On Tue, 13 Feb 2024 10:49:43 +0100 Heinrich Schuchardt xypron.glpk@gmx.de wrote:
On 2/13/24 10:16, Stefan Roese wrote:
Hi Max,
mostly some nitpicking comments below.
On 2/11/24 14:04, Max Resch wrote:
A RNG driver for Armada 3720 boards running the Turris Mox rWTM firmware from CZ.NIC in the secure processor.
Signed-off-by: Max Resch resch.max@gmail.com
Changes in v4: - wrongful/missing git rebase
Changes in v3: - More meaningful variable names in accordance with review
Changes in v2: - Removed ring buffer implementation
drivers/rng/Kconfig | 8 +++ drivers/rng/Makefile | 1 + drivers/rng/turris_rwtm_rng.c | 122 ++++++++++++++++++++++++++++++++++ 3 files changed, 131 insertions(+) create mode 100644 drivers/rng/turris_rwtm_rng.c
diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig index a89c899568..cd72852a47 100644 --- a/drivers/rng/Kconfig +++ b/drivers/rng/Kconfig @@ -105,4 +105,12 @@ config RNG_JH7110 help Enable True Random Number Generator in StarFive JH7110 SoCs. +config RNG_TURRIS_RWTM + bool "Turris Mox TRNG in Secure Processor" + depends on DM_RNG && ARMADA_3700 + help + Use TRNG in Turris Mox Secure Processor Firmware. Can be used + on other Armada-3700 devices (like EspressoBin) if Secure + Firmware from CZ.NIC is used.
endif diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile index 7e64c4cdfc..ecae1a3da3 100644 --- a/drivers/rng/Makefile +++ b/drivers/rng/Makefile @@ -17,3 +17,4 @@ obj-$(CONFIG_RNG_SMCCC_TRNG) += smccc_trng.o obj-$(CONFIG_RNG_ARM_RNDR) += arm_rndr.o obj-$(CONFIG_TPM_RNG) += tpm_rng.o obj-$(CONFIG_RNG_JH7110) += jh7110_rng.o +obj-$(CONFIG_RNG_TURRIS_RWTM) += turris_rwtm_rng.o diff --git a/drivers/rng/turris_rwtm_rng.c b/drivers/rng/turris_rwtm_rng.c new file mode 100644 index 0000000000..ec2cb0bca3 --- /dev/null +++ b/drivers/rng/turris_rwtm_rng.c @@ -0,0 +1,122 @@ +// SPDX-License-Identifier: GPL-2.0-or-later OR BSD-3-Clause +/*
- Copyright (c) 2024, Max Resch
- */
+#include <dm.h> +#include <malloc.h> +#include <rng.h> +#include <asm/dma-mapping.h> +#include <asm/types.h> +#include <mach/mbox.h>
+/* size of entropy buffer */ +#define RNG_BUFFER_SIZE 128U
+struct turris_rwtm_rng_priv { + phys_addr_t buffer; +};
+static int turris_rwtm_rng_fill_entropy(phys_addr_t entropy, size_t size) +{ + u32 args[3] = { 1, (u32)entropy, size };
On a device with memory above 4 GiB this (u32) conversion may point to a different location than rwtm_rng_priv.
Is the Armada 3700 family restricted to below 4 GiB?
Indeed it is. Only virtual memory can be mapped to higher locations, all physical resources (DDR, registers, PCIe, DMA, rWTM) can only be confiured with 32 bits.
Should we add a check in the probe function?
No need.