kernel/linux.git/drivers/base/firmware_loader/main.c, branch v5.7.3

firmware: Add new platform fallback mechanism and firmware_request_platform()

2020-03-20T13:54:04+00:00

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 Suggested-by: Peter Jones Acked-by: Luis Chamberlain Signed-off-by: Hans de Goede Link: https://lore.kernel.org/r/20200115163554.101315-5-hdegoede@redhat.com Signed-off-by: Greg Kroah-Hartman

firmware_loader: load files from the mount namespace of init

2020-02-10T23:39:28+00:00

I have an experimental setup where almost every possible system service (even early startup ones) runs in separate namespace, using a dedicated, minimal file system. In process of minimizing the contents of the file systems with regards to modules and firmware files, I noticed that in my system, the firmware files are loaded from three different mount namespaces, those of systemd-udevd, init and systemd-networkd. The logic of the source namespace is not very clear, it seems to depend on the driver, but the namespace of the current process is used. So, this patch tries to make things a bit clearer and changes the loading of firmware files only from the mount namespace of init. This may also improve security, though I think that using firmware files as attack vector could be too impractical anyway. Later, it might make sense to make the mount namespace configurable, for example with a new file in /proc/sys/kernel/firmware_config/. That would allow a dedicated file system only for firmware files and those need not be present anywhere else. This configurability would make more sense if made also for kernel modules and /sbin/modprobe. Modules are already loaded from init namespace (usermodehelper uses kthreadd namespace) except when directly loaded by systemd-udevd. Instead of using the mount namespace of the current process to load firmware files, use the mount namespace of init process. Link: https://lore.kernel.org/lkml/bb46ebae-4746-90d9-ec5b-fce4c9328c86@gmail.com/ Link: https://lore.kernel.org/lkml/0e3f7653-c59d-9341-9db2-c88f5b988c68@gmail.com/ Signed-off-by: Topi Miettinen Link: https://lore.kernel.org/r/20200123125839.37168-1-toiwoton@gmail.com Signed-off-by: Greg Kroah-Hartman

firmware: Rename FW_OPT_NOFALLBACK to FW_OPT_NOFALLBACK_SYSFS

2020-01-24T08:56:58+00:00

This is a preparation patch for adding a new platform fallback mechanism, which will have its own enable/disable FW_OPT_xxx option. Note this also fixes a typo in one of the re-wordwrapped comments: enfoce -> enforce. Acked-by: Luis Chamberlain Signed-off-by: Hans de Goede Link: https://lore.kernel.org/r/20200115163554.101315-4-hdegoede@redhat.com Signed-off-by: Greg Kroah-Hartman

firmware_class: make firmware caching configurable

2019-11-14T00:14:16+00:00

Because firmware caching generates uevent messages that are sent over a netlink socket, it can prevent suspend on many platforms. It's also not always useful, so make it a configurable option. Signed-off-by: Mark Salyzyn Cc: Tim Murray Cc: Venkata Narendra Kumar Gutta Cc: Luis Chamberlain Cc: Greg Kroah-Hartman Cc: Rafael J. Wysocki Cc: linux-kernel@vger.kernel.org Cc: kernel-team@android.com Acked-by: Luis Chamberlain Link: https://lore.kernel.org/r/20191113225429.118495-1-salyzyn@android.com Signed-off-by: Greg Kroah-Hartman

firmware loader: log path to loaded firmwares

2019-11-03T18:44:17+00:00

This is useful for users who are trying to identify the firmwares in use on their system. Signed-off-by: Drew DeVault Link: https://lore.kernel.org/r/20191103180646.34880-1-sir@cmpwn.com Signed-off-by: Greg Kroah-Hartman

firmware: Update pointer to documentation

2019-10-11T06:46:08+00:00

Documentation was revamped in 113ccc but link in firmware_loader/main.c hasn't been updated. Signed-off-by: Arkadiusz Drabczyk Link: https://lore.kernel.org/r/20190912205606.31095-1-arkadiusz@drabczyk.org Signed-off-by: Greg Kroah-Hartman

firmware: Add support for loading compressed files

2019-06-18T07:11:22+00:00

This patch adds the support for loading compressed firmware files. The primary motivation is to reduce the storage size; e.g. currently the files in /lib/firmware on my machine counts up to 419MB, while they can be reduced to 130MB by file compression. The patch introduces a new kconfig option CONFIG_FW_LOADER_COMPRESS. Even with this option set, the firmware loader still tries to load the original firmware file as-is at first, but then falls back to the file with ".xz" extension when it's not found, and the decompressed file content is returned to the caller of request_firmware(). So, no change is needed for the rest. Currently only XZ format is supported. A caveat is that the kernel XZ helper code supports only CRC32 (or none) integrity check type, so you'll have to compress the files via xz -C crc32 option. Since we can't determine the expanded size immediately from an XZ file, the patch re-uses the paged buffer that was used for the user-mode fallback; it puts the decompressed content page, which are vmapped at the end. The paged buffer code is conditionally built with a new Kconfig that is selected automatically. Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman

firmware: Factor out the paged buffer handling code

2019-06-18T07:11:21+00:00

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

firmware: Use kvmalloc for page tables

2019-06-10T17:20:37+00:00

This is a minor optimization to use kvmalloc() variant for allocating the page table for the SG-buffer. They aren't so big in general, so kmalloc() would fit often better. Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman

firmware: Unify the paged buffer release helper

2019-06-10T17:20:37+00:00

Use a common helper to release the paged buffer resources. This is rather a preparation for the upcoming decompression support. Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman