firmware loader: always let firmware_buf own the pages buffer
This patch always let firmware_buf own the pages buffer allocated
inside firmware_data_write, and add all instances of firmware_buf
into the firmware cache global list. Also introduce one private field
in 'struct firmware', so release_firmware will see the instance of
firmware_buf associated with the current firmware instance, then just
'free' the instance of firmware_buf.
The firmware_buf instance represents one pages buffer for one
firmware image, so lots of firmware loading requests can share
the same firmware_buf instance if they request the same firmware
image file.
This patch will make implementation of the following cache_firmware/
uncache_firmware very easy and simple.
In fact, the patch improves request_formware/release_firmware:
- only request userspace to write firmware image once if
several devices share one same firmware image and its drivers
call request_firmware concurrently.
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ming Lei
Greg Kroah-Hartman
parent
1244691c73
commit
1f2b79599e
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@ -21,6 +21,7 @@
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#include <linux/firmware.h>
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#include <linux/slab.h>
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#include <linux/sched.h>
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#include <linux/list.h>
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MODULE_AUTHOR("Manuel Estrada Sainz");
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MODULE_DESCRIPTION("Multi purpose firmware loading support");
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@ -85,13 +86,17 @@ static inline long firmware_loading_timeout(void)
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return loading_timeout > 0 ? loading_timeout * HZ : MAX_SCHEDULE_TIMEOUT;
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}
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/* fw_lock could be moved to 'struct firmware_priv' but since it is just
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* guarding for corner cases a global lock should be OK */
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static DEFINE_MUTEX(fw_lock);
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struct firmware_cache {
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/* firmware_buf instance will be added into the below list */
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spinlock_t lock;
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struct list_head head;
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};
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struct firmware_buf {
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struct kref ref;
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struct list_head list;
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struct completion completion;
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struct firmware *fw;
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struct firmware_cache *fwc;
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unsigned long status;
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void *data;
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size_t size;
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@ -106,8 +111,94 @@ struct firmware_priv {
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bool nowait;
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struct device dev;
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struct firmware_buf *buf;
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struct firmware *fw;
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};
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#define to_fwbuf(d) container_of(d, struct firmware_buf, ref)
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/* fw_lock could be moved to 'struct firmware_priv' but since it is just
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* guarding for corner cases a global lock should be OK */
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static DEFINE_MUTEX(fw_lock);
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static struct firmware_cache fw_cache;
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static struct firmware_buf *__allocate_fw_buf(const char *fw_name,
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struct firmware_cache *fwc)
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{
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struct firmware_buf *buf;
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buf = kzalloc(sizeof(*buf) + strlen(fw_name) + 1 , GFP_ATOMIC);
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if (!buf)
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return buf;
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kref_init(&buf->ref);
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strcpy(buf->fw_id, fw_name);
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buf->fwc = fwc;
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init_completion(&buf->completion);
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pr_debug("%s: fw-%s buf=%p\n", __func__, fw_name, buf);
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return buf;
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}
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static int fw_lookup_and_allocate_buf(const char *fw_name,
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struct firmware_cache *fwc,
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struct firmware_buf **buf)
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{
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struct firmware_buf *tmp;
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spin_lock(&fwc->lock);
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list_for_each_entry(tmp, &fwc->head, list)
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if (!strcmp(tmp->fw_id, fw_name)) {
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kref_get(&tmp->ref);
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spin_unlock(&fwc->lock);
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*buf = tmp;
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return 1;
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}
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tmp = __allocate_fw_buf(fw_name, fwc);
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if (tmp)
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list_add(&tmp->list, &fwc->head);
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spin_unlock(&fwc->lock);
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*buf = tmp;
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return tmp ? 0 : -ENOMEM;
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}
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static void __fw_free_buf(struct kref *ref)
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{
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struct firmware_buf *buf = to_fwbuf(ref);
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struct firmware_cache *fwc = buf->fwc;
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int i;
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pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
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__func__, buf->fw_id, buf, buf->data,
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(unsigned int)buf->size);
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spin_lock(&fwc->lock);
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list_del(&buf->list);
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spin_unlock(&fwc->lock);
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vunmap(buf->data);
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for (i = 0; i < buf->nr_pages; i++)
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__free_page(buf->pages[i]);
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kfree(buf->pages);
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kfree(buf);
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}
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static void fw_free_buf(struct firmware_buf *buf)
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{
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kref_put(&buf->ref, __fw_free_buf);
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}
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static void __init fw_cache_init(void)
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{
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spin_lock_init(&fw_cache.lock);
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INIT_LIST_HEAD(&fw_cache.head);
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}
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static struct firmware_priv *to_firmware_priv(struct device *dev)
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{
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return container_of(dev, struct firmware_priv, dev);
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@ -118,7 +209,7 @@ static void fw_load_abort(struct firmware_priv *fw_priv)
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struct firmware_buf *buf = fw_priv->buf;
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set_bit(FW_STATUS_ABORT, &buf->status);
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complete(&buf->completion);
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complete_all(&buf->completion);
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}
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static ssize_t firmware_timeout_show(struct class *class,
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@ -158,18 +249,6 @@ static struct class_attribute firmware_class_attrs[] = {
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__ATTR_NULL
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};
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static void fw_free_buf(struct firmware_buf *buf)
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{
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int i;
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if (!buf)
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return;
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for (i = 0; i < buf->nr_pages; i++)
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__free_page(buf->pages[i]);
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kfree(buf->pages);
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}
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static void fw_dev_release(struct device *dev)
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{
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struct firmware_priv *fw_priv = to_firmware_priv(dev);
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@ -212,13 +291,8 @@ static ssize_t firmware_loading_show(struct device *dev,
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/* firmware holds the ownership of pages */
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static void firmware_free_data(const struct firmware *fw)
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{
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int i;
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vunmap(fw->data);
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if (fw->pages) {
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for (i = 0; i < PFN_UP(fw->size); i++)
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__free_page(fw->pages[i]);
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kfree(fw->pages);
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}
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WARN_ON(!fw->priv);
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fw_free_buf(fw->priv);
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}
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/* Some architectures don't have PAGE_KERNEL_RO */
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@ -269,7 +343,7 @@ static ssize_t firmware_loading_store(struct device *dev,
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if (test_bit(FW_STATUS_LOADING, &fw_buf->status)) {
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set_bit(FW_STATUS_DONE, &fw_buf->status);
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clear_bit(FW_STATUS_LOADING, &fw_buf->status);
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complete(&fw_buf->completion);
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complete_all(&fw_buf->completion);
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break;
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}
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/* fallthrough */
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@ -448,7 +522,6 @@ fw_create_instance(struct firmware *firmware, const char *fw_name,
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struct device *device, bool uevent, bool nowait)
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{
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struct firmware_priv *fw_priv;
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struct firmware_buf *buf;
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struct device *f_dev;
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fw_priv = kzalloc(sizeof(*fw_priv), GFP_KERNEL);
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@ -458,21 +531,10 @@ fw_create_instance(struct firmware *firmware, const char *fw_name,
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goto exit;
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}
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buf = kzalloc(sizeof(*buf) + strlen(fw_name) + 1, GFP_KERNEL);
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if (!buf) {
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dev_err(device, "%s: kmalloc failed\n", __func__);
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kfree(fw_priv);
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fw_priv = ERR_PTR(-ENOMEM);
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goto exit;
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}
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buf->fw = firmware;
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fw_priv->buf = buf;
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fw_priv->nowait = nowait;
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fw_priv->fw = firmware;
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setup_timer(&fw_priv->timeout,
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firmware_class_timeout, (u_long) fw_priv);
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strcpy(buf->fw_id, fw_name);
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init_completion(&buf->completion);
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f_dev = &fw_priv->dev;
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@ -484,12 +546,42 @@ exit:
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return fw_priv;
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}
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/* one pages buffer is mapped/unmapped only once */
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static int fw_map_pages_buf(struct firmware_buf *buf)
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{
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buf->data = vmap(buf->pages, buf->nr_pages, 0, PAGE_KERNEL_RO);
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if (!buf->data)
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return -ENOMEM;
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return 0;
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}
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/* store the pages buffer info firmware from buf */
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static void fw_set_page_data(struct firmware_buf *buf, struct firmware *fw)
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{
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fw->priv = buf;
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fw->pages = buf->pages;
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fw->size = buf->size;
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fw->data = buf->data;
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pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
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__func__, buf->fw_id, buf, buf->data,
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(unsigned int)buf->size);
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}
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static void _request_firmware_cleanup(const struct firmware **firmware_p)
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{
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release_firmware(*firmware_p);
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*firmware_p = NULL;
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}
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static struct firmware_priv *
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_request_firmware_prepare(const struct firmware **firmware_p, const char *name,
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struct device *device, bool uevent, bool nowait)
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{
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struct firmware *firmware;
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struct firmware_priv *fw_priv;
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struct firmware_priv *fw_priv = NULL;
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struct firmware_buf *buf;
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int ret;
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if (!firmware_p)
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return ERR_PTR(-EINVAL);
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return NULL;
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}
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fw_priv = fw_create_instance(firmware, name, device, uevent, nowait);
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if (IS_ERR(fw_priv)) {
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release_firmware(firmware);
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ret = fw_lookup_and_allocate_buf(name, &fw_cache, &buf);
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if (!ret)
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fw_priv = fw_create_instance(firmware, name, device,
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uevent, nowait);
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if (IS_ERR(fw_priv) || ret < 0) {
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kfree(firmware);
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*firmware_p = NULL;
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return ERR_PTR(-ENOMEM);
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} else if (fw_priv) {
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fw_priv->buf = buf;
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/*
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* bind with 'buf' now to avoid warning in failure path
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* of requesting firmware.
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*/
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firmware->priv = buf;
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return fw_priv;
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}
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/* share the cached buf, which is inprogessing or completed */
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check_status:
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mutex_lock(&fw_lock);
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if (test_bit(FW_STATUS_ABORT, &buf->status)) {
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fw_priv = ERR_PTR(-ENOENT);
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_request_firmware_cleanup(firmware_p);
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goto exit;
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} else if (test_bit(FW_STATUS_DONE, &buf->status)) {
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fw_priv = NULL;
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fw_set_page_data(buf, firmware);
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goto exit;
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}
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mutex_unlock(&fw_lock);
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wait_for_completion(&buf->completion);
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goto check_status;
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exit:
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mutex_unlock(&fw_lock);
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return fw_priv;
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}
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static void _request_firmware_cleanup(const struct firmware **firmware_p)
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{
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release_firmware(*firmware_p);
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*firmware_p = NULL;
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}
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/* transfer the ownership of pages to firmware */
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static int fw_set_page_data(struct firmware_buf *buf)
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{
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struct firmware *fw = buf->fw;
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buf->data = vmap(buf->pages, buf->nr_pages, 0, PAGE_KERNEL_RO);
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if (!buf->data)
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return -ENOMEM;
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fw->data = buf->data;
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fw->pages = buf->pages;
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fw->size = buf->size;
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WARN_ON(PFN_UP(fw->size) != buf->nr_pages);
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return 0;
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}
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static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent,
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long timeout)
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{
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@ -585,13 +687,12 @@ static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent,
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if (!buf->size || test_bit(FW_STATUS_ABORT, &buf->status))
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retval = -ENOENT;
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/* transfer pages ownership at the last minute */
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if (!retval)
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retval = fw_set_page_data(buf);
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if (retval)
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fw_free_buf(buf); /* free untransfered pages buffer */
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retval = fw_map_pages_buf(buf);
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/* pass the pages buffer to driver at the last minute */
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fw_set_page_data(buf, fw_priv->fw);
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kfree(buf);
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fw_priv->buf = NULL;
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mutex_unlock(&fw_lock);
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@ -753,6 +854,7 @@ request_firmware_nowait(
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static int __init firmware_class_init(void)
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{
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fw_cache_init();
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return class_register(&firmware_class);
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}
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@ -12,6 +12,9 @@ struct firmware {
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size_t size;
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const u8 *data;
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struct page **pages;
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/* firmware loader private fields */
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void *priv;
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};
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struct module;
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