Add a uclass for reading a random number seed from a random number generator device.

Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org Reviewed-by: Patrice Chotard patrice.chotard@st.com Reviewed-by: Heinrich Schuchardt xypron.glpk@gmx.de Reviewed-by: Simon Glass sjg@chromium.org --- Changes since V6: * Handle review comment from Simon Glass to declare struct udevice in rng.h instead of including dm.h

drivers/Kconfig | 2 ++ drivers/Makefile | 1 + drivers/rng/Kconfig | 7 +++++++ drivers/rng/Makefile | 6 ++++++ drivers/rng/rng-uclass.c | 23 +++++++++++++++++++++++ include/dm/uclass-id.h | 1 + include/rng.h | 33 +++++++++++++++++++++++++++++++++ 7 files changed, 73 insertions(+) create mode 100644 drivers/rng/Kconfig create mode 100644 drivers/rng/Makefile create mode 100644 drivers/rng/rng-uclass.c create mode 100644 include/rng.h

diff --git a/drivers/Kconfig b/drivers/Kconfig index 9d99ce0..e34a227 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -90,6 +90,8 @@ source "drivers/remoteproc/Kconfig"

source "drivers/reset/Kconfig"

+source "drivers/rng/Kconfig" + source "drivers/rtc/Kconfig"

source "drivers/scsi/Kconfig" diff --git a/drivers/Makefile b/drivers/Makefile index e977f19..6c619b1 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -115,4 +115,5 @@ obj-$(CONFIG_W1_EEPROM) += w1-eeprom/

obj-$(CONFIG_MACH_PIC32) += ddr/microchip/ obj-$(CONFIG_DM_HWSPINLOCK) += hwspinlock/ +obj-$(CONFIG_DM_RNG) += rng/ endif diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig new file mode 100644 index 0000000..dd44cc0 --- /dev/null +++ b/drivers/rng/Kconfig @@ -0,0 +1,7 @@ +config DM_RNG + bool "Driver support for Random Number Generator devices" + depends on DM + help + Enable driver model for random number generator(rng) devices. + This interface is used to initialise the rng device and to + read the random seed from the device. diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile new file mode 100644 index 0000000..311705b --- /dev/null +++ b/drivers/rng/Makefile @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0+ +# +# Copyright (c) 2019, Linaro Limited +# + +obj-$(CONFIG_DM_RNG) += rng-uclass.o diff --git a/drivers/rng/rng-uclass.c b/drivers/rng/rng-uclass.c new file mode 100644 index 0000000..b6af3b8 --- /dev/null +++ b/drivers/rng/rng-uclass.c @@ -0,0 +1,23 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (c) 2019, Linaro Limited + */ + +#include <common.h> +#include <dm.h> +#include <rng.h> + +int dm_rng_read(struct udevice *dev, void *buffer, size_t size) +{ + const struct dm_rng_ops *ops = device_get_ops(dev); + + if (!ops->read) + return -ENOSYS; + + return ops->read(dev, buffer, size); +} + +UCLASS_DRIVER(rng) = { + .name = "rng", + .id = UCLASS_RNG, +}; diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h index 0c563d8..192202d 100644 --- a/include/dm/uclass-id.h +++ b/include/dm/uclass-id.h @@ -86,6 +86,7 @@ enum uclass_id { UCLASS_REGULATOR, /* Regulator device */ UCLASS_REMOTEPROC, /* Remote Processor device */ UCLASS_RESET, /* Reset controller device */ + UCLASS_RNG, /* Random Number Generator */ UCLASS_RTC, /* Real time clock device */ UCLASS_SCSI, /* SCSI device */ UCLASS_SERIAL, /* Serial UART */ diff --git a/include/rng.h b/include/rng.h new file mode 100644 index 0000000..d2c0f9a --- /dev/null +++ b/include/rng.h @@ -0,0 +1,33 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (c) 2019, Linaro Limited + */ + +#if !defined _RNG_H_ +#define _RNG_H_ + +struct udevice; + +/** + * dm_rng_read() - read a random number seed from the rng device + * @buffer: input buffer to put the read random seed into + * @size: number of bytes of random seed read + * + * Return: 0 if OK, -ve on error + */ +int dm_rng_read(struct udevice *dev, void *buffer, size_t size); + +/* struct dm_rng_ops - Operations for the hwrng uclass */ +struct dm_rng_ops { + /** + * @read() - read a random number seed + * + * @data: input buffer to read the random seed + * @max: total number of bytes to read + * + * Return: 0 if OK, -ve on error + */ + int (*read)(struct udevice *dev, void *data, size_t max); +}; + +#endif /* _RNG_H_ */

Add a driver for the rng device found on stm32mp1 platforms. The driver provides a routine for reading the random number seed from the hardware device.

Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org Reviewed-by: Patrice Chotard patrice.chotard@st.com Acked-by: Patrick Delaunay patrick.delaunay@st.com --- drivers/rng/Kconfig | 7 ++ drivers/rng/Makefile | 1 + drivers/rng/stm32mp1_rng.c | 161 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 169 insertions(+) create mode 100644 drivers/rng/stm32mp1_rng.c

diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig index dd44cc0..c9c4751 100644 --- a/drivers/rng/Kconfig +++ b/drivers/rng/Kconfig @@ -5,3 +5,10 @@ config DM_RNG Enable driver model for random number generator(rng) devices. This interface is used to initialise the rng device and to read the random seed from the device. + +config RNG_STM32MP1 + bool "Enable random number generator for STM32MP1" + depends on ARCH_STM32MP && DM_RNG + default n + help + Enable STM32MP1 rng driver. diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile index 311705b..699beb3 100644 --- a/drivers/rng/Makefile +++ b/drivers/rng/Makefile @@ -4,3 +4,4 @@ #

obj-$(CONFIG_DM_RNG) += rng-uclass.o +obj-$(CONFIG_RNG_STM32MP1) += stm32mp1_rng.o diff --git a/drivers/rng/stm32mp1_rng.c b/drivers/rng/stm32mp1_rng.c new file mode 100644 index 0000000..ec6af7e --- /dev/null +++ b/drivers/rng/stm32mp1_rng.c @@ -0,0 +1,161 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2019, Linaro Limited + */ + +#include <common.h> +#include <clk.h> +#include <dm.h> +#include <reset.h> +#include <rng.h> + +#include <asm/io.h> +#include <linux/iopoll.h> +#include <linux/kernel.h> + +#define RNG_CR 0x00 +#define RNG_CR_RNGEN BIT(2) +#define RNG_CR_CED BIT(5) + +#define RNG_SR 0x04 +#define RNG_SR_SEIS BIT(6) +#define RNG_SR_CEIS BIT(5) +#define RNG_SR_SECS BIT(2) +#define RNG_SR_DRDY BIT(0) + +#define RNG_DR 0x08 + +struct stm32_rng_platdata { + fdt_addr_t base; + struct clk clk; + struct reset_ctl rst; +}; + +static int stm32_rng_read(struct udevice *dev, void *data, size_t len) +{ + int retval = 0, i; + u32 sr, count, reg; + size_t increment; + struct stm32_rng_platdata *pdata = dev_get_platdata(dev); + + while (len > 0) { + retval = readl_poll_timeout(pdata->base + RNG_SR, sr, + sr & RNG_SR_DRDY, 10000); + if (retval) + return retval; + + if (sr & (RNG_SR_SEIS | RNG_SR_SECS)) { + /* As per SoC TRM */ + clrbits_le32(pdata->base + RNG_SR, RNG_SR_SEIS); + for (i = 0; i < 12; i++) + readl(pdata->base + RNG_DR); + if (readl(pdata->base + RNG_SR) & RNG_SR_SEIS) { + printf("RNG Noise"); + return -EIO; + } + /* start again */ + continue; + } + + /* + * Once the DRDY bit is set, the RNG_DR register can + * be read four consecutive times. + */ + count = 4; + while (len && count) { + reg = readl(pdata->base + RNG_DR); + memcpy(data, &reg, min(len, sizeof(u32))); + increment = min(len, sizeof(u32)); + data += increment; + len -= increment; + count--; + } + } + + return 0; +} + +static int stm32_rng_init(struct stm32_rng_platdata *pdata) +{ + int err; + + err = clk_enable(&pdata->clk); + if (err) + return err; + + /* Disable CED */ + writel(RNG_CR_RNGEN | RNG_CR_CED, pdata->base + RNG_CR); + + /* clear error indicators */ + writel(0, pdata->base + RNG_SR); + + return 0; +} + +static int stm32_rng_cleanup(struct stm32_rng_platdata *pdata) +{ + + writel(0, pdata->base + RNG_CR); + + return clk_disable(&pdata->clk); +} + +static int stm32_rng_probe(struct udevice *dev) +{ + struct stm32_rng_platdata *pdata = dev_get_platdata(dev); + + reset_assert(&pdata->rst); + udelay(20); + reset_deassert(&pdata->rst); + + return stm32_rng_init(pdata); +} + +static int stm32_rng_remove(struct udevice *dev) +{ + struct stm32_rng_platdata *pdata = dev_get_platdata(dev); + + return stm32_rng_cleanup(pdata); +} + +static int stm32_rng_ofdata_to_platdata(struct udevice *dev) +{ + struct stm32_rng_platdata *pdata = dev_get_platdata(dev); + int err; + + pdata->base = dev_read_addr(dev); + if (!pdata->base) + return -ENOMEM; + + err = clk_get_by_index(dev, 0, &pdata->clk); + if (err) + return err; + + err = reset_get_by_index(dev, 0, &pdata->rst); + if (err) + return err; + + return 0; +} + +static const struct dm_rng_ops stm32_rng_ops = { + .read = stm32_rng_read, +}; + +static const struct udevice_id stm32_rng_match[] = { + { + .compatible = "st,stm32-rng", + }, + {}, +}; + +U_BOOT_DRIVER(stm32_rng) = { + .name = "stm32-rng", + .id = UCLASS_RNG, + .of_match = stm32_rng_match, + .ops = &stm32_rng_ops, + .probe = stm32_rng_probe, + .remove = stm32_rng_remove, + .platdata_auto_alloc_size = sizeof(struct stm32_rng_platdata), + .ofdata_to_platdata = stm32_rng_ofdata_to_platdata, +};

Add a sandbox driver for random number generation. Mostly aimed at providing a unit test for rng uclass.

Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org Reviewed-by: Patrice Chotard patrice.chotard@st.com Reviewed-by: Simon Glass sjg@chromium.org --- arch/sandbox/dts/test.dts | 4 ++++ drivers/rng/Kconfig | 8 +++++++ drivers/rng/Makefile | 1 + drivers/rng/sandbox_rng.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 69 insertions(+) create mode 100644 drivers/rng/sandbox_rng.c

diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts index fdb08f2..fe1d14a 100644 --- a/arch/sandbox/dts/test.dts +++ b/arch/sandbox/dts/test.dts @@ -599,6 +599,10 @@ reset-names = "other", "test"; };

+ rng { + compatible = "sandbox,sandbox-rng"; + }; + rproc_1: rproc@1 { compatible = "sandbox,test-processor"; remoteproc-name = "remoteproc-test-dev1"; diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig index c9c4751..35a3bd1 100644 --- a/drivers/rng/Kconfig +++ b/drivers/rng/Kconfig @@ -6,6 +6,14 @@ config DM_RNG This interface is used to initialise the rng device and to read the random seed from the device.

+config RNG_SANDBOX + bool "Sandbox random number generator" + depends on SANDBOX && DM_RNG + select CONFIG_LIB_RAND + help + Enable random number generator for sandbox. This is an + emulation of a rng device. + config RNG_STM32MP1 bool "Enable random number generator for STM32MP1" depends on ARCH_STM32MP && DM_RNG diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile index 699beb3..3517005 100644 --- a/drivers/rng/Makefile +++ b/drivers/rng/Makefile @@ -4,4 +4,5 @@ #

obj-$(CONFIG_DM_RNG) += rng-uclass.o +obj-$(CONFIG_RNG_SANDBOX) += sandbox_rng.o obj-$(CONFIG_RNG_STM32MP1) += stm32mp1_rng.o diff --git a/drivers/rng/sandbox_rng.c b/drivers/rng/sandbox_rng.c new file mode 100644 index 0000000..cd0b0ac --- /dev/null +++ b/drivers/rng/sandbox_rng.c @@ -0,0 +1,56 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2019, Linaro Limited + */ + +#include <common.h> +#include <dm.h> +#include <rng.h> + +#include <linux/string.h> + +static int sandbox_rng_read(struct udevice *dev, void *data, size_t len) +{ + unsigned int i, seed, random; + unsigned char *buf = data; + size_t nrem, nloops; + + if (!len) + return 0; + + nloops = len / sizeof(random); + seed = get_timer(0) ^ rand(); + srand(seed); + + for (i = 0, nrem = len; i < nloops; i++) { + random = rand(); + memcpy(buf, &random, sizeof(random)); + buf += sizeof(random); + nrem -= sizeof(random); + } + + if (nrem) { + random = rand(); + memcpy(buf, &random, nrem); + } + + return 0; +} + +static const struct dm_rng_ops sandbox_rng_ops = { + .read = sandbox_rng_read, +}; + +static const struct udevice_id sandbox_rng_match[] = { + { + .compatible = "sandbox,sandbox-rng", + }, + {}, +}; + +U_BOOT_DRIVER(sandbox_rng) = { + .name = "sandbox-rng", + .id = UCLASS_RNG, + .of_match = sandbox_rng_match, + .ops = &sandbox_rng_ops, +};

Add a unit test for testing the rng uclass functionality using the sandbox rng driver.

Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org Reviewed-by: Patrice Chotard patrice.chotard@st.com Reviewed-by: Simon Glass sjg@chromium.org --- test/dm/Makefile | 1 + test/dm/rng.c | 26 ++++++++++++++++++++++++++ 2 files changed, 27 insertions(+) create mode 100644 test/dm/rng.c

diff --git a/test/dm/Makefile b/test/dm/Makefile index 0c2fd5c..f61bf65 100644 --- a/test/dm/Makefile +++ b/test/dm/Makefile @@ -65,4 +65,5 @@ obj-$(CONFIG_VIRTIO_SANDBOX) += virtio.o obj-$(CONFIG_DMA) += dma.o obj-$(CONFIG_DM_MDIO) += mdio.o obj-$(CONFIG_DM_MDIO_MUX) += mdio_mux.o +obj-$(CONFIG_DM_RNG) += rng.o endif diff --git a/test/dm/rng.c b/test/dm/rng.c new file mode 100644 index 0000000..ce20e2d --- /dev/null +++ b/test/dm/rng.c @@ -0,0 +1,26 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2019, Linaro Limited + */ + +#include <common.h> +#include <dm.h> +#include <rng.h> +#include <dm/test.h> +#include <test/ut.h> + +/* Basic test of the rng uclass */ +static int dm_test_rng_read(struct unit_test_state *uts) +{ + unsigned long rand1 = 0, rand2 = 0; + struct udevice *dev; + + ut_assertok(uclass_get_device(UCLASS_RNG, 0, &dev)); + ut_assertnonnull(dev); + ut_assertok(dm_rng_read(dev, &rand1, sizeof(rand1))); + ut_assertok(dm_rng_read(dev, &rand2, sizeof(rand2))); + ut_assert(rand1 != rand2); + + return 0; +} +DM_TEST(dm_test_rng_read, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);