kernel/drivers/firmware/google/coreboot_table.c, branch linux-6.9.y

firmware: coreboot: Replace tag with id table in driver struct

2024-02-17T00:53:06Z

Switch the plain 'tag' field in struct coreboot_driver for the newly created coreboot_device_id struct, which also contains a tag field and has the benefit of allowing modalias generation, and update all coreboot drivers accordingly. While at it, also add the id table for each driver to the module device table to allow automatically loading the module. Reviewed-by: AngeloGioacchino Del Regno Reviewed-by: Brian Norris Signed-off-by: Nícolas F. R. A. Prado Link: https://lore.kernel.org/r/20240212-coreboot-mod-defconfig-v4-3-d14172676f6d@collabora.com Signed-off-by: Tzung-Bi Shih

firmware: coreboot: Generate modalias uevent for devices

2024-02-17T00:53:05Z

Generate a modalias uevent for devices in the coreboot bus to allow userspace to automatically load the corresponding modules. Acked-by: Brian Norris Reviewed-by: AngeloGioacchino Del Regno Reviewed-by: Brian Norris Signed-off-by: Nícolas F. R. A. Prado Link: https://lore.kernel.org/r/20240212-coreboot-mod-defconfig-v4-1-d14172676f6d@collabora.com Signed-off-by: Tzung-Bi Shih

firmware: coreboot: make coreboot_bus_type const

2024-02-06T03:56:17Z

Now that the driver core can properly handle constant struct bus_type, move the coreboot_bus_type variable to be a constant structure as well, placing it into read-only memory which can not be modified at runtime. Cc: Greg Kroah-Hartman Suggested-by: Greg Kroah-Hartman Signed-off-by: "Ricardo B. Marliere" Reviewed-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20240204-bus_cleanup-firmware-v1-1-d1bff946606d@marliere.net Signed-off-by: Tzung-Bi Shih

firmware: coreboot: Convert to platform remove callback returning void

2023-12-28T02:42:25Z

The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new(), which already returns void. Eventually after all drivers are converted, .remove_new() will be renamed to .remove(). Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König Link: https://lore.kernel.org/r/d323e4f24bfab3ac1480933deb51e7c5cb025b09.1703693980.git.u.kleine-koenig@pengutronix.de Signed-off-by: Tzung-Bi Shih

firmware: coreboot: Check size of table entry and use flex-array

2023-01-13T23:22:03Z

The memcpy() of the data following a coreboot_table_entry couldn't be evaluated by the compiler under CONFIG_FORTIFY_SOURCE. To make it easier to reason about, add an explicit flexible array member to struct coreboot_device so the entire entry can be copied at once. Additionally, validate the sizes before copying. Avoids this run-time false positive warning: memcpy: detected field-spanning write (size 168) of single field "&device->entry" at drivers/firmware/google/coreboot_table.c:103 (size 8) Reported-by: Paul Menzel Link: https://lore.kernel.org/all/03ae2704-8c30-f9f0-215b-7cdf4ad35a9a@molgen.mpg.de/ Cc: Jack Rosenthal Cc: Guenter Roeck Cc: Julius Werner Cc: Brian Norris Cc: Stephen Boyd Cc: Greg Kroah-Hartman Signed-off-by: Kees Cook Reviewed-by: Julius Werner Reviewed-by: Guenter Roeck Link: https://lore.kernel.org/r/20230107031406.gonna.761-kees@kernel.org Reviewed-by: Stephen Boyd Reviewed-by: Jack Rosenthal Link: https://lore.kernel.org/r/20230112230312.give.446-kees@kernel.org

Merge 6.1-rc6 into char-misc-next

2022-11-21T09:05:34Z

We need the char/misc fixes in here as well. Signed-off-by: Greg Kroah-Hartman

firmware: google: Implement cbmem in sysfs driver

2022-11-10T17:51:56Z

The CBMEM area is a downward-growing memory region used by coreboot to dynamically allocate tagged data structures ("CBMEM entries") that remain resident during boot. This implements a driver which exports access to the CBMEM entries via sysfs under /sys/bus/coreboot/devices/cbmem-. This implementation is quite versatile. Examples of how it could be used are given below: * Tools like util/cbmem from the coreboot tree could use this driver instead of finding CBMEM in /dev/mem directly. Alternatively, firmware developers debugging an issue may find the sysfs interface more ergonomic than the cbmem tool and choose to use it directly. * The crossystem tool, which exposes verified boot variables, can use this driver to read the vboot work buffer. * Tools which read the BIOS SPI flash (e.g., flashrom) can find the flash layout in CBMEM directly, which is significantly faster than searching the flash directly. Write access is provided to all CBMEM regions via /sys/bus/coreboot/devices/cbmem-/mem, as the existing cbmem tooling updates this memory region, and envisioned use cases with crossystem can benefit from updating memory regions. Link: https://issuetracker.google.com/239604743 Cc: Stephen Boyd Cc: Tzung-Bi Shih Reviewed-by: Guenter Roeck Reviewed-by: Julius Werner Tested-by: Jack Rosenthal Signed-off-by: Jack Rosenthal Link: https://lore.kernel.org/r/20221104161528.531248-1-jrosenth@chromium.org Signed-off-by: Greg Kroah-Hartman

firmware: coreboot: Register bus in module init

2022-11-10T17:47:53Z

The coreboot_table driver registers a coreboot bus while probing a "coreboot_table" device representing the coreboot table memory region. Probing this device (i.e., registering the bus) is a dependency for the module_init() functions of any driver for this bus (e.g., memconsole-coreboot.c / memconsole_driver_init()). With synchronous probe, this dependency works OK, as the link order in the Makefile ensures coreboot_table_driver_init() (and thus, coreboot_table_probe()) completes before a coreboot device driver tries to add itself to the bus. With asynchronous probe, however, coreboot_table_probe() may race with memconsole_driver_init(), and so we're liable to hit one of these two: 1. coreboot_driver_register() eventually hits "[...] the bus was not initialized.", and the memconsole driver fails to register; or 2. coreboot_driver_register() gets past #1, but still races with bus_register() and hits some other undefined/crashing behavior (e.g., in driver_find() [1]) We can resolve this by registering the bus in our initcall, and only deferring "device" work (scanning the coreboot memory region and creating sub-devices) to probe(). [1] Example failure, using 'driver_async_probe=*' kernel command line: [ 0.114217] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010 ... [ 0.114307] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.1.0-rc1 #63 [ 0.114316] Hardware name: Google Scarlet (DT) ... [ 0.114488] Call trace: [ 0.114494] _raw_spin_lock+0x34/0x60 [ 0.114502] kset_find_obj+0x28/0x84 [ 0.114511] driver_find+0x30/0x50 [ 0.114520] driver_register+0x64/0x10c [ 0.114528] coreboot_driver_register+0x30/0x3c [ 0.114540] memconsole_driver_init+0x24/0x30 [ 0.114550] do_one_initcall+0x154/0x2e0 [ 0.114560] do_initcall_level+0x134/0x160 [ 0.114571] do_initcalls+0x60/0xa0 [ 0.114579] do_basic_setup+0x28/0x34 [ 0.114588] kernel_init_freeable+0xf8/0x150 [ 0.114596] kernel_init+0x2c/0x12c [ 0.114607] ret_from_fork+0x10/0x20 [ 0.114624] Code: 5280002b 1100054a b900092a f9800011 (885ffc01) [ 0.114631] ---[ end trace 0000000000000000 ]--- Fixes: b81e3140e412 ("firmware: coreboot: Make bus registration symmetric") Cc: Signed-off-by: Brian Norris Reviewed-by: Guenter Roeck Reviewed-by: Stephen Boyd Link: https://lore.kernel.org/r/20221019180934.1.If29e167d8a4771b0bf4a39c89c6946ed764817b9@changeid Signed-off-by: Greg Kroah-Hartman

bus: Make remove callback return void

2021-07-21T09:53:42Z

The driver core ignores the return value of this callback because there is only little it can do when a device disappears. This is the final bit of a long lasting cleanup quest where several buses were converted to also return void from their remove callback. Additionally some resource leaks were fixed that were caused by drivers returning an error code in the expectation that the driver won't go away. With struct bus_type::remove returning void it's prevented that newly implemented buses return an ignored error code and so don't anticipate wrong expectations for driver authors. Reviewed-by: Tom Rix (For fpga) Reviewed-by: Mathieu Poirier Reviewed-by: Cornelia Huck (For drivers/s390 and drivers/vfio) Acked-by: Russell King (Oracle) (For ARM, Amba and related parts) Acked-by: Mark Brown Acked-by: Chen-Yu Tsai (for sunxi-rsb) Acked-by: Pali Rohár Acked-by: Mauro Carvalho Chehab (for media) Acked-by: Hans de Goede (For drivers/platform) Acked-by: Alexandre Belloni Acked-By: Vinod Koul Acked-by: Juergen Gross (For xen) Acked-by: Lee Jones (For mfd) Acked-by: Johannes Thumshirn (For mcb) Acked-by: Johan Hovold Acked-by: Srinivas Kandagatla (For slimbus) Acked-by: Kirti Wankhede (For vfio) Acked-by: Maximilian Luz Acked-by: Heikki Krogerus (For ulpi and typec) Acked-by: Samuel Iglesias Gonsálvez (For ipack) Acked-by: Geoff Levand (For ps3) Acked-by: Yehezkel Bernat (For thunderbolt) Acked-by: Alexander Shishkin (For intel_th) Acked-by: Dominik Brodowski (For pcmcia) Acked-by: Rafael J. Wysocki (For ACPI) Acked-by: Bjorn Andersson (rpmsg and apr) Acked-by: Srinivas Pandruvada (For intel-ish-hid) Acked-by: Dan Williams (For CXL, DAX, and NVDIMM) Acked-by: William Breathitt Gray (For isa) Acked-by: Stefan Richter (For firewire) Acked-by: Benjamin Tissoires (For hid) Acked-by: Thorsten Scherer (For siox) Acked-by: Sven Van Asbroeck (For anybuss) Acked-by: Ulf Hansson (For MMC) Acked-by: Wolfram Sang # for I2C Acked-by: Sudeep Holla Acked-by: Geert Uytterhoeven Acked-by: Dmitry Torokhov Acked-by: Finn Thain Signed-off-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20210713193522.1770306-6-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman

firmware: google: make coreboot driver's remove callback return void

2021-02-09T11:12:43Z

All coreboot drivers return 0 unconditionally in their remove callback. Also the device core ignores the return value of the struct bus_type::remove(), so make the coreboot remove callback return void instead of giving driver authors the illusion they could return an error code here. All drivers are adapted accordingly. Signed-off-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20210126215339.706021-1-uwe@kleine-koenig.org Signed-off-by: Greg Kroah-Hartman