[RFC PATCH 09/13] driver core: firmware loader: store firmware name into devres list

[Ming Lei <ming.lei@canonical.com>]

This patch will store firmware name into devres list of the device
which is requesting firmware loading, so that we can implement
auto cache firmware for devices in need.

Signed-off-by: Ming Lei <ming.lei@canonical.com>
---
 drivers/base/firmware_class.c |   66 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 66 insertions(+)

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 540b2e1..c181e6d 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -115,6 +115,11 @@ struct firmware_priv {
 	struct firmware *fw;
 };
 
+struct fw_name_devm {
+	unsigned long magic;
+	char name[];
+};
+
 #define to_fwbuf(d) container_of(d, struct firmware_buf, ref)
 
 /* fw_lock could be moved to 'struct firmware_priv' but since it is just
@@ -574,6 +579,56 @@ static void fw_set_page_data(struct firmware_buf *buf, struct firmware *fw)
 	fw->priv = buf;
 }
 
+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;
+}
+
 static void _request_firmware_cleanup(const struct firmware **firmware_p)
 {
 	release_firmware(*firmware_p);
@@ -690,6 +745,17 @@ static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent,
 
 	fw_set_page_data(buf, fw_priv->fw);
 
+	/*
+	 * add firmware name into devres list so that we can auto cache
+	 * firmware for device.
+	 *
+	 * f_dev->parent may has been deleted already, but the problem
+	 * should be fixed in devres.
+	 *
+	 */
+	if (!retval && f_dev->parent)
+		fw_add_devm_name(f_dev->parent, buf->fw_id);
+
 	fw_priv->buf = NULL;
 	mutex_unlock(&fw_lock);
 
-- 
1.7.9.5