diff mbox series

[2/3] firmware: add offset to request_firmware_into_buf

Message ID 20190523025113.4605-3-scott.branden@broadcom.com (mailing list archive)
State New, archived
Headers show
Series fs: add partial file read support | expand

Commit Message

Scott Branden May 23, 2019, 2:51 a.m. UTC
Add offset to request_firmware_into_buf to allow for portions
of firmware file to be read into a buffer.  Necessary where firmware
needs to be loaded in portions from file in memory constrained systems.

Signed-off-by: Scott Branden <scott.branden@broadcom.com>
---
 drivers/base/firmware_loader/firmware.h |  5 +++
 drivers/base/firmware_loader/main.c     | 49 +++++++++++++++++--------
 include/linux/firmware.h                |  8 +++-
 3 files changed, 45 insertions(+), 17 deletions(-)

Comments

Greg Kroah-Hartman May 23, 2019, 5:52 a.m. UTC | #1
On Wed, May 22, 2019 at 07:51:12PM -0700, Scott Branden wrote:
> Add offset to request_firmware_into_buf to allow for portions
> of firmware file to be read into a buffer.  Necessary where firmware
> needs to be loaded in portions from file in memory constrained systems.
> 
> Signed-off-by: Scott Branden <scott.branden@broadcom.com>
> ---
>  drivers/base/firmware_loader/firmware.h |  5 +++
>  drivers/base/firmware_loader/main.c     | 49 +++++++++++++++++--------
>  include/linux/firmware.h                |  8 +++-
>  3 files changed, 45 insertions(+), 17 deletions(-)

No new firmware test for this new option?  How do we know it even works?
:)

thanks,

greg k-h
Scott Branden May 23, 2019, 4:36 p.m. UTC | #2
Hi Greg,

On 2019-05-22 10:52 p.m., Greg Kroah-Hartman wrote:
> On Wed, May 22, 2019 at 07:51:12PM -0700, Scott Branden wrote:
>> Add offset to request_firmware_into_buf to allow for portions
>> of firmware file to be read into a buffer.  Necessary where firmware
>> needs to be loaded in portions from file in memory constrained systems.
>>
>> Signed-off-by: Scott Branden <scott.branden@broadcom.com>
>> ---
>>   drivers/base/firmware_loader/firmware.h |  5 +++
>>   drivers/base/firmware_loader/main.c     | 49 +++++++++++++++++--------
>>   include/linux/firmware.h                |  8 +++-
>>   3 files changed, 45 insertions(+), 17 deletions(-)
> No new firmware test for this new option?  How do we know it even works?

I was unaware there are existing firmware tests.  Please let me know 
where these tests exists and I can add a test for this new option.

We have tested this with a new driver in development which requires the 
firmware file to be read in portions into memory.  I can add my 
tested-by and others to the commit message if desired.

> :)
>
> thanks,
>
> greg k-h

Regards,

Scott
Greg Kroah-Hartman May 23, 2019, 4:54 p.m. UTC | #3
On Thu, May 23, 2019 at 09:36:02AM -0700, Scott Branden wrote:
> Hi Greg,
> 
> On 2019-05-22 10:52 p.m., Greg Kroah-Hartman wrote:
> > On Wed, May 22, 2019 at 07:51:12PM -0700, Scott Branden wrote:
> > > Add offset to request_firmware_into_buf to allow for portions
> > > of firmware file to be read into a buffer.  Necessary where firmware
> > > needs to be loaded in portions from file in memory constrained systems.
> > > 
> > > Signed-off-by: Scott Branden <scott.branden@broadcom.com>
> > > ---
> > >   drivers/base/firmware_loader/firmware.h |  5 +++
> > >   drivers/base/firmware_loader/main.c     | 49 +++++++++++++++++--------
> > >   include/linux/firmware.h                |  8 +++-
> > >   3 files changed, 45 insertions(+), 17 deletions(-)
> > No new firmware test for this new option?  How do we know it even works?
> 
> I was unaware there are existing firmware tests.  Please let me know where
> these tests exists and I can add a test for this new option.

tools/testing/selftests/firmware/

> We have tested this with a new driver in development which requires the
> firmware file to be read in portions into memory.  I can add my tested-by
> and others to the commit message if desired.

I can't take new apis without an in-kernel user, you all know this...

thanks,

greg k-h
Scott Branden May 24, 2019, 5:01 a.m. UTC | #4
On 2019-05-23 9:54 a.m., Greg Kroah-Hartman wrote:
> On Thu, May 23, 2019 at 09:36:02AM -0700, Scott Branden wrote:
>> Hi Greg,
>>
>> On 2019-05-22 10:52 p.m., Greg Kroah-Hartman wrote:
>>> On Wed, May 22, 2019 at 07:51:12PM -0700, Scott Branden wrote:
>>>> Add offset to request_firmware_into_buf to allow for portions
>>>> of firmware file to be read into a buffer.  Necessary where firmware
>>>> needs to be loaded in portions from file in memory constrained systems.
>>>>
>>>> Signed-off-by: Scott Branden <scott.branden@broadcom.com>
>>>> ---
>>>>    drivers/base/firmware_loader/firmware.h |  5 +++
>>>>    drivers/base/firmware_loader/main.c     | 49 +++++++++++++++++--------
>>>>    include/linux/firmware.h                |  8 +++-
>>>>    3 files changed, 45 insertions(+), 17 deletions(-)
>>> No new firmware test for this new option?  How do we know it even works?
>> I was unaware there are existing firmware tests.  Please let me know where
>> these tests exists and I can add a test for this new option.
> tools/testing/selftests/firmware/

Unfortunately, there doesn't seem to be a test for the existing 
request_firmware_into_buf api.

Looks like it will be more work that I thought enhancing a test that 
doesn't exist.


>
>> We have tested this with a new driver in development which requires the
>> firmware file to be read in portions into memory.  I can add my tested-by
>> and others to the commit message if desired.
> I can't take new apis without an in-kernel user, you all know this...

OK, It will have to wait then as I was hoping to get this in before my 
leave.

But adding a selftest and upstreaming the necessary driver

won't be possible for a few months now.

>
> thanks,
>
> greg k-h

Thanks for explaining the requirements.


Scott
Greg Kroah-Hartman May 24, 2019, 5:22 a.m. UTC | #5
On Thu, May 23, 2019 at 10:01:38PM -0700, Scott Branden wrote:
> 
> On 2019-05-23 9:54 a.m., Greg Kroah-Hartman wrote:
> > On Thu, May 23, 2019 at 09:36:02AM -0700, Scott Branden wrote:
> > > Hi Greg,
> > > 
> > > On 2019-05-22 10:52 p.m., Greg Kroah-Hartman wrote:
> > > > On Wed, May 22, 2019 at 07:51:12PM -0700, Scott Branden wrote:
> > > > > Add offset to request_firmware_into_buf to allow for portions
> > > > > of firmware file to be read into a buffer.  Necessary where firmware
> > > > > needs to be loaded in portions from file in memory constrained systems.
> > > > > 
> > > > > Signed-off-by: Scott Branden <scott.branden@broadcom.com>
> > > > > ---
> > > > >    drivers/base/firmware_loader/firmware.h |  5 +++
> > > > >    drivers/base/firmware_loader/main.c     | 49 +++++++++++++++++--------
> > > > >    include/linux/firmware.h                |  8 +++-
> > > > >    3 files changed, 45 insertions(+), 17 deletions(-)
> > > > No new firmware test for this new option?  How do we know it even works?
> > > I was unaware there are existing firmware tests.  Please let me know where
> > > these tests exists and I can add a test for this new option.
> > tools/testing/selftests/firmware/
> 
> Unfortunately, there doesn't seem to be a test for the existing
> request_firmware_into_buf api.

Are you sure?  The test is for userspace functionality, there isn't
kernel unit tests here.  You need to verify that you didn't break
existing functionality as well as verify that your new functionality
works.

> > > We have tested this with a new driver in development which requires the
> > > firmware file to be read in portions into memory.  I can add my tested-by
> > > and others to the commit message if desired.
> > I can't take new apis without an in-kernel user, you all know this...
> 
> OK, It will have to wait then as I was hoping to get this in before my
> leave.

Throwing new code over the wall and running away is a sure way to ensure
that your code will be ignored :)

thanks,

greg k-h
Scott Branden Aug. 1, 2019, 12:18 a.m. UTC | #6
Hi Greg,

I am now back from leave to continue this patch.  Comment below.

On 2019-05-23 10:22 p.m., Greg Kroah-Hartman wrote:
> On Thu, May 23, 2019 at 10:01:38PM -0700, Scott Branden wrote:
>> On 2019-05-23 9:54 a.m., Greg Kroah-Hartman wrote:
>>> On Thu, May 23, 2019 at 09:36:02AM -0700, Scott Branden wrote:
>>>> Hi Greg,
>>>>
>>>> On 2019-05-22 10:52 p.m., Greg Kroah-Hartman wrote:
>>>>> On Wed, May 22, 2019 at 07:51:12PM -0700, Scott Branden wrote:
>>>>>> Add offset to request_firmware_into_buf to allow for portions
>>>>>> of firmware file to be read into a buffer.  Necessary where firmware
>>>>>> needs to be loaded in portions from file in memory constrained systems.
>>>>>>
>>>>>> Signed-off-by: Scott Branden <scott.branden@broadcom.com>
>>>>>> ---
>>>>>>     drivers/base/firmware_loader/firmware.h |  5 +++
>>>>>>     drivers/base/firmware_loader/main.c     | 49 +++++++++++++++++--------
>>>>>>     include/linux/firmware.h                |  8 +++-
>>>>>>     3 files changed, 45 insertions(+), 17 deletions(-)
>>>>> No new firmware test for this new option?  How do we know it even works?
>>>> I was unaware there are existing firmware tests.  Please let me know where
>>>> these tests exists and I can add a test for this new option.
>>> tools/testing/selftests/firmware/
>> Unfortunately, there doesn't seem to be a test for the existing
>> request_firmware_into_buf api.
> Are you sure?  The test is for userspace functionality, there isn't
> kernel unit tests here.  You need to verify that you didn't break
> existing functionality as well as verify that your new functionality
> works.

I managed to figure out how to build and run 
tools/testing/selftest/firmware/fw_run_tests.sh

and my changes don't break existing functionality.

But, I find no use of request_firmware_into_buf in lib/test_firmware.c 
(triggered by fw_run_tests.sh).

Is there another test for request_firmware_into_buf?

>>>> We have tested this with a new driver in development which requires the
>>>> firmware file to be read in portions into memory.  I can add my tested-by
>>>> and others to the commit message if desired.
>>> I can't take new apis without an in-kernel user, you all know this...
>> OK, It will have to wait then as I was hoping to get this in before my
>> leave.
> Throwing new code over the wall and running away is a sure way to ensure
> that your code will be ignored :)
>
> thanks,
>
> greg k-h
Greg Kroah-Hartman Aug. 1, 2019, 6:18 a.m. UTC | #7
On Wed, Jul 31, 2019 at 05:18:32PM -0700, Scott Branden wrote:
> Hi Greg,
> 
> I am now back from leave to continue this patch.  Comment below.
> 
> On 2019-05-23 10:22 p.m., Greg Kroah-Hartman wrote:
> > On Thu, May 23, 2019 at 10:01:38PM -0700, Scott Branden wrote:
> > > On 2019-05-23 9:54 a.m., Greg Kroah-Hartman wrote:
> > > > On Thu, May 23, 2019 at 09:36:02AM -0700, Scott Branden wrote:
> > > > > Hi Greg,
> > > > > 
> > > > > On 2019-05-22 10:52 p.m., Greg Kroah-Hartman wrote:
> > > > > > On Wed, May 22, 2019 at 07:51:12PM -0700, Scott Branden wrote:
> > > > > > > Add offset to request_firmware_into_buf to allow for portions
> > > > > > > of firmware file to be read into a buffer.  Necessary where firmware
> > > > > > > needs to be loaded in portions from file in memory constrained systems.
> > > > > > > 
> > > > > > > Signed-off-by: Scott Branden <scott.branden@broadcom.com>
> > > > > > > ---
> > > > > > >     drivers/base/firmware_loader/firmware.h |  5 +++
> > > > > > >     drivers/base/firmware_loader/main.c     | 49 +++++++++++++++++--------
> > > > > > >     include/linux/firmware.h                |  8 +++-
> > > > > > >     3 files changed, 45 insertions(+), 17 deletions(-)
> > > > > > No new firmware test for this new option?  How do we know it even works?
> > > > > I was unaware there are existing firmware tests.  Please let me know where
> > > > > these tests exists and I can add a test for this new option.
> > > > tools/testing/selftests/firmware/
> > > Unfortunately, there doesn't seem to be a test for the existing
> > > request_firmware_into_buf api.
> > Are you sure?  The test is for userspace functionality, there isn't
> > kernel unit tests here.  You need to verify that you didn't break
> > existing functionality as well as verify that your new functionality
> > works.
> 
> I managed to figure out how to build and run
> tools/testing/selftest/firmware/fw_run_tests.sh
> 
> and my changes don't break existing functionality.
> 
> But, I find no use of request_firmware_into_buf in lib/test_firmware.c
> (triggered by fw_run_tests.sh).
> 
> Is there another test for request_firmware_into_buf?

I have no idea, sorry.

greg k-h
Luis Chamberlain Aug. 1, 2019, 5:42 p.m. UTC | #8
On Thu, Aug 01, 2019 at 08:18:01AM +0200, Greg Kroah-Hartman wrote:
> On Wed, Jul 31, 2019 at 05:18:32PM -0700, Scott Branden wrote:
> > Hi Greg,
> > 
> > I am now back from leave to continue this patch.  Comment below.
> > 
> > On 2019-05-23 10:22 p.m., Greg Kroah-Hartman wrote:
> > > On Thu, May 23, 2019 at 10:01:38PM -0700, Scott Branden wrote:
> > > > On 2019-05-23 9:54 a.m., Greg Kroah-Hartman wrote:
> > > > > On Thu, May 23, 2019 at 09:36:02AM -0700, Scott Branden wrote:
> > > > > > Hi Greg,
> > > > > > 
> > > > > > On 2019-05-22 10:52 p.m., Greg Kroah-Hartman wrote:
> > > > > > > On Wed, May 22, 2019 at 07:51:12PM -0700, Scott Branden wrote:
> > > > > > > > Add offset to request_firmware_into_buf to allow for portions
> > > > > > > > of firmware file to be read into a buffer.  Necessary where firmware
> > > > > > > > needs to be loaded in portions from file in memory constrained systems.
> > > > > > > > 
> > > > > > > > Signed-off-by: Scott Branden <scott.branden@broadcom.com>
> > > > > > > > ---
> > > > > > > >     drivers/base/firmware_loader/firmware.h |  5 +++
> > > > > > > >     drivers/base/firmware_loader/main.c     | 49 +++++++++++++++++--------
> > > > > > > >     include/linux/firmware.h                |  8 +++-
> > > > > > > >     3 files changed, 45 insertions(+), 17 deletions(-)
> > > > > > > No new firmware test for this new option?  How do we know it even works?
> > > > > > I was unaware there are existing firmware tests.  Please let me know where
> > > > > > these tests exists and I can add a test for this new option.
> > > > > tools/testing/selftests/firmware/
> > > > Unfortunately, there doesn't seem to be a test for the existing
> > > > request_firmware_into_buf api.
> > > Are you sure?  The test is for userspace functionality, there isn't
> > > kernel unit tests here.  You need to verify that you didn't break
> > > existing functionality as well as verify that your new functionality
> > > works.
> > 
> > I managed to figure out how to build and run
> > tools/testing/selftest/firmware/fw_run_tests.sh
> > 
> > and my changes don't break existing functionality.

I'm soon going to release something that is going to let you do this 
faster and easier, let me know if you had troubles in trying to figure
out how to not regress the kernel using this.

> > But, I find no use of request_firmware_into_buf in lib/test_firmware.c
> > (triggered by fw_run_tests.sh).
> > 
> > Is there another test for request_firmware_into_buf?
> 
> I have no idea, sorry.

The folks who implemented request_firmware_into_buf() didn't add a
respective test, because, well, this API went upstream IMO without much
ACKs / review, and even no damn users. Now we have a user so we're stuck
with it.

So new testing calls for it would be appreciated. If you have questions
I am happy to help.

  Luis
Scott Branden Aug. 1, 2019, 6:15 p.m. UTC | #9
Hi Luis,

On 2019-08-01 10:42 a.m., Luis Chamberlain wrote:
> On Thu, Aug 01, 2019 at 08:18:01AM +0200, Greg Kroah-Hartman wrote:
>> On Wed, Jul 31, 2019 at 05:18:32PM -0700, Scott Branden wrote:
>>> Hi Greg,
>>>
>>> I am now back from leave to continue this patch.  Comment below.
>>>
>>> On 2019-05-23 10:22 p.m., Greg Kroah-Hartman wrote:
>>>> On Thu, May 23, 2019 at 10:01:38PM -0700, Scott Branden wrote:
>>>>> On 2019-05-23 9:54 a.m., Greg Kroah-Hartman wrote:
>>>>>> On Thu, May 23, 2019 at 09:36:02AM -0700, Scott Branden wrote:
>>>>>>> Hi Greg,
>>>>>>>
>>>>>>> On 2019-05-22 10:52 p.m., Greg Kroah-Hartman wrote:
>>>>>>>> On Wed, May 22, 2019 at 07:51:12PM -0700, Scott Branden wrote:
>>>>>>>>> Add offset to request_firmware_into_buf to allow for portions
>>>>>>>>> of firmware file to be read into a buffer.  Necessary where firmware
>>>>>>>>> needs to be loaded in portions from file in memory constrained systems.
>>>>>>>>>
>>>>>>>>> Signed-off-by: Scott Branden <scott.branden@broadcom.com>
>>>>>>>>> ---
>>>>>>>>>      drivers/base/firmware_loader/firmware.h |  5 +++
>>>>>>>>>      drivers/base/firmware_loader/main.c     | 49 +++++++++++++++++--------
>>>>>>>>>      include/linux/firmware.h                |  8 +++-
>>>>>>>>>      3 files changed, 45 insertions(+), 17 deletions(-)
>>>>>>>> No new firmware test for this new option?  How do we know it even works?
>>>>>>> I was unaware there are existing firmware tests.  Please let me know where
>>>>>>> these tests exists and I can add a test for this new option.
>>>>>> tools/testing/selftests/firmware/
>>>>> Unfortunately, there doesn't seem to be a test for the existing
>>>>> request_firmware_into_buf api.
>>>> Are you sure?  The test is for userspace functionality, there isn't
>>>> kernel unit tests here.  You need to verify that you didn't break
>>>> existing functionality as well as verify that your new functionality
>>>> works.
>>> I managed to figure out how to build and run
>>> tools/testing/selftest/firmware/fw_run_tests.sh
>>>
>>> and my changes don't break existing functionality.
> I'm soon going to release something that is going to let you do this
> faster and easier, let me know if you had troubles in trying to figure
> out how to not regress the kernel using this.

Yes, I had troubles in trying to figure it out.  The kernel build should

create an entire initrd with all the necessary components in it for 
testing purposes.

And the firmware test will now take me some time to figure out how it 
all works.

Could you please explain what you are going to release soon?  I don't 
want to waste

my time getting something working if everything is going to change on me 
right away?

>
>>> But, I find no use of request_firmware_into_buf in lib/test_firmware.c
>>> (triggered by fw_run_tests.sh).
>>>
>>> Is there another test for request_firmware_into_buf?
>> I have no idea, sorry.
> The folks who implemented request_firmware_into_buf() didn't add a
> respective test, because, well, this API went upstream IMO without much
> ACKs / review, and even no damn users. Now we have a user so we're stuck
> with it.

The request_firmware_into_buf is a necessity for me as well

(along with the need for a partial request of the file which I'm adding).

>
> So new testing calls for it would be appreciated. If you have questions
> I am happy to help.

If you're an expert on the firmware test and can quickly add a simple 
test of request_firmware_into_buf

it would be appreciated.  If not, I'm going to have to dig further into 
this and send early versions of

a test out which would be great for you to comment on.

>
>    Luis

Thanks,

Scott
Luis Chamberlain Aug. 19, 2019, 10:22 p.m. UTC | #10
On Thu, Aug 01, 2019 at 11:15:19AM -0700, Scott Branden wrote:
> Hi Luis,
> 
> On 2019-08-01 10:42 a.m., Luis Chamberlain wrote:
> > On Thu, Aug 01, 2019 at 08:18:01AM +0200, Greg Kroah-Hartman wrote:
> > > On Wed, Jul 31, 2019 at 05:18:32PM -0700, Scott Branden wrote:
> > > > Hi Greg,
> > > > 
> > > > I am now back from leave to continue this patch.  Comment below.
> > > > 
> > > > On 2019-05-23 10:22 p.m., Greg Kroah-Hartman wrote:
> > > > > On Thu, May 23, 2019 at 10:01:38PM -0700, Scott Branden wrote:
> > > > > > On 2019-05-23 9:54 a.m., Greg Kroah-Hartman wrote:
> > > > > > > On Thu, May 23, 2019 at 09:36:02AM -0700, Scott Branden wrote:
> > > > > > > > Hi Greg,
> > > > > > > > 
> > > > > > > > On 2019-05-22 10:52 p.m., Greg Kroah-Hartman wrote:
> > > > > > > > > On Wed, May 22, 2019 at 07:51:12PM -0700, Scott Branden wrote:
> > > > > > > > > > Add offset to request_firmware_into_buf to allow for portions
> > > > > > > > > > of firmware file to be read into a buffer.  Necessary where firmware
> > > > > > > > > > needs to be loaded in portions from file in memory constrained systems.
> > > > > > > > > > 
> > > > > > > > > > Signed-off-by: Scott Branden <scott.branden@broadcom.com>
> > > > > > > > > > ---
> > > > > > > > > >      drivers/base/firmware_loader/firmware.h |  5 +++
> > > > > > > > > >      drivers/base/firmware_loader/main.c     | 49 +++++++++++++++++--------
> > > > > > > > > >      include/linux/firmware.h                |  8 +++-
> > > > > > > > > >      3 files changed, 45 insertions(+), 17 deletions(-)
> > > > > > > > > No new firmware test for this new option?  How do we know it even works?
> > > > > > > > I was unaware there are existing firmware tests.  Please let me know where
> > > > > > > > these tests exists and I can add a test for this new option.
> > > > > > > tools/testing/selftests/firmware/
> > > > > > Unfortunately, there doesn't seem to be a test for the existing
> > > > > > request_firmware_into_buf api.
> > > > > Are you sure?  The test is for userspace functionality, there isn't
> > > > > kernel unit tests here.  You need to verify that you didn't break
> > > > > existing functionality as well as verify that your new functionality
> > > > > works.
> > > > I managed to figure out how to build and run
> > > > tools/testing/selftest/firmware/fw_run_tests.sh
> > > > 
> > > > and my changes don't break existing functionality.
> > I'm soon going to release something that is going to let you do this
> > faster and easier, let me know if you had troubles in trying to figure
> > out how to not regress the kernel using this.
> 
> Yes, I had troubles in trying to figure it out.  The kernel build should
> 
> create an entire initrd with all the necessary components in it for testing
> purposes.
> 
> And the firmware test will now take me some time to figure out how it all
> works.
> 
> Could you please explain what you are going to release soon?  I don't want
> to waste

Sorry for the delay but I promise that I tried hard to get this out ASAP.

https://github.com/mcgrof/fw-kdevops

This now can be used to more easily let you start an environment to
test the firmware API.

Too late for you I gather, but perhaps others can take advantage.

  Luis
diff mbox series

Patch

diff --git a/drivers/base/firmware_loader/firmware.h b/drivers/base/firmware_loader/firmware.h
index 4c1395f8e7ed..d73d400c2023 100644
--- a/drivers/base/firmware_loader/firmware.h
+++ b/drivers/base/firmware_loader/firmware.h
@@ -29,6 +29,8 @@ 
  *	firmware caching mechanism.
  * @FW_OPT_NOFALLBACK: Disable the fallback mechanism. Takes precedence over
  *	&FW_OPT_UEVENT and &FW_OPT_USERHELPER.
+ * @FW_OPT_PARTIAL: Allow partial read of firmware instead of needing to read
+ *	entire file.
  */
 enum fw_opt {
 	FW_OPT_UEVENT =         BIT(0),
@@ -37,6 +39,7 @@  enum fw_opt {
 	FW_OPT_NO_WARN =        BIT(3),
 	FW_OPT_NOCACHE =        BIT(4),
 	FW_OPT_NOFALLBACK =     BIT(5),
+	FW_OPT_PARTIAL =        BIT(6),
 };
 
 enum fw_status {
@@ -64,6 +67,8 @@  struct fw_priv {
 	void *data;
 	size_t size;
 	size_t allocated_size;
+	size_t offset;
+	unsigned int flags;
 #ifdef CONFIG_FW_LOADER_USER_HELPER
 	bool is_paged_buf;
 	bool need_uevent;
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index 7eaaf5ee5ba6..34d4f043b7c8 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -166,7 +166,8 @@  static int fw_cache_piggyback_on_request(const char *name);
 
 static struct fw_priv *__allocate_fw_priv(const char *fw_name,
 					  struct firmware_cache *fwc,
-					  void *dbuf, size_t size)
+					  void *dbuf, size_t size,
+					  size_t offset, unsigned int flags)
 {
 	struct fw_priv *fw_priv;
 
@@ -184,6 +185,8 @@  static struct fw_priv *__allocate_fw_priv(const char *fw_name,
 	fw_priv->fwc = fwc;
 	fw_priv->data = dbuf;
 	fw_priv->allocated_size = size;
+	fw_priv->offset = offset;
+	fw_priv->flags = flags;
 	fw_state_init(fw_priv);
 #ifdef CONFIG_FW_LOADER_USER_HELPER
 	INIT_LIST_HEAD(&fw_priv->pending_list);
@@ -209,9 +212,11 @@  static struct fw_priv *__lookup_fw_priv(const char *fw_name)
 static int alloc_lookup_fw_priv(const char *fw_name,
 				struct firmware_cache *fwc,
 				struct fw_priv **fw_priv, void *dbuf,
-				size_t size, enum fw_opt opt_flags)
+				size_t size, enum fw_opt opt_flags,
+				size_t offset)
 {
 	struct fw_priv *tmp;
+	unsigned int pread_flags;
 
 	spin_lock(&fwc->lock);
 	if (!(opt_flags & FW_OPT_NOCACHE)) {
@@ -225,7 +230,12 @@  static int alloc_lookup_fw_priv(const char *fw_name,
 		}
 	}
 
-	tmp = __allocate_fw_priv(fw_name, fwc, dbuf, size);
+	if (opt_flags & FW_OPT_PARTIAL)
+		pread_flags = KERNEL_PREAD_FLAG_PART;
+	else
+		pread_flags = KERNEL_PREAD_FLAG_WHOLE;
+
+	tmp = __allocate_fw_priv(fw_name, fwc, dbuf, size, offset, pread_flags);
 	if (tmp) {
 		INIT_LIST_HEAD(&tmp->list);
 		if (!(opt_flags & FW_OPT_NOCACHE))
@@ -325,8 +335,9 @@  fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv)
 		}
 
 		fw_priv->size = 0;
-		rc = kernel_read_file_from_path(path, &fw_priv->data, &size,
-						msize, id);
+		rc = kernel_pread_file_from_path(path, &fw_priv->data, &size,
+						 fw_priv->offset, msize,
+						 fw_priv->flags, id);
 		if (rc) {
 			if (rc != -ENOENT)
 				dev_warn(device, "loading %s failed with error %d\n",
@@ -500,7 +511,7 @@  int assign_fw(struct firmware *fw, struct device *device,
 static int
 _request_firmware_prepare(struct firmware **firmware_p, const char *name,
 			  struct device *device, void *dbuf, size_t size,
-			  enum fw_opt opt_flags)
+			  enum fw_opt opt_flags, size_t offset)
 {
 	struct firmware *firmware;
 	struct fw_priv *fw_priv;
@@ -519,7 +530,7 @@  _request_firmware_prepare(struct firmware **firmware_p, const char *name,
 	}
 
 	ret = alloc_lookup_fw_priv(name, &fw_cache, &fw_priv, dbuf, size,
-				  opt_flags);
+				  opt_flags, offset);
 
 	/*
 	 * bind with 'priv' now to avoid warning in failure path
@@ -566,7 +577,7 @@  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,
-		  enum fw_opt opt_flags)
+		  enum fw_opt opt_flags, size_t offset)
 {
 	struct firmware *fw = NULL;
 	int ret;
@@ -580,7 +591,7 @@  _request_firmware(const struct firmware **firmware_p, const char *name,
 	}
 
 	ret = _request_firmware_prepare(&fw, name, device, buf, size,
-					opt_flags);
+					opt_flags, offset);
 	if (ret <= 0) /* error or already assigned */
 		goto out;
 
@@ -634,7 +645,7 @@  request_firmware(const struct firmware **firmware_p, const char *name,
 	/* Need to pin this module until return */
 	__module_get(THIS_MODULE);
 	ret = _request_firmware(firmware_p, name, device, NULL, 0,
-				FW_OPT_UEVENT);
+				FW_OPT_UEVENT, 0);
 	module_put(THIS_MODULE);
 	return ret;
 }
@@ -661,7 +672,7 @@  int firmware_request_nowarn(const struct firmware **firmware, const char *name,
 	/* 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);
+				FW_OPT_UEVENT | FW_OPT_NO_WARN, 0);
 	module_put(THIS_MODULE);
 	return ret;
 }
@@ -686,7 +697,7 @@  int request_firmware_direct(const struct firmware **firmware_p,
 	__module_get(THIS_MODULE);
 	ret = _request_firmware(firmware_p, name, device, NULL, 0,
 				FW_OPT_UEVENT | FW_OPT_NO_WARN |
-				FW_OPT_NOFALLBACK);
+				FW_OPT_NOFALLBACK, 0);
 	module_put(THIS_MODULE);
 	return ret;
 }
@@ -723,6 +734,8 @@  EXPORT_SYMBOL_GPL(firmware_request_cache);
  * @device: device for which firmware is being loaded and DMA region allocated
  * @buf: address of buffer to load firmware into
  * @size: size of buffer
+ * @offset: offset into file to read
+ * @pread_flags: KERNEL_PREAD_FLAG_PART to allow partial file read
  *
  * This function works pretty much like request_firmware(), but it doesn't
  * allocate a buffer to hold the firmware data. Instead, the firmware
@@ -733,16 +746,22 @@  EXPORT_SYMBOL_GPL(firmware_request_cache);
  */
 int
 request_firmware_into_buf(const struct firmware **firmware_p, const char *name,
-			  struct device *device, void *buf, size_t size)
+			  struct device *device, void *buf, size_t size,
+			  size_t offset, unsigned int pread_flags)
 {
 	int ret;
+	enum fw_opt opt_flags;
 
 	if (fw_cache_is_setup(device, name))
 		return -EOPNOTSUPP;
 
 	__module_get(THIS_MODULE);
+	opt_flags = FW_OPT_UEVENT | FW_OPT_NOCACHE;
+	if (pread_flags & KERNEL_PREAD_FLAG_PART)
+		opt_flags |= FW_OPT_PARTIAL;
+
 	ret = _request_firmware(firmware_p, name, device, buf, size,
-				FW_OPT_UEVENT | FW_OPT_NOCACHE);
+				opt_flags, offset);
 	module_put(THIS_MODULE);
 	return ret;
 }
@@ -781,7 +800,7 @@  static void request_firmware_work_func(struct work_struct *work)
 	fw_work = container_of(work, struct firmware_work, work);
 
 	_request_firmware(&fw, fw_work->name, fw_work->device, NULL, 0,
-			  fw_work->opt_flags);
+			  fw_work->opt_flags, 0);
 	fw_work->cont(fw, fw_work->context);
 	put_device(fw_work->device); /* taken in request_firmware_nowait() */
 
diff --git a/include/linux/firmware.h b/include/linux/firmware.h
index 2dd566c91d44..c81162a8d709 100644
--- a/include/linux/firmware.h
+++ b/include/linux/firmware.h
@@ -4,6 +4,7 @@ 
 
 #include <linux/types.h>
 #include <linux/compiler.h>
+#include <linux/fs.h>
 #include <linux/gfp.h>
 
 #define FW_ACTION_NOHOTPLUG 0
@@ -51,7 +52,9 @@  int request_firmware_nowait(
 int request_firmware_direct(const struct firmware **fw, const char *name,
 			    struct device *device);
 int request_firmware_into_buf(const struct firmware **firmware_p,
-	const char *name, struct device *device, void *buf, size_t size);
+			      const char *name, struct device *device,
+			      void *buf, size_t size,
+			      size_t offset, unsigned int pread_flags);
 
 void release_firmware(const struct firmware *fw);
 #else
@@ -89,7 +92,8 @@  static inline int request_firmware_direct(const struct firmware **fw,
 }
 
 static inline int request_firmware_into_buf(const struct firmware **firmware_p,
-	const char *name, struct device *device, void *buf, size_t size)
+	const char *name, struct device *device, void *buf, size_t size,
+	size_t offset, unsigned int pread_flags);
 {
 	return -EINVAL;
 }