hi Simon, On Thu, 3 Mar 2022 at 09:17, Simon Glass <s...@chromium.org> wrote: > > Hi Sughosh, > > On Tue, 1 Mar 2022 at 21:36, Sughosh Ganu <sughosh.g...@linaro.org> wrote: > > > > hi Simon, > > > > On Tue, 1 Mar 2022 at 20:28, Simon Glass <s...@chromium.org> wrote: > > > > > > Hi Sughosh, > > > > > > On Mon, 28 Feb 2022 at 05:07, Sughosh Ganu <sughosh.g...@linaro.org> > > > wrote: > > > > > > > > Currently, the TPM random number generator(RNG) functions are defined > > > > as part of the library functions under the corresponding tpm files for > > > > tpmv1 and tpmv2. Move the RNG functionality under TPM RNG drivers > > > > complying with the driver model. > > > > > > > > Also make changes to the tpm_get_random function to have it call the > > > > TPM RNG driver functions instead of the library functions. > > > > > > > > Signed-off-by: Sughosh Ganu <sughosh.g...@linaro.org> > > > > --- > > > > > > > > Changes since V1: > > > > * Added existing copyrights for the rng functions taken from the tpm > > > > library routines > > > > * Return -EIO for TPM command returning an error > > > > * Simplify the logic in tpm_get_random based on the review comments > > > > from Ilias > > > > > > > > drivers/rng/Makefile | 1 + > > > > drivers/rng/tpm1_rng.c | 87 ++++++++++++++++++++++++++++++++++++++++++ > > > > drivers/rng/tpm2_rng.c | 86 +++++++++++++++++++++++++++++++++++++++++ > > > > lib/tpm-v1.c | 44 --------------------- > > > > lib/tpm-v2.c | 44 --------------------- > > > > lib/tpm_api.c | 23 +++++++++-- > > > > 6 files changed, 193 insertions(+), 92 deletions(-) > > > > create mode 100644 drivers/rng/tpm1_rng.c > > > > create mode 100644 drivers/rng/tpm2_rng.c > > > > > > > > diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile > > > > index 39f7ee3f03..129cfbd006 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) += tpm1_rng.o tpm2_rng.o > > > > diff --git a/drivers/rng/tpm1_rng.c b/drivers/rng/tpm1_rng.c > > > > new file mode 100644 > > > > index 0000000000..7e629756b3 > > > > --- /dev/null > > > > +++ b/drivers/rng/tpm1_rng.c > > > > @@ -0,0 +1,87 @@ > > > > +// SPDX-License-Identifier: GPL-2.0+ > > > > +/* > > > > + * Copyright (c) 2013 The Chromium OS Authors. > > > > + * Coypright (c) 2013 Guntermann & Drunck GmbH > > > > + * Copyright (c) 2022, Linaro Limited > > > > + */ > > > > + > > > > +#include <common.h> > > > > +#include <dm.h> > > > > +#include <rng.h> > > > > +#include <tpm-utils.h> > > > > +#include <tpm-v1.h> > > > > + > > > > +#include <linux/errno.h> > > > > + > > > > +#define TPM_HEADER_SIZE 10 > > > > + > > > > +#define TPMV1_DATA_OFFSET 14 > > > > + > > > > +/** > > > > + * tpm1_rng_read() - Read the random bytes from TPMv1 device > > > > + * @param dev TPMv1 RNG device > > > > + * @param data data buffer to write random bytes > > > > + * @param count number of random bytes to read from > > > > + * the device > > > > + * > > > > + * Function to read the random bytes from the RNG pseudo device > > > > + * built into the TPMv1 device. Reads 'count' number of bytes > > > > + * from the random number generator and copies them into the > > > > + * 'data' buffer. > > > > + * > > > > + * Return: 0 if OK, -ve on error. > > > > + * > > > > + */ > > > > +static int tpm1_rng_read(struct udevice *dev, void *data, size_t count) > > > > +{ > > > > + const u8 command[14] = { > > > > + 0x0, 0xc1, /* TPM_TAG */ > > > > + 0x0, 0x0, 0x0, 0xe, /* parameter size */ > > > > + 0x0, 0x0, 0x0, 0x46, /* TPM_COMMAND_CODE */ > > > > + }; > > > > + const size_t length_offset = TPM_HEADER_SIZE; > > > > + const size_t data_size_offset = TPM_HEADER_SIZE; > > > > + const size_t data_offset = TPMV1_DATA_OFFSET; > > > > + u8 buf[COMMAND_BUFFER_SIZE], response[COMMAND_BUFFER_SIZE]; > > > > + size_t response_length = sizeof(response); > > > > + u32 data_size; > > > > + u8 *out = data; > > > > + > > > > > > The current model is that all TPM calls are set up in lib/tpm and I > > > don't think we should change it. You should be able to move these > > > functions into lib/tpm and add your random_read function to tpm_api.h > > > > I moved these functions under separate drivers as I thought that > > looked cleaner as against exporting the driver interface in > > But you are now creating TPM messages in a different file so I don't > think it is cleaner. The message pack/unpack should happen in the > tpm_... functions. > > > tpm-v{1,2}.c. If you strongly feel that these should remain under > > lib/tpm, I will make the change. But I believe you do not have a > > problem with exporting these rng functions as part of the driver > > model. We do need that so that the EFI_RNG_PROTOCOL can use these for > > getting the random bytes. > > I think you might misunderstand me. I mean that the code that calls > pack_byte_string() should be in lib/ like the other code. I agree that > the driver should be were you have put it, I just don't like having > the tpm message creation in that driver. It should call a tpm_... > function to create and send the message, like elsewhere.
I tried putting a wrapper around the pack/unpack functions like you suggest, but it is getting more complicated than required. Even after putting the wrapper, there still is an issue of tpm_sendrecv being declared in tpm-utils.h, along with some other necessary macros like COMMAND_BUFFER_SIZE. You have mentioned in another review that you don't want tpm-utils.h to be moved to the include/ directory. If we are not to move tpm-utils.h and also not call functions like pack_byte_string directly from the driver, I feel it will be easier to simply export the rng functions to the driver model from within lib/tpm/ instead of moving them under drivers/rng/. Will you be okay with this. -sughosh > > Regards, > Simon