firmware: Factor out the paged buffer handling code

This is merely a preparation for the upcoming compressed firmware
support and no functional changes.  It moves the code to handle the
paged buffer allocation and mapping out of fallback.c into the main
code, so that they can be used commonly.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/firmware_loader/fallback.c

@@ -219,25 +219,6 @@ static ssize_t firmware_loading_show(struct device *dev,
 	return sprintf(buf, "%d\n", loading);
 }
 
-/* one pages buffer should be mapped/unmapped only once */
-static int map_fw_priv_pages(struct fw_priv *fw_priv)
-{
-	if (!fw_priv->pages)
-		return 0;
-
-	vunmap(fw_priv->data);
-	fw_priv->data = vmap(fw_priv->pages, fw_priv->nr_pages, 0,
-			     PAGE_KERNEL_RO);
-	if (!fw_priv->data)
-		return -ENOMEM;
-
-	/* page table is no longer needed after mapping, let's free */
-	kvfree(fw_priv->pages);
-	fw_priv->pages = NULL;
-
-	return 0;
-}
-
 /**
  * firmware_loading_store() - set value in the 'loading' control file
  * @dev: device pointer
@@ -283,7 +264,7 @@ static ssize_t firmware_loading_store(struct device *dev,
 			 * see the mapped 'buf->data' once the loading
 			 * is completed.
 			 * */
-			rc = map_fw_priv_pages(fw_priv);
+			rc = fw_map_paged_buf(fw_priv);
 			if (rc)
 				dev_err(dev, "%s: map pages failed\n",
 					__func__);
@@ -388,41 +369,13 @@ static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
 
 static int fw_realloc_pages(struct fw_sysfs *fw_sysfs, int min_size)
 {
-	struct fw_priv *fw_priv= fw_sysfs->fw_priv;
-	int pages_needed = PAGE_ALIGN(min_size) >> PAGE_SHIFT;
-
-	/* If the array of pages is too small, grow it... */
-	if (fw_priv->page_array_size < pages_needed) {
-		int new_array_size = max(pages_needed,
-					 fw_priv->page_array_size * 2);
-		struct page **new_pages;
+	int err;
 
-		new_pages = kvmalloc_array(new_array_size, sizeof(void *),
-					   GFP_KERNEL);
-		if (!new_pages) {
-			fw_load_abort(fw_sysfs);
-			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));
-		kvfree(fw_priv->pages);
-		fw_priv->pages = new_pages;
-		fw_priv->page_array_size = new_array_size;
-	}
-
-	while (fw_priv->nr_pages < pages_needed) {
-		fw_priv->pages[fw_priv->nr_pages] =
-			alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
-
-		if (!fw_priv->pages[fw_priv->nr_pages]) {
-			fw_load_abort(fw_sysfs);
-			return -ENOMEM;
-		}
-		fw_priv->nr_pages++;
-	}
-	return 0;
+	err = fw_grow_paged_buf(fw_sysfs->fw_priv,
+				PAGE_ALIGN(min_size) >> PAGE_SHIFT);
+	if (err)
+		fw_load_abort(fw_sysfs);
+	return err;
 }
 
 /**

drivers/base/firmware_loader/firmware.h

@@ -135,8 +135,12 @@ int assign_fw(struct firmware *fw, struct device *device,
 
 #ifdef CONFIG_FW_LOADER_USER_HELPER
 void fw_free_paged_buf(struct fw_priv *fw_priv);
+int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed);
+int fw_map_paged_buf(struct fw_priv *fw_priv);
 #else
 static inline void fw_free_paged_buf(struct fw_priv *fw_priv) {}
+int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed) { return -ENXIO; }
+int fw_map_paged_buf(struct fw_priv *fw_priv) { return -ENXIO; }
 #endif
 
 #endif /* __FIRMWARE_LOADER_H */

drivers/base/firmware_loader/main.c

@@ -281,6 +281,58 @@ void fw_free_paged_buf(struct fw_priv *fw_priv)
 	fw_priv->page_array_size = 0;
 	fw_priv->nr_pages = 0;
 }
+
+int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed)
+{
+	/* If the array of pages is too small, grow it */
+	if (fw_priv->page_array_size < pages_needed) {
+		int new_array_size = max(pages_needed,
+					 fw_priv->page_array_size * 2);
+		struct page **new_pages;
+
+		new_pages = kvmalloc_array(new_array_size, sizeof(void *),
+					   GFP_KERNEL);
+		if (!new_pages)
+			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));
+		kvfree(fw_priv->pages);
+		fw_priv->pages = new_pages;
+		fw_priv->page_array_size = new_array_size;
+	}
+
+	while (fw_priv->nr_pages < pages_needed) {
+		fw_priv->pages[fw_priv->nr_pages] =
+			alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
+
+		if (!fw_priv->pages[fw_priv->nr_pages])
+			return -ENOMEM;
+		fw_priv->nr_pages++;
+	}
+
+	return 0;
+}
+
+int fw_map_paged_buf(struct fw_priv *fw_priv)
+{
+	/* one pages buffer should be mapped/unmapped only once */
+	if (!fw_priv->pages)
+		return 0;
+
+	vunmap(fw_priv->data);
+	fw_priv->data = vmap(fw_priv->pages, fw_priv->nr_pages, 0,
+			     PAGE_KERNEL_RO);
+	if (!fw_priv->data)
+		return -ENOMEM;
+
+	/* page table is no longer needed after mapping, let's free */
+	kvfree(fw_priv->pages);
+	fw_priv->pages = NULL;
+
+	return 0;
+}
 #endif
 
 /* direct firmware loading support */