Commit Graph

33 Commits

Author SHA1 Message Date
Stefan Wahren b58a36008b hwrng: bcm2835 - Fix hwrng throughput regression
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: 96cb9d0554 ("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>
2023-09-15 18:29:45 +08:00
Andrei Coardos 75b2d50d0d hwrng: bcm2835 - removed call to platform_set_drvdata()
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>
2023-09-15 18:29:44 +08:00
Rob Herring 0788257aee hwrng: Explicitly include correct DT includes
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>
2023-08-04 17:09:26 +08:00
Jason A. Donenfeld 96cb9d0554 hwrng: bcm2835 - use hwrng_msleep() instead of cpu_relax()
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>
2022-10-14 19:03:09 +08:00
Álvaro Fernández Rojas e5f9f41d5e hwrng: bcm2835 - add reset support
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>
2021-03-13 00:04:06 +11:00
Tian Tao e06da499d6 hwrng: bcm2835 - remove redundant null check
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>
2021-03-07 15:13:14 +11:00
Rikard Falkeborn d4f6d92323 hwrng: bcm2835 - Constify bcm2835_rng_devtype[]
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>
2020-07-09 18:25:21 +10:00
Herbert Xu 64f8153a2f hwrng: bcm2835 - Fix W=1 unused variable warning
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>
2020-07-09 18:25:12 +10:00
Masahiro Yamada 45586c7078 treewide: remove redundant IS_ERR() before error code check
'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>
2020-02-04 03:05:27 +00:00
YueHaibing 3e46bd3497 hwrng: bcm2835 - use devm_platform_ioremap_resource() to simplify code
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>
2019-10-26 02:09:53 +11:00
Jonas Gorski 984798de67 hwrng: bcm2835 - fix probe as platform device
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: 8705f24f7b ("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>
2019-02-28 14:17:58 +08:00
Stefan Wahren 05ba88468b hwrng: bcm2835 - Switch to SPDX identifier
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>
2018-11-16 14:11:04 +08:00
Stefan Wahren 7b4c5d30d0 hwrng: bcm2835 - Handle deferred clock properly
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: 791af4f490 ("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>
2018-02-22 22:16:21 +08:00
weiyongjun \(A\) c4fc5d6d0b hwrng: bcm2835 - Remove redundant dev_err call in bcm2835_rng_probe()
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>
2018-01-26 01:10:31 +11:00
Florian Fainelli 8705f24f7b hwrng: bcm2835 - Enable BCM2835 RNG to work on BCM63xx platforms
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>
2017-11-29 16:43:48 +11:00
Florian Fainelli 6f09359a68 hwrng: bcm2835 - Add Broadcom MIPS I/O accessors
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>
2017-11-29 16:43:46 +11:00
Florian Fainelli abd42026ea hwrng: bcm2835 - Abstract I/O accessors
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>
2017-11-29 16:43:46 +11:00
Florian Fainelli 791af4f490 hwrng: bcm2835 - Manage an optional clock
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>
2017-11-29 16:43:45 +11:00
Florian Fainelli 04b154fa86 hwrng: bcm2835 - Rework interrupt masking
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>
2017-11-29 16:43:45 +11:00
Florian Fainelli 16a4c04b37 hwrng: bcm2835 - Use device managed helpers
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>
2017-11-29 16:43:44 +11:00
Florian Fainelli ec94bca7be hwrng: bcm2835 - Implementation cleanup callback
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>
2017-11-29 16:43:44 +11:00
Florian Fainelli a815777553 hwrng: bcm2835 - Move enabling to hwrng::init
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>
2017-11-29 16:43:43 +11:00
Florian Fainelli b788479f68 hwrng: bcm2835 - Define a driver private context
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>
2017-11-29 16:43:43 +11:00
Florian Fainelli 21bb0ef43c hwrng: bcm2835 - Obtain base register via resource
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>
2017-11-29 16:43:42 +11:00
Arvind Yadav da59c51cf2 hwrng: bcm2835 - handle of_iomap failures
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>
2016-09-07 21:08:24 +08:00
Florian Fainelli 52140993d4 hwrng: bcm2835 - Add support for Broadcom BCM5301x
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>
2016-06-24 21:24:58 +08:00
Yendapally Reddy Dhananjaya Reddy 4f8de65bab hwrng: bcm2835 - Read as much data as available
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>
2016-05-31 17:52:29 +08:00
Yendapally Reddy Dhananjaya Reddy 422a749145 hwrng: bcm2835 - Support Broadcom NSP SoC rng
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>
2016-05-31 17:52:23 +08:00
Wolfram Sang eff54802fe char: hw_random: drop owner assignment from platform_drivers
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>
2014-10-20 16:20:20 +02:00
Matt Porter eb4a5346e7 hwrng: bcm2835 - fix oops when rng h/w is accessed during registration
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>
2014-04-11 11:31:13 +08:00
Paul Gortmaker 4c020b032b drivers/char: delete non-required instances of include <linux/init.h>
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>
2014-02-07 15:10:19 -08:00
Arnd Bergmann 22e8099f4f hwrng: bcm2835: fix MODULE_LICENSE tag
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>
2013-06-19 17:52:20 +02:00
Lubomir Rintel 8c4196a2fd hwrng: bcm2835 - Add Broadcom BCM2835 RNG driver
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>
2013-04-25 21:01:44 +08:00