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 <u.kleine-koenig@pengutronix.de>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add hw_random interface support in qcom-rng driver as new IP block
in Qualcomm SoC has inbuilt NIST SP800 90B compliant entropic source
to generate true random number.
Keeping current rng_alg interface as well for random number generation
using Kernel Crypto API.
Signed-off-by: Om Prakash Singh <quic_omprsing@quicinc.com>
Reviewed-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Acked-by: Om Prakash Singh <quic_omprsing@quicinc.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Some newer SoCs (like SM8450) do not require a clock vote for the PRNG
to function. Make it entirely optional and rely on the bindings checker
to ensure platforms that need it, consume one.
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Module device tables need to be declared as maybe_unused because
they will be unused when built-in and the corresponding option is
also disabled.
This patch adds the maybe_unused attributes to OF and ACPI. This
also allows us to remove the ifdef around the ACPI data structure.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The commit referenced in the Fixes tag removed the 'break' from the else
branch in qcom_rng_read(), causing an infinite loop whenever 'max' is
not a multiple of WORD_SZ. This can be reproduced e.g. by running:
kcapi-rng -b 67 >/dev/null
There are many ways to fix this without adding back the 'break', but
they all seem more awkward than simply adding it back, so do just that.
Tested on a machine with Qualcomm Amberwing processor.
Fixes: a680b1832c ("crypto: qcom-rng - ensure buffer for generate is completely filled")
Cc: stable@vger.kernel.org
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Brian Masney <bmasney@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The generate function in struct rng_alg expects that the destination
buffer is completely filled if the function returns 0. qcom_rng_read()
can run into a situation where the buffer is partially filled with
randomness and the remaining part of the buffer is zeroed since
qcom_rng_generate() doesn't check the return value. This issue can
be reproduced by running the following from libkcapi:
kcapi-rng -b 9000000 > OUTFILE
The generated OUTFILE will have three huge sections that contain all
zeros, and this is caused by the code where the test
'val & PRNG_STATUS_DATA_AVAIL' fails.
Let's fix this issue by ensuring that qcom_rng_read() always returns
with a full buffer if the function returns success. Let's also have
qcom_rng_generate() return the correct value.
Here's some statistics from the ent project
(https://www.fourmilab.ch/random/) that shows information about the
quality of the generated numbers:
$ ent -c qcom-random-before
Value Char Occurrences Fraction
0 606748 0.067416
1 33104 0.003678
2 33001 0.003667
...
253 � 32883 0.003654
254 � 33035 0.003671
255 � 33239 0.003693
Total: 9000000 1.000000
Entropy = 7.811590 bits per byte.
Optimum compression would reduce the size
of this 9000000 byte file by 2 percent.
Chi square distribution for 9000000 samples is 9329962.81, and
randomly would exceed this value less than 0.01 percent of the
times.
Arithmetic mean value of data bytes is 119.3731 (127.5 = random).
Monte Carlo value for Pi is 3.197293333 (error 1.77 percent).
Serial correlation coefficient is 0.159130 (totally uncorrelated =
0.0).
Without this patch, the results of the chi-square test is 0.01%, and
the numbers are certainly not random according to ent's project page.
The results improve with this patch:
$ ent -c qcom-random-after
Value Char Occurrences Fraction
0 35432 0.003937
1 35127 0.003903
2 35424 0.003936
...
253 � 35201 0.003911
254 � 34835 0.003871
255 � 35368 0.003930
Total: 9000000 1.000000
Entropy = 7.999979 bits per byte.
Optimum compression would reduce the size
of this 9000000 byte file by 0 percent.
Chi square distribution for 9000000 samples is 258.77, and randomly
would exceed this value 42.24 percent of the times.
Arithmetic mean value of data bytes is 127.5006 (127.5 = random).
Monte Carlo value for Pi is 3.141277333 (error 0.01 percent).
Serial correlation coefficient is 0.000468 (totally uncorrelated =
0.0).
This change was tested on a Nexus 5 phone (msm8974 SoC).
Signed-off-by: Brian Masney <bmasney@redhat.com>
Fixes: ceec5f5b59 ("crypto: qcom-rng - Add Qcom prng driver")
Cc: stable@vger.kernel.org # 4.19+
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Andrew Halaney <ahalaney@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The header file algapi.h includes skbuff.h unnecessarily since
all we need is a forward declaration for struct sk_buff. This
patch removes that inclusion.
Unfortunately skbuff.h pulls in a lot of things and drivers over
the years have come to rely on it so this patch adds a lot of
missing inclusions that result from this.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Use devm_platform_ioremap_resource() to simplify the code a bit.
This is detected by coccinelle.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add support for probing on ACPI systems, with ACPI HID QCOM8160.
On ACPI systems, clocks are always enabled, the PRNG should
already be enabled, and the register region is read-only.
The driver only verifies that the hardware is already
enabled never tries to disable or configure it.
Signed-off-by: Timur Tabi <timur@codeaurora.org>
Tested-by: Jeffrey Hugo <jhugo@codeaurora.org>
[port to crypto API]
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Qcom 8996 and later chips features multiple Execution Environments
(EE) and secure world is typically responsible for configuring the
prng.
Add driver data for qcom,prng as 0 and qcom,prng-ee as 1 and use
that to skip initialization routine.
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This ports the Qcom prng from older hw_random driver.
No change of functionality and move from hw_random to crypto
APIs is done.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
