On Wed, Sep 20, 2023 at 08:34:08AM +0530, Om Prakash Singh wrote: > 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@xxxxxxxxxxx> > --- > > Changes in V2: > - Updated patch to fix the return value from qcom_rng_generate() to be > consistent with current implementation As far as I can tell you didn't change this, see below. > - Updated patch to make it more concise > - Removed unnecessary use local variable and it's initialization > - Updated patch to use devm_hwrng_register() instead of hwrng_register() > - Updated subject line of the patch > > This patch is depends on [1] > [1] https://lore.kernel.org/lkml/20230824-topic-sm8550-rng-v2-4-dfcafbb16a3e@xxxxxxxxxx/ > > drivers/crypto/qcom-rng.c | 65 ++++++++++++++++++++++++++++++++++----- > 1 file changed, 58 insertions(+), 7 deletions(-) > > diff --git a/drivers/crypto/qcom-rng.c b/drivers/crypto/qcom-rng.c > index fb54b8cfc35f..e5a574a3cc59 100644 > --- a/drivers/crypto/qcom-rng.c > +++ b/drivers/crypto/qcom-rng.c > @@ -7,6 +7,7 @@ > #include <linux/acpi.h> > #include <linux/clk.h> > #include <linux/crypto.h> > +#include <linux/hw_random.h> > #include <linux/io.h> > #include <linux/iopoll.h> > #include <linux/kernel.h> > @@ -32,13 +33,18 @@ struct qcom_rng { > struct mutex lock; > void __iomem *base; > struct clk *clk; > - unsigned int skip_init; > + struct qcom_rng_of_data *of_data; > }; > > struct qcom_rng_ctx { > struct qcom_rng *rng; > }; > > +struct qcom_rng_of_data { > + bool skip_init; > + bool hwrng_support; > +}; > + > static struct qcom_rng *qcom_rng_dev; > > static int qcom_rng_read(struct qcom_rng *rng, u8 *data, unsigned int max) > @@ -70,7 +76,7 @@ static int qcom_rng_read(struct qcom_rng *rng, u8 *data, unsigned int max) > } > } while (currsize < max); > > - return 0; > + return currsize; As I pointed out in my previous review, if the qcom_rng_read() is requested to read a number of bytes (max) that is not evenly divisible with 4 (WORD_SZ) the loop will exit without accounting for the last bytes copied... > } > > static int qcom_rng_generate(struct crypto_rng *tfm, > @@ -92,6 +98,9 @@ static int qcom_rng_generate(struct crypto_rng *tfm, > mutex_unlock(&rng->lock); > clk_disable_unprepare(rng->clk); > > + if (ret == dlen) ...this means that if dlen % 4, you're changing the return value of this function from 0 to dlen. > + ret = 0; > + > return ret; > } > > @@ -101,6 +110,13 @@ static int qcom_rng_seed(struct crypto_rng *tfm, const u8 *seed, > return 0; > } > > +static int qcom_hwrng_read(struct hwrng *rng, void *data, size_t max, bool wait) > +{ > + struct qcom_rng *qrng = (struct qcom_rng *)rng->priv; You missed Herbert's request in [1], which I presume implies that qcom_hwrng should be moved into struct qcom_rng, which would mean that you can get the qrng by container_of(). [1] https://lore.kernel.org/lkml/ZQQvlXvGy8p01uJS@xxxxxxxxxxxxxxxxxxx/ > + > + return qcom_rng_read(qrng, data, max); > +} > + > static int qcom_rng_enable(struct qcom_rng *rng) > { > u32 val; > @@ -136,7 +152,7 @@ static int qcom_rng_init(struct crypto_tfm *tfm) > > ctx->rng = qcom_rng_dev; > > - if (!ctx->rng->skip_init) > + if (!ctx->rng->of_data->skip_init) > return qcom_rng_enable(ctx->rng); > > return 0; > @@ -157,6 +173,12 @@ static struct rng_alg qcom_rng_alg = { > } > }; > > +static struct hwrng qcom_hwrng = { > + .name = "qcom-hwrng", > + .read = qcom_hwrng_read, > + .quality = 1024, > +}; Which would mean not adding this static global variable... Regards, Bjorn
