| Message ID | 1557287937-2410-4-git-send-email-neal.liu@mediatek.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Herbert Xu |
| Headers | show |
| Series | MT67XX random number generator support | expand |
Am Mittwoch, 8. Mai 2019, 05:58:57 CEST schrieb neal.liu@mediatek.com: Hi liu, > From: Neal Liu <neal.liu@mediatek.com> > > For Mediatek SoCs on ARMv8 with TrustZone enabled, peripherals like > entropy sources is not accessible from normal world (linux) and > rather accessible from secure world (ATF/TEE) only. This driver aims > to provide a generic interface to ATF rng service. > > Signed-off-by: Neal Liu <neal.liu@mediatek.com> > --- > drivers/char/hw_random/Kconfig | 16 ++++++ > drivers/char/hw_random/Makefile | 1 + > drivers/char/hw_random/mt67xx-rng.c | 104 > +++++++++++++++++++++++++++++++++++ 3 files changed, 121 insertions(+) > create mode 100644 drivers/char/hw_random/mt67xx-rng.c > > diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig > index 25a7d8f..98751d3 100644 > --- a/drivers/char/hw_random/Kconfig > +++ b/drivers/char/hw_random/Kconfig > @@ -398,6 +398,22 @@ config HW_RANDOM_MTK > > If unsure, say Y. > > +config HW_RANDOM_MT67XX > + tristate "Mediatek MT67XX Random Number Generator support" > + depends on HW_RANDOM > + depends on ARCH_MEDIATEK || COMPILE_TEST > + default HW_RANDOM > + help > + This driver provides kernel-side support for the Random Number > + Generator hardware found on Mediatek MT67xx SoCs. The difference > + with mtk-rng is the Random Number Generator hardware is secure > + access only. > + > + To compile this driver as a module, choose M here. the > + module will be called mt67xx-rng. > + > + If unsure, say Y. > + > config HW_RANDOM_S390 > tristate "S390 True Random Number Generator support" > depends on S390 > diff --git a/drivers/char/hw_random/Makefile > b/drivers/char/hw_random/Makefile index 7c9ef4a..4be95ab 100644 > --- a/drivers/char/hw_random/Makefile > +++ b/drivers/char/hw_random/Makefile > @@ -36,6 +36,7 @@ obj-$(CONFIG_HW_RANDOM_PIC32) += pic32-rng.o > obj-$(CONFIG_HW_RANDOM_MESON) += meson-rng.o > obj-$(CONFIG_HW_RANDOM_CAVIUM) += cavium-rng.o cavium-rng-vf.o > obj-$(CONFIG_HW_RANDOM_MTK) += mtk-rng.o > +obj-$(CONFIG_HW_RANDOM_MT67XX) += mt67xx-rng.o > obj-$(CONFIG_HW_RANDOM_S390) += s390-trng.o > obj-$(CONFIG_HW_RANDOM_KEYSTONE) += ks-sa-rng.o > obj-$(CONFIG_HW_RANDOM_OPTEE) += optee-rng.o > diff --git a/drivers/char/hw_random/mt67xx-rng.c > b/drivers/char/hw_random/mt67xx-rng.c new file mode 100644 > index 0000000..e70cbbe > --- /dev/null > +++ b/drivers/char/hw_random/mt67xx-rng.c > @@ -0,0 +1,104 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) 2019 MediaTek Inc. > + */ > + > +#include <linux/module.h> > +#include <linux/platform_device.h> > +#include <linux/hw_random.h> > +#include <linux/of.h> > +#include <linux/arm-smccc.h> > +#include <linux/soc/mediatek/mtk_sip_svc.h> > + > +#define PFX KBUILD_MODNAME ": " > +#define MT67XX_RNG_MAGIC 0x74726e67 > +#define SMC_RET_NUM 4 > + > +struct mt67xx_rng_priv { > + struct hwrng rng; > +}; > + > + > +static void __rng_sec_read(uint32_t *val) > +{ > + struct arm_smccc_res res; > + > + arm_smccc_smc(MTK_SIP_KERNEL_GET_RND, > + MT67XX_RNG_MAGIC, 0, 0, 0, 0, 0, 0, &res); > + > + val[0] = res.a0; > + val[1] = res.a1; > + val[2] = res.a2; > + val[3] = res.a3; > +} > + > +static int mt67xx_rng_read(struct hwrng *rng, void *buf, size_t max, bool > wait) +{ > + int i, retval = 0; > + uint32_t val[4] = {0}; > + size_t get_rnd_size = sizeof(u32) * SMC_RET_NUM; > + > + if (!buf) { > + pr_err("%s, buf is NULL\n", __func__); > + return -EFAULT; > + } > + > + while (max >= get_rnd_size) { > + __rng_sec_read(val); > + > + for (i = 0; i < SMC_RET_NUM; i++) { > + *(u32 *)buf = val[i]; I am not sure this cast is right - or how is it guaranteed that buf is word- aligned? > + buf += sizeof(u32); > + } > + > + retval += get_rnd_size; > + max -= get_rnd_size; > + } > + > + return retval; > +} > + > +static int mt67xx_rng_probe(struct platform_device *pdev) > +{ > + int ret; > + struct mt67xx_rng_priv *priv; > + > + pr_info(PFX "driver registered\n"); > + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + priv->rng.name = KBUILD_MODNAME; > + priv->rng.read = mt67xx_rng_read; > + priv->rng.priv = (unsigned long)&pdev->dev; > + priv->rng.quality = 900; > + > + ret = devm_hwrng_register(&pdev->dev, &priv->rng); > + if (ret) { > + dev_err(&pdev->dev, "failed to register rng device: %d\n", ret); > + return ret; > + } > + > + return 0; > +} > + > +static const struct of_device_id mt67xx_rng_match[] = { > + { .compatible = "mediatek,mt67xx-rng", }, > + {} > +}; > +MODULE_DEVICE_TABLE(of, mt67xx_rng_match); > + > +static struct platform_driver mt67xx_rng_driver = { > + .probe = mt67xx_rng_probe, > + .driver = { > + .name = KBUILD_MODNAME, > + .owner = THIS_MODULE, > + .of_match_table = mt67xx_rng_match, > + }, > +}; > + > +module_platform_driver(mt67xx_rng_driver); > + > +MODULE_DESCRIPTION("Mediatek MT67XX Random Number Generator Driver"); > +MODULE_AUTHOR("Neal Liu <neal.liu@mediatek.com>"); > +MODULE_LICENSE("GPL"); Ciao Stephan
Hi Stephan, We think the cast is fine, and it cannot guarantee the buf is word-align. I reference multiple rng driver's implementation and found it's common usage for this. So it might be general usage for community. Is there any suggestion that is more appropriate? Thanks Best Regards, -Neal Liu On Wed, 2019-05-08 at 08:34 +0200, Stephan Mueller wrote: > Am Mittwoch, 8. Mai 2019, 05:58:57 CEST schrieb neal.liu@mediatek.com: > > Hi liu, > > > From: Neal Liu <neal.liu@mediatek.com> > > > > For Mediatek SoCs on ARMv8 with TrustZone enabled, peripherals like > > entropy sources is not accessible from normal world (linux) and > > rather accessible from secure world (ATF/TEE) only. This driver aims > > to provide a generic interface to ATF rng service. > > > > Signed-off-by: Neal Liu <neal.liu@mediatek.com> > > --- > > drivers/char/hw_random/Kconfig | 16 ++++++ > > drivers/char/hw_random/Makefile | 1 + > > drivers/char/hw_random/mt67xx-rng.c | 104 > > +++++++++++++++++++++++++++++++++++ 3 files changed, 121 insertions(+) > > create mode 100644 drivers/char/hw_random/mt67xx-rng.c > > > > diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig > > index 25a7d8f..98751d3 100644 > > --- a/drivers/char/hw_random/Kconfig > > +++ b/drivers/char/hw_random/Kconfig > > @@ -398,6 +398,22 @@ config HW_RANDOM_MTK > > > > If unsure, say Y. > > > > +config HW_RANDOM_MT67XX > > + tristate "Mediatek MT67XX Random Number Generator support" > > + depends on HW_RANDOM > > + depends on ARCH_MEDIATEK || COMPILE_TEST > > + default HW_RANDOM > > + help > > + This driver provides kernel-side support for the Random Number > > + Generator hardware found on Mediatek MT67xx SoCs. The difference > > + with mtk-rng is the Random Number Generator hardware is secure > > + access only. > > + > > + To compile this driver as a module, choose M here. the > > + module will be called mt67xx-rng. > > + > > + If unsure, say Y. > > + > > config HW_RANDOM_S390 > > tristate "S390 True Random Number Generator support" > > depends on S390 > > diff --git a/drivers/char/hw_random/Makefile > > b/drivers/char/hw_random/Makefile index 7c9ef4a..4be95ab 100644 > > --- a/drivers/char/hw_random/Makefile > > +++ b/drivers/char/hw_random/Makefile > > @@ -36,6 +36,7 @@ obj-$(CONFIG_HW_RANDOM_PIC32) += pic32-rng.o > > obj-$(CONFIG_HW_RANDOM_MESON) += meson-rng.o > > obj-$(CONFIG_HW_RANDOM_CAVIUM) += cavium-rng.o cavium-rng-vf.o > > obj-$(CONFIG_HW_RANDOM_MTK) += mtk-rng.o > > +obj-$(CONFIG_HW_RANDOM_MT67XX) += mt67xx-rng.o > > obj-$(CONFIG_HW_RANDOM_S390) += s390-trng.o > > obj-$(CONFIG_HW_RANDOM_KEYSTONE) += ks-sa-rng.o > > obj-$(CONFIG_HW_RANDOM_OPTEE) += optee-rng.o > > diff --git a/drivers/char/hw_random/mt67xx-rng.c > > b/drivers/char/hw_random/mt67xx-rng.c new file mode 100644 > > index 0000000..e70cbbe > > --- /dev/null > > +++ b/drivers/char/hw_random/mt67xx-rng.c > > @@ -0,0 +1,104 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * Copyright (C) 2019 MediaTek Inc. > > + */ > > + > > +#include <linux/module.h> > > +#include <linux/platform_device.h> > > +#include <linux/hw_random.h> > > +#include <linux/of.h> > > +#include <linux/arm-smccc.h> > > +#include <linux/soc/mediatek/mtk_sip_svc.h> > > + > > +#define PFX KBUILD_MODNAME ": " > > +#define MT67XX_RNG_MAGIC 0x74726e67 > > +#define SMC_RET_NUM 4 > > + > > +struct mt67xx_rng_priv { > > + struct hwrng rng; > > +}; > > + > > + > > +static void __rng_sec_read(uint32_t *val) > > +{ > > + struct arm_smccc_res res; > > + > > + arm_smccc_smc(MTK_SIP_KERNEL_GET_RND, > > + MT67XX_RNG_MAGIC, 0, 0, 0, 0, 0, 0, &res); > > + > > + val[0] = res.a0; > > + val[1] = res.a1; > > + val[2] = res.a2; > > + val[3] = res.a3; > > +} > > + > > +static int mt67xx_rng_read(struct hwrng *rng, void *buf, size_t max, bool > > wait) +{ > > + int i, retval = 0; > > + uint32_t val[4] = {0}; > > + size_t get_rnd_size = sizeof(u32) * SMC_RET_NUM; > > + > > + if (!buf) { > > + pr_err("%s, buf is NULL\n", __func__); > > + return -EFAULT; > > + } > > + > > + while (max >= get_rnd_size) { > > + __rng_sec_read(val); > > + > > + for (i = 0; i < SMC_RET_NUM; i++) { > > + *(u32 *)buf = val[i]; > > I am not sure this cast is right - or how is it guaranteed that buf is word- > aligned? > > > + buf += sizeof(u32); > > + } > > + > > + retval += get_rnd_size; > > + max -= get_rnd_size; > > + } > > + > > + return retval; > > +} > > + > > +static int mt67xx_rng_probe(struct platform_device *pdev) > > +{ > > + int ret; > > + struct mt67xx_rng_priv *priv; > > + > > + pr_info(PFX "driver registered\n"); > > + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); > > + if (!priv) > > + return -ENOMEM; > > + > > + priv->rng.name = KBUILD_MODNAME; > > + priv->rng.read = mt67xx_rng_read; > > + priv->rng.priv = (unsigned long)&pdev->dev; > > + priv->rng.quality = 900; > > + > > + ret = devm_hwrng_register(&pdev->dev, &priv->rng); > > + if (ret) { > > + dev_err(&pdev->dev, "failed to register rng device: %d\n", > ret); > > + return ret; > > + } > > + > > + return 0; > > +} > > + > > +static const struct of_device_id mt67xx_rng_match[] = { > > + { .compatible = "mediatek,mt67xx-rng", }, > > + {} > > +}; > > +MODULE_DEVICE_TABLE(of, mt67xx_rng_match); > > + > > +static struct platform_driver mt67xx_rng_driver = { > > + .probe = mt67xx_rng_probe, > > + .driver = { > > + .name = KBUILD_MODNAME, > > + .owner = THIS_MODULE, > > + .of_match_table = mt67xx_rng_match, > > + }, > > +}; > > + > > +module_platform_driver(mt67xx_rng_driver); > > + > > +MODULE_DESCRIPTION("Mediatek MT67XX Random Number Generator Driver"); > > +MODULE_AUTHOR("Neal Liu <neal.liu@mediatek.com>"); > > +MODULE_LICENSE("GPL"); > > > > Ciao > Stephan > >
On Wed, May 08, 2019 at 06:35:37PM +0800, Neal Liu wrote: > Hi Stephan, > We think the cast is fine, and it cannot guarantee the buf is > word-align. > I reference multiple rng driver's implementation and found it's common > usage for this. So it might be general usage for community. Is there any > suggestion that is more appropriate? If you don't know whether it's unaligned or not then you should do an unaligned operation. Cheers,
On Thu, 2019-05-09 at 13:26 +0800, Herbert Xu wrote: > On Wed, May 08, 2019 at 06:35:37PM +0800, Neal Liu wrote: > > Hi Stephan, > > We think the cast is fine, and it cannot guarantee the buf is > > word-align. > > I reference multiple rng driver's implementation and found it's common > > usage for this. So it might be general usage for community. Is there any > > suggestion that is more appropriate? > > If you don't know whether it's unaligned or not then you should > do an unaligned operation. Hi Stephan/Herbert, My mistake. This buffer is allocated by kmalloc with larger than 32 bytes. So yes, it's word-align for sure. reference: https://elixir.bootlin.com/linux/latest/source/drivers/char/hw_random/core.c#L590 Thanks Best Regards, -Neal Liu
On Thu, May 09, 2019 at 10:54:46PM +0800, Neal Liu wrote: > > Hi Stephan/Herbert, > My mistake. This buffer is allocated by kmalloc with larger than 32 > bytes. So yes, it's word-align for sure. > reference: > https://elixir.bootlin.com/linux/latest/source/drivers/char/hw_random/core.c#L590 Yes you're right. Cheers,
Hi Herbert, Could you kindly help to review our patches? Thanks From Neal Liu <> Subject [PATCH 0/3] MT67XX random number generator support Date Wed, 8 May 2019 11:58:54 +0800 share These patch series introduce a generic rng driver for Trustzone based kernel driver which would like to communicate with ATF SIP services. Patch #1 initials SMC fid table for Mediatek SIP interfaces and adds HWRNG related SMC call. Patch #2..3 adds mt67xx-rng kernel driver for Trustzone based SoCs. For Mediatek SoCs on ARMv8 with TrustZone enabled, peripherals like entropy sources is not accessible from normal world (linux) and rather accessible from secure world (ATF/TEE) only. This driver aims to provide a generic interface to ATF rng service. Neal Liu (3): soc: mediatek: add SMC fid table for SIP interface dt-bindings: rng: update bindings for MT67xx SoCs hwrng: add mt67xx-rng driver Documentation/devicetree/bindings/rng/mtk-rng.txt | 13 ++- drivers/char/hw_random/Kconfig | 16 ++++ drivers/char/hw_random/Makefile | 1 + drivers/char/hw_random/mt67xx-rng.c | 104 +++++++++++++++++++++ include/linux/soc/mediatek/mtk_sip_svc.h | 55 +++++++++++ 5 files changed, 186 insertions(+), 3 deletions(-) create mode 100644 drivers/char/hw_random/mt67xx-rng.c create mode 100644 include/linux/soc/mediatek/mtk_sip_svc.h
On Fri, May 24, 2019 at 03:42:34PM +0800, Neal Liu wrote: > Hi Herbert, > Could you kindly help to review our patches? You need acks for patches 1 and 2. Cheers,
Hi Neal, On Tue, May 7, 2019 at 9:00 PM <neal.liu@mediatek.com> wrote: > > From: Neal Liu <neal.liu@mediatek.com> > > For Mediatek SoCs on ARMv8 with TrustZone enabled, peripherals like MediaTek > entropy sources is not accessible from normal world (linux) and > rather accessible from secure world (ATF/TEE) only. This driver aims > to provide a generic interface to ATF rng service. Could we rename the mt67xx-rng.c to mtk-sec-rng.c? It seems all MediaTek SoCs with ATF/TEE can reuse this driver, not be limited in MT67xx. > > Signed-off-by: Neal Liu <neal.liu@mediatek.com> > --- > drivers/char/hw_random/Kconfig | 16 ++++++ > drivers/char/hw_random/Makefile | 1 + > drivers/char/hw_random/mt67xx-rng.c | 104 +++++++++++++++++++++++++++++++++++ > 3 files changed, 121 insertions(+) > create mode 100644 drivers/char/hw_random/mt67xx-rng.c > > diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig > index 25a7d8f..98751d3 100644 > --- a/drivers/char/hw_random/Kconfig > +++ b/drivers/char/hw_random/Kconfig > @@ -398,6 +398,22 @@ config HW_RANDOM_MTK > > If unsure, say Y. > > +config HW_RANDOM_MT67XX > + tristate "Mediatek MT67XX Random Number Generator support" MediaTek Security > + depends on HW_RANDOM > + depends on ARCH_MEDIATEK || COMPILE_TEST > + default HW_RANDOM > + help > + This driver provides kernel-side support for the Random Number > + Generator hardware found on Mediatek MT67xx SoCs. The difference MediaTek > + with mtk-rng is the Random Number Generator hardware is secure > + access only. > + > + To compile this driver as a module, choose M here. the > + module will be called mt67xx-rng. > + > + If unsure, say Y. > + > config HW_RANDOM_S390 > tristate "S390 True Random Number Generator support" > depends on S390 > diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile > index 7c9ef4a..4be95ab 100644 > --- a/drivers/char/hw_random/Makefile > +++ b/drivers/char/hw_random/Makefile > @@ -36,6 +36,7 @@ obj-$(CONFIG_HW_RANDOM_PIC32) += pic32-rng.o > obj-$(CONFIG_HW_RANDOM_MESON) += meson-rng.o > obj-$(CONFIG_HW_RANDOM_CAVIUM) += cavium-rng.o cavium-rng-vf.o > obj-$(CONFIG_HW_RANDOM_MTK) += mtk-rng.o > +obj-$(CONFIG_HW_RANDOM_MT67XX) += mt67xx-rng.o > obj-$(CONFIG_HW_RANDOM_S390) += s390-trng.o > obj-$(CONFIG_HW_RANDOM_KEYSTONE) += ks-sa-rng.o > obj-$(CONFIG_HW_RANDOM_OPTEE) += optee-rng.o > diff --git a/drivers/char/hw_random/mt67xx-rng.c b/drivers/char/hw_random/mt67xx-rng.c > new file mode 100644 > index 0000000..e70cbbe > --- /dev/null > +++ b/drivers/char/hw_random/mt67xx-rng.c > @@ -0,0 +1,104 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) 2019 MediaTek Inc. > + */ > + > +#include <linux/module.h> > +#include <linux/platform_device.h> > +#include <linux/hw_random.h> > +#include <linux/of.h> > +#include <linux/arm-smccc.h> > +#include <linux/soc/mediatek/mtk_sip_svc.h> > + sort these headers in alphabetical order > +#define PFX KBUILD_MODNAME ": " PFX can be dropped that is less useful > +#define MT67XX_RNG_MAGIC 0x74726e67 > +#define SMC_RET_NUM 4 > + > +struct mt67xx_rng_priv { > + struct hwrng rng; > +}; > + > + > +static void __rng_sec_read(uint32_t *val) > +{ add a prefix like mt67xx, the function call is specific to mtk > + struct arm_smccc_res res; > + > + arm_smccc_smc(MTK_SIP_KERNEL_GET_RND, > + MT67XX_RNG_MAGIC, 0, 0, 0, 0, 0, 0, &res); > + > + val[0] = res.a0; > + val[1] = res.a1; > + val[2] = res.a2; > + val[3] = res.a3; > +} > + > +static int mt67xx_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) > +{ > + int i, retval = 0; > + uint32_t val[4] = {0}; > + size_t get_rnd_size = sizeof(u32) * SMC_RET_NUM; sort declarations in the reverse-Xmas tree. and get_rnd_size always be unchanged so it can be a macro > + > + if (!buf) { the sanity check is unnecessary, the parameter max would ensure the size of the whole buffer > + pr_err("%s, buf is NULL\n", __func__); > + return -EFAULT; > + } > + > + while (max >= get_rnd_size) { > + __rng_sec_read(val); > + > + for (i = 0; i < SMC_RET_NUM; i++) { > + *(u32 *)buf = val[i]; > + buf += sizeof(u32); > + } > + > + retval += get_rnd_size; > + max -= get_rnd_size; > + } > + > + return retval; > +} > + > +static int mt67xx_rng_probe(struct platform_device *pdev) > +{ > + int ret; > + struct mt67xx_rng_priv *priv; sort declarations in the reverse-Xmas tree. > + > + pr_info(PFX "driver registered\n"); drop the message > + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + priv->rng.name = KBUILD_MODNAME; suggest using the device name priv->rng.name = pdev->name; > + priv->rng.read = mt67xx_rng_read; > + priv->rng.priv = (unsigned long)&pdev->dev; > + priv->rng.quality = 900; > + > + ret = devm_hwrng_register(&pdev->dev, &priv->rng); > + if (ret) { > + dev_err(&pdev->dev, "failed to register rng device: %d\n", ret); > + return ret; > + } > + > + return 0; > +} > + > +static const struct of_device_id mt67xx_rng_match[] = { > + { .compatible = "mediatek,mt67xx-rng", }, > + {} > +}; > +MODULE_DEVICE_TABLE(of, mt67xx_rng_match); > + > +static struct platform_driver mt67xx_rng_driver = { > + .probe = mt67xx_rng_probe, > + .driver = { > + .name = KBUILD_MODNAME, > + .owner = THIS_MODULE, > + .of_match_table = mt67xx_rng_match, > + }, > +}; > + > +module_platform_driver(mt67xx_rng_driver); > + > +MODULE_DESCRIPTION("Mediatek MT67XX Random Number Generator Driver"); MediaTek > +MODULE_AUTHOR("Neal Liu <neal.liu@mediatek.com>"); > +MODULE_LICENSE("GPL"); > -- > 1.7.9.5 > > > _______________________________________________ > Linux-mediatek mailing list > Linux-mediatek@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-mediatek
diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig index 25a7d8f..98751d3 100644 --- a/drivers/char/hw_random/Kconfig +++ b/drivers/char/hw_random/Kconfig @@ -398,6 +398,22 @@ config HW_RANDOM_MTK If unsure, say Y. +config HW_RANDOM_MT67XX + tristate "Mediatek MT67XX Random Number Generator support" + depends on HW_RANDOM + depends on ARCH_MEDIATEK || COMPILE_TEST + default HW_RANDOM + help + This driver provides kernel-side support for the Random Number + Generator hardware found on Mediatek MT67xx SoCs. The difference + with mtk-rng is the Random Number Generator hardware is secure + access only. + + To compile this driver as a module, choose M here. the + module will be called mt67xx-rng. + + If unsure, say Y. + config HW_RANDOM_S390 tristate "S390 True Random Number Generator support" depends on S390 diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile index 7c9ef4a..4be95ab 100644 --- a/drivers/char/hw_random/Makefile +++ b/drivers/char/hw_random/Makefile @@ -36,6 +36,7 @@ obj-$(CONFIG_HW_RANDOM_PIC32) += pic32-rng.o obj-$(CONFIG_HW_RANDOM_MESON) += meson-rng.o obj-$(CONFIG_HW_RANDOM_CAVIUM) += cavium-rng.o cavium-rng-vf.o obj-$(CONFIG_HW_RANDOM_MTK) += mtk-rng.o +obj-$(CONFIG_HW_RANDOM_MT67XX) += mt67xx-rng.o obj-$(CONFIG_HW_RANDOM_S390) += s390-trng.o obj-$(CONFIG_HW_RANDOM_KEYSTONE) += ks-sa-rng.o obj-$(CONFIG_HW_RANDOM_OPTEE) += optee-rng.o diff --git a/drivers/char/hw_random/mt67xx-rng.c b/drivers/char/hw_random/mt67xx-rng.c new file mode 100644 index 0000000..e70cbbe --- /dev/null +++ b/drivers/char/hw_random/mt67xx-rng.c @@ -0,0 +1,104 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 MediaTek Inc. + */ + +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/hw_random.h> +#include <linux/of.h> +#include <linux/arm-smccc.h> +#include <linux/soc/mediatek/mtk_sip_svc.h> + +#define PFX KBUILD_MODNAME ": " +#define MT67XX_RNG_MAGIC 0x74726e67 +#define SMC_RET_NUM 4 + +struct mt67xx_rng_priv { + struct hwrng rng; +}; + + +static void __rng_sec_read(uint32_t *val) +{ + struct arm_smccc_res res; + + arm_smccc_smc(MTK_SIP_KERNEL_GET_RND, + MT67XX_RNG_MAGIC, 0, 0, 0, 0, 0, 0, &res); + + val[0] = res.a0; + val[1] = res.a1; + val[2] = res.a2; + val[3] = res.a3; +} + +static int mt67xx_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) +{ + int i, retval = 0; + uint32_t val[4] = {0}; + size_t get_rnd_size = sizeof(u32) * SMC_RET_NUM; + + if (!buf) { + pr_err("%s, buf is NULL\n", __func__); + return -EFAULT; + } + + while (max >= get_rnd_size) { + __rng_sec_read(val); + + for (i = 0; i < SMC_RET_NUM; i++) { + *(u32 *)buf = val[i]; + buf += sizeof(u32); + } + + retval += get_rnd_size; + max -= get_rnd_size; + } + + return retval; +} + +static int mt67xx_rng_probe(struct platform_device *pdev) +{ + int ret; + struct mt67xx_rng_priv *priv; + + pr_info(PFX "driver registered\n"); + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->rng.name = KBUILD_MODNAME; + priv->rng.read = mt67xx_rng_read; + priv->rng.priv = (unsigned long)&pdev->dev; + priv->rng.quality = 900; + + ret = devm_hwrng_register(&pdev->dev, &priv->rng); + if (ret) { + dev_err(&pdev->dev, "failed to register rng device: %d\n", ret); + return ret; + } + + return 0; +} + +static const struct of_device_id mt67xx_rng_match[] = { + { .compatible = "mediatek,mt67xx-rng", }, + {} +}; +MODULE_DEVICE_TABLE(of, mt67xx_rng_match); + +static struct platform_driver mt67xx_rng_driver = { + .probe = mt67xx_rng_probe, + .driver = { + .name = KBUILD_MODNAME, + .owner = THIS_MODULE, + .of_match_table = mt67xx_rng_match, + }, +}; + +module_platform_driver(mt67xx_rng_driver); + +MODULE_DESCRIPTION("Mediatek MT67XX Random Number Generator Driver"); +MODULE_AUTHOR("Neal Liu <neal.liu@mediatek.com>"); +MODULE_LICENSE("GPL");