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path: root/drivers/char/hw_random/bcm2835-rng.c
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2023-09-15hwrng: bcm2835 - Fix hwrng throughput regressionStefan Wahren
The last RCU stall fix caused a massive throughput regression of the hwrng on Raspberry Pi 0 - 3. hwrng_msleep doesn't sleep precisely enough and usleep_range doesn't allow scheduling. So try to restore the best possible throughput by introducing hwrng_yield which interruptable sleeps for one jiffy. Some performance measurements on Raspberry Pi 3B+ (arm64/defconfig): sudo dd if=/dev/hwrng of=/dev/null count=1 bs=10000 cpu_relax ~138025 Bytes / sec hwrng_msleep(1000) ~13 Bytes / sec hwrng_yield ~2510 Bytes / sec Fixes: 96cb9d055445 ("hwrng: bcm2835 - use hwrng_msleep() instead of cpu_relax()") Link: https://lore.kernel.org/linux-arm-kernel/bc97ece5-44a3-4c4e-77da-2db3eb66b128@gmx.net/ Signed-off-by: Stefan Wahren <wahrenst@gmx.net> Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2023-09-15hwrng: bcm2835 - removed call to platform_set_drvdata()Andrei Coardos
This function call was found to be unnecessary as there is no equivalent platform_get_drvdata() call to access the private data of the driver. Also, the private data is defined in this driver, so there is no risk of it being accessed outside of this driver file. Signed-off-by: Andrei Coardos <aboutphysycs@gmail.com> Reviewed-by: Martin Kaiser <martin@kaiser.cx> Reviewed-by: Alexandru Ardelean <alex@shruggie.ro> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2023-08-04hwrng: Explicitly include correct DT includesRob Herring
The DT of_device.h and of_platform.h date back to the separate of_platform_bus_type before it was merged into the regular platform bus. As part of that merge prepping Arm DT support 13 years ago, they "temporarily" include each other. They also include platform_device.h and of.h. As a result, there's a pretty much random mix of those include files used throughout the tree. In order to detangle these headers and replace the implicit includes with struct declarations, users need to explicitly include the correct includes. Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2022-10-14hwrng: bcm2835 - use hwrng_msleep() instead of cpu_relax()Jason A. Donenfeld
Rather than busy looping, yield back to the scheduler and sleep for a bit in the event that there's no data. This should hopefully prevent the stalls that Mark reported: <6>[ 3.362859] Freeing initrd memory: 16196K <3>[ 23.160131] rcu: INFO: rcu_sched self-detected stall on CPU <3>[ 23.166057] rcu: 0-....: (2099 ticks this GP) idle=03b4/1/0x40000002 softirq=28/28 fqs=1050 <4>[ 23.174895] (t=2101 jiffies g=-1147 q=2353 ncpus=4) <4>[ 23.180203] CPU: 0 PID: 49 Comm: hwrng Not tainted 6.0.0 #1 <4>[ 23.186125] Hardware name: BCM2835 <4>[ 23.189837] PC is at bcm2835_rng_read+0x30/0x6c <4>[ 23.194709] LR is at hwrng_fillfn+0x71/0xf4 <4>[ 23.199218] pc : [<c07ccdc8>] lr : [<c07cb841>] psr: 40000033 <4>[ 23.205840] sp : f093df70 ip : 00000000 fp : 00000000 <4>[ 23.211404] r10: c3c7e800 r9 : 00000000 r8 : c17e6b20 <4>[ 23.216968] r7 : c17e6b64 r6 : c18b0a74 r5 : c07ccd99 r4 : c3f171c0 <4>[ 23.223855] r3 : 000fffff r2 : 00000040 r1 : c3c7e800 r0 : c3f171c0 <4>[ 23.230743] Flags: nZcv IRQs on FIQs on Mode SVC_32 ISA Thumb Segment none <4>[ 23.238426] Control: 50c5387d Table: 0020406a DAC: 00000051 <4>[ 23.244519] CPU: 0 PID: 49 Comm: hwrng Not tainted 6.0.0 #1 Link: https://lore.kernel.org/all/Y0QJLauamRnCDUef@sirena.org.uk/ Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-03-13hwrng: bcm2835 - add reset supportÁlvaro Fernández Rojas
BCM6368 devices need to reset the IPSEC controller in order to generate true random numbers. This is what BCM6368 produces without a reset: root@OpenWrt:/# cat /dev/hwrng | rngtest -c 1000 rngtest 6.10 Copyright (c) 2004 by Henrique de Moraes Holschuh This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. rngtest: starting FIPS tests... rngtest: bits received from input: 20000032 rngtest: FIPS 140-2 successes: 0 rngtest: FIPS 140-2 failures: 1000 rngtest: FIPS 140-2(2001-10-10) Monobit: 2 rngtest: FIPS 140-2(2001-10-10) Poker: 1000 rngtest: FIPS 140-2(2001-10-10) Runs: 1000 rngtest: FIPS 140-2(2001-10-10) Long run: 30 rngtest: FIPS 140-2(2001-10-10) Continuous run: 0 rngtest: input channel speed: (min=37.253; avg=320.827; max=635.783)Mibits/s rngtest: FIPS tests speed: (min=12.141; avg=15.034; max=16.428)Mibits/s rngtest: Program run time: 1336176 microseconds Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com> Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-03-07hwrng: bcm2835 - remove redundant null checkTian Tao
clk_prepare_enable() and clk_disable_unprepare() will check NULL clock parameter, so It is not necessary to add additional checks. Signed-off-by: Tian Tao <tiantao6@hisilicon.com> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-07-09hwrng: bcm2835 - Constify bcm2835_rng_devtype[]Rikard Falkeborn
bcm2835_rng_devtype[] is not modified and can be made const to allow the compiler to put it in read-only memory. Before: text data bss dec hex filename 2392 176 0 2568 a08 drivers/char/hw_random/bcm2835-rng.o After: text data bss dec hex filename 2464 104 0 2568 a08 drivers/char/hw_random/bcm2835-rng.o Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-07-09hwrng: bcm2835 - Fix W=1 unused variable warningHerbert Xu
This patch fixes an unused variable warning when this driver is built with CONFIG_OF=n. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-02-04treewide: remove redundant IS_ERR() before error code checkMasahiro Yamada
'PTR_ERR(p) == -E*' is a stronger condition than IS_ERR(p). Hence, IS_ERR(p) is unneeded. The semantic patch that generates this commit is as follows: // <smpl> @@ expression ptr; constant error_code; @@ -IS_ERR(ptr) && (PTR_ERR(ptr) == - error_code) +PTR_ERR(ptr) == - error_code // </smpl> Link: http://lkml.kernel.org/r/20200106045833.1725-1-masahiroy@kernel.org Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Cc: Julia Lawall <julia.lawall@lip6.fr> Acked-by: Stephen Boyd <sboyd@kernel.org> [drivers/clk/clk.c] Acked-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> [GPIO] Acked-by: Wolfram Sang <wsa@the-dreams.de> [drivers/i2c] Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> [acpi/scan.c] Acked-by: Rob Herring <robh@kernel.org> Cc: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-10-26hwrng: bcm2835 - use devm_platform_ioremap_resource() to simplify codeYueHaibing
Use devm_platform_ioremap_resource() to simplify the code a bit. This is detected by coccinelle. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-02-28hwrng: bcm2835 - fix probe as platform deviceJonas Gorski
BCM63XX (MIPS) does not use device tree, so there cannot be any of_device_id, causing the driver to fail on probe: [ 0.904564] bcm2835-rng: probe of bcm63xx-rng failed with error -22 Fix this by checking for match data only if we are probing from device tree. Fixes: 8705f24f7b57 ("hwrng: bcm2835 - Enable BCM2835 RNG to work on BCM63xx platforms") Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-11-16hwrng: bcm2835 - Switch to SPDX identifierStefan Wahren
Adopt the SPDX license identifier headers to ease license compliance management. While we are at this fix the comment style, too. Cc: Lubomir Rintel <lkundrak@v3.sk> Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Eric Anholt <eric@anholt.net> Acked-by: Lubomir Rintel <lkundrak@v3.sk> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-02-22hwrng: bcm2835 - Handle deferred clock properlyStefan Wahren
In case the probe of the clock is deferred, we would assume it is optional. This is wrong, so defer the probe of this driver until the clock is available. Fixes: 791af4f4907a ("hwrng: bcm2835 - Manage an optional clock") Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-01-26hwrng: bcm2835 - Remove redundant dev_err call in bcm2835_rng_probe()weiyongjun \(A\)
There is a error message within devm_ioremap_resource already, so remove the dev_err call to avoid redundant error message. Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Reviewed-by: Eric Anholt <eric@anholt.net> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-11-29hwrng: bcm2835 - Enable BCM2835 RNG to work on BCM63xx platformsFlorian Fainelli
We have now incorporated all necessary functionality for the BCM63xx platforms to successfully migrate over bcm2835-rng, so add the final bits: Kconfig selection and proper platform_device device type matching to keep the same platform device name for registration to work. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-11-29hwrng: bcm2835 - Add Broadcom MIPS I/O accessorsFlorian Fainelli
Broadcom MIPS HW is always strapped to match the system-wide endian such that all I/O access to this RNG block is done with the native CPU endian, account for that. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-11-29hwrng: bcm2835 - Abstract I/O accessorsFlorian Fainelli
In preparation for allowing BCM63xx to use this driver, we abstract I/O accessors such that we can easily change those later on. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-11-29hwrng: bcm2835 - Manage an optional clockFlorian Fainelli
One of the last steps before bcm63xx-rng can be eliminated is to manage a clock during hwrng::init and hwrng::cleanup, so fetch it in the probe function, and manage it during these two steps when valid. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-11-29hwrng: bcm2835 - Rework interrupt maskingFlorian Fainelli
The interrupt masking done for Northstart Plus and Northstar (BCM5301X) is moved from being a function pointer mapped to of_device_id::data into a proper part of the hwrng::init callback. While at it, we also make the of_data be a proper structure indicating the platform specifics, since the day we need to add a second type of platform information, we would have to do that anyway. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-11-29hwrng: bcm2835 - Use device managed helpersFlorian Fainelli
Now that we have moved the RNG disabling into a hwrng::cleanup callback, we can use the device managed registration operation and remove our remove callback since it won't do anything necessary. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-11-29hwrng: bcm2835 - Implementation cleanup callbackFlorian Fainelli
We should be disabling the RNG in a hwrng::cleanup callback if we are not longer the system selected RNG, not wait until the device driver is removed. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-11-29hwrng: bcm2835 - Move enabling to hwrng::initFlorian Fainelli
We should be moving the enabling of the HWRNG into a hwrng::init callback since we can be disabled and enabled every time a different hwrng is selected in the system. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-11-29hwrng: bcm2835 - Define a driver private contextFlorian Fainelli
Instead of making hwrng::priv host the base register address, define a driver private context, make it per platform device instance and pass it down the different functions. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-11-29hwrng: bcm2835 - Obtain base register via resourceFlorian Fainelli
In preparation for consolidating bcm63xx-rng into bcm2835-rng, make sure that we obtain the base register via platform_get_resource() since we need to support the non-DT enabled MIPS-based BCM63xx DSL SoCs. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-09-07hwrng: bcm2835 - handle of_iomap failuresArvind Yadav
Check return value of of_iomap and handle errors correctly. Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Acked-by: Eric Anholt <eric@anholt.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-06-24hwrng: bcm2835 - Add support for Broadcom BCM5301xFlorian Fainelli
The Broadcom BCM5301x SoCs (Northstar) utilize the same random number generator peripheral as Northstar Plus and BCM2835, but just like the NSP SoC, we need to enable the interrupt. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-05-31hwrng: bcm2835 - Read as much data as availableYendapally Reddy Dhananjaya Reddy
Read the requested number of data from the fifo Signed-off-by: Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-05-31hwrng: bcm2835 - Support Broadcom NSP SoC rngYendapally Reddy Dhananjaya Reddy
This supports the random number generator available in NSP SoC. Masks the rng interrupt for NSP. Signed-off-by: Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com> Acked-by: Eric Anholt <eric@anholt.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2014-10-20char: hw_random: drop owner assignment from platform_driversWolfram Sang
A platform_driver does not need to set an owner, it will be populated by the driver core. Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-04-11hwrng: bcm2835 - fix oops when rng h/w is accessed during registrationMatt Porter
Commit "d9e7972 hwrng: add randomness to system from rng sources" exposed a bug in the bcm2835-rng driver resulting in boot failure on Raspberry Pi due to the following oops: [ 28.261523] BUG: soft lockup - CPU#0 stuck for 23s! [swapper:1] [ 28.271058] [ 28.275958] CPU: 0 PID: 1 Comm: swapper Not tainted 3.14.0+ #11 [ 28.285374] task: db480000 ti: db484000 task.ti: db484000 [ 28.294279] PC is at bcm2835_rng_read+0x28/0x48 [ 28.302276] LR is at hwrng_register+0x1a8/0x238 . . . The RNG h/w is not completely initialized and enabled before hwrng_register() is called and so the bcm2835_rng_read() fails. Fix this by making the warmup/enable writes before registering the RNG source with the hwrng core. Signed-off-by: Matt Porter <mporter@linaro.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2014-02-07drivers/char: delete non-required instances of include <linux/init.h>Paul Gortmaker
None of these files are actually using any __init type directives and hence don't need to include <linux/init.h>. Most are just a left over from __devinit and __cpuinit removal, or simply due to code getting copied from one driver to the next. Cc: David Airlie <airlied@linux.ie> Cc: Matt Mackall <mpm@selenic.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Kukjin Kim <kgene.kim@samsung.com> Cc: Corey Minyard <minyard@acm.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Peter Huewe <peterhuewe@gmx.de> Cc: Ashley Lai <ashley@ashleylai.com> Cc: Marcel Selhorst <tpmdd@selhorst.net> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-19hwrng: bcm2835: fix MODULE_LICENSE tagArnd Bergmann
The MODULE_LICENSE macro invocation must use either "GPL" or "GPL v2", but not "GPLv2" in order to be detected by the module loader. This fixes the allmodconfig build error: FATAL: modpost: GPL-incompatible module bcm2835-rng.ko uses GPL-only symbol 'platform_driver_unregister' Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Lubomir Rintel <lkundrak@v3.sk> Cc: Dom Cobley <popcornmix@gmail.com> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Matt Mackall <mpm@selenic.com> Cc: linux-rpi-kernel@lists.infradead.org Cc: Herbert Xu <herbert@gondor.apana.org.au>
2013-04-25hwrng: bcm2835 - Add Broadcom BCM2835 RNG driverLubomir Rintel
This adds a driver for random number generator present on Broadcom BCM2835 SoC, used in Raspberry Pi and Roku 2 devices. Signed-off-by: Dom Cobley <popcornmix@gmail.com> Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> Tested-by: Stephen Warren <swarren@wwwdotorg.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Matt Mackall <mpm@selenic.com> Cc: linux-rpi-kernel@lists.infradead.org Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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