| Message ID | 20220307154023.813158-2-conor.dooley@microchip.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Herbert Xu |
| Headers | show |
| Series | Add support for hwrng on PolarFire SoC | expand |
Am Mon, Mar 07, 2022 at 03:40:23PM +0000 schrieb conor.dooley@microchip.com: > From: Conor Dooley <conor.dooley@microchip.com> > > Add a driver to access the hardware random number generator on the > Polarfire SoC. The hwrng can only be accessed via the system controller, > so use the mailbox interface the system controller exposes to access the > hwrng. > > Signed-off-by: Conor Dooley <conor.dooley@microchip.com> > --- > drivers/char/hw_random/Kconfig | 13 ++++ > drivers/char/hw_random/Makefile | 1 + > drivers/char/hw_random/mpfs-rng.c | 103 ++++++++++++++++++++++++++++++ > 3 files changed, 117 insertions(+) > create mode 100644 drivers/char/hw_random/mpfs-rng.c > > diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig > index 9704963f9d50..69f1fd538589 100644 > --- a/drivers/char/hw_random/Kconfig > +++ b/drivers/char/hw_random/Kconfig > @@ -385,6 +385,19 @@ config HW_RANDOM_PIC32 > > If unsure, say Y. > > +config HW_RANDOM_POLARFIRE_SOC > + tristate "Microchip PolarFire SoC Random Number Generator support" > + depends on HW_RANDOM && POLARFIRE_SOC_SYS_CTRL > + help > + This driver provides kernel-side support for the Random Number > + Generator hardware found on PolarFire SoC (MPFS). > + > + To compile this driver as a module, choose M here. The > + module will be called mfps_rng. > + > + If unsure, say N. > + > + > config HW_RANDOM_MESON > tristate "Amlogic Meson Random Number Generator support" > depends on HW_RANDOM > diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile > index 584d47ba32f7..3e948cf04476 100644 > --- a/drivers/char/hw_random/Makefile > +++ b/drivers/char/hw_random/Makefile > @@ -46,3 +46,4 @@ obj-$(CONFIG_HW_RANDOM_CCTRNG) += cctrng.o > obj-$(CONFIG_HW_RANDOM_XIPHERA) += xiphera-trng.o > obj-$(CONFIG_HW_RANDOM_ARM_SMCCC_TRNG) += arm_smccc_trng.o > obj-$(CONFIG_HW_RANDOM_CN10K) += cn10k-rng.o > +obj-$(CONFIG_HW_RANDOM_POLARFIRE_SOC) += mpfs-rng.o > diff --git a/drivers/char/hw_random/mpfs-rng.c b/drivers/char/hw_random/mpfs-rng.c > new file mode 100644 > index 000000000000..a103c765d021 > --- /dev/null > +++ b/drivers/char/hw_random/mpfs-rng.c > @@ -0,0 +1,103 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Microchip PolarFire SoC (MPFS) hardware random driver > + * > + * Copyright (c) 2020-2022 Microchip Corporation. All rights reserved. > + * > + * Author: Conor Dooley <conor.dooley@microchip.com> > + */ > + > +#include <linux/module.h> > +#include <linux/hw_random.h> > +#include <linux/platform_device.h> > +#include <soc/microchip/mpfs.h> > + > +#define CMD_OPCODE 0x21 > +#define CMD_DATA_SIZE 0U > +#define CMD_DATA NULL > +#define MBOX_OFFSET 0U > +#define RESP_OFFSET 0U > +#define RNG_RESP_BYTES 32U > + > +struct mpfs_rng { > + struct mpfs_sys_controller *sys_controller; > + struct hwrng rng; > +}; > + > +static int mpfs_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) > +{ > + struct mpfs_rng *rng_priv = container_of(rng, struct mpfs_rng, rng); > + u32 response_msg[RNG_RESP_BYTES / sizeof(u32)]; > + unsigned int count = 0, copy_size_bytes; > + int ret; > + > + struct mpfs_mss_response response = { > + .resp_status = 0U, > + .resp_msg = (u32 *)response_msg, > + .resp_size = RNG_RESP_BYTES > + }; > + struct mpfs_mss_msg msg = { > + .cmd_opcode = CMD_OPCODE, > + .cmd_data_size = CMD_DATA_SIZE, > + .response = &response, > + .cmd_data = CMD_DATA, > + .mbox_offset = MBOX_OFFSET, > + .resp_offset = RESP_OFFSET > + }; > + > + while (count < max) { > + ret = mpfs_blocking_transaction(rng_priv->sys_controller, &msg); > + if (ret) > + return ret; > + > + copy_size_bytes = max - count > RNG_RESP_BYTES ? RNG_RESP_BYTES : max - count; > + memcpy(buf + count, response_msg, copy_size_bytes); > + > + count += copy_size_bytes; > + if (!wait) > + break; > + } > + > + return count; > +} > + > +static int mpfs_rng_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct mpfs_rng *rng_priv; > + int ret; > + > + rng_priv = devm_kzalloc(dev, sizeof(*rng_priv), GFP_KERNEL); > + if (!rng_priv) > + return -ENOMEM; > + > + rng_priv->sys_controller = mpfs_sys_controller_get(&pdev->dev); > + if (IS_ERR(rng_priv->sys_controller)) > + return dev_err_probe(dev, PTR_ERR(rng_priv->sys_controller), > + "Failed to register system controller hwrng sub device\n"); > + > + rng_priv->rng.read = mpfs_rng_read; > + rng_priv->rng.name = pdev->name; Is there also some quality estimation, or should this hwrng only be trusted if it passes validation by userspace? Thanks, Dominik
On 08/03/2022 07:55, Dominik Brodowski wrote: > [You don't often get email from linux@dominikbrodowski.net. Learn why this is important at http://aka.ms/LearnAboutSenderIdentification.] > > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > Am Mon, Mar 07, 2022 at 03:40:23PM +0000 schrieb conor.dooley@microchip.com: >> From: Conor Dooley <conor.dooley@microchip.com> >> >> Add a driver to access the hardware random number generator on the >> Polarfire SoC. The hwrng can only be accessed via the system controller, >> so use the mailbox interface the system controller exposes to access the >> hwrng. >> >> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> >> --- >> drivers/char/hw_random/Kconfig | 13 ++++ >> drivers/char/hw_random/Makefile | 1 + >> drivers/char/hw_random/mpfs-rng.c | 103 ++++++++++++++++++++++++++++++ >> 3 files changed, 117 insertions(+) >> create mode 100644 drivers/char/hw_random/mpfs-rng.c >> >> diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig >> index 9704963f9d50..69f1fd538589 100644 >> --- a/drivers/char/hw_random/Kconfig >> +++ b/drivers/char/hw_random/Kconfig >> @@ -385,6 +385,19 @@ config HW_RANDOM_PIC32 >> >> If unsure, say Y. >> >> +config HW_RANDOM_POLARFIRE_SOC >> + tristate "Microchip PolarFire SoC Random Number Generator support" >> + depends on HW_RANDOM && POLARFIRE_SOC_SYS_CTRL >> + help >> + This driver provides kernel-side support for the Random Number >> + Generator hardware found on PolarFire SoC (MPFS). >> + >> + To compile this driver as a module, choose M here. The >> + module will be called mfps_rng. >> + >> + If unsure, say N. >> + >> + >> config HW_RANDOM_MESON >> tristate "Amlogic Meson Random Number Generator support" >> depends on HW_RANDOM >> diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile >> index 584d47ba32f7..3e948cf04476 100644 >> --- a/drivers/char/hw_random/Makefile >> +++ b/drivers/char/hw_random/Makefile >> @@ -46,3 +46,4 @@ obj-$(CONFIG_HW_RANDOM_CCTRNG) += cctrng.o >> obj-$(CONFIG_HW_RANDOM_XIPHERA) += xiphera-trng.o >> obj-$(CONFIG_HW_RANDOM_ARM_SMCCC_TRNG) += arm_smccc_trng.o >> obj-$(CONFIG_HW_RANDOM_CN10K) += cn10k-rng.o >> +obj-$(CONFIG_HW_RANDOM_POLARFIRE_SOC) += mpfs-rng.o >> diff --git a/drivers/char/hw_random/mpfs-rng.c b/drivers/char/hw_random/mpfs-rng.c >> new file mode 100644 >> index 000000000000..a103c765d021 >> --- /dev/null >> +++ b/drivers/char/hw_random/mpfs-rng.c >> @@ -0,0 +1,103 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * Microchip PolarFire SoC (MPFS) hardware random driver >> + * >> + * Copyright (c) 2020-2022 Microchip Corporation. All rights reserved. >> + * >> + * Author: Conor Dooley <conor.dooley@microchip.com> >> + */ >> + >> +#include <linux/module.h> >> +#include <linux/hw_random.h> >> +#include <linux/platform_device.h> >> +#include <soc/microchip/mpfs.h> >> + >> +#define CMD_OPCODE 0x21 >> +#define CMD_DATA_SIZE 0U >> +#define CMD_DATA NULL >> +#define MBOX_OFFSET 0U >> +#define RESP_OFFSET 0U >> +#define RNG_RESP_BYTES 32U >> + >> +struct mpfs_rng { >> + struct mpfs_sys_controller *sys_controller; >> + struct hwrng rng; >> +}; >> + >> +static int mpfs_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) >> +{ >> + struct mpfs_rng *rng_priv = container_of(rng, struct mpfs_rng, rng); >> + u32 response_msg[RNG_RESP_BYTES / sizeof(u32)]; >> + unsigned int count = 0, copy_size_bytes; >> + int ret; >> + >> + struct mpfs_mss_response response = { >> + .resp_status = 0U, >> + .resp_msg = (u32 *)response_msg, >> + .resp_size = RNG_RESP_BYTES >> + }; >> + struct mpfs_mss_msg msg = { >> + .cmd_opcode = CMD_OPCODE, >> + .cmd_data_size = CMD_DATA_SIZE, >> + .response = &response, >> + .cmd_data = CMD_DATA, >> + .mbox_offset = MBOX_OFFSET, >> + .resp_offset = RESP_OFFSET >> + }; >> + >> + while (count < max) { >> + ret = mpfs_blocking_transaction(rng_priv->sys_controller, &msg); >> + if (ret) >> + return ret; >> + >> + copy_size_bytes = max - count > RNG_RESP_BYTES ? RNG_RESP_BYTES : max - count; >> + memcpy(buf + count, response_msg, copy_size_bytes); >> + >> + count += copy_size_bytes; >> + if (!wait) >> + break; >> + } >> + >> + return count; >> +} >> + >> +static int mpfs_rng_probe(struct platform_device *pdev) >> +{ >> + struct device *dev = &pdev->dev; >> + struct mpfs_rng *rng_priv; >> + int ret; >> + >> + rng_priv = devm_kzalloc(dev, sizeof(*rng_priv), GFP_KERNEL); >> + if (!rng_priv) >> + return -ENOMEM; >> + >> + rng_priv->sys_controller = mpfs_sys_controller_get(&pdev->dev); >> + if (IS_ERR(rng_priv->sys_controller)) >> + return dev_err_probe(dev, PTR_ERR(rng_priv->sys_controller), >> + "Failed to register system controller hwrng sub device\n"); >> + >> + rng_priv->rng.read = mpfs_rng_read; >> + rng_priv->rng.name = pdev->name; > > Is there also some quality estimation, or should this hwrng only be trusted > if it passes validation by userspace? There should be a quality estimation, I'll add one in v2. Thanks, Conor.
diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig index 9704963f9d50..69f1fd538589 100644 --- a/drivers/char/hw_random/Kconfig +++ b/drivers/char/hw_random/Kconfig @@ -385,6 +385,19 @@ config HW_RANDOM_PIC32 If unsure, say Y. +config HW_RANDOM_POLARFIRE_SOC + tristate "Microchip PolarFire SoC Random Number Generator support" + depends on HW_RANDOM && POLARFIRE_SOC_SYS_CTRL + help + This driver provides kernel-side support for the Random Number + Generator hardware found on PolarFire SoC (MPFS). + + To compile this driver as a module, choose M here. The + module will be called mfps_rng. + + If unsure, say N. + + config HW_RANDOM_MESON tristate "Amlogic Meson Random Number Generator support" depends on HW_RANDOM diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile index 584d47ba32f7..3e948cf04476 100644 --- a/drivers/char/hw_random/Makefile +++ b/drivers/char/hw_random/Makefile @@ -46,3 +46,4 @@ obj-$(CONFIG_HW_RANDOM_CCTRNG) += cctrng.o obj-$(CONFIG_HW_RANDOM_XIPHERA) += xiphera-trng.o obj-$(CONFIG_HW_RANDOM_ARM_SMCCC_TRNG) += arm_smccc_trng.o obj-$(CONFIG_HW_RANDOM_CN10K) += cn10k-rng.o +obj-$(CONFIG_HW_RANDOM_POLARFIRE_SOC) += mpfs-rng.o diff --git a/drivers/char/hw_random/mpfs-rng.c b/drivers/char/hw_random/mpfs-rng.c new file mode 100644 index 000000000000..a103c765d021 --- /dev/null +++ b/drivers/char/hw_random/mpfs-rng.c @@ -0,0 +1,103 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Microchip PolarFire SoC (MPFS) hardware random driver + * + * Copyright (c) 2020-2022 Microchip Corporation. All rights reserved. + * + * Author: Conor Dooley <conor.dooley@microchip.com> + */ + +#include <linux/module.h> +#include <linux/hw_random.h> +#include <linux/platform_device.h> +#include <soc/microchip/mpfs.h> + +#define CMD_OPCODE 0x21 +#define CMD_DATA_SIZE 0U +#define CMD_DATA NULL +#define MBOX_OFFSET 0U +#define RESP_OFFSET 0U +#define RNG_RESP_BYTES 32U + +struct mpfs_rng { + struct mpfs_sys_controller *sys_controller; + struct hwrng rng; +}; + +static int mpfs_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) +{ + struct mpfs_rng *rng_priv = container_of(rng, struct mpfs_rng, rng); + u32 response_msg[RNG_RESP_BYTES / sizeof(u32)]; + unsigned int count = 0, copy_size_bytes; + int ret; + + struct mpfs_mss_response response = { + .resp_status = 0U, + .resp_msg = (u32 *)response_msg, + .resp_size = RNG_RESP_BYTES + }; + struct mpfs_mss_msg msg = { + .cmd_opcode = CMD_OPCODE, + .cmd_data_size = CMD_DATA_SIZE, + .response = &response, + .cmd_data = CMD_DATA, + .mbox_offset = MBOX_OFFSET, + .resp_offset = RESP_OFFSET + }; + + while (count < max) { + ret = mpfs_blocking_transaction(rng_priv->sys_controller, &msg); + if (ret) + return ret; + + copy_size_bytes = max - count > RNG_RESP_BYTES ? RNG_RESP_BYTES : max - count; + memcpy(buf + count, response_msg, copy_size_bytes); + + count += copy_size_bytes; + if (!wait) + break; + } + + return count; +} + +static int mpfs_rng_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct mpfs_rng *rng_priv; + int ret; + + rng_priv = devm_kzalloc(dev, sizeof(*rng_priv), GFP_KERNEL); + if (!rng_priv) + return -ENOMEM; + + rng_priv->sys_controller = mpfs_sys_controller_get(&pdev->dev); + if (IS_ERR(rng_priv->sys_controller)) + return dev_err_probe(dev, PTR_ERR(rng_priv->sys_controller), + "Failed to register system controller hwrng sub device\n"); + + rng_priv->rng.read = mpfs_rng_read; + rng_priv->rng.name = pdev->name; + + platform_set_drvdata(pdev, rng_priv); + + ret = devm_hwrng_register(&pdev->dev, &rng_priv->rng); + if (ret) + return dev_err_probe(&pdev->dev, ret, "Failed to register MPFS hwrng\n"); + + dev_info(&pdev->dev, "Registered MPFS hwrng\n"); + + return 0; +} + +static struct platform_driver mpfs_rng_driver = { + .driver = { + .name = "mpfs-rng", + }, + .probe = mpfs_rng_probe, +}; +module_platform_driver(mpfs_rng_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Conor Dooley <conor.dooley@microchip.com>"); +MODULE_DESCRIPTION("PolarFire SoC (MPFS) hardware random driver");