[PATCH v6 00/13] firmware_loader changes for v4.18

[PATCH v6 00/13] firmware_loader changes for v4.18

[Luis R. Rodriguez]

Greg,

Here is what I have queued up for the firmware_loader for v4.18. It
includes a slew of cleanup work, and the new firmware_request_nowarn()
which is quiet but enables the sysfs fallback mechanism. I've gone ahead
and also queued up a few minor fixes for the firmware loader documentation
which have come up recently. These changes are available on my git tree
both based on linux-next [0] and Linus' latest tree [1]. Folks working
on new developments for the firmware loader can use my linux-next
branch 20180508-firmware_loader_for-v4.18-try2 for now.

0-day sends its blessings.

The patches from Mimi's series still require a bit more discussion and
review. The discussion over the EFI firmware fallback mechanism is still
ongoing.

As for the rename that you wanted, perhaps we can do this late in the
merge window considering we're at rc4 now. I can prep something up for
that later.

Question, and specially rants are warmly welcomed.

[0] https://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux-next.git/log/?h=20180508-firmware_loader_for-v4.18-try2
[1] https://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux.git/log/?h=20180508-firmware_loader_for-v4.18-try2

Andres Rodriguez (6):
  firmware: wrap FW_OPT_* into an enum
  firmware: use () to terminate kernel-doc function names
  firmware: rename fw_sysfs_fallback to firmware_fallback_sysfs()
  firmware: add firmware_request_nowarn() - load firmware without
    warnings
  ath10k: use firmware_request_nowarn() to load firmware
  ath10k: re-enable the firmware fallback mechanism for testmode

Luis R. Rodriguez (7):
  firmware_loader: document firmware_sysfs_fallback()
  firmware_loader: enhance Kconfig documentation over FW_LOADER
  firmware_loader: move kconfig FW_LOADER entries to its own file
  firmware_loader: make firmware_fallback_sysfs() print more useful
  Documentation: fix few typos and clarifications for the firmware
    loader
  Documentation: remove stale firmware API reference
  Documentation: clarify firmware_class provenance and why we can't
    rename the module

 Documentation/dell_rbu.txt                    |   3 -
 .../firmware/fallback-mechanisms.rst          |  14 +-
 .../driver-api/firmware/firmware_cache.rst    |   4 +-
 .../driver-api/firmware/request_firmware.rst  |   5 +
 drivers/base/Kconfig                          |  90 ++--------
 drivers/base/firmware_loader/Kconfig          | 154 ++++++++++++++++++
 drivers/base/firmware_loader/fallback.c       |  53 ++++--
 drivers/base/firmware_loader/fallback.h       |  18 +-
 drivers/base/firmware_loader/firmware.h       |  37 ++++-
 drivers/base/firmware_loader/main.c           |  57 +++++--
 drivers/net/wireless/ath/ath10k/core.c        |   2 +-
 drivers/net/wireless/ath/ath10k/testmode.c    |   2 +-
 include/linux/firmware.h                      |  10 ++
 13 files changed, 319 insertions(+), 130 deletions(-)
 create mode 100644 drivers/base/firmware_loader/Kconfig

-- 
2.17.0

[PATCH v6 01/13] firmware: wrap FW_OPT_* into an enum

[Luis R. Rodriguez]

From: Andres Rodriguez <andresx7@gmail.com>

This should let us associate enum kdoc to these values.
While at it, kdocify the fw_opt.

Signed-off-by: Andres Rodriguez <andresx7@gmail.com>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
[mcgrof: coding style fixes, merge kdoc with enum move]
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
---
 drivers/base/firmware_loader/fallback.c | 12 ++++----
 drivers/base/firmware_loader/fallback.h |  6 ++--
 drivers/base/firmware_loader/firmware.h | 37 +++++++++++++++++++------
 drivers/base/firmware_loader/main.c     |  6 ++--
 4 files changed, 42 insertions(+), 19 deletions(-)

diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
index 358354148dec..b57a7b3b4122 100644
--- a/drivers/base/firmware_loader/fallback.c
+++ b/drivers/base/firmware_loader/fallback.c
@@ -512,7 +512,7 @@ static const struct attribute_group *fw_dev_attr_groups[] = {
 
 static struct fw_sysfs *
 fw_create_instance(struct firmware *firmware, const char *fw_name,
-		   struct device *device, unsigned int opt_flags)
+		   struct device *device, enum fw_opt opt_flags)
 {
 	struct fw_sysfs *fw_sysfs;
 	struct device *f_dev;
@@ -545,7 +545,7 @@ fw_create_instance(struct firmware *firmware, const char *fw_name,
  * In charge of constructing a sysfs fallback interface for firmware loading.
  **/
 static int fw_load_sysfs_fallback(struct fw_sysfs *fw_sysfs,
-				  unsigned int opt_flags, long timeout)
+				  enum fw_opt opt_flags, long timeout)
 {
 	int retval = 0;
 	struct device *f_dev = &fw_sysfs->dev;
@@ -599,7 +599,7 @@ static int fw_load_sysfs_fallback(struct fw_sysfs *fw_sysfs,
 
 static int fw_load_from_user_helper(struct firmware *firmware,
 				    const char *name, struct device *device,
-				    unsigned int opt_flags)
+				    enum fw_opt opt_flags)
 {
 	struct fw_sysfs *fw_sysfs;
 	long timeout;
@@ -640,7 +640,7 @@ static int fw_load_from_user_helper(struct firmware *firmware,
 	return ret;
 }
 
-static bool fw_force_sysfs_fallback(unsigned int opt_flags)
+static bool fw_force_sysfs_fallback(enum fw_opt opt_flags)
 {
 	if (fw_fallback_config.force_sysfs_fallback)
 		return true;
@@ -649,7 +649,7 @@ static bool fw_force_sysfs_fallback(unsigned int opt_flags)
 	return true;
 }
 
-static bool fw_run_sysfs_fallback(unsigned int opt_flags)
+static bool fw_run_sysfs_fallback(enum fw_opt opt_flags)
 {
 	if (fw_fallback_config.ignore_sysfs_fallback) {
 		pr_info_once("Ignoring firmware sysfs fallback due to sysctl knob\n");
@@ -664,7 +664,7 @@ static bool fw_run_sysfs_fallback(unsigned int opt_flags)
 
 int fw_sysfs_fallback(struct firmware *fw, const char *name,
 		      struct device *device,
-		      unsigned int opt_flags,
+		      enum fw_opt opt_flags,
 		      int ret)
 {
 	if (!fw_run_sysfs_fallback(opt_flags))
diff --git a/drivers/base/firmware_loader/fallback.h b/drivers/base/firmware_loader/fallback.h
index f8255670a663..a3b73a09db6c 100644
--- a/drivers/base/firmware_loader/fallback.h
+++ b/drivers/base/firmware_loader/fallback.h
@@ -5,6 +5,8 @@
 #include <linux/firmware.h>
 #include <linux/device.h>
 
+#include "firmware.h"
+
 /**
  * struct firmware_fallback_config - firmware fallback configuration settings
  *
@@ -31,7 +33,7 @@ struct firmware_fallback_config {
 #ifdef CONFIG_FW_LOADER_USER_HELPER
 int fw_sysfs_fallback(struct firmware *fw, const char *name,
 		      struct device *device,
-		      unsigned int opt_flags,
+		      enum fw_opt opt_flags,
 		      int ret);
 void kill_pending_fw_fallback_reqs(bool only_kill_custom);
 
@@ -43,7 +45,7 @@ void unregister_sysfs_loader(void);
 #else /* CONFIG_FW_LOADER_USER_HELPER */
 static inline int fw_sysfs_fallback(struct firmware *fw, const char *name,
 				    struct device *device,
-				    unsigned int opt_flags,
+				    enum fw_opt opt_flags,
 				    int ret)
 {
 	/* Keep carrying over the same error */
diff --git a/drivers/base/firmware_loader/firmware.h b/drivers/base/firmware_loader/firmware.h
index 64acbb1a392c..4f433b447367 100644
--- a/drivers/base/firmware_loader/firmware.h
+++ b/drivers/base/firmware_loader/firmware.h
@@ -2,6 +2,7 @@
 #ifndef __FIRMWARE_LOADER_H
 #define __FIRMWARE_LOADER_H
 
+#include <linux/bitops.h>
 #include <linux/firmware.h>
 #include <linux/types.h>
 #include <linux/kref.h>
@@ -10,13 +11,33 @@
 
 #include <generated/utsrelease.h>
 
-/* firmware behavior options */
-#define FW_OPT_UEVENT			(1U << 0)
-#define FW_OPT_NOWAIT			(1U << 1)
-#define FW_OPT_USERHELPER		(1U << 2)
-#define FW_OPT_NO_WARN			(1U << 3)
-#define FW_OPT_NOCACHE			(1U << 4)
-#define FW_OPT_NOFALLBACK		(1U << 5)
+/**
+ * enum fw_opt - options to control firmware loading behaviour
+ *
+ * @FW_OPT_UEVENT: Enables the fallback mechanism to send a kobject uevent
+ *	when the firmware is not found. Userspace is in charge to load the
+ *	firmware using the sysfs loading facility.
+ * @FW_OPT_NOWAIT: Used to describe the firmware request is asynchronous.
+ * @FW_OPT_USERHELPER: Enable the fallback mechanism, in case the direct
+ *	filesystem lookup fails at finding the firmware.  For details refer to
+ *	fw_sysfs_fallback().
+ * @FW_OPT_NO_WARN: Quiet, avoid printing warning messages.
+ * @FW_OPT_NOCACHE: Disables firmware caching. Firmware caching is used to
+ *	cache the firmware upon suspend, so that upon resume races against the
+ *	firmware file lookup on storage is avoided. Used for calls where the
+ *	file may be too big, or where the driver takes charge of its own
+ *	firmware caching mechanism.
+ * @FW_OPT_NOFALLBACK: Disable the fallback mechanism. Takes precedence over
+ *	&FW_OPT_UEVENT and &FW_OPT_USERHELPER.
+ */
+enum fw_opt {
+	FW_OPT_UEVENT =         BIT(0),
+	FW_OPT_NOWAIT =         BIT(1),
+	FW_OPT_USERHELPER =     BIT(2),
+	FW_OPT_NO_WARN =        BIT(3),
+	FW_OPT_NOCACHE =        BIT(4),
+	FW_OPT_NOFALLBACK =     BIT(5),
+};
 
 enum fw_status {
 	FW_STATUS_UNKNOWN,
@@ -110,6 +131,6 @@ static inline void fw_state_done(struct fw_priv *fw_priv)
 }
 
 int assign_fw(struct firmware *fw, struct device *device,
-	      unsigned int opt_flags);
+	      enum fw_opt opt_flags);
 
 #endif /* __FIRMWARE_LOADER_H */
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index eb34089e4299..9919f0e6a7cc 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -443,7 +443,7 @@ static int fw_add_devm_name(struct device *dev, const char *name)
 #endif
 
 int assign_fw(struct firmware *fw, struct device *device,
-	      unsigned int opt_flags)
+	      enum fw_opt opt_flags)
 {
 	struct fw_priv *fw_priv = fw->priv;
 	int ret;
@@ -558,7 +558,7 @@ static void fw_abort_batch_reqs(struct firmware *fw)
 static int
 _request_firmware(const struct firmware **firmware_p, const char *name,
 		  struct device *device, void *buf, size_t size,
-		  unsigned int opt_flags)
+		  enum fw_opt opt_flags)
 {
 	struct firmware *fw = NULL;
 	int ret;
@@ -734,7 +734,7 @@ struct firmware_work {
 	struct device *device;
 	void *context;
 	void (*cont)(const struct firmware *fw, void *context);
-	unsigned int opt_flags;
+	enum fw_opt opt_flags;
 };
 
 static void request_firmware_work_func(struct work_struct *work)
-- 
2.17.0

[PATCH v6 02/13] firmware: use () to terminate kernel-doc function names

[Luis R. Rodriguez]

From: Andres Rodriguez <andresx7@gmail.com>

The kernel-doc spec dictates a function name ends in ().

Signed-off-by: Andres Rodriguez <andresx7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
[mcgrof: adjust since the wide API rename is not yet merged]
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
---
 drivers/base/firmware_loader/fallback.c |  8 ++++----
 drivers/base/firmware_loader/main.c     | 22 +++++++++++-----------
 2 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
index b57a7b3b4122..529f7013616f 100644
--- a/drivers/base/firmware_loader/fallback.c
+++ b/drivers/base/firmware_loader/fallback.c
@@ -125,7 +125,7 @@ static ssize_t timeout_show(struct class *class, struct class_attribute *attr,
 }
 
 /**
- * firmware_timeout_store - set number of seconds to wait for firmware
+ * firmware_timeout_store() - set number of seconds to wait for firmware
  * @class: device class pointer
  * @attr: device attribute pointer
  * @buf: buffer to scan for timeout value
@@ -239,7 +239,7 @@ static int map_fw_priv_pages(struct fw_priv *fw_priv)
 }
 
 /**
- * firmware_loading_store - set value in the 'loading' control file
+ * firmware_loading_store() - set value in the 'loading' control file
  * @dev: device pointer
  * @attr: device attribute pointer
  * @buf: buffer to scan for loading control value
@@ -431,7 +431,7 @@ static int fw_realloc_pages(struct fw_sysfs *fw_sysfs, int min_size)
 }
 
 /**
- * firmware_data_write - write method for firmware
+ * firmware_data_write() - write method for firmware
  * @filp: open sysfs file
  * @kobj: kobject for the device
  * @bin_attr: bin_attr structure
@@ -537,7 +537,7 @@ fw_create_instance(struct firmware *firmware, const char *fw_name,
 }
 
 /**
- * fw_load_sysfs_fallback - load a firmware via the sysfs fallback mechanism
+ * fw_load_sysfs_fallback() - load a firmware via the sysfs fallback mechanism
  * @fw_sysfs: firmware sysfs information for the firmware to load
  * @opt_flags: flags of options, FW_OPT_*
  * @timeout: timeout to wait for the load
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index 9919f0e6a7cc..4d11efadb3a4 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -597,7 +597,7 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
 }
 
 /**
- * request_firmware: - send firmware request and wait for it
+ * request_firmware() - send firmware request and wait for it
  * @firmware_p: pointer to firmware image
  * @name: name of firmware file
  * @device: device for which firmware is being loaded
@@ -632,7 +632,7 @@ request_firmware(const struct firmware **firmware_p, const char *name,
 EXPORT_SYMBOL(request_firmware);
 
 /**
- * request_firmware_direct: - load firmware directly without usermode helper
+ * request_firmware_direct() - load firmware directly without usermode helper
  * @firmware_p: pointer to firmware image
  * @name: name of firmware file
  * @device: device for which firmware is being loaded
@@ -657,7 +657,7 @@ int request_firmware_direct(const struct firmware **firmware_p,
 EXPORT_SYMBOL_GPL(request_firmware_direct);
 
 /**
- * firmware_request_cache: - cache firmware for suspend so resume can use it
+ * firmware_request_cache() - cache firmware for suspend so resume can use it
  * @name: name of firmware file
  * @device: device for which firmware should be cached for
  *
@@ -681,7 +681,7 @@ int firmware_request_cache(struct device *device, const char *name)
 EXPORT_SYMBOL_GPL(firmware_request_cache);
 
 /**
- * request_firmware_into_buf - load firmware into a previously allocated buffer
+ * request_firmware_into_buf() - load firmware into a previously allocated buffer
  * @firmware_p: pointer to firmware image
  * @name: name of firmware file
  * @device: device for which firmware is being loaded and DMA region allocated
@@ -713,7 +713,7 @@ request_firmware_into_buf(const struct firmware **firmware_p, const char *name,
 EXPORT_SYMBOL(request_firmware_into_buf);
 
 /**
- * release_firmware: - release the resource associated with a firmware image
+ * release_firmware() - release the resource associated with a firmware image
  * @fw: firmware resource to release
  **/
 void release_firmware(const struct firmware *fw)
@@ -755,7 +755,7 @@ static void request_firmware_work_func(struct work_struct *work)
 }
 
 /**
- * request_firmware_nowait - asynchronous version of request_firmware
+ * request_firmware_nowait() - asynchronous version of request_firmware
  * @module: module requesting the firmware
  * @uevent: sends uevent to copy the firmware image if this flag
  *	is non-zero else the firmware copy must be done manually.
@@ -824,7 +824,7 @@ EXPORT_SYMBOL(request_firmware_nowait);
 static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
 
 /**
- * cache_firmware - cache one firmware image in kernel memory space
+ * 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
@@ -866,7 +866,7 @@ static struct fw_priv *lookup_fw_priv(const char *fw_name)
 }
 
 /**
- * uncache_firmware - remove one cached firmware image
+ * uncache_firmware() - remove one cached firmware image
  * @fw_name: the firmware image name
  *
  * Uncache one firmware image which has been cached successfully
@@ -1042,7 +1042,7 @@ static void __device_uncache_fw_images(void)
 }
 
 /**
- * device_cache_fw_images - cache devices' firmware
+ * 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
@@ -1075,7 +1075,7 @@ static void device_cache_fw_images(void)
 }
 
 /**
- * device_uncache_fw_images - uncache devices' firmware
+ * device_uncache_fw_images() - uncache devices' firmware
  *
  * uncache all firmwares which have been cached successfully
  * by device_uncache_fw_images earlier
@@ -1092,7 +1092,7 @@ static void device_uncache_fw_images_work(struct work_struct *work)
 }
 
 /**
- * device_uncache_fw_images_delay - uncache devices firmwares
+ * 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
-- 
2.17.0

[PATCH v6 03/13] firmware: rename fw_sysfs_fallback to firmware_fallback_sysfs()

[Luis R. Rodriguez]

From: Andres Rodriguez <andresx7@gmail.com>

This is done since this call is now exposed through kernel-doc,
and since this also paves the way for different future types of
fallback mechanims.

Signed-off-by: Andres Rodriguez <andresx7@gmail.com>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
[mcgrof: small coding style changes]
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
---
 drivers/base/firmware_loader/fallback.c |  8 ++++----
 drivers/base/firmware_loader/fallback.h | 16 ++++++++--------
 drivers/base/firmware_loader/firmware.h |  2 +-
 drivers/base/firmware_loader/main.c     |  2 +-
 4 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
index 529f7013616f..3db9e0f225ac 100644
--- a/drivers/base/firmware_loader/fallback.c
+++ b/drivers/base/firmware_loader/fallback.c
@@ -662,10 +662,10 @@ static bool fw_run_sysfs_fallback(enum fw_opt opt_flags)
 	return fw_force_sysfs_fallback(opt_flags);
 }
 
-int fw_sysfs_fallback(struct firmware *fw, const char *name,
-		      struct device *device,
-		      enum fw_opt opt_flags,
-		      int ret)
+int firmware_fallback_sysfs(struct firmware *fw, const char *name,
+			    struct device *device,
+			    enum fw_opt opt_flags,
+			    int ret)
 {
 	if (!fw_run_sysfs_fallback(opt_flags))
 		return ret;
diff --git a/drivers/base/firmware_loader/fallback.h b/drivers/base/firmware_loader/fallback.h
index a3b73a09db6c..21063503e4ea 100644
--- a/drivers/base/firmware_loader/fallback.h
+++ b/drivers/base/firmware_loader/fallback.h
@@ -31,10 +31,10 @@ struct firmware_fallback_config {
 };
 
 #ifdef CONFIG_FW_LOADER_USER_HELPER
-int fw_sysfs_fallback(struct firmware *fw, const char *name,
-		      struct device *device,
-		      enum fw_opt opt_flags,
-		      int ret);
+int firmware_fallback_sysfs(struct firmware *fw, const char *name,
+			    struct device *device,
+			    enum fw_opt opt_flags,
+			    int ret);
 void kill_pending_fw_fallback_reqs(bool only_kill_custom);
 
 void fw_fallback_set_cache_timeout(void);
@@ -43,10 +43,10 @@ void fw_fallback_set_default_timeout(void);
 int register_sysfs_loader(void);
 void unregister_sysfs_loader(void);
 #else /* CONFIG_FW_LOADER_USER_HELPER */
-static inline int fw_sysfs_fallback(struct firmware *fw, const char *name,
-				    struct device *device,
-				    enum fw_opt opt_flags,
-				    int ret)
+static inline int firmware_fallback_sysfs(struct firmware *fw, const char *name,
+					  struct device *device,
+					  enum fw_opt opt_flags,
+					  int ret)
 {
 	/* Keep carrying over the same error */
 	return ret;
diff --git a/drivers/base/firmware_loader/firmware.h b/drivers/base/firmware_loader/firmware.h
index 4f433b447367..4c1395f8e7ed 100644
--- a/drivers/base/firmware_loader/firmware.h
+++ b/drivers/base/firmware_loader/firmware.h
@@ -20,7 +20,7 @@
  * @FW_OPT_NOWAIT: Used to describe the firmware request is asynchronous.
  * @FW_OPT_USERHELPER: Enable the fallback mechanism, in case the direct
  *	filesystem lookup fails at finding the firmware.  For details refer to
- *	fw_sysfs_fallback().
+ *	firmware_fallback_sysfs().
  * @FW_OPT_NO_WARN: Quiet, avoid printing warning messages.
  * @FW_OPT_NOCACHE: Disables firmware caching. Firmware caching is used to
  *	cache the firmware upon suspend, so that upon resume races against the
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index 4d11efadb3a4..abdc4e4d55f1 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -581,7 +581,7 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
 			dev_warn(device,
 				 "Direct firmware load for %s failed with error %d\n",
 				 name, ret);
-		ret = fw_sysfs_fallback(fw, name, device, opt_flags, ret);
+		ret = firmware_fallback_sysfs(fw, name, device, opt_flags, ret);
 	} else
 		ret = assign_fw(fw, device, opt_flags);
 
-- 
2.17.0

[PATCH v6 04/13] firmware_loader: document firmware_sysfs_fallback()

[Luis R. Rodriguez]

This also sets the expecations for future fallback interfaces, even
if they are not exported.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
---
 drivers/base/firmware_loader/fallback.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
index 3db9e0f225ac..9169e7b9800c 100644
--- a/drivers/base/firmware_loader/fallback.c
+++ b/drivers/base/firmware_loader/fallback.c
@@ -662,6 +662,26 @@ static bool fw_run_sysfs_fallback(enum fw_opt opt_flags)
 	return fw_force_sysfs_fallback(opt_flags);
 }
 
+/**
+ * firmware_fallback_sysfs() - use the fallback mechanism to find firmware
+ * @fw: pointer to firmware image
+ * @name: name of firmware file to look for
+ * @device: device for which firmware is being loaded
+ * @opt_flags: options to control firmware loading behaviour
+ * @ret: return value from direct lookup which triggered the fallback mechanism
+ *
+ * This function is called if direct lookup for the firmware failed, it enables
+ * a fallback mechanism through userspace by exposing a sysfs loading
+ * interface. Userspace is in charge of loading the firmware through the syfs
+ * loading interface. This syfs fallback mechanism may be disabled completely
+ * on a system by setting the proc sysctl value ignore_sysfs_fallback to true.
+ * If this false we check if the internal API caller set the @FW_OPT_NOFALLBACK
+ * flag, if so it would also disable the fallback mechanism. A system may want
+ * to enfoce the sysfs fallback mechanism at all times, it can do this by
+ * setting ignore_sysfs_fallback to false and force_sysfs_fallback to true.
+ * Enabling force_sysfs_fallback is functionally equivalent to build a kernel
+ * with CONFIG_FW_LOADER_USER_HELPER_FALLBACK.
+ **/
 int firmware_fallback_sysfs(struct firmware *fw, const char *name,
 			    struct device *device,
 			    enum fw_opt opt_flags,
-- 
2.17.0

[PATCH v6 05/13] firmware_loader: enhance Kconfig documentation over FW_LOADER

[Luis R. Rodriguez]

If you try to read FW_LOADER today it speaks of old riddles and
unless you have been following development closely you will loose
track of what is what. Even the documentation for PREVENT_FIRMWARE_BUILD
is a bit fuzzy and how it fits into this big picture.

Give the FW_LOADER kconfig documentation some love with more up to
date developments and recommendations. While at it, wrap the FW_LOADER
code into its own menu to compartamentalize and make it clearer which
components really are part of the FW_LOADER. This should also make
it easier to later move these kconfig entries into the firmware_loader/
directory later.

This also now recommends using firmwared [0] for folks left needing a uevent
handler in userspace for the sysfs firmware fallback mechanis given udev's
uevent firmware mechanism was ripped out a while ago.

[0] https://github.com/teg/firmwared

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
---
 drivers/base/Kconfig | 165 ++++++++++++++++++++++++++++++++++---------
 1 file changed, 131 insertions(+), 34 deletions(-)

diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index 29b0eb452b3a..a4fe86caecca 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -70,39 +70,64 @@ config STANDALONE
 	  If unsure, say Y.
 
 config PREVENT_FIRMWARE_BUILD
-	bool "Prevent firmware from being built"
+	bool "Disable drivers features which enable custom firmware building"
 	default y
 	help
-	  Say yes to avoid building firmware. Firmware is usually shipped
-	  with the driver and only when updating the firmware should a
-	  rebuild be made.
-	  If unsure, say Y here.
+	  Say yes to disable driver features which enable building a custom
+	  driver firmwar at kernel build time. These drivers do not use the
+	  kernel firmware API to load firmware (CONFIG_FW_LOADER), instead they
+	  use their own custom loading mechanism. The required firmware is
+	  usually shipped with the driver, building the driver firmware
+	  should only be needed if you have an updated firmware source.
+
+	  Firmware should not be being built as part of kernel, these days
+	  you should always prevent this and say Y here. There are only two
+	  old drivers which enable building of its firmware at kernel build
+	  time:
+
+	    o CONFIG_WANXL through CONFIG_WANXL_BUILD_FIRMWARE
+	    o CONFIG_SCSI_AIC79XX through CONFIG_AIC79XX_BUILD_FIRMWARE
+
+menu "Firmware loader"
 
 config FW_LOADER
-	tristate "Userspace firmware loading support" if EXPERT
+	tristate "Firmware loading facility" if EXPERT
 	default y
 	---help---
-	  This option is provided for the case where none of the in-tree modules
-	  require userspace firmware loading support, but a module built
-	  out-of-tree does.
+	  This enables the firmware loading facility in the kernel. The kernel
+	  will first look for built-in firmware, if it has any. Next, it will
+	  look for the requested firmware in a series of filesystem paths:
+
+		o firmware_class path module parameter or kernel boot param
+		o /lib/firmware/updates/UTS_RELEASE
+		o /lib/firmware/updates
+		o /lib/firmware/UTS_RELEASE
+		o /lib/firmware
+
+	  Enabling this feature only increases your kernel image by about
+	  828 bytes, enable this option unless you are certain you don't
+	  need firmware.
+
+	  You typically want this built-in (=y) but you can also enable this
+	  as a module, in which case the firmware_class module will be built.
+	  You also want to be sure to enable this built-in if you are going to
+	  enable built-in firmware (CONFIG_EXTRA_FIRMWARE).
+
+if FW_LOADER
 
 config EXTRA_FIRMWARE
-	string "External firmware blobs to build into the kernel binary"
-	depends on FW_LOADER
+	string "Build these firmware blobs into the kernel binary"
 	help
-	  Various drivers in the kernel source tree may require firmware,
-	  which is generally available in your distribution's linux-firmware
-	  package.
+	  Device drivers which require firmware can typically deal with
+	  having the kernel load firmware from the various supported
+	  /lib/firmware/ paths. This option enables you to build into the
+	  kernel firmware files. Built-in firmware searches are preceeded
+	  over firmware lookups using your filesystem over the supported
+	  /lib/firmware paths documented on CONFIG_FW_LOADER.
 
-	  The linux-firmware package should install firmware into
-	  /lib/firmware/ on your system, so they can be loaded by userspace
-	  helpers on request.
-
-	  This option allows firmware to be built into the kernel for the case
-	  where the user either cannot or doesn't want to provide it from
-	  userspace at runtime (for example, when the firmware in question is
-	  required for accessing the boot device, and the user doesn't want to
-	  use an initrd).
+	  This may be useful for testing or if the firmware is required early on
+	  in boot and cannot rely on the firmware being placed in an initrd or
+	  initramfs.
 
 	  This option is a string and takes the (space-separated) names of the
 	  firmware files -- the same names that appear in MODULE_FIRMWARE()
@@ -113,7 +138,7 @@ config EXTRA_FIRMWARE
 	  For example, you might set CONFIG_EXTRA_FIRMWARE="usb8388.bin", copy
 	  the usb8388.bin file into /lib/firmware, and build the kernel. Then
 	  any request_firmware("usb8388.bin") will be satisfied internally
-	  without needing to call out to userspace.
+	  inside the kernel without ever looking at your filesystem at runtime.
 
 	  WARNING: If you include additional firmware files into your binary
 	  kernel image that are not available under the terms of the GPL,
@@ -130,22 +155,94 @@ config EXTRA_FIRMWARE_DIR
 	  looks for the firmware files listed in the EXTRA_FIRMWARE option.
 
 config FW_LOADER_USER_HELPER
-	bool
+	bool "Enable the firmware sysfs fallback mechanism"
+	help
+	  This option enables a sysfs loading facility to enable firmware
+	  loading to the kernel through userspace as a fallback mechanism
+	  if and only if the kernel's direct filesystem lookup for the
+	  firmware failed using the different /lib/firmware/ paths, or the
+	  path specified in the firmware_class path module parameter, or the
+	  firmware_class path kernel boot parameter if the firmware_class is
+	  built-in. For details on how to work with the sysfs fallback mechanism
+	  refer to Documentation/driver-api/firmware/fallback-mechanisms.rst.
+
+	  The direct filesystem lookup for firwmare is always used first now.
+
+	  If the kernel's direct filesystem lookup for firware fails to find
+	  the requested firmware a sysfs fallback loading facility is made
+	  available and userspace is informed about this through uevents.
+	  The uevent can be supressed if the driver explicitly requested it,
+	  this is known as the driver using the custom fallback mechanism.
+	  If the custom fallback mechanism is used userspace must always
+	  acknowledge failure to find firmware as the timeout for the fallback
+	  mechanism is disabled, and failed requests will linger forever.
+
+	  This used to be the default firmware loading facility, and udev used
+	  to listen for uvents to load firmware for the kernel. The firmware
+	  loading facility functionality in udev has been removed, as such it
+	  can no longer be relied upon as a fallback mechanism. Linux no longer
+	  relies on or uses a fallback mechanism in userspace. If you need to
+	  rely on one refer to the permissively licensed firmwared:
+
+	  https://github.com/teg/firmwared
+
+	  Since this was the default firmware loading facility at one point,
+	  old userspace may exist which relies upon it, and as such this
+	  mechanism can never be removed from the kernel.
+
+	  You should only enable this functionality if you are certain you
+	  require a fallback mechanism and have a userspace mechanism ready to
+	  load firmware in case it is not found. One main reason for this may
+	  be if you have drivers which require firmware built-in and for
+	  whatever reason cannot place the required firmware in initramfs.
+	  Another reason kernels may have this feature enabled is to support a
+	  driver which explicitly relies on this fallback mechanism. Only two
+	  drivers need this today:
+
+	    o CONFIG_LEDS_LP55XX_COMMON
+	    o CONFIG_DELL_RBU
+
+	  Outside of supporting the above drivers, another reason for needing
+	  this may be that your firmware resides outside of the paths the kernel
+	  looks for and cannot possibily be specified using the firmware_class
+	  path module parameter or kernel firmware_class path boot parameter
+	  if firmware_class is built-in.
+
+	  A modern use case may be to temporarily mount a custom partition
+	  during provisioning which is only accessible to userspace, and then
+	  to use it to look for and fetch the required firmware. Such type of
+	  driver functionality may not even ever be desirable upstream by
+	  vendors, and as such is only required to be supported as an interface
+	  for provisioning. Since udev's firmware loading facility has been
+	  removed you can use firmwared or a fork of it to customize how you
+	  want to load firmware based on uevents issued.
+
+	  Enabling this option will increase your kernel image size by about
+	  13436 bytes.
+
+	  If you are unsure about this, say N here, unless you are Linux
+	  distribution and need to support the above two drivers, or you are
+	  certain you need to support some really custom firmware loading
+	  facility in userspace.
 
 config FW_LOADER_USER_HELPER_FALLBACK
-	bool "Fallback user-helper invocation for firmware loading"
-	depends on FW_LOADER
-	select FW_LOADER_USER_HELPER
+	bool "Force the firmware sysfs fallback mechanism when possible"
+	depends on FW_LOADER_USER_HELPER
 	help
-	  This option enables / disables the invocation of user-helper
-	  (e.g. udev) for loading firmware files as a fallback after the
-	  direct file loading in kernel fails.  The user-mode helper is
-	  no longer required unless you have a special firmware file that
-	  resides in a non-standard path. Moreover, the udev support has
-	  been deprecated upstream.
+	  Enabling this option forces a sysfs userspace fallback mechanism
+	  to be used for all firmware requests which explicitly do not disable a
+	  a fallback mechanism. Firmware calls which do prohibit a fallback
+	  mechanism is request_firmware_direct(). This option is kept for
+          backward compatibility purposes given this precise mechanism can also
+	  be enabled by setting the proc sysctl value to true:
+
+	       /proc/sys/kernel/firmware_config/force_sysfs_fallback
 
 	  If you are unsure about this, say N here.
 
+endif # FW_LOADER
+endmenu
+
 config WANT_DEV_COREDUMP
 	bool
 	help
-- 
2.17.0

Re: [PATCH v6 05/13] firmware_loader: enhance Kconfig documentation over FW_LOADER

[Kees Cook]

On Tue, May 8, 2018 at 11:12 AM, Luis R. Rodriguez <mcgrof@kernel.org> wrote:
> If you try to read FW_LOADER today it speaks of old riddles and
> unless you have been following development closely you will loose

Typo: lose

> track of what is what. Even the documentation for PREVENT_FIRMWARE_BUILD
> is a bit fuzzy and how it fits into this big picture.
>
> Give the FW_LOADER kconfig documentation some love with more up to
> date developments and recommendations. While at it, wrap the FW_LOADER
> code into its own menu to compartamentalize and make it clearer which

Typo: compartmentalize

> components really are part of the FW_LOADER. This should also make
> it easier to later move these kconfig entries into the firmware_loader/
> directory later.
>
> This also now recommends using firmwared [0] for folks left needing a uevent
> handler in userspace for the sysfs firmware fallback mechanis given udev's
> uevent firmware mechanism was ripped out a while ago.
>
> [0] https://github.com/teg/firmwared
>
> Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
> ---
>  drivers/base/Kconfig | 165 ++++++++++++++++++++++++++++++++++---------
>  1 file changed, 131 insertions(+), 34 deletions(-)
>
> diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
> index 29b0eb452b3a..a4fe86caecca 100644
> --- a/drivers/base/Kconfig
> +++ b/drivers/base/Kconfig
> @@ -70,39 +70,64 @@ config STANDALONE
>           If unsure, say Y.
>
>  config PREVENT_FIRMWARE_BUILD
> -       bool "Prevent firmware from being built"
> +       bool "Disable drivers features which enable custom firmware building"
>         default y
>         help
> -         Say yes to avoid building firmware. Firmware is usually shipped
> -         with the driver and only when updating the firmware should a
> -         rebuild be made.
> -         If unsure, say Y here.
> +         Say yes to disable driver features which enable building a custom
> +         driver firmwar at kernel build time. These drivers do not use the

Typo: firmware

> +         kernel firmware API to load firmware (CONFIG_FW_LOADER), instead they
> +         use their own custom loading mechanism. The required firmware is
> +         usually shipped with the driver, building the driver firmware
> +         should only be needed if you have an updated firmware source.
> +
> +         Firmware should not be being built as part of kernel, these days
> +         you should always prevent this and say Y here. There are only two
> +         old drivers which enable building of its firmware at kernel build
> +         time:
> +
> +           o CONFIG_WANXL through CONFIG_WANXL_BUILD_FIRMWARE
> +           o CONFIG_SCSI_AIC79XX through CONFIG_AIC79XX_BUILD_FIRMWARE
> +
> +menu "Firmware loader"
>
>  config FW_LOADER
> -       tristate "Userspace firmware loading support" if EXPERT
> +       tristate "Firmware loading facility" if EXPERT
>         default y
>         ---help---
> -         This option is provided for the case where none of the in-tree modules
> -         require userspace firmware loading support, but a module built
> -         out-of-tree does.
> +         This enables the firmware loading facility in the kernel. The kernel
> +         will first look for built-in firmware, if it has any. Next, it will
> +         look for the requested firmware in a series of filesystem paths:
> +
> +               o firmware_class path module parameter or kernel boot param
> +               o /lib/firmware/updates/UTS_RELEASE
> +               o /lib/firmware/updates
> +               o /lib/firmware/UTS_RELEASE
> +               o /lib/firmware
> +
> +         Enabling this feature only increases your kernel image by about
> +         828 bytes, enable this option unless you are certain you don't
> +         need firmware.
> +
> +         You typically want this built-in (=y) but you can also enable this
> +         as a module, in which case the firmware_class module will be built.
> +         You also want to be sure to enable this built-in if you are going to
> +         enable built-in firmware (CONFIG_EXTRA_FIRMWARE).
> +
> +if FW_LOADER
>
>  config EXTRA_FIRMWARE
> -       string "External firmware blobs to build into the kernel binary"
> -       depends on FW_LOADER
> +       string "Build these firmware blobs into the kernel binary"

Maybe "Build named firmware blobs ..." "these" took me a while to figure out.

>         help
> -         Various drivers in the kernel source tree may require firmware,
> -         which is generally available in your distribution's linux-firmware
> -         package.
> +         Device drivers which require firmware can typically deal with
> +         having the kernel load firmware from the various supported
> +         /lib/firmware/ paths. This option enables you to build into the
> +         kernel firmware files. Built-in firmware searches are preceeded

Typo: preceded

> +         over firmware lookups using your filesystem over the supported
> +         /lib/firmware paths documented on CONFIG_FW_LOADER.
>
> -         The linux-firmware package should install firmware into
> -         /lib/firmware/ on your system, so they can be loaded by userspace
> -         helpers on request.
> -
> -         This option allows firmware to be built into the kernel for the case
> -         where the user either cannot or doesn't want to provide it from
> -         userspace at runtime (for example, when the firmware in question is
> -         required for accessing the boot device, and the user doesn't want to
> -         use an initrd).
> +         This may be useful for testing or if the firmware is required early on
> +         in boot and cannot rely on the firmware being placed in an initrd or
> +         initramfs.
>
>           This option is a string and takes the (space-separated) names of the
>           firmware files -- the same names that appear in MODULE_FIRMWARE()
> @@ -113,7 +138,7 @@ config EXTRA_FIRMWARE
>           For example, you might set CONFIG_EXTRA_FIRMWARE="usb8388.bin", copy
>           the usb8388.bin file into /lib/firmware, and build the kernel. Then
>           any request_firmware("usb8388.bin") will be satisfied internally
> -         without needing to call out to userspace.
> +         inside the kernel without ever looking at your filesystem at runtime.
>
>           WARNING: If you include additional firmware files into your binary
>           kernel image that are not available under the terms of the GPL,
> @@ -130,22 +155,94 @@ config EXTRA_FIRMWARE_DIR
>           looks for the firmware files listed in the EXTRA_FIRMWARE option.
>
>  config FW_LOADER_USER_HELPER
> -       bool
> +       bool "Enable the firmware sysfs fallback mechanism"
> +       help
> +         This option enables a sysfs loading facility to enable firmware
> +         loading to the kernel through userspace as a fallback mechanism
> +         if and only if the kernel's direct filesystem lookup for the
> +         firmware failed using the different /lib/firmware/ paths, or the
> +         path specified in the firmware_class path module parameter, or the
> +         firmware_class path kernel boot parameter if the firmware_class is
> +         built-in. For details on how to work with the sysfs fallback mechanism
> +         refer to Documentation/driver-api/firmware/fallback-mechanisms.rst.
> +
> +         The direct filesystem lookup for firwmare is always used first now.

Typo: firmware

> +
> +         If the kernel's direct filesystem lookup for firware fails to find
> +         the requested firmware a sysfs fallback loading facility is made
> +         available and userspace is informed about this through uevents.
> +         The uevent can be supressed if the driver explicitly requested it,
> +         this is known as the driver using the custom fallback mechanism.
> +         If the custom fallback mechanism is used userspace must always
> +         acknowledge failure to find firmware as the timeout for the fallback
> +         mechanism is disabled, and failed requests will linger forever.
> +
> +         This used to be the default firmware loading facility, and udev used
> +         to listen for uvents to load firmware for the kernel. The firmware
> +         loading facility functionality in udev has been removed, as such it
> +         can no longer be relied upon as a fallback mechanism. Linux no longer
> +         relies on or uses a fallback mechanism in userspace. If you need to
> +         rely on one refer to the permissively licensed firmwared:

Typo: firmware

> +
> +         https://github.com/teg/firmwared
> +
> +         Since this was the default firmware loading facility at one point,
> +         old userspace may exist which relies upon it, and as such this
> +         mechanism can never be removed from the kernel.
> +
> +         You should only enable this functionality if you are certain you
> +         require a fallback mechanism and have a userspace mechanism ready to
> +         load firmware in case it is not found. One main reason for this may
> +         be if you have drivers which require firmware built-in and for
> +         whatever reason cannot place the required firmware in initramfs.
> +         Another reason kernels may have this feature enabled is to support a
> +         driver which explicitly relies on this fallback mechanism. Only two
> +         drivers need this today:
> +
> +           o CONFIG_LEDS_LP55XX_COMMON
> +           o CONFIG_DELL_RBU
> +
> +         Outside of supporting the above drivers, another reason for needing
> +         this may be that your firmware resides outside of the paths the kernel
> +         looks for and cannot possibily be specified using the firmware_class
> +         path module parameter or kernel firmware_class path boot parameter
> +         if firmware_class is built-in.
> +
> +         A modern use case may be to temporarily mount a custom partition
> +         during provisioning which is only accessible to userspace, and then
> +         to use it to look for and fetch the required firmware. Such type of
> +         driver functionality may not even ever be desirable upstream by
> +         vendors, and as such is only required to be supported as an interface
> +         for provisioning. Since udev's firmware loading facility has been
> +         removed you can use firmwared or a fork of it to customize how you
> +         want to load firmware based on uevents issued.
> +
> +         Enabling this option will increase your kernel image size by about
> +         13436 bytes.
> +
> +         If you are unsure about this, say N here, unless you are Linux
> +         distribution and need to support the above two drivers, or you are
> +         certain you need to support some really custom firmware loading
> +         facility in userspace.
>
>  config FW_LOADER_USER_HELPER_FALLBACK
> -       bool "Fallback user-helper invocation for firmware loading"
> -       depends on FW_LOADER
> -       select FW_LOADER_USER_HELPER
> +       bool "Force the firmware sysfs fallback mechanism when possible"
> +       depends on FW_LOADER_USER_HELPER
>         help
> -         This option enables / disables the invocation of user-helper
> -         (e.g. udev) for loading firmware files as a fallback after the
> -         direct file loading in kernel fails.  The user-mode helper is
> -         no longer required unless you have a special firmware file that
> -         resides in a non-standard path. Moreover, the udev support has
> -         been deprecated upstream.
> +         Enabling this option forces a sysfs userspace fallback mechanism
> +         to be used for all firmware requests which explicitly do not disable a
> +         a fallback mechanism. Firmware calls which do prohibit a fallback
> +         mechanism is request_firmware_direct(). This option is kept for
> +          backward compatibility purposes given this precise mechanism can also
> +         be enabled by setting the proc sysctl value to true:
> +
> +              /proc/sys/kernel/firmware_config/force_sysfs_fallback
>
>           If you are unsure about this, say N here.
>
> +endif # FW_LOADER
> +endmenu
> +
>  config WANT_DEV_COREDUMP
>         bool
>         help
> --
> 2.17.0
>


-Kees

-- 
Kees Cook
Pixel Security

Re: [PATCH v6 05/13] firmware_loader: enhance Kconfig documentation over FW_LOADER

[Luis R. Rodriguez]

On Tue, May 08, 2018 at 03:42:33PM -0700, Kees Cook wrote:
> On Tue, May 8, 2018 at 11:12 AM, Luis R. Rodriguez <mcgrof@kernel.org> wrote:
> > +         This used to be the default firmware loading facility, and udev used
> > +         to listen for uvents to load firmware for the kernel. The firmware
> > +         loading facility functionality in udev has been removed, as such it
> > +         can no longer be relied upon as a fallback mechanism. Linux no longer
> > +         relies on or uses a fallback mechanism in userspace. If you need to
> > +         rely on one refer to the permissively licensed firmwared:
> 
> Typo: firmware

Thanks fixed all typos except this one, this one is meant to be firmwared as
that is the name of the project, the url is below.

> 
> > +
> > +         https://github.com/teg/firmwared

  Luis

Re: [PATCH v6 05/13] firmware_loader: enhance Kconfig documentation over FW_LOADER

[Kees Cook]

On Wed, May 9, 2018 at 1:55 PM, Luis R. Rodriguez <mcgrof@kernel.org> wrote:
> On Tue, May 08, 2018 at 03:42:33PM -0700, Kees Cook wrote:
>> On Tue, May 8, 2018 at 11:12 AM, Luis R. Rodriguez <mcgrof@kernel.org> wrote:
>> > +         This used to be the default firmware loading facility, and udev used
>> > +         to listen for uvents to load firmware for the kernel. The firmware
>> > +         loading facility functionality in udev has been removed, as such it
>> > +         can no longer be relied upon as a fallback mechanism. Linux no longer
>> > +         relies on or uses a fallback mechanism in userspace. If you need to
>> > +         rely on one refer to the permissively licensed firmwared:
>>
>> Typo: firmware
>
> Thanks fixed all typos except this one, this one is meant to be firmwared as
> that is the name of the project, the url is below.
>
>>
>> > +
>> > +         https://github.com/teg/firmwared

Oh! Yes, hah. :) Thanks!

-Kees

-- 
Kees Cook
Pixel Security

[PATCH v6 06/13] firmware_loader: move kconfig FW_LOADER entries to its own file

[Luis R. Rodriguez]

This will make it easier to track and easier to understand
what components and features are part of the FW_LOADER. There
are some components related to firmware which have *nothing* to
do with the FW_LOADER, souch as PREVENT_FIRMWARE_BUILD.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
---
 drivers/base/Kconfig                 | 155 +--------------------------
 drivers/base/firmware_loader/Kconfig | 154 ++++++++++++++++++++++++++
 2 files changed, 155 insertions(+), 154 deletions(-)
 create mode 100644 drivers/base/firmware_loader/Kconfig

diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index a4fe86caecca..06d6e27784fa 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -88,160 +88,7 @@ config PREVENT_FIRMWARE_BUILD
 	    o CONFIG_WANXL through CONFIG_WANXL_BUILD_FIRMWARE
 	    o CONFIG_SCSI_AIC79XX through CONFIG_AIC79XX_BUILD_FIRMWARE
 
-menu "Firmware loader"
-
-config FW_LOADER
-	tristate "Firmware loading facility" if EXPERT
-	default y
-	---help---
-	  This enables the firmware loading facility in the kernel. The kernel
-	  will first look for built-in firmware, if it has any. Next, it will
-	  look for the requested firmware in a series of filesystem paths:
-
-		o firmware_class path module parameter or kernel boot param
-		o /lib/firmware/updates/UTS_RELEASE
-		o /lib/firmware/updates
-		o /lib/firmware/UTS_RELEASE
-		o /lib/firmware
-
-	  Enabling this feature only increases your kernel image by about
-	  828 bytes, enable this option unless you are certain you don't
-	  need firmware.
-
-	  You typically want this built-in (=y) but you can also enable this
-	  as a module, in which case the firmware_class module will be built.
-	  You also want to be sure to enable this built-in if you are going to
-	  enable built-in firmware (CONFIG_EXTRA_FIRMWARE).
-
-if FW_LOADER
-
-config EXTRA_FIRMWARE
-	string "Build these firmware blobs into the kernel binary"
-	help
-	  Device drivers which require firmware can typically deal with
-	  having the kernel load firmware from the various supported
-	  /lib/firmware/ paths. This option enables you to build into the
-	  kernel firmware files. Built-in firmware searches are preceeded
-	  over firmware lookups using your filesystem over the supported
-	  /lib/firmware paths documented on CONFIG_FW_LOADER.
-
-	  This may be useful for testing or if the firmware is required early on
-	  in boot and cannot rely on the firmware being placed in an initrd or
-	  initramfs.
-
-	  This option is a string and takes the (space-separated) names of the
-	  firmware files -- the same names that appear in MODULE_FIRMWARE()
-	  and request_firmware() in the source. These files should exist under
-	  the directory specified by the EXTRA_FIRMWARE_DIR option, which is
-	  /lib/firmware by default.
-
-	  For example, you might set CONFIG_EXTRA_FIRMWARE="usb8388.bin", copy
-	  the usb8388.bin file into /lib/firmware, and build the kernel. Then
-	  any request_firmware("usb8388.bin") will be satisfied internally
-	  inside the kernel without ever looking at your filesystem at runtime.
-
-	  WARNING: If you include additional firmware files into your binary
-	  kernel image that are not available under the terms of the GPL,
-	  then it may be a violation of the GPL to distribute the resulting
-	  image since it combines both GPL and non-GPL work. You should
-	  consult a lawyer of your own before distributing such an image.
-
-config EXTRA_FIRMWARE_DIR
-	string "Firmware blobs root directory"
-	depends on EXTRA_FIRMWARE != ""
-	default "/lib/firmware"
-	help
-	  This option controls the directory in which the kernel build system
-	  looks for the firmware files listed in the EXTRA_FIRMWARE option.
-
-config FW_LOADER_USER_HELPER
-	bool "Enable the firmware sysfs fallback mechanism"
-	help
-	  This option enables a sysfs loading facility to enable firmware
-	  loading to the kernel through userspace as a fallback mechanism
-	  if and only if the kernel's direct filesystem lookup for the
-	  firmware failed using the different /lib/firmware/ paths, or the
-	  path specified in the firmware_class path module parameter, or the
-	  firmware_class path kernel boot parameter if the firmware_class is
-	  built-in. For details on how to work with the sysfs fallback mechanism
-	  refer to Documentation/driver-api/firmware/fallback-mechanisms.rst.
-
-	  The direct filesystem lookup for firwmare is always used first now.
-
-	  If the kernel's direct filesystem lookup for firware fails to find
-	  the requested firmware a sysfs fallback loading facility is made
-	  available and userspace is informed about this through uevents.
-	  The uevent can be supressed if the driver explicitly requested it,
-	  this is known as the driver using the custom fallback mechanism.
-	  If the custom fallback mechanism is used userspace must always
-	  acknowledge failure to find firmware as the timeout for the fallback
-	  mechanism is disabled, and failed requests will linger forever.
-
-	  This used to be the default firmware loading facility, and udev used
-	  to listen for uvents to load firmware for the kernel. The firmware
-	  loading facility functionality in udev has been removed, as such it
-	  can no longer be relied upon as a fallback mechanism. Linux no longer
-	  relies on or uses a fallback mechanism in userspace. If you need to
-	  rely on one refer to the permissively licensed firmwared:
-
-	  https://github.com/teg/firmwared
-
-	  Since this was the default firmware loading facility at one point,
-	  old userspace may exist which relies upon it, and as such this
-	  mechanism can never be removed from the kernel.
-
-	  You should only enable this functionality if you are certain you
-	  require a fallback mechanism and have a userspace mechanism ready to
-	  load firmware in case it is not found. One main reason for this may
-	  be if you have drivers which require firmware built-in and for
-	  whatever reason cannot place the required firmware in initramfs.
-	  Another reason kernels may have this feature enabled is to support a
-	  driver which explicitly relies on this fallback mechanism. Only two
-	  drivers need this today:
-
-	    o CONFIG_LEDS_LP55XX_COMMON
-	    o CONFIG_DELL_RBU
-
-	  Outside of supporting the above drivers, another reason for needing
-	  this may be that your firmware resides outside of the paths the kernel
-	  looks for and cannot possibily be specified using the firmware_class
-	  path module parameter or kernel firmware_class path boot parameter
-	  if firmware_class is built-in.
-
-	  A modern use case may be to temporarily mount a custom partition
-	  during provisioning which is only accessible to userspace, and then
-	  to use it to look for and fetch the required firmware. Such type of
-	  driver functionality may not even ever be desirable upstream by
-	  vendors, and as such is only required to be supported as an interface
-	  for provisioning. Since udev's firmware loading facility has been
-	  removed you can use firmwared or a fork of it to customize how you
-	  want to load firmware based on uevents issued.
-
-	  Enabling this option will increase your kernel image size by about
-	  13436 bytes.
-
-	  If you are unsure about this, say N here, unless you are Linux
-	  distribution and need to support the above two drivers, or you are
-	  certain you need to support some really custom firmware loading
-	  facility in userspace.
-
-config FW_LOADER_USER_HELPER_FALLBACK
-	bool "Force the firmware sysfs fallback mechanism when possible"
-	depends on FW_LOADER_USER_HELPER
-	help
-	  Enabling this option forces a sysfs userspace fallback mechanism
-	  to be used for all firmware requests which explicitly do not disable a
-	  a fallback mechanism. Firmware calls which do prohibit a fallback
-	  mechanism is request_firmware_direct(). This option is kept for
-          backward compatibility purposes given this precise mechanism can also
-	  be enabled by setting the proc sysctl value to true:
-
-	       /proc/sys/kernel/firmware_config/force_sysfs_fallback
-
-	  If you are unsure about this, say N here.
-
-endif # FW_LOADER
-endmenu
+source "drivers/base/firmware_loader/Kconfig"
 
 config WANT_DEV_COREDUMP
 	bool
diff --git a/drivers/base/firmware_loader/Kconfig b/drivers/base/firmware_loader/Kconfig
new file mode 100644
index 000000000000..bff3606bc7fa
--- /dev/null
+++ b/drivers/base/firmware_loader/Kconfig
@@ -0,0 +1,154 @@
+menu "Firmware loader"
+
+config FW_LOADER
+	tristate "Firmware loading facility" if EXPERT
+	default y
+	---help---
+	  This enables the firmware loading facility in the kernel. The kernel
+	  will first look for built-in firmware, if it has any. Next, it will
+	  look for the requested firmware in a series of filesystem paths:
+
+		o firmware_class path module parameter or kernel boot param
+		o /lib/firmware/updates/UTS_RELEASE
+		o /lib/firmware/updates
+		o /lib/firmware/UTS_RELEASE
+		o /lib/firmware
+
+	  Enabling this feature only increases your kernel image by about
+	  828 bytes, enable this option unless you are certain you don't
+	  need firmware.
+
+	  You typically want this built-in (=y) but you can also enable this
+	  as a module, in which case the firmware_class module will be built.
+	  You also want to be sure to enable this built-in if you are going to
+	  enable built-in firmware (CONFIG_EXTRA_FIRMWARE).
+
+if FW_LOADER
+
+config EXTRA_FIRMWARE
+	string "Build these firmware blobs into the kernel binary"
+	help
+	  Device drivers which require firmware can typically deal with
+	  having the kernel load firmware from the various supported
+	  /lib/firmware/ paths. This option enables you to build into the
+	  kernel firmware files. Built-in firmware searches are preceeded
+	  over firmware lookups using your filesystem over the supported
+	  /lib/firmware paths documented on CONFIG_FW_LOADER.
+
+	  This may be useful for testing or if the firmware is required early on
+	  in boot and cannot rely on the firmware being placed in an initrd or
+	  initramfs.
+
+	  This option is a string and takes the (space-separated) names of the
+	  firmware files -- the same names that appear in MODULE_FIRMWARE()
+	  and request_firmware() in the source. These files should exist under
+	  the directory specified by the EXTRA_FIRMWARE_DIR option, which is
+	  /lib/firmware by default.
+
+	  For example, you might set CONFIG_EXTRA_FIRMWARE="usb8388.bin", copy
+	  the usb8388.bin file into /lib/firmware, and build the kernel. Then
+	  any request_firmware("usb8388.bin") will be satisfied internally
+	  inside the kernel without ever looking at your filesystem at runtime.
+
+	  WARNING: If you include additional firmware files into your binary
+	  kernel image that are not available under the terms of the GPL,
+	  then it may be a violation of the GPL to distribute the resulting
+	  image since it combines both GPL and non-GPL work. You should
+	  consult a lawyer of your own before distributing such an image.
+
+config EXTRA_FIRMWARE_DIR
+	string "Firmware blobs root directory"
+	depends on EXTRA_FIRMWARE != ""
+	default "/lib/firmware"
+	help
+	  This option controls the directory in which the kernel build system
+	  looks for the firmware files listed in the EXTRA_FIRMWARE option.
+
+config FW_LOADER_USER_HELPER
+	bool "Enable the firmware sysfs fallback mechanism"
+	help
+	  This option enables a sysfs loading facility to enable firmware
+	  loading to the kernel through userspace as a fallback mechanism
+	  if and only if the kernel's direct filesystem lookup for the
+	  firmware failed using the different /lib/firmware/ paths, or the
+	  path specified in the firmware_class path module parameter, or the
+	  firmware_class path kernel boot parameter if the firmware_class is
+	  built-in. For details on how to work with the sysfs fallback mechanism
+	  refer to Documentation/driver-api/firmware/fallback-mechanisms.rst.
+
+	  The direct filesystem lookup for firwmare is always used first now.
+
+	  If the kernel's direct filesystem lookup for firware fails to find
+	  the requested firmware a sysfs fallback loading facility is made
+	  available and userspace is informed about this through uevents.
+	  The uevent can be supressed if the driver explicitly requested it,
+	  this is known as the driver using the custom fallback mechanism.
+	  If the custom fallback mechanism is used userspace must always
+	  acknowledge failure to find firmware as the timeout for the fallback
+	  mechanism is disabled, and failed requests will linger forever.
+
+	  This used to be the default firmware loading facility, and udev used
+	  to listen for uvents to load firmware for the kernel. The firmware
+	  loading facility functionality in udev has been removed, as such it
+	  can no longer be relied upon as a fallback mechanism. Linux no longer
+	  relies on or uses a fallback mechanism in userspace. If you need to
+	  rely on one refer to the permissively licensed firmwared:
+
+	  https://github.com/teg/firmwared
+
+	  Since this was the default firmware loading facility at one point,
+	  old userspace may exist which relies upon it, and as such this
+	  mechanism can never be removed from the kernel.
+
+	  You should only enable this functionality if you are certain you
+	  require a fallback mechanism and have a userspace mechanism ready to
+	  load firmware in case it is not found. One main reason for this may
+	  be if you have drivers which require firmware built-in and for
+	  whatever reason cannot place the required firmware in initramfs.
+	  Another reason kernels may have this feature enabled is to support a
+	  driver which explicitly relies on this fallback mechanism. Only two
+	  drivers need this today:
+
+	    o CONFIG_LEDS_LP55XX_COMMON
+	    o CONFIG_DELL_RBU
+
+	  Outside of supporting the above drivers, another reason for needing
+	  this may be that your firmware resides outside of the paths the kernel
+	  looks for and cannot possibily be specified using the firmware_class
+	  path module parameter or kernel firmware_class path boot parameter
+	  if firmware_class is built-in.
+
+	  A modern use case may be to temporarily mount a custom partition
+	  during provisioning which is only accessible to userspace, and then
+	  to use it to look for and fetch the required firmware. Such type of
+	  driver functionality may not even ever be desirable upstream by
+	  vendors, and as such is only required to be supported as an interface
+	  for provisioning. Since udev's firmware loading facility has been
+	  removed you can use firmwared or a fork of it to customize how you
+	  want to load firmware based on uevents issued.
+
+	  Enabling this option will increase your kernel image size by about
+	  13436 bytes.
+
+	  If you are unsure about this, say N here, unless you are Linux
+	  distribution and need to support the above two drivers, or you are
+	  certain you need to support some really custom firmware loading
+	  facility in userspace.
+
+config FW_LOADER_USER_HELPER_FALLBACK
+	bool "Force the firmware sysfs fallback mechanism when possible"
+	depends on FW_LOADER_USER_HELPER
+	help
+	  Enabling this option forces a sysfs userspace fallback mechanism
+	  to be used for all firmware requests which explicitly do not disable a
+	  a fallback mechanism. Firmware calls which do prohibit a fallback
+	  mechanism is request_firmware_direct(). This option is kept for
+          backward compatibility purposes given this precise mechanism can also
+	  be enabled by setting the proc sysctl value to true:
+
+	       /proc/sys/kernel/firmware_config/force_sysfs_fallback
+
+	  If you are unsure about this, say N here.
+
+endif # FW_LOADER
+endmenu
-- 
2.17.0

[PATCH v6 07/13] firmware_loader: make firmware_fallback_sysfs() print more useful

[Luis R. Rodriguez]

If we resort to using the sysfs fallback mechanism we don't print
the filename. This can be deceiving given we could have a series of
callers intertwined and it'd be unclear exactly for what firmware
this was meant for.

Additionally, although we don't currently use FW_OPT_NO_WARN when
dealing with the fallback mechanism, we will soon, so just respect
its use consistently.

And even if you *don't* want to print always on failure, you may
want to print when debugging so enable dynamic debug print when
FW_OPT_NO_WARN is used.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
---
 drivers/base/firmware_loader/fallback.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
index 9169e7b9800c..b676a99c469c 100644
--- a/drivers/base/firmware_loader/fallback.c
+++ b/drivers/base/firmware_loader/fallback.c
@@ -690,6 +690,11 @@ int firmware_fallback_sysfs(struct firmware *fw, const char *name,
 	if (!fw_run_sysfs_fallback(opt_flags))
 		return ret;
 
-	dev_warn(device, "Falling back to user helper\n");
+	if (!(opt_flags & FW_OPT_NO_WARN))
+		dev_warn(device, "Falling back to syfs fallback for: %s\n",
+				 name);
+	else
+		dev_dbg(device, "Falling back to sysfs fallback for: %s\n",
+				name);
 	return fw_load_from_user_helper(fw, name, device, opt_flags);
 }
-- 
2.17.0

[PATCH v6 08/13] firmware: add firmware_request_nowarn() - load firmware without warnings

[Luis R. Rodriguez]

From: Andres Rodriguez <andresx7@gmail.com>

Currently the firmware loader only exposes one silent path for querying
optional firmware, and that is firmware_request_direct(). This function
also disables the sysfs fallback mechanism, which might not always be the
desired behaviour [0].

This patch introduces a variations of request_firmware() that enable the
caller to disable the undesired warning messages but enables the sysfs
fallback mechanism. This is equivalent to adding FW_OPT_NO_WARN to the
old behaviour.

[0]: https://git.kernel.org/linus/c0cc00f250e1

Signed-off-by: Andres Rodriguez <andresx7@gmail.com>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
[mcgrof: used the old API calls as the full rename is not done yet, and
 add the caller for when FW_LOADER is disabled, enhance documentation ]
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
---
 .../driver-api/firmware/request_firmware.rst  |  5 ++++
 drivers/base/firmware_loader/main.c           | 27 +++++++++++++++++++
 include/linux/firmware.h                      | 10 +++++++
 3 files changed, 42 insertions(+)

diff --git a/Documentation/driver-api/firmware/request_firmware.rst b/Documentation/driver-api/firmware/request_firmware.rst
index d5ec95a7195b..f62bdcbfed5b 100644
--- a/Documentation/driver-api/firmware/request_firmware.rst
+++ b/Documentation/driver-api/firmware/request_firmware.rst
@@ -20,6 +20,11 @@ request_firmware
 .. kernel-doc:: drivers/base/firmware_loader/main.c
    :functions: request_firmware
 
+firmware_request_nowarn
+-----------------------
+.. kernel-doc:: drivers/base/firmware_loader/main.c
+   :functions: firmware_request_nowarn
+
 request_firmware_direct
 -----------------------
 .. kernel-doc:: drivers/base/firmware_loader/main.c
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index abdc4e4d55f1..2be79ee773c0 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -631,6 +631,33 @@ request_firmware(const struct firmware **firmware_p, const char *name,
 }
 EXPORT_SYMBOL(request_firmware);
 
+/**
+ * firmware_request_nowarn() - request for an optional fw module
+ * @firmware: pointer to firmware image
+ * @name: name of firmware file
+ * @device: device for which firmware is being loaded
+ *
+ * This function is similar in behaviour to request_firmware(), except
+ * it doesn't produce warning messages when the file is not found.
+ * The sysfs fallback mechanism is enabled if direct filesystem lookup fails,
+ * however, however failures to find the firmware file with it are still
+ * supressed. It is therefore up to the driver to check for the return value
+ * of this call and to decide when to inform the users of errors.
+ **/
+int firmware_request_nowarn(const struct firmware **firmware, const char *name,
+			    struct device *device)
+{
+	int ret;
+
+	/* Need to pin this module until return */
+	__module_get(THIS_MODULE);
+	ret = _request_firmware(firmware, name, device, NULL, 0,
+				FW_OPT_UEVENT | FW_OPT_NO_WARN);
+	module_put(THIS_MODULE);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(firmware_request_nowarn);
+
 /**
  * request_firmware_direct() - load firmware directly without usermode helper
  * @firmware_p: pointer to firmware image
diff --git a/include/linux/firmware.h b/include/linux/firmware.h
index 41050417cafb..2dd566c91d44 100644
--- a/include/linux/firmware.h
+++ b/include/linux/firmware.h
@@ -42,6 +42,8 @@ struct builtin_fw {
 #if defined(CONFIG_FW_LOADER) || (defined(CONFIG_FW_LOADER_MODULE) && defined(MODULE))
 int request_firmware(const struct firmware **fw, const char *name,
 		     struct device *device);
+int firmware_request_nowarn(const struct firmware **fw, const char *name,
+			    struct device *device);
 int request_firmware_nowait(
 	struct module *module, bool uevent,
 	const char *name, struct device *device, gfp_t gfp, void *context,
@@ -59,6 +61,14 @@ static inline int request_firmware(const struct firmware **fw,
 {
 	return -EINVAL;
 }
+
+static inline int firmware_request_nowarn(const struct firmware **fw,
+					  const char *name,
+					  struct device *device)
+{
+	return -EINVAL;
+}
+
 static inline int request_firmware_nowait(
 	struct module *module, bool uevent,
 	const char *name, struct device *device, gfp_t gfp, void *context,
-- 
2.17.0

[PATCH v6 09/13] ath10k: use firmware_request_nowarn() to load firmware

[Luis R. Rodriguez]

From: Andres Rodriguez <andresx7@gmail.com>

This reduces the unnecessary spew when trying to load optional firmware:
"Direct firmware load for ... failed with error -2"

Signed-off-by: Andres Rodriguez <andresx7@gmail.com>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
---
 drivers/net/wireless/ath/ath10k/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath10k/core.c b/drivers/net/wireless/ath/ath10k/core.c
index 4cf54a7ef09a..ad4f6e3c0737 100644
--- a/drivers/net/wireless/ath/ath10k/core.c
+++ b/drivers/net/wireless/ath/ath10k/core.c
@@ -694,7 +694,7 @@ static const struct firmware *ath10k_fetch_fw_file(struct ath10k *ar,
 		dir = ".";
 
 	snprintf(filename, sizeof(filename), "%s/%s", dir, file);
-	ret = request_firmware(&fw, filename, ar->dev);
+	ret = firmware_request_nowarn(&fw, filename, ar->dev);
 	ath10k_dbg(ar, ATH10K_DBG_BOOT, "boot fw request '%s': %d\n",
 		   filename, ret);
 
-- 
2.17.0

[PATCH v6 10/13] ath10k: re-enable the firmware fallback mechanism for testmode

[Luis R. Rodriguez]

From: Andres Rodriguez <andresx7@gmail.com>

The ath10k testmode uses request_firmware_direct() in order to avoid
producing firmware load warnings. Disabling the fallback mechanism was a
side effect of disabling warnings.

We now have a new API that allows us to avoid warnings while keeping the
fallback mechanism enabled. So use that instead.

Signed-off-by: Andres Rodriguez <andresx7@gmail.com>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
---
 drivers/net/wireless/ath/ath10k/testmode.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath10k/testmode.c b/drivers/net/wireless/ath/ath10k/testmode.c
index 568810b41657..c24ee616833c 100644
--- a/drivers/net/wireless/ath/ath10k/testmode.c
+++ b/drivers/net/wireless/ath/ath10k/testmode.c
@@ -157,7 +157,7 @@ static int ath10k_tm_fetch_utf_firmware_api_1(struct ath10k *ar,
 		 ar->hw_params.fw.dir, ATH10K_FW_UTF_FILE);
 
 	/* load utf firmware image */
-	ret = request_firmware_direct(&fw_file->firmware, filename, ar->dev);
+	ret = firmware_request_nowarn(&fw_file->firmware, filename, ar->dev);
 	ath10k_dbg(ar, ATH10K_DBG_TESTMODE, "testmode fw request '%s': %d\n",
 		   filename, ret);
 
-- 
2.17.0

[PATCH v6 11/13] Documentation: fix few typos and clarifications for the firmware loader

[Luis R. Rodriguez]

Fix a few typos, and clarify a few sentences.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
---
 Documentation/driver-api/firmware/fallback-mechanisms.rst | 5 +++--
 Documentation/driver-api/firmware/firmware_cache.rst      | 4 ++--
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/Documentation/driver-api/firmware/fallback-mechanisms.rst b/Documentation/driver-api/firmware/fallback-mechanisms.rst
index f353783ae0be..a39323ef7d29 100644
--- a/Documentation/driver-api/firmware/fallback-mechanisms.rst
+++ b/Documentation/driver-api/firmware/fallback-mechanisms.rst
@@ -83,7 +83,7 @@ and a file upload firmware into:
   * /sys/$DEVPATH/data
 
 To upload firmware you will echo 1 onto the loading file to indicate
-you are loading firmware. You then cat the firmware into the data file,
+you are loading firmware. You then write the firmware into the data file,
 and you notify the kernel the firmware is ready by echo'ing 0 onto
 the loading file.
 
@@ -136,7 +136,8 @@ by kobject uevents. This is specially exacerbated due to the fact that most
 distributions today disable CONFIG_FW_LOADER_USER_HELPER_FALLBACK.
 
 Refer to do_firmware_uevent() for details of the kobject event variables
-setup. Variables passwdd with a kobject add event:
+setup. The variables currently passed to userspace with a "kobject add"
+event are:
 
 * FIRMWARE=firmware name
 * TIMEOUT=timeout value
diff --git a/Documentation/driver-api/firmware/firmware_cache.rst b/Documentation/driver-api/firmware/firmware_cache.rst
index 2210e5bfb332..c2e69d9c6bf1 100644
--- a/Documentation/driver-api/firmware/firmware_cache.rst
+++ b/Documentation/driver-api/firmware/firmware_cache.rst
@@ -29,8 +29,8 @@ Some implementation details about the firmware cache setup:
 * If an asynchronous call is used the firmware cache is only set up for a
   device if if the second argument (uevent) to request_firmware_nowait() is
   true. When uevent is true it requests that a kobject uevent be sent to
-  userspace for the firmware request. For details refer to the Fackback
-  mechanism documented below.
+  userspace for the firmware request through the sysfs fallback mechanism
+  if the firmware file is not found.
 
 * If the firmware cache is determined to be needed as per the above two
   criteria the firmware cache is setup by adding a devres entry for the
-- 
2.17.0

[PATCH v6 12/13] Documentation: remove stale firmware API reference

[Luis R. Rodriguez]

It refers to a pending patch, but this was merged eons ago.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
---
 Documentation/dell_rbu.txt | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/Documentation/dell_rbu.txt b/Documentation/dell_rbu.txt
index 0fdb6aa2704c..077fdc29a0d0 100644
--- a/Documentation/dell_rbu.txt
+++ b/Documentation/dell_rbu.txt
@@ -121,9 +121,6 @@ read back the image downloaded.
 
 .. note::
 
-   This driver requires a patch for firmware_class.c which has the modified
-   request_firmware_nowait function.
-
    Also after updating the BIOS image a user mode application needs to execute
    code which sends the BIOS update request to the BIOS. So on the next reboot
    the BIOS knows about the new image downloaded and it updates itself.
-- 
2.17.0

Re: [PATCH v6 12/13] Documentation: remove stale firmware API reference

[Mauro Carvalho Chehab]

Em Tue,  8 May 2018 11:12:46 -0700
"Luis R. Rodriguez" <mcgrof@kernel.org> escreveu:

> It refers to a pending patch, but this was merged eons ago.

Didn't know that such patch was already merged. Great!

Regards,
Mauro

> 
> Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
> ---
>  Documentation/dell_rbu.txt | 3 ---
>  1 file changed, 3 deletions(-)
> 
> diff --git a/Documentation/dell_rbu.txt b/Documentation/dell_rbu.txt
> index 0fdb6aa2704c..077fdc29a0d0 100644
> --- a/Documentation/dell_rbu.txt
> +++ b/Documentation/dell_rbu.txt
> @@ -121,9 +121,6 @@ read back the image downloaded.
>  
>  .. note::
>  
> -   This driver requires a patch for firmware_class.c which has the modified
> -   request_firmware_nowait function.
> -

>     Also after updating the BIOS image a user mode application needs to execute
>     code which sends the BIOS update request to the BIOS. So on the next reboot
>     the BIOS knows about the new image downloaded and it updates itself.

You should likely remove the "Also" here.

With that,

Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Regards,
Mauro

Re: [PATCH v6 12/13] Documentation: remove stale firmware API reference

[Luis R. Rodriguez]

On Wed, May 09, 2018 at 12:12:09PM -0300, Mauro Carvalho Chehab wrote:
> Em Tue,  8 May 2018 11:12:46 -0700
> "Luis R. Rodriguez" <mcgrof@kernel.org> escreveu:
> 
> > It refers to a pending patch, but this was merged eons ago.
> 
> Didn't know that such patch was already merged. Great!
> 
> Regards,
> Mauro
> 
> > 
> > Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
> > ---
> >  Documentation/dell_rbu.txt | 3 ---
> >  1 file changed, 3 deletions(-)
> > 
> > diff --git a/Documentation/dell_rbu.txt b/Documentation/dell_rbu.txt
> > index 0fdb6aa2704c..077fdc29a0d0 100644
> > --- a/Documentation/dell_rbu.txt
> > +++ b/Documentation/dell_rbu.txt
> > @@ -121,9 +121,6 @@ read back the image downloaded.
> >  
> >  .. note::
> >  
> > -   This driver requires a patch for firmware_class.c which has the modified
> > -   request_firmware_nowait function.
> > -
> 
> >     Also after updating the BIOS image a user mode application needs to execute
> >     code which sends the BIOS update request to the BIOS. So on the next reboot
> >     the BIOS knows about the new image downloaded and it updates itself.
> 
> You should likely remove the "Also" here.

Good catch. Will adjust.

> 
> With that,
> 
> Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Great, thanks.

  Luis

[PATCH v6 13/13] Documentation: clarify firmware_class provenance and why we can't rename the module

[Luis R. Rodriguez]

Clarify the provenance of the firmware loader firmware_class module name
and why we cannot rename the module in the future.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
---
 .../driver-api/firmware/fallback-mechanisms.rst          | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/Documentation/driver-api/firmware/fallback-mechanisms.rst b/Documentation/driver-api/firmware/fallback-mechanisms.rst
index a39323ef7d29..a8047be4a96e 100644
--- a/Documentation/driver-api/firmware/fallback-mechanisms.rst
+++ b/Documentation/driver-api/firmware/fallback-mechanisms.rst
@@ -72,9 +72,12 @@ the firmware requested, and establishes it in the device hierarchy by
 associating the device used to make the request as the device's parent.
 The sysfs directory's file attributes are defined and controlled through
 the new device's class (firmware_class) and group (fw_dev_attr_groups).
-This is actually where the original firmware_class.c file name comes from,
-as originally the only firmware loading mechanism available was the
-mechanism we now use as a fallback mechanism.
+This is actually where the original firmware_class module name came from,
+given that originally the only firmware loading mechanism available was the
+mechanism we now use as a fallback mechanism, which which registers a
+struct class firmware_class. Because the attributes exposed are part of the
+module name, the module name firmware_class cannot be renamed in the future, to
+ensure backward compatibilty with old userspace.
 
 To load firmware using the sysfs interface we expose a loading indicator,
 and a file upload firmware into:
-- 
2.17.0

Re: [PATCH v6 13/13] Documentation: clarify firmware_class provenance and why we can't rename the module

[Andres Rodriguez]

On 2018-05-08 02:12 PM, Luis R. Rodriguez wrote:
> Clarify the provenance of the firmware loader firmware_class module name
> and why we cannot rename the module in the future.
> 
> Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
> ---
>   .../driver-api/firmware/fallback-mechanisms.rst          | 9 ++++++---
>   1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/driver-api/firmware/fallback-mechanisms.rst b/Documentation/driver-api/firmware/fallback-mechanisms.rst
> index a39323ef7d29..a8047be4a96e 100644
> --- a/Documentation/driver-api/firmware/fallback-mechanisms.rst
> +++ b/Documentation/driver-api/firmware/fallback-mechanisms.rst
> @@ -72,9 +72,12 @@ the firmware requested, and establishes it in the device hierarchy by
>   associating the device used to make the request as the device's parent.
>   The sysfs directory's file attributes are defined and controlled through
>   the new device's class (firmware_class) and group (fw_dev_attr_groups).
> -This is actually where the original firmware_class.c file name comes from,
> -as originally the only firmware loading mechanism available was the
> -mechanism we now use as a fallback mechanism.
> +This is actually where the original firmware_class module name came from,
> +given that originally the only firmware loading mechanism available was the
> +mechanism we now use as a fallback mechanism, which which registers a

Just a tiny repeated word here, "which which".

-Andres


> +struct class firmware_class. Because the attributes exposed are part of the
> +module name, the module name firmware_class cannot be renamed in the future, to
> +ensure backward compatibilty with old userspace.
>   
>   To load firmware using the sysfs interface we expose a loading indicator,
>   and a file upload firmware into:
> 

Re: [PATCH v6 13/13] Documentation: clarify firmware_class provenance and why we can't rename the module

[Mauro Carvalho Chehab]

Em Tue,  8 May 2018 11:12:47 -0700
"Luis R. Rodriguez" <mcgrof@kernel.org> escreveu:

> Clarify the provenance of the firmware loader firmware_class module name
> and why we cannot rename the module in the future.
> 
> Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
> ---
>  .../driver-api/firmware/fallback-mechanisms.rst          | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/driver-api/firmware/fallback-mechanisms.rst b/Documentation/driver-api/firmware/fallback-mechanisms.rst
> index a39323ef7d29..a8047be4a96e 100644
> --- a/Documentation/driver-api/firmware/fallback-mechanisms.rst
> +++ b/Documentation/driver-api/firmware/fallback-mechanisms.rst
> @@ -72,9 +72,12 @@ the firmware requested, and establishes it in the device hierarchy by
>  associating the device used to make the request as the device's parent.
>  The sysfs directory's file attributes are defined and controlled through
>  the new device's class (firmware_class) and group (fw_dev_attr_groups).
> -This is actually where the original firmware_class.c file name comes from,
> -as originally the only firmware loading mechanism available was the
> -mechanism we now use as a fallback mechanism.
> +This is actually where the original firmware_class module name came from,
> +given that originally the only firmware loading mechanism available was the
> +mechanism we now use as a fallback mechanism, which which registers a
> +struct class firmware_class. Because the attributes exposed are part of the
> +module name, the module name firmware_class cannot be renamed in the future, to
> +ensure backward compatibilty with old userspace.

Ah, now the explanation makes a lot more sense to me :-)

Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

>  
>  To load firmware using the sysfs interface we expose a loading indicator,
>  and a file upload firmware into:



Thanks,
Mauro

Re: [PATCH v6 00/13] firmware_loader changes for v4.18

[Kees Cook]

On Tue, May 8, 2018 at 11:12 AM, Luis R. Rodriguez <mcgrof@kernel.org> wrote:
> Greg,
>
> Here is what I have queued up for the firmware_loader for v4.18. It
> includes a slew of cleanup work, and the new firmware_request_nowarn()
> which is quiet but enables the sysfs fallback mechanism. I've gone ahead
> and also queued up a few minor fixes for the firmware loader documentation
> which have come up recently. These changes are available on my git tree
> both based on linux-next [0] and Linus' latest tree [1]. Folks working
> on new developments for the firmware loader can use my linux-next
> branch 20180508-firmware_loader_for-v4.18-try2 for now.
>
> 0-day sends its blessings.
>
> The patches from Mimi's series still require a bit more discussion and
> review. The discussion over the EFI firmware fallback mechanism is still
> ongoing.
>
> As for the rename that you wanted, perhaps we can do this late in the
> merge window considering we're at rc4 now. I can prep something up for
> that later.
>
> Question, and specially rants are warmly welcomed.

I sent some typo catches, but with those fixed, please consider the
whole series:

Reviewed-by: Kees Cook <keescook@chromium.org>

Thanks!

-Kees

-- 
Kees Cook
Pixel Security