_cache;
+
+	list_for_each_entry(tmp, &fwc->head, list)
+		if (!strcmp(tmp->fw_id, fw_name))
+			return tmp;
+	return NULL;
+}
+
+static int fw_lookup_and_allocate_buf(const char *fw_name,
+				      struct firmware_cache *fwc,
+				      struct firmware_buf **buf)
+{
+	struct firmware_buf *tmp;
+
+	spin_lock(&fwc->lock);
+	tmp = __fw_lookup_buf(fw_name);
+	if (tmp) {
+		kref_get(&tmp->ref);
+		spin_unlock(&fwc->lock);
+		*buf = tmp;
+		return 1;
+	}
+	tmp = __allocate_fw_buf(fw_name, fwc);
+	if (tmp)
+		list_add(&tmp->list, &fwc->head);
+	spin_unlock(&fwc->lock);
+
+	*buf = tmp;
+
+	return tmp ? 0 : -ENOMEM;
+}
+
+static struct firmware_buf *fw_lookup_buf(const char *fw_name)
+{
+	struct firmware_buf *tmp;
+	struct firmware_cache *fwc = &fw_cache;
+
+	spin_lock(&fwc->lock);
+	tmp = __fw_lookup_buf(fw_name);
+	spin_unlock(&fwc->lock);
+
+	return tmp;
+}
+
+static void __fw_free_buf(struct kref *ref)
+{
+	struct firmware_buf *buf = to_fwbuf(ref);
+	struct firmware_cache *fwc = buf->fwc;
+	int i;
+
+	pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
+		 __func__, buf->fw_id, buf, buf->data,
+		 (unsigned int)buf->size);
+
+	spin_lock(&fwc->lock);
+	list_del(&buf->list);
+	spin_unlock(&fwc->lock);
+
+	vunmap(buf->data);
+	for (i = 0; i < buf->nr_pages; i++)
+		__free_page(buf->pages[i]);
+	kfree(buf->pages);
+	kfree(buf);
+}
+
+static void fw_free_buf(struct firmware_buf *buf)
+{
+	kref_put(&buf->ref, __fw_free_buf);
+}
+
 static struct firmware_priv *to_firmware_priv(struct device *dev)
 {
 	return container_of(dev, struct firmware_priv, dev);
@@ -109,9 +326,10 @@ static struct firmware_priv *to_firmware_priv(struct device *dev)
 
 static void fw_load_abort(struct firmware_priv *fw_priv)
 {
-	set_bit(FW_STATUS_ABORT, &fw_priv->status);
-	wmb();
-	complete(&fw_priv->completion);
+	struct firmware_buf *buf = fw_priv->buf;
+
+	set_bit(FW_STATUS_ABORT, &buf->status);
+	complete_all(&buf->completion);
 }
 
 static ssize_t firmware_timeout_show(struct class *class,
@@ -154,11 +372,7 @@ static struct class_attribute firmware_class_attrs[] = {
 static void fw_dev_release(struct device *dev)
 {
 	struct firmware_priv *fw_priv = to_firmware_priv(dev);
-	int i;
 
-	for (i = 0; i < fw_priv->nr_pages; i++)
-		__free_page(fw_priv->pages[i]);
-	kfree(fw_priv->pages);
 	kfree(fw_priv);
 
 	module_put(THIS_MODULE);
@@ -168,7 +382,7 @@ static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
 	struct firmware_priv *fw_priv = to_firmware_priv(dev);
 
-	if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->fw_id))
+	if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->buf->fw_id))
 		return -ENOMEM;
 	if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
 		return -ENOMEM;
@@ -189,20 +403,20 @@ static ssize_t firmware_loading_show(struct device *dev,
 				     struct device_attribute *attr, char *buf)
 {
 	struct firmware_priv *fw_priv = to_firmware_priv(dev);
-	int loading = test_bit(FW_STATUS_LOADING, &fw_priv->status);
+	int loading = test_bit(FW_STATUS_LOADING, &fw_priv->buf->status);
 
 	return sprintf(buf, "%d\n", loading);
 }
 
+/* firmware holds the ownership of pages */
 static void firmware_free_data(const struct firmware *fw)
 {
-	int i;
-	vunmap(fw->data);
-	if (fw->pages) {
-		for (i = 0; i < PFN_UP(fw->size); i++)
-			__free_page(fw->pages[i]);
-		kfree(fw->pages);
+	/* Loaded directly? */
+	if (!fw->priv) {
+		vfree(fw->data);
+		return;
 	}
+	fw_free_buf(fw->priv);
 }
 
 /* Some architectures don't have PAGE_KERNEL_RO */
@@ -227,45 +441,33 @@ static ssize_t firmware_loading_store(struct device *dev,
 				      const char *buf, size_t count)
 {
 	struct firmware_priv *fw_priv = to_firmware_priv(dev);
+	struct firmware_buf *fw_buf = fw_priv->buf;
 	int loading = simple_strtol(buf, NULL, 10);
 	int i;
 
 	mutex_lock(&fw_lock);
 
-	if (!fw_priv->fw)
+	if (!fw_buf)
 		goto out;
 
 	switch (loading) {
 	case 1:
-		firmware_free_data(fw_priv->fw);
-		memset(fw_priv->fw, 0, sizeof(struct firmware));
-		/* If the pages are not owned by 'struct firmware' */
-		for (i = 0; i < fw_priv->nr_pages; i++)
-			__free_page(fw_priv->pages[i]);
-		kfree(fw_priv->pages);
-		fw_priv->pages = NULL;
-		fw_priv->page_array_size = 0;
-		fw_priv->nr_pages = 0;
-		set_bit(FW_STATUS_LOADING, &fw_priv->status);
+		/* discarding any previous partial load */
+		if (!test_bit(FW_STATUS_DONE, &fw_buf->status)) {
+			for (i = 0; i < fw_buf->nr_pages; i++)
+				__free_page(fw_buf->pages[i]);
+			kfree(fw_buf->pages);
+			fw_buf->pages = NULL;
+			fw_buf->page_array_size = 0;
+			fw_buf->nr_pages = 0;
+			set_bit(FW_STATUS_LOADING, &fw_buf->status);
+		}
 		break;
 	case 0:
-		if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) {
-			vunmap(fw_priv->fw->data);
-			fw_priv->fw->data = vmap(fw_priv->pages,
-						 fw_priv->nr_pages,
-						 0, PAGE_KERNEL_RO);
-			if (!fw_priv->fw->data) {
-				dev_err(dev, "%s: vmap() failed\n", __func__);
-				goto err;
-			}
-			/* Pages are now owned by 'struct firmware' */
-			fw_priv->fw->pages = fw_priv->pages;
-			fw_priv->pages = NULL;
-
-			fw_priv->page_array_size = 0;
-			fw_priv->nr_pages = 0;
-			complete(&fw_priv->completion);
-			clear_bit(FW_STATUS_LOADING, &fw_priv->status);
+		if (test_bit(FW_STATUS_LOADING, &fw_buf->status)) {
+			set_bit(FW_STATUS_DONE, &fw_buf->status);
+			clear_bit(FW_STATUS_LOADING, &fw_buf->status);
+			complete_all(&fw_buf->completion);
 			break;
 		}
 		/* fallthrough */
@@ -273,7 +475,6 @@ static ssize_t firmware_loading_store(struct device *dev,
 		dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
 		/* fallthrough */
 	case -1:
-	err:
 		fw_load_abort(fw_priv);
 		break;
 	}
@@ -290,21 +491,21 @@ static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
 {
 	struct device *dev = kobj_to_dev(kobj);
 	struct firmware_priv *fw_priv = to_firmware_priv(dev);
-	struct firmware *fw;
+	struct firmware_buf *buf;
 	ssize_t ret_count;
 
 	mutex_lock(&fw_lock);
-	fw = fw_priv->fw;
-	if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
+	buf = fw_priv->buf;
+	if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) {
 		ret_count = -ENODEV;
 		goto out;
 	}
-	if (offset > fw->size) {
+	if (offset > buf->size) {
 		ret_count = 0;
 		goto out;
 	}
-	if (count > fw->size - offset)
-		count = fw->size - offset;
+	if (count > buf->size - offset)
+		count = buf->size - offset;
 
 	ret_count = count;
 
@@ -314,11 +515,11 @@ static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
 		int page_ofs = offset & (PAGE_SIZE-1);
 		int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 
-		page_data = kmap(fw_priv->pages[page_nr]);
+		page_data = kmap(buf->pages[page_nr]);
 
 		memcpy(buffer, page_data + page_ofs, page_cnt);
 
-		kunmap(fw_priv->pages[page_nr]);
+		kunmap(buf->pages[page_nr]);
 		buffer += page_cnt;
 		offset += page_cnt;
 		count -= page_cnt;
@@ -330,12 +531,13 @@ out:
 
 static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
 {
+	struct firmware_buf *buf = fw_priv->buf;
 	int pages_needed = ALIGN(min_size, PAGE_SIZE) >> PAGE_SHIFT;
 
 	/* If the array of pages is too small, grow it... */
-	if (fw_priv->page_array_size < pages_needed) {
+	if (buf->page_array_size < pages_needed) {
 		int new_array_size = max(pages_needed,
-					 fw_priv->page_array_size * 2);
+					 buf->page_array_size * 2);
 		struct page **new_pages;
 
 		new_pages = kmalloc(new_array_size * sizeof(void *),
@@ -344,24 +546,24 @@ static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
 			fw_load_abort(fw_priv);
 			return -ENOMEM;
 		}
-		memcpy(new_pages, fw_priv->pages,
-		       fw_priv->page_array_size * sizeof(void *));
-		memset(&new_pages[fw_priv->page_array_size], 0, sizeof(void *) *
-		       (new_array_size - fw_priv->page_array_size));
-		kfree(fw_priv->pages);
-		fw_priv->pages = new_pages;
-		fw_priv->page_array_size = new_array_size;
+		memcpy(new_pages, buf->pages,
+		       buf->page_array_size * sizeof(void *));
+		memset(&new_pages[buf->page_array_size], 0, sizeof(void *) *
+		       (new_array_size - buf->page_array_size));
+		kfree(buf->pages);
+		buf->pages = new_pages;
+		buf->page_array_size = new_array_size;
 	}
 
-	while (fw_priv->nr_pages < pages_needed) {
-		fw_priv->pages[fw_priv->nr_pages] =
+	while (buf->nr_pages < pages_needed) {
+		buf->pages[buf->nr_pages] =
 			alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
 
-		if (!fw_priv->pages[fw_priv->nr_pages]) {
+		if (!buf->pages[buf->nr_pages]) {
 			fw_load_abort(fw_priv);
 			return -ENOMEM;
 		}
-		fw_priv->nr_pages++;
+		buf->nr_pages++;
 	}
 	return 0;
 }
@@ -384,18 +586,19 @@ static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,
 {
 	struct device *dev = kobj_to_dev(kobj);
 	struct firmware_priv *fw_priv = to_firmware_priv(dev);
-	struct firmware *fw;
+	struct firmware_buf *buf;
 	ssize_t retval;
 
 	if (!capable(CAP_SYS_RAWIO))
 		return -EPERM;
 
 	mutex_lock(&fw_lock);
-	fw = fw_priv->fw;
-	if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
+	buf = fw_priv->buf;
+	if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) {
 		retval = -ENODEV;
 		goto out;
 	}
+
 	retval = fw_realloc_buffer(fw_priv, offset + count);
 	if (retval)
 		goto out;
@@ -408,17 +611,17 @@ static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,
 		int page_ofs = offset & (PAGE_SIZE - 1);
 		int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 
-		page_data = kmap(fw_priv->pages[page_nr]);
+		page_data = kmap(buf->pages[page_nr]);
 
 		memcpy(page_data + page_ofs, buffer, page_cnt);
 
-		kunmap(fw_priv->pages[page_nr]);
+		kunmap(buf->pages[page_nr]);
 		buffer += page_cnt;
 		offset += page_cnt;
 		count -= page_cnt;
 	}
 
-	fw->size = max_t(size_t, offset, fw->size);
+	buf->size = max_t(size_t, offset, buf->size);
 out:
 	mutex_unlock(&fw_lock);
 	return retval;
@@ -445,35 +648,120 @@ fw_create_instance(struct firmware *firmware, const char *fw_name,
 	struct firmware_priv *fw_priv;
 	struct device *f_dev;
 
-	fw_priv = kzalloc(sizeof(*fw_priv) + strlen(fw_name) + 1 , GFP_KERNEL);
+	fw_priv = kzalloc(sizeof(*fw_priv), GFP_KERNEL);
 	if (!fw_priv) {
 		dev_err(device, "%s: kmalloc failed\n", __func__);
-		return ERR_PTR(-ENOMEM);
+		fw_priv = ERR_PTR(-ENOMEM);
+		goto exit;
 	}
 
-	fw_priv->fw = firmware;
 	fw_priv->nowait = nowait;
-	strcpy(fw_priv->fw_id, fw_name);
-	init_completion(&fw_priv->completion);
+	fw_priv->fw = firmware;
 	setup_timer(&fw_priv->timeout,
 		    firmware_class_timeout, (u_long) fw_priv);
 
 	f_dev = &fw_priv->dev;
 
 	device_initialize(f_dev);
-	dev_set_name(f_dev, "%s", dev_name(device));
+	dev_set_name(f_dev, "%s", fw_name);
 	f_dev->parent = device;
 	f_dev->class = &firmware_class;
-
+exit:
 	return fw_priv;
 }
 
+/* one pages buffer is mapped/unmapped only once */
+static int fw_map_pages_buf(struct firmware_buf *buf)
+{
+	buf->data = vmap(buf->pages, buf->nr_pages, 0, PAGE_KERNEL_RO);
+	if (!buf->data)
+		return -ENOMEM;
+	return 0;
+}
+
+/* store the pages buffer info firmware from buf */
+static void fw_set_page_data(struct firmware_buf *buf, struct firmware *fw)
+{
+	fw->priv = buf;
+	fw->pages = buf->pages;
+	fw->size = buf->size;
+	fw->data = buf->data;
+
+	pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
+		 __func__, buf->fw_id, buf, buf->data,
+		 (unsigned int)buf->size);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static void fw_name_devm_release(struct device *dev, void *res)
+{
+	struct fw_name_devm *fwn = res;
+
+	if (fwn->magic == (unsigned long)&fw_cache)
+		pr_debug("%s: fw_name-%s devm-%p released\n",
+				__func__, fwn->name, res);
+}
+
+static int fw_devm_match(struct device *dev, void *res,
+		void *match_data)
+{
+	struct fw_name_devm *fwn = res;
+
+	return (fwn->magic == (unsigned long)&fw_cache) &&
+		!strcmp(fwn->name, match_data);
+}
+
+static struct fw_name_devm *fw_find_devm_name(struct device *dev,
+		const char *name)
+{
+	struct fw_name_devm *fwn;
+
+	fwn = devres_find(dev, fw_name_devm_release,
+			  fw_devm_match, (void *)name);
+	return fwn;
+}
+
+/* add firmware name into devres list */
+static int fw_add_devm_name(struct device *dev, const char *name)
+{
+	struct fw_name_devm *fwn;
+
+	fwn = fw_find_devm_name(dev, name);
+	if (fwn)
+		return 1;
+
+	fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm) +
+			   strlen(name) + 1, GFP_KERNEL);
+	if (!fwn)
+		return -ENOMEM;
+
+	fwn->magic = (unsigned long)&fw_cache;
+	strcpy(fwn->name, name);
+	devres_add(dev, fwn);
+
+	return 0;
+}
+#else
+static int fw_add_devm_name(struct device *dev, const char *name)
+{
+	return 0;
+}
+#endif
+
+static void _request_firmware_cleanup(const struct firmware **firmware_p)
+{
+	release_firmware(*firmware_p);
+	*firmware_p = NULL;
+}
+
 static struct firmware_priv *
 _request_firmware_prepare(const struct firmware **firmware_p, const char *name,
 			  struct device *device, bool uevent, bool nowait)
 {
 	struct firmware *firmware;
-	struct firmware_priv *fw_priv;
+	struct firmware_priv *fw_priv = NULL;
+	struct firmware_buf *buf;
+	int ret;
 
 	if (!firmware_p)
 		return ERR_PTR(-EINVAL);
@@ -490,18 +778,51 @@ _request_firmware_prepare(const struct firmware **firmware_p, const char *name,
 		return NULL;
 	}
 
-	fw_priv = fw_create_instance(firmware, name, device, uevent, nowait);
-	if (IS_ERR(fw_priv)) {
-		release_firmware(firmware);
+	if (fw_get_filesystem_firmware(firmware, name)) {
+		dev_dbg(device, "firmware: direct-loading firmware %s\n", name);
+		return NULL;
+	}
+
+	ret = fw_lookup_and_allocate_buf(name, &fw_cache, &buf);
+	if (!ret)
+		fw_priv = fw_create_instance(firmware, name, device,
+				uevent, nowait);
+
+	if (IS_ERR(fw_priv) || ret < 0) {
+		kfree(firmware);
 		*firmware_p = NULL;
+		return ERR_PTR(-ENOMEM);
+	} else if (fw_priv) {
+		fw_priv->buf = buf;
+
+		/*
+		 * bind with 'buf' now to avoid warning in failure path
+		 * of requesting firmware.
+		 */
+		firmware->priv = buf;
+		return fw_priv;
 	}
-	return fw_priv;
-}
 
-static void _request_firmware_cleanup(const struct firmware **firmware_p)
-{
-	release_firmware(*firmware_p);
-	*firmware_p = NULL;
+	/* share the cached buf, which is inprogessing or completed */
+ check_status:
+	mutex_lock(&fw_lock);
+	if (test_bit(FW_STATUS_ABORT, &buf->status)) {
+		fw_priv = ERR_PTR(-ENOENT);
+		firmware->priv = buf;
+		_request_firmware_cleanup(firmware_p);
+		goto exit;
+	} else if (test_bit(FW_STATUS_DONE, &buf->status)) {
+		fw_priv = NULL;
+		fw_set_page_data(buf, firmware);
+		goto exit;
+	}
+	mutex_unlock(&fw_lock);
+	wait_for_completion(&buf->completion);
+	goto check_status;
+
+exit:
+	mutex_unlock(&fw_lock);
+	return fw_priv;
 }
 
 static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent,
@@ -509,6 +830,8 @@ static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent,
 {
 	int retval = 0;
 	struct device *f_dev = &fw_priv->dev;
+	struct firmware_buf *buf = fw_priv->buf;
+	struct firmware_cache *fwc = &fw_cache;
 
 	dev_set_uevent_suppress(f_dev, true);
 
@@ -535,7 +858,7 @@ static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent,
 
 	if (uevent) {
 		dev_set_uevent_suppress(f_dev, false);
-		dev_dbg(f_dev, "firmware: requesting %s\n", fw_priv->fw_id);
+		dev_dbg(f_dev, "firmware: requesting %s\n", buf->fw_id);
 		if (timeout != MAX_SCHEDULE_TIMEOUT)
 			mod_timer(&fw_priv->timeout,
 				  round_jiffies_up(jiffies + timeout));
@@ -543,15 +866,40 @@ static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent,
 		kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD);
 	}
 
-	wait_for_completion(&fw_priv->completion);
+	wait_for_completion(&buf->completion);
 
-	set_bit(FW_STATUS_DONE, &fw_priv->status);
 	del_timer_sync(&fw_priv->timeout);
 
 	mutex_lock(&fw_lock);
-	if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status))
+	if (!buf->size || test_bit(FW_STATUS_ABORT, &buf->status))
 		retval = -ENOENT;
-	fw_priv->fw = NULL;
+
+	/*
+	 * add firmware name into devres list so that we can auto cache
+	 * and uncache firmware for device.
+	 *
+	 * f_dev->parent may has been deleted already, but the problem
+	 * should be fixed in devres or driver core.
+	 */
+	if (!retval && f_dev->parent)
+		fw_add_devm_name(f_dev->parent, buf->fw_id);
+
+	if (!retval)
+		retval = fw_map_pages_buf(buf);
+
+	/*
+	 * After caching firmware image is started, let it piggyback
+	 * on request firmware.
+	 */
+	if (!retval && fwc->state == FW_LOADER_START_CACHE) {
+		if (fw_cache_piggyback_on_request(buf->fw_id))
+			kref_get(&buf->ref);
+	}
+
+	/* pass the pages buffer to driver at the last minute */
+	fw_set_page_data(buf, fw_priv->fw);
+
+	fw_priv->buf = NULL;
 	mutex_unlock(&fw_lock);
 
 	device_remove_file(f_dev, &dev_attr_loading);
@@ -578,6 +926,8 @@ err_put_dev:
  *      @name will be used as $FIRMWARE in the uevent environment and
  *      should be distinctive enough not to be confused with any other
  *      firmware image for this or any other device.
+ *
+ *	Caller must hold the reference count of @device.
  **/
 int
 request_firmware(const struct firmware **firmware_p, const char *name,
@@ -659,6 +1009,7 @@ static void request_firmware_work_func(struct work_struct *work)
 
  out:
 	fw_work->cont(fw, fw_work->context);
+	put_device(fw_work->device);
 
 	module_put(fw_work->module);
 	kfree(fw_work);
@@ -677,9 +1028,15 @@ static void request_firmware_work_func(struct work_struct *work)
  * @cont: function will be called asynchronously when the firmware
  *	request is over.
  *
- *	Asynchronous variant of request_firmware() for user contexts where
- *	it is not possible to sleep for long time. It can't be called
- *	in atomic contexts.
+ *	Caller must hold the reference count of @device.
+ *
+ *	Asynchronous variant of request_firmware() for user contexts:
+ *		- sleep for as small periods as possible since it may
+ *		increase kernel boot time of built-in device drivers
+ *		requesting firmware in their ->probe() methods, if
+ *		@gfp is GFP_KERNEL.
+ *
+ *		- can't sleep at all if @gfp is GFP_ATOMIC.
  **/
 int
 request_firmware_nowait(
@@ -705,18 +1062,363 @@ request_firmware_nowait(
 		return -EFAULT;
 	}
 
+	get_device(fw_work->device);
 	INIT_WORK(&fw_work->work, request_firmware_work_func);
 	schedule_work(&fw_work->work);
 	return 0;
 }
 
+/**
+ * cache_firmware - cache one firmware image in kernel memory space
+ * @fw_name: the firmware image name
+ *
+ * Cache firmware in kernel memory so that drivers can use it when
+ * system isn't ready for them to request firmware image from userspace.
+ * Once it returns successfully, driver can use request_firmware or its
+ * nowait version to get the cached firmware without any interacting
+ * with userspace
+ *
+ * Return 0 if the firmware image has been cached successfully
+ * Return !0 otherwise
+ *
+ */
+int cache_firmware(const char *fw_name)
+{
+	int ret;
+	const struct firmware *fw;
+
+	pr_debug("%s: %s\n", __func__, fw_name);
+
+	ret = request_firmware(&fw, fw_name, NULL);
+	if (!ret)
+		kfree(fw);
+
+	pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
+
+	return ret;
+}
+
+/**
+ * uncache_firmware - remove one cached firmware image
+ * @fw_name: the firmware image name
+ *
+ * Uncache one firmware image which has been cached successfully
+ * before.
+ *
+ * Return 0 if the firmware cache has been removed successfully
+ * Return !0 otherwise
+ *
+ */
+int uncache_firmware(const char *fw_name)
+{
+	struct firmware_buf *buf;
+	struct firmware fw;
+
+	pr_debug("%s: %s\n", __func__, fw_name);
+
+	if (fw_get_builtin_firmware(&fw, fw_name))
+		return 0;
+
+	buf = fw_lookup_buf(fw_name);
+	if (buf) {
+		fw_free_buf(buf);
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
+{
+	struct fw_cache_entry *fce;
+
+	fce = kzalloc(sizeof(*fce) + strlen(name) + 1, GFP_ATOMIC);
+	if (!fce)
+		goto exit;
+
+	strcpy(fce->name, name);
+exit:
+	return fce;
+}
+
+static int fw_cache_piggyback_on_request(const char *name)
+{
+	struct firmware_cache *fwc = &fw_cache;
+	struct fw_cache_entry *fce;
+	int ret = 0;
+
+	spin_lock(&fwc->name_lock);
+	list_for_each_entry(fce, &fwc->fw_names, list) {
+		if (!strcmp(fce->name, name))
+			goto found;
+	}
+
+	fce = alloc_fw_cache_entry(name);
+	if (fce) {
+		ret = 1;
+		list_add(&fce->list, &fwc->fw_names);
+		pr_debug("%s: fw: %s\n", __func__, name);
+	}
+found:
+	spin_unlock(&fwc->name_lock);
+	return ret;
+}
+
+static void free_fw_cache_entry(struct fw_cache_entry *fce)
+{
+	kfree(fce);
+}
+
+static void __async_dev_cache_fw_image(void *fw_entry,
+				       async_cookie_t cookie)
+{
+	struct fw_cache_entry *fce = fw_entry;
+	struct firmware_cache *fwc = &fw_cache;
+	int ret;
+
+	ret = cache_firmware(fce->name);
+	if (ret) {
+		spin_lock(&fwc->name_lock);
+		list_del(&fce->list);
+		spin_unlock(&fwc->name_lock);
+
+		free_fw_cache_entry(fce);
+	}
+
+	spin_lock(&fwc->name_lock);
+	fwc->cnt--;
+	spin_unlock(&fwc->name_lock);
+
+	wake_up(&fwc->wait_queue);
+}
+
+/* called with dev->devres_lock held */
+static void dev_create_fw_entry(struct device *dev, void *res,
+				void *data)
+{
+	struct fw_name_devm *fwn = res;
+	const char *fw_name = fwn->name;
+	struct list_head *head = data;
+	struct fw_cache_entry *fce;
+
+	fce = alloc_fw_cache_entry(fw_name);
+	if (fce)
+		list_add(&fce->list, head);
+}
+
+static int devm_name_match(struct device *dev, void *res,
+			   void *match_data)
+{
+	struct fw_name_devm *fwn = res;
+	return (fwn->magic == (unsigned long)match_data);
+}
+
+static void dev_cache_fw_image(struct device *dev, void *data)
+{
+	LIST_HEAD(todo);
+	struct fw_cache_entry *fce;
+	struct fw_cache_entry *fce_next;
+	struct firmware_cache *fwc = &fw_cache;
+
+	devres_for_each_res(dev, fw_name_devm_release,
+			    devm_name_match, &fw_cache,
+			    dev_create_fw_entry, &todo);
+
+	list_for_each_entry_safe(fce, fce_next, &todo, list) {
+		list_del(&fce->list);
+
+		spin_lock(&fwc->name_lock);
+		fwc->cnt++;
+		list_add(&fce->list, &fwc->fw_names);
+		spin_unlock(&fwc->name_lock);
+
+		async_schedule(__async_dev_cache_fw_image, (void *)fce);
+	}
+}
+
+static void __device_uncache_fw_images(void)
+{
+	struct firmware_cache *fwc = &fw_cache;
+	struct fw_cache_entry *fce;
+
+	spin_lock(&fwc->name_lock);
+	while (!list_empty(&fwc->fw_names)) {
+		fce = list_entry(fwc->fw_names.next,
+				struct fw_cache_entry, list);
+		list_del(&fce->list);
+		spin_unlock(&fwc->name_lock);
+
+		uncache_firmware(fce->name);
+		free_fw_cache_entry(fce);
+
+		spin_lock(&fwc->name_lock);
+	}
+	spin_unlock(&fwc->name_lock);
+}
+
+/**
+ * device_cache_fw_images - cache devices' firmware
+ *
+ * If one device called request_firmware or its nowait version
+ * successfully before, the firmware names are recored into the
+ * device's devres link list, so device_cache_fw_images can call
+ * cache_firmware() to cache these firmwares for the device,
+ * then the device driver can load its firmwares easily at
+ * time when system is not ready to complete loading firmware.
+ */
+static void device_cache_fw_images(void)
+{
+	struct firmware_cache *fwc = &fw_cache;
+	int old_timeout;
+	DEFINE_WAIT(wait);
+
+	pr_debug("%s\n", __func__);
+
+	/*
+	 * use small loading timeout for caching devices' firmware
+	 * because all these firmware images have been loaded
+	 * successfully at lease once, also system is ready for
+	 * completing firmware loading now. The maximum size of
+	 * firmware in current distributions is about 2M bytes,
+	 * so 10 secs should be enough.
+	 */
+	old_timeout = loading_timeout;
+	loading_timeout = 10;
+
+	mutex_lock(&fw_lock);
+	fwc->state = FW_LOADER_START_CACHE;
+	dpm_for_each_dev(NULL, dev_cache_fw_image);
+	mutex_unlock(&fw_lock);
+
+	/* wait for completion of caching firmware for all devices */
+	spin_lock(&fwc->name_lock);
+	for (;;) {
+		prepare_to_wait(&fwc->wait_queue, &wait,
+				TASK_UNINTERRUPTIBLE);
+		if (!fwc->cnt)
+			break;
+
+		spin_unlock(&fwc->name_lock);
+
+		schedule();
+
+		spin_lock(&fwc->name_lock);
+	}
+	spin_unlock(&fwc->name_lock);
+	finish_wait(&fwc->wait_queue, &wait);
+
+	loading_timeout = old_timeout;
+}
+
+/**
+ * device_uncache_fw_images - uncache devices' firmware
+ *
+ * uncache all firmwares which have been cached successfully
+ * by device_uncache_fw_images earlier
+ */
+static void device_uncache_fw_images(void)
+{
+	pr_debug("%s\n", __func__);
+	__device_uncache_fw_images();
+}
+
+static void device_uncache_fw_images_work(struct work_struct *work)
+{
+	device_uncache_fw_images();
+}
+
+/**
+ * device_uncache_fw_images_delay - uncache devices firmwares
+ * @delay: number of milliseconds to delay uncache device firmwares
+ *
+ * uncache all devices's firmwares which has been cached successfully
+ * by device_cache_fw_images after @delay milliseconds.
+ */
+static void device_uncache_fw_images_delay(unsigned long delay)
+{
+	schedule_delayed_work(&fw_cache.work,
+			msecs_to_jiffies(delay));
+}
+
+static int fw_pm_notify(struct notifier_block *notify_block,
+			unsigned long mode, void *unused)
+{
+	switch (mode) {
+	case PM_HIBERNATION_PREPARE:
+	case PM_SUSPEND_PREPARE:
+		device_cache_fw_images();
+		break;
+
+	case PM_POST_SUSPEND:
+	case PM_POST_HIBERNATION:
+	case PM_POST_RESTORE:
+		/*
+		 * In case that system sleep failed and syscore_suspend is
+		 * not called.
+		 */
+		mutex_lock(&fw_lock);
+		fw_cache.state = FW_LOADER_NO_CACHE;
+		mutex_unlock(&fw_lock);
+
+		device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
+		break;
+	}
+
+	return 0;
+}
+
+/* stop caching firmware once syscore_suspend is reached */
+static int fw_suspend(void)
+{
+	fw_cache.state = FW_LOADER_NO_CACHE;
+	return 0;
+}
+
+static struct syscore_ops fw_syscore_ops = {
+	.suspend = fw_suspend,
+};
+#else
+static int fw_cache_piggyback_on_request(const char *name)
+{
+	return 0;
+}
+#endif
+
+static void __init fw_cache_init(void)
+{
+	spin_lock_init(&fw_cache.lock);
+	INIT_LIST_HEAD(&fw_cache.head);
+	fw_cache.state = FW_LOADER_NO_CACHE;
+
+#ifdef CONFIG_PM_SLEEP
+	spin_lock_init(&fw_cache.name_lock);
+	INIT_LIST_HEAD(&fw_cache.fw_names);
+	fw_cache.cnt = 0;
+
+	init_waitqueue_head(&fw_cache.wait_queue);
+	INIT_DELAYED_WORK(&fw_cache.work,
+			  device_uncache_fw_images_work);
+
+	fw_cache.pm_notify.notifier_call = fw_pm_notify;
+	register_pm_notifier(&fw_cache.pm_notify);
+
+	register_syscore_ops(&fw_syscore_ops);
+#endif
+}
+
 static int __init firmware_class_init(void)
 {
+	fw_cache_init();
 	return class_register(&firmware_class);
 }
 
 static void __exit firmware_class_exit(void)
 {
+#ifdef CONFIG_PM_SLEEP
+	unregister_syscore_ops(&fw_syscore_ops);
+	unregister_pm_notifier(&fw_cache.pm_notify);
+#endif
 	class_unregister(&firmware_class);
 }
 
@@ -726,3 +1428,5 @@ module_exit(firmware_class_exit);
 EXPORT_SYMBOL(release_firmware);
 EXPORT_SYMBOL(request_firmware);
 EXPORT_SYMBOL(request_firmware_nowait);
+EXPORT_SYMBOL_GPL(cache_firmware);
+EXPORT_SYMBOL_GPL(uncache_firmware);