Add support for STMicroelectronics STM32 random number generator.

The config value defaults to N, reflecting the fact that STM32 is a
very low resource microcontroller platform and unlikely to be targeted
by any "grown up" defconfigs.
Signed-off-by: NDaniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

The original representation of FIFO size in the driver coupled with the
ambiguity in the documentation meant that it was easy to confuse readers.
This lead to a false positive BUG-find and subsequently time wastage
debugging this phantom issue.

Hopefully this patch can prevent future readers from falling into the
same trap.
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Samples are documented to be available every 0.667us, so in theory
the 8 sample deep FIFO should take 5.336us to fill.  However, during
thorough testing, it became apparent that filling the FIFO actually
takes closer to 12us.

Also take into consideration that udelay() can behave oddly i.e. not
delay for as long as requested.

  Suggested-by: Russell King <rmk+kernel@arm.linux.org.uk>:

    "IIRC, Linus recommends a x2 factor on delays, especially
     timeouts generated by these functions.
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: NPankaj Dev <pankaj.dev@st.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Acked-by: NKieran Bingham <kieranbingham@gmail.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

If we attempt to use sysfs to change the current RNG in the usual
way i.e. issuing something like:

`echo 8a8a000.rng > /sys/devices/virtual/misc/hw_random/rng_current`

... it will fail because the code doesn't currently take the '\n'
into consideration.  Well, now it does.
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Acked-by: NPeter Korsgaard <peter@korsgaard.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

In April 2009, commit d4056405 ("Driver Core: misc: add node name support
for misc devices.") inadvertently changed the device node name from
/dev/hw_random to /dev/hwrng.  Since 6 years has passed since the change
it seems unpractical to change it back, as this node name is probably
considered ABI by now.  So instead, we'll just change the Kconfig help
to match the current situation.

NB: It looks like rng-tools have already been updated.
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Acked-by: NKieran Bingham <kieranbingham@gmail.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

This platform drivers have a OF device ID table but the OF module
alias information is not created so module autoloading won't work.
Signed-off-by: NLuis de Bethencourt <luisbg@osg.samsung.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

According to Documentation/CodingStyle:

"The preferred form for passing a size of a struct is the following:

	p = kmalloc(sizeof(*p), ...);"

,so do as suggested.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

There is no need to print a message simply saying that a kernel
driver has been registered, so remove it.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

There is no need to pre-initialize variable 'err' as this
initial value will be overwritten later on.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

We can simplify the code by returning the error code immediately
instead of jumping to a goto label.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Use resource managed function devm_hwrng_register instead of
hwrng_register to make the error-path simpler. Also, remove
octeon_rng_remove as it is now redundant.
Signed-off-by: NVaishali Thakkar <vthakkar1994@gmail.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

The kthread_run() function can return two different error values
but the hwrng core only checks for -ENOMEM. If the other error
value -EINTR is returned it is assigned to hwrng_fill and later
used on a kthread_stop() call which naturally crashes.

Cc: stable@vger.kernel.org
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

We already have fpu/types.h, move i387.h to fpu/api.h.

The file name has become a misnomer anyway: it offers generic FPU APIs,
but is not limited to i387 functionality.
Reviewed-by: NBorislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

- s/clk_didsable_unprepare/clk_disable_unprepare
- s/prov/priv
- s/error/ret (bcm63xx_rng_probe)

Fixes: 6229c160 ("hwrng: bcm63xx - make use of devm_hwrng_register")
Signed-off-by: NÁlvaro Fernández Rojas <noltari@gmail.com>
Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Use the new group field of struct miscdevice for managing the sysfs
entries instead of manually adding/removing via device_create_file()
and device_remove_file().  This simplifies the code a lot and fixes
the possible races.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Hardware random number quality is measured from 0 (no entropy) to 1024
(perfect entropy). Allow hardware devices to assert the full range by
truncating the device-provided value at 1024 instead of 1023.
Signed-off-by: NKeith Packard <keithp@keithp.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

omap4_rng_init() checks bit 10 of the RNG_CONFIG_REG to determine whether
the RNG is already running before performing any initiliasation. This is not
the correct register to check, as the enable bit is in RNG_CONFIG_CONTROL.
Read from RNG_CONTROL_REG instead.
Signed-off-by: NAndre Wolokita <Andre.Wolokita@analog.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

In omap4_rng_init(), a check of bit 10 of the RNG_CONFIG_REG is done to determine
whether the RNG is running. This is suspicious firstly due to the use of
RNG_CONTROL_ENABLE_TRNG_MASK and secondly because the same mask is written to
RNG_CONTROL_REG after configuration of the FROs. Similar suspicious logic is
repeated in omap4_rng_cleanup() when RNG_CONTROL_REG masked with
RNG_CONTROL_ENABLE_TRNG_MASK is read, the same mask bit is cleared, and then
written to RNG_CONFIG_REG. Unless the TRNG is enabled with one bit in RNG_CONTROL
and disabled with another in RNG_CONFIG and these bits are mirrored in some way,
I believe that the TRNG is not really shutting off.

Apart from the strange logic, I have reason to suspect that the OMAP4 related
code in this driver is driving an Inside Secure IP hardware RNG and strongly
suspect that bit 10 of RNG_CONFIG_REG is one of the bits configuring the
sampling rate of the FROs. This option is by default set to 0 and is not being
set anywhere in omap-rng.c. Reading this bit during omap4_rng_init() will
always return 0. It will remain 0 because ~(value of TRNG_MASK in control) will
always be 0, because the TRNG is never shut off. This is of course presuming
that the OMAP4 features the Inside Secure IP.

I'm interested in knowing what the guys at TI think about this, as only they
can confirm or deny the detailed structure of these registers.
Signed-off-by: NAndre Wolokita <Andre.Wolokita@analog.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

of_device_id is always used as const.
(See driver.of_match_table and open firmware functions)
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This allows us to get rid of driver's remove() method.
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Instead of using static hwrng structure that is reused between
binds/unbinds of the device let's embed it into driver's private
structure that we allocate. This way we are guaranteed not to stumble
onto something left from previous bind attempt.
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

This allows us to get rid of remove() method.
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

This allows us to get rid of remove() method.
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

This change converts bcm63xx-rng to use devm* API for managing all
resources, which allows us to dispense with the rest of error handling
path and remove() function. Also we combine hwern and driver-private
data into a single allocation, use clk_prepare_enable() instead
of "naked" clk_enable() and move clock enabling/disabling into hwrnd
inti(0 and cleanup() methods so the clock stays off until rng is
used.
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

This change adds devm_hwrng_register and devm_hwrng_unregister which
use can simplify error unwinding and unbinding code paths in device
drivers.
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Instead of using #ifdefs let's mark suspend and resume methods as
__maybe_unused which will suppress compiler warnings about them being
unused and provide better compile coverage.

Because SIMPLE_DEV_PM_OPS() produces an empty omap_rng_pm structure in
case of !CONFIG_PM_SLEEP neither omap_rng_suspend nor omap_rng_resume
will end up being referenced and the change will not result in
increasing image size.
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Even if bus is not hot-pluggable, the devices can be unbound from the
driver via sysfs, so we should not be using __exit annotations on
remove() methods. The only exception is drivers registered with
platform_driver_probe() which specifically disables sysfs bind/unbind
attributes.

Similarly probe() methods should not be marked __init unless
platform_driver_probe() is used.
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Even if bus is not hot-pluggable, the devices can be unbound from the
driver via sysfs, so we should not be using __exit annotations on
remove() methods. The only exception is drivers registered with
platform_driver_probe() which specifically disables sysfs bind/unbind
attributes
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Even if bus is not hot-pluggable, the devices can be unbound from the
driver via sysfs, so we should not be using __exit annotations on
remove() methods. The only exception is drivers registered with
platform_driver_probe() which specifically disables sysfs bind/unbind
attributes.
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

This adds ACPI support for APM X-Gene RNG unit.
Signed-off-by: NFeng Kan <fkan@apm.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

This adds a driver for random number generator present on Broadcom
IPROC devices.
Reviewed-by: NRay Jui <rjui@broadcom.com>
Signed-off-by: NScott Branden <sbranden@broadcom.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Simplify the driver's probe function and error handling by using the
device managed allocators, while at it, drop the redundant "out of
memory" messages since these are already printed by the allocator.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

arch/mips/include/asm/mach-bcm63xx/bcm63xx_regs.h contains the register
definitions for this random number generator block, incorporate these
register definitions directly into the bcm63xx-rng driver so we do not
rely on this header to be provided.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

bcm_{readl,writel} macros expand to __raw_{readl,writel}, use these
directly such that we do not rely on the platform to provide these for
us. As a result, we no longer use bcm63xx_io.h, so remove that inclusion
too.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

makes code look a bit prettier.

Cc: linux-crypto@vger.kernel.org.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

makes code look a bit prettier.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

We always do hwrng_init in set_current_rng.  In fact, our current
reference count system relies on this.  So make this explicit by
moving hwrng_init into set_current_rng.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Rather than having callers of set_current_rng call drop_current_rng,
we can do it directly in set_current_rng.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Currently we only register the device when a valid RNG is added.
However the way it's done is buggy because we test whether there
is a current RNG to determine whether we need to register.  As
the current RNG may be missing due to a reinitialisation error
this can lead to a reregistration of the device.

As the device already has to handle a NULL current RNG anyway,
let's just register the device always and remove the complexity.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>