Commit Graph

24 Commits

Author SHA1 Message Date
Jonathan Neuschäfer
f118dbf4e7 docs: driver-api: firmware: fallback-mechanisms: Fix rendering of bullet point
Without this patch, the "Firmware is not accessible [...]" line is
rendered in bold, which does not seem intentional.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Link: https://lore.kernel.org/r/20200905184131.1280337-1-j.neuschaefer@gmx.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-08 13:32:06 +02:00
Randy Dunlap
726b5bd3cf Documentation/driver-api: firmware/request_firmware: drop doubled word
Drop the doubled word "call".

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20200704034502.17199-6-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-10 14:58:01 +02:00
Randy Dunlap
e2e4e8f5ac Documentation/driver-api: firmware/direct-fs-lookup: drop doubled word
Drop the doubled word "firmware".

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20200704034502.17199-5-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-10 14:58:01 +02:00
Randy Dunlap
20b33f84f9 Documentation/driver-api: firmware/firmware_cache: drop doubled word
Drop the doubled word "if".

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20200704034502.17199-4-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-10 14:58:00 +02:00
Randy Dunlap
c7d4a0b711 Documentation/driver-api: firmware/built-in-fw: drop doubled word
Drop the doubled word "for".

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20200704034502.17199-3-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-10 14:58:00 +02:00
Linus Torvalds
a776c270a0 Merge branch 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI updates from Ingo Molnar:
 "The EFI changes in this cycle are much larger than usual, for two
  (positive) reasons:

   - The GRUB project is showing signs of life again, resulting in the
     introduction of the generic Linux/UEFI boot protocol, instead of
     x86 specific hacks which are increasingly difficult to maintain.
     There's hope that all future extensions will now go through that
     boot protocol.

   - Preparatory work for RISC-V EFI support.

  The main changes are:

   - Boot time GDT handling changes

   - Simplify handling of EFI properties table on arm64

   - Generic EFI stub cleanups, to improve command line handling, file
     I/O, memory allocation, etc.

   - Introduce a generic initrd loading method based on calling back
     into the firmware, instead of relying on the x86 EFI handover
     protocol or device tree.

   - Introduce a mixed mode boot method that does not rely on the x86
     EFI handover protocol either, and could potentially be adopted by
     other architectures (if another one ever surfaces where one
     execution mode is a superset of another)

   - Clean up the contents of 'struct efi', and move out everything that
     doesn't need to be stored there.

   - Incorporate support for UEFI spec v2.8A changes that permit
     firmware implementations to return EFI_UNSUPPORTED from UEFI
     runtime services at OS runtime, and expose a mask of which ones are
     supported or unsupported via a configuration table.

   - Partial fix for the lack of by-VA cache maintenance in the
     decompressor on 32-bit ARM.

   - Changes to load device firmware from EFI boot service memory
     regions

   - Various documentation updates and minor code cleanups and fixes"

* 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (114 commits)
  efi/libstub/arm: Fix spurious message that an initrd was loaded
  efi/libstub/arm64: Avoid image_base value from efi_loaded_image
  partitions/efi: Fix partition name parsing in GUID partition entry
  efi/x86: Fix cast of image argument
  efi/libstub/x86: Use ULONG_MAX as upper bound for all allocations
  efi: Fix a mistype in comments mentioning efivar_entry_iter_begin()
  efi/libstub: Avoid linking libstub/lib-ksyms.o into vmlinux
  efi/x86: Preserve %ebx correctly in efi_set_virtual_address_map()
  efi/x86: Ignore the memory attributes table on i386
  efi/x86: Don't relocate the kernel unless necessary
  efi/x86: Remove extra headroom for setup block
  efi/x86: Add kernel preferred address to PE header
  efi/x86: Decompress at start of PE image load address
  x86/boot/compressed/32: Save the output address instead of recalculating it
  efi/libstub/x86: Deal with exit() boot service returning
  x86/boot: Use unsigned comparison for addresses
  efi/x86: Avoid using code32_start
  efi/x86: Make efi32_pe_entry() more readable
  efi/x86: Respect 32-bit ABI in efi32_pe_entry()
  efi/x86: Annotate the LOADED_IMAGE_PROTOCOL_GUID with SYM_DATA
  ...
2020-03-30 16:13:08 -07:00
Hans de Goede
e4c2c0ff00 firmware: Add new platform fallback mechanism and firmware_request_platform()
In some cases the platform's main firmware (e.g. the UEFI fw) may contain
an embedded copy of device firmware which needs to be (re)loaded into the
peripheral. Normally such firmware would be part of linux-firmware, but in
some cases this is not feasible, for 2 reasons:

1) The firmware is customized for a specific use-case of the chipset / use
with a specific hardware model, so we cannot have a single firmware file
for the chipset. E.g. touchscreen controller firmwares are compiled
specifically for the hardware model they are used with, as they are
calibrated for a specific model digitizer.

2) Despite repeated attempts we have failed to get permission to
redistribute the firmware. This is especially a problem with customized
firmwares, these get created by the chip vendor for a specific ODM and the
copyright may partially belong with the ODM, so the chip vendor cannot
give a blanket permission to distribute these.

This commit adds a new platform fallback mechanism to the firmware loader
which will try to lookup a device fw copy embedded in the platform's main
firmware if direct filesystem lookup fails.

Drivers which need such embedded fw copies can enable this fallback
mechanism by using the new firmware_request_platform() function.

Note that for now this is only supported on EFI platforms and even on
these platforms firmware_fallback_platform() only works if
CONFIG_EFI_EMBEDDED_FIRMWARE is enabled (this gets selected by drivers
which need this), in all other cases firmware_fallback_platform() simply
always returns -ENOENT.

Reported-by: Dave Olsthoorn <dave@bewaar.me>
Suggested-by: Peter Jones <pjones@redhat.com>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20200115163554.101315-5-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-20 14:54:04 +01:00
Heinrich Schuchardt
f9834f18f0 efi/libstub: Add libstub/mem.c to the documentation tree
Let the description of the efi/libstub/mem.c functions appear in the kernel
API documentation in the following chapters:

    The Linux driver implementer’s API guide
        Linux Firmware API
            UEFI Support
                UEFI stub library functions

Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200221035832.144960-1-xypron.glpk@gmx.de
Link: https://lore.kernel.org/r/20200308080859.21568-9-ardb@kernel.org
2020-03-08 09:58:13 +01:00
Jonathan Corbet
e8d4f892bb docs: Fix a misdirected kerneldoc directive
The stratix10 service layer documentation tried to include a kerneldoc
comments for a nonexistent struct; leading to a "no structured comments
found" message.  Switch it to stratix10_svc_command_config_type, which
appears at that spot in the sequence and was not included.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-05-24 14:31:50 -06:00
Richard Gong
0d5c06aa0e Documentation: driver-api: add stratix10 service layer
Add Intel Stratix10 service layer driver document

Signed-off-by: Richard Gong <richard.gong@intel.com>
Signed-off-by: Alan Tull <atull@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-26 20:15:07 +01:00
Luis R. Rodriguez
8a1ed14ebf Documentation: update firmware loader fallback reference
The firmware loader has a fallback mechanism, and it now has some proper
kdoc, but we forgot to update the Documentation to use the new kdoc. Fix
that.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-07 17:45:25 +02:00
Luis R. Rodriguez
f0a462970e Documentation: clarify firmware_class provenance and why we can't rename the module
Clarify the provenance of the firmware loader firmware_class module name
and why we cannot rename the module in the future.

Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-14 16:46:10 +02:00
Luis R. Rodriguez
4fde24d416 Documentation: fix few typos and clarifications for the firmware loader
Fix a few typos, and clarify a few sentences.

Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-14 16:44:41 +02:00
Andres Rodriguez
7dcc01343e firmware: add firmware_request_nowarn() - load firmware without warnings
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>
Reviewed-by: Kees Cook <keescook@chromium.org>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-14 16:44:41 +02:00
Andres Rodriguez
b93815d0f3 firmware: some documentation fixes
Including:
 - Fixup outdated kernel-doc paths
 - Slightly too short title underline
 - Some typos

Signed-off-by: Andres Rodriguez <andresx7@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-25 18:37:20 +02:00
Hans de Goede
df9267f1fb firmware: Fix firmware documentation for recent file renames
firmware_class.c was split into several files under
drivers/base/firmware_loader. The new main.c has the functions which
/request_firmware.rst references.

Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-23 13:03:26 +02:00
Luis R. Rodriguez
5d42c96e1c firmware: add firmware_request_cache() to help with cache on reboot
Some devices have an optimization in place to enable the firmware to
be retaineed during a system reboot, so after reboot the device can skip
requesting and loading the firmware. This can save up to 1s in load
time. The mt7601u 802.11 device happens to be such a device.

When these devices retain the firmware on a reboot and then suspend
they can miss looking for the firmware on resume. To help with this we
need a way to cache the firmware when such an optimization has taken
place.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-22 18:33:26 +01:00
Luis R. Rodriguez
60fa74263c rename: _request_firmware_load() fw_load_sysfs_fallback()
This reflects much clearer what is being done.
While at it, kdoc'ify it.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-20 09:28:47 +01:00
Benjamin Gilbert
c508c46e6e firmware: Fix up docs referring to FIRMWARE_IN_KERNEL
We've removed the option, so stop talking about it.

Signed-off-by: Benjamin Gilbert <benjamin.gilbert@coreos.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-25 12:46:30 +01:00
Masanari Iida
a9afc573db firmware: Fix a typo in fallback-mechanisms.rst
This patch fix a spelling typo found in fallback-mechanisms.rst

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-09 17:54:53 +01:00
Linus Torvalds
f007cad159 Revert "firmware: add sanity check on shutdown/suspend"
This reverts commit 81f9507628.

It causes random failures of firmware loading at resume time (well,
random for me, it seems to be more reliable for others) because the
firmware disabling is not actually synchronous with any particular
resume event, and at least the btusb driver that uses a workqueue to
load the firmware at resume seems to occasionally hit the "firmware
loading is disabled" logic because the firmware loader hasn't gotten the
resume event yet.

Some kind of sanity check for not trying to load firmware when it's not
possible might be a good thing, but this commit was not it.

Greg seems to have silently suffered the same issue, and pointed to the
likely culprit, and Gabriel C verified the revert fixed it for him too.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Pointed-at-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Gabriel C <nix.or.die@gmail.com>
Cc: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-10 21:19:06 -07:00
Luis R. Rodriguez
81f9507628 firmware: add sanity check on shutdown/suspend
The firmware API should not be used after we go to suspend
and after we reboot/halt. The suspend/resume case is a bit
complex, so this documents that so things are clearer.

We want to know about users of the API in incorrect places so
that their callers are corrected, so this also adds a warn
for those cases.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 19:15:49 +09:00
Mauro Carvalho Chehab
c7e2c0643d docs-rst: core_api: move driver-specific stuff to drivers_api
There are several stuff there that are actually driver-specific.

Move those to the driver_api book.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-04-02 14:17:43 -06:00
Luis R. Rodriguez
113ccc3837 firmware: revamp firmware documentation
Understanding this code is getting out of control without any
notes. Give the firmware_class driver a much needed documentation love,
and while at it convert it to the new sphinx documentation format.

v2: typos and small fixes

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-11 09:42:59 +01:00