hi Simon, On Mon, 14 Mar 2022 at 23:55, Simon Glass <s...@chromium.org> wrote: > > Hi Sughosh, > > On Mon, 14 Mar 2022 at 05:39, Sughosh Ganu <sughosh.g...@linaro.org> wrote: > > > > hi Simon, > > > > On Mon, 14 Mar 2022 at 03:53, Simon Glass <s...@chromium.org> wrote: > > > > > > Hi Sughosh, > > > > > > On Sun, 13 Mar 2022 at 08:48, Sughosh Ganu <sughosh.g...@linaro.org> > > > wrote: > > > > > > > > The TPM device has a builtin random number generator(RNG) > > > > functionality. Expose the RNG functions of the TPM device to the > > > > driver model so that they can be used by the EFI_RNG_PROTOCOL if the > > > > protocol is installed. > > > > > > > > Also change the function arguments and return type of the random > > > > number functions to comply with the driver model api. > > > > > > Please don't do that > > > > > > > > > > > Signed-off-by: Sughosh Ganu <sughosh.g...@linaro.org> > > > > --- > > > > > > > > Changes since V4: > > > > > > > > * Call the existing tpm_get_random API function from the TPM RNG > > > > driver, instead of the tpm{1,2}_get_random API's > > > > * Introduce a new Kconfig symbol TPM_RNG and build the corresponding > > > > driver if the symbol is enabled > > > > * Change the last parameter of the tpm_get_random API to have a data > > > > type of size_t instead of u32 to comply with the RNG driver model > > > > API > > > > > > > > drivers/rng/Kconfig | 7 +++++++ > > > > drivers/rng/Makefile | 1 + > > > > drivers/rng/tpm_rng.c | 23 +++++++++++++++++++++++ > > > > include/tpm-v1.h | 4 ++-- > > > > include/tpm-v2.h | 4 ++-- > > > > include/tpm_api.h | 2 +- > > > > lib/Kconfig | 1 + > > > > lib/tpm-v1.c | 16 +++++++++------- > > > > lib/tpm-v2.c | 9 +++++---- > > > > lib/tpm_api.c | 16 +++++++++++----- > > > > 10 files changed, 62 insertions(+), 21 deletions(-) > > > > create mode 100644 drivers/rng/tpm_rng.c > > > > > > > > diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig > > > > index b1c5ab93d1..a89fa99ffa 100644 > > > > --- a/drivers/rng/Kconfig > > > > +++ b/drivers/rng/Kconfig > > > > @@ -49,4 +49,11 @@ config RNG_IPROC200 > > > > depends on DM_RNG > > > > help > > > > Enable random number generator for RPI4. > > > > + > > > > +config TPM_RNG > > > > + bool "Enable random number generator on TPM device" > > > > + depends on TPM > > > > + default y > > > > + help > > > > + Enable random number generator on TPM devices > > > > > > Needs 3 lines of text so please add more detail > > > > Okay > > > > > > > > > endif > > > > diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile > > > > index 39f7ee3f03..a21f3353ea 100644 > > > > --- a/drivers/rng/Makefile > > > > +++ b/drivers/rng/Makefile > > > > @@ -10,3 +10,4 @@ obj-$(CONFIG_RNG_MSM) += msm_rng.o > > > > obj-$(CONFIG_RNG_STM32MP1) += stm32mp1_rng.o > > > > obj-$(CONFIG_RNG_ROCKCHIP) += rockchip_rng.o > > > > obj-$(CONFIG_RNG_IPROC200) += iproc_rng200.o > > > > +obj-$(CONFIG_TPM_RNG) += tpm_rng.o > > > > diff --git a/drivers/rng/tpm_rng.c b/drivers/rng/tpm_rng.c > > > > new file mode 100644 > > > > index 0000000000..69b41dbbf5 > > > > --- /dev/null > > > > +++ b/drivers/rng/tpm_rng.c > > > > @@ -0,0 +1,23 @@ > > > > +// SPDX-License-Identifier: GPL-2.0-or-later > > > > +/* > > > > + * Copyright (c) 2022, Linaro Limited > > > > + */ > > > > + > > > > +#include <dm.h> > > > > +#include <rng.h> > > > > +#include <tpm_api.h> > > > > + > > > > +static int rng_tpm_random_read(struct udevice *dev, void *data, size_t > > > > count) > > > > +{ > > > > + return tpm_get_random(dev->parent, data, count); > > > > > > dev_get_parent(dev) > > > > > > Here you should check the return value and decide whether to return an > > > error, such as -EIO > > > > > > > +} > > > > + > > > > +static const struct dm_rng_ops tpm_rng_ops = { > > > > + .read = rng_tpm_random_read, > > > > +}; > > > > + > > > > +U_BOOT_DRIVER(tpm_rng) = { > > > > + .name = "tpm-rng", > > > > + .id = UCLASS_RNG, > > > > + .ops = &tpm_rng_ops, > > > > +}; > > > > diff --git a/include/tpm-v1.h b/include/tpm-v1.h > > > > index 33d53fb695..d2ff8b446d 100644 > > > > --- a/include/tpm-v1.h > > > > +++ b/include/tpm-v1.h > > > > @@ -555,9 +555,9 @@ u32 tpm1_find_key_sha1(struct udevice *dev, const > > > > u8 auth[20], > > > > * @param dev TPM device > > > > * @param data output buffer for the random bytes > > > > * @param count size of output buffer > > > > - * Return: return code of the operation > > > > + * Return: 0 if OK, -ve on error > > > > */ > > > > -u32 tpm1_get_random(struct udevice *dev, void *data, u32 count); > > > > +int tpm1_get_random(struct udevice *dev, void *data, size_t count); > > > > > > I think I mentioned this last time, but you should not change these > > > > Can you please explain in a little more detail why? I have mentioned > > in my earlier email that I am changing this to bring it in line with > > the rest of the rng drivers which use a size_t data type for the > > number of random bytes to read. What is the issue in changing the > > signature? In any case, currently, the api is not being called from > > any other module, so it is not like changing the signature is breaking > > some code. > > Every other function in the TPM API uses u32 as the return value, so > it is odd to change this. It also isn't necessary, as I have > explained. We should aim for consistency.
Well, you have given a R-b on another patch of this series[1] which is doing exactly the same thing. I really don't understand what is wrong in bringing the signature of the random byte generation functions in the TPM API in line with the RNG driver model. But I will not argue any more on this and revert back the signatures in my next version. Thanks. -sughosh [1] - https://lists.denx.de/pipermail/u-boot/2022-March/476519.html > > > > > > > > > > > > > > /** > > > > * tpm_finalise_physical_presence() - Finalise physical presence > > > > diff --git a/include/tpm-v2.h b/include/tpm-v2.h > > > > index e79c90b939..4fb1e7a948 100644 > > > > --- a/include/tpm-v2.h > > > > +++ b/include/tpm-v2.h > > > > @@ -619,9 +619,9 @@ u32 tpm2_pcr_setauthvalue(struct udevice *dev, > > > > const char *pw, > > > > * @param data output buffer for the random bytes > > > > * @param count size of output buffer > > > > * > > > > - * Return: return code of the operation > > > > + * Return: 0 if OK, -ve on error > > > > */ > > > > -u32 tpm2_get_random(struct udevice *dev, void *data, u32 count); > > > > +int tpm2_get_random(struct udevice *dev, void *data, size_t count); > > > > > > > > /** > > > > * Lock data in the TPM > > > > diff --git a/include/tpm_api.h b/include/tpm_api.h > > > > index 4d77a49719..6d9214b335 100644 > > > > --- a/include/tpm_api.h > > > > +++ b/include/tpm_api.h > > > > @@ -276,7 +276,7 @@ u32 tpm_find_key_sha1(struct udevice *dev, const u8 > > > > auth[20], > > > > * @param count size of output buffer > > > > * Return: 0 if OK, -ve on error > > > > */ > > > > -int tpm_get_random(struct udevice *dev, void *data, u32 count); > > > > +int tpm_get_random(struct udevice *dev, void *data, size_t count); > > > > > > [..] > > Regards, > Simon