diff mbox series

[v2,3/3] hwrng: add mtk-sec-rng driver

Message ID 1558946326-13630-4-git-send-email-neal.liu@mediatek.com (mailing list archive)
State Changes Requested
Delegated to: Herbert Xu
Headers show
Series MediaTek Security random number generator support | expand

Commit Message

Neal Liu May 27, 2019, 8:38 a.m. UTC 
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/mtk-sec-rng.c |   97 ++++++++++++++++++++++++++++++++++
 3 files changed, 114 insertions(+)
 create mode 100644 drivers/char/hw_random/mtk-sec-rng.c

Comments

Sean Wang May 30, 2019, 10:59 p.m. UTC | #1 
Hi, Neal

On Mon, May 27, 2019 at 1:39 AM Neal Liu <neal.liu@mediatek.com> wrote:
>
> 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/mtk-sec-rng.c |   97 ++++++++++++++++++++++++++++++++++
>  3 files changed, 114 insertions(+)
>  create mode 100644 drivers/char/hw_random/mtk-sec-rng.c
>
> diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
> index 25a7d8f..6c82a3b 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_MTK_SEC
> +       tristate "MediaTek Security 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 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 mtk-sec-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..0ae4993 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-$(CONFIG_HW_RANDOM_MTK_SEC) += mtk-sec-rng.o
>  obj-$(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/mtk-sec-rng.c b/drivers/char/hw_random/mtk-sec-rng.c
> new file mode 100644
> index 0000000..4c6e5bf
> --- /dev/null
> +++ b/drivers/char/hw_random/mtk-sec-rng.c
> @@ -0,0 +1,97 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2019 MediaTek Inc.
> + */
> +
> +#include <linux/arm-smccc.h>
> +#include <linux/hw_random.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/soc/mediatek/mtk_sip_svc.h>
> +
> +#define MT67XX_RNG_MAGIC       0x74726e67
> +#define SMC_RET_NUM            4
> +#define MTK_SEC_RND_SIZE       (sizeof(u32) * SMC_RET_NUM)
> +
> +struct mtk_sec_rng_priv {
> +       struct hwrng rng;
> +};
> +
> +static void mtk_sec_get_rnd(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 mtk_sec_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
> +{
> +       size_t get_rnd_size = MTK_SEC_RND_SIZE;

the variable get_rnd_size can be further eliminated

> +       u32 val[4] = {0};
> +       int i, retval = 0;
> +
> +       while (max >= get_rnd_size) {
> +               mtk_sec_get_rnd(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 mtk_sec_rng_probe(struct platform_device *pdev)
> +{
> +       struct mtk_sec_rng_priv *priv;
> +       int ret;
> +
> +       priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> +       if (!priv)
> +               return -ENOMEM;
> +
> +       priv->rng.name = pdev->name;
> +       priv->rng.read = mtk_sec_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 mtk_sec_rng_match[] = {
> +       { .compatible = "mediatek,mtk-sec-rng", },
> +       {}
> +};
> +MODULE_DEVICE_TABLE(of, mtk_sec_rng_match);
> +
> +static struct platform_driver mtk_sec_rng_driver = {
> +       .probe = mtk_sec_rng_probe,
> +       .driver = {
> +               .name = KBUILD_MODNAME,
> +               .owner = THIS_MODULE,
> +               .of_match_table = mtk_sec_rng_match,
> +       },
> +};
> +
> +module_platform_driver(mtk_sec_rng_driver);
> +
> +MODULE_DESCRIPTION("MediaTek Security Random Number Generator Driver");
> +MODULE_AUTHOR("Neal Liu <neal.liu@mediatek.com>");
> +MODULE_LICENSE("GPL");
> --
> 1.7.9.5
>
Neal Liu June 3, 2019, 2:36 a.m. UTC | #2 
Hi Sean,

On Thu, 2019-05-30 at 15:59 -0700, Sean Wang wrote:
> Hi, Neal
> 
> On Mon, May 27, 2019 at 1:39 AM Neal Liu <neal.liu@mediatek.com> wrote:
> >
> > 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/mtk-sec-rng.c |   97 ++++++++++++++++++++++++++++++++++
> >  3 files changed, 114 insertions(+)
> >  create mode 100644 drivers/char/hw_random/mtk-sec-rng.c
> >
> > diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
> > index 25a7d8f..6c82a3b 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_MTK_SEC
> > +       tristate "MediaTek Security 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 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 mtk-sec-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..0ae4993 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-$(CONFIG_HW_RANDOM_MTK_SEC) += mtk-sec-rng.o
> >  obj-$(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/mtk-sec-rng.c b/drivers/char/hw_random/mtk-sec-rng.c
> > new file mode 100644
> > index 0000000..4c6e5bf
> > --- /dev/null
> > +++ b/drivers/char/hw_random/mtk-sec-rng.c
> > @@ -0,0 +1,97 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2019 MediaTek Inc.
> > + */
> > +
> > +#include <linux/arm-smccc.h>
> > +#include <linux/hw_random.h>
> > +#include <linux/module.h>
> > +#include <linux/of.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/soc/mediatek/mtk_sip_svc.h>
> > +
> > +#define MT67XX_RNG_MAGIC       0x74726e67
> > +#define SMC_RET_NUM            4
> > +#define MTK_SEC_RND_SIZE       (sizeof(u32) * SMC_RET_NUM)
> > +
> > +struct mtk_sec_rng_priv {
> > +       struct hwrng rng;
> > +};
> > +
> > +static void mtk_sec_get_rnd(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 mtk_sec_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
> > +{
> > +       size_t get_rnd_size = MTK_SEC_RND_SIZE;
> 
> the variable get_rnd_size can be further eliminated

Yes, sure. I'll send new patchset to eliminate this variable, Thanks

> 
> > +       u32 val[4] = {0};
> > +       int i, retval = 0;
> > +
> > +       while (max >= get_rnd_size) {
> > +               mtk_sec_get_rnd(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 mtk_sec_rng_probe(struct platform_device *pdev)
> > +{
> > +       struct mtk_sec_rng_priv *priv;
> > +       int ret;
> > +
> > +       priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> > +       if (!priv)
> > +               return -ENOMEM;
> > +
> > +       priv->rng.name = pdev->name;
> > +       priv->rng.read = mtk_sec_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 mtk_sec_rng_match[] = {
> > +       { .compatible = "mediatek,mtk-sec-rng", },
> > +       {}
> > +};
> > +MODULE_DEVICE_TABLE(of, mtk_sec_rng_match);
> > +
> > +static struct platform_driver mtk_sec_rng_driver = {
> > +       .probe = mtk_sec_rng_probe,
> > +       .driver = {
> > +               .name = KBUILD_MODNAME,
> > +               .owner = THIS_MODULE,
> > +               .of_match_table = mtk_sec_rng_match,
> > +       },
> > +};
> > +
> > +module_platform_driver(mtk_sec_rng_driver);
> > +
> > +MODULE_DESCRIPTION("MediaTek Security Random Number Generator Driver");
> > +MODULE_AUTHOR("Neal Liu <neal.liu@mediatek.com>");
> > +MODULE_LICENSE("GPL");
> > --
> > 1.7.9.5
> >
diff mbox series

Patch

diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 25a7d8f..6c82a3b 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_MTK_SEC
+	tristate "MediaTek Security 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 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 mtk-sec-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..0ae4993 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-$(CONFIG_HW_RANDOM_MTK_SEC) += mtk-sec-rng.o
 obj-$(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/mtk-sec-rng.c b/drivers/char/hw_random/mtk-sec-rng.c
new file mode 100644
index 0000000..4c6e5bf
--- /dev/null
+++ b/drivers/char/hw_random/mtk-sec-rng.c
@@ -0,0 +1,97 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 MediaTek Inc.
+ */
+
+#include <linux/arm-smccc.h>
+#include <linux/hw_random.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/soc/mediatek/mtk_sip_svc.h>
+
+#define MT67XX_RNG_MAGIC	0x74726e67
+#define SMC_RET_NUM		4
+#define MTK_SEC_RND_SIZE	(sizeof(u32) * SMC_RET_NUM)
+
+struct mtk_sec_rng_priv {
+	struct hwrng rng;
+};
+
+static void mtk_sec_get_rnd(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 mtk_sec_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
+{
+	size_t get_rnd_size = MTK_SEC_RND_SIZE;
+	u32 val[4] = {0};
+	int i, retval = 0;
+
+	while (max >= get_rnd_size) {
+		mtk_sec_get_rnd(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 mtk_sec_rng_probe(struct platform_device *pdev)
+{
+	struct mtk_sec_rng_priv *priv;
+	int ret;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->rng.name = pdev->name;
+	priv->rng.read = mtk_sec_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 mtk_sec_rng_match[] = {
+	{ .compatible = "mediatek,mtk-sec-rng", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, mtk_sec_rng_match);
+
+static struct platform_driver mtk_sec_rng_driver = {
+	.probe = mtk_sec_rng_probe,
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.owner = THIS_MODULE,
+		.of_match_table = mtk_sec_rng_match,
+	},
+};
+
+module_platform_driver(mtk_sec_rng_driver);
+
+MODULE_DESCRIPTION("MediaTek Security Random Number Generator Driver");
+MODULE_AUTHOR("Neal Liu <neal.liu@mediatek.com>");
+MODULE_LICENSE("GPL");