[PATCH v6 0/8] Add a random number generator uclass

[PATCH v6 0/8] Add a random number generator uclass

[Sughosh Ganu]

Add a random number generator(rng) uclass to facilitate adding drivers
for rng devices. I plan to add an implementation of the
EFI_RNG_PROTOCOL, which would get the random number from the rng
uclass -- the protocol would be used by the efi stub for getting a
random number for the kaslr feature.

The patch series also adds a driver for the rng device found on the
stm32mp1 and qemu platforms. A dummy rng driver for sandbox has also
been added, along with the unit test for the rng uclass.

Changes since V5:
* Handle review comments from Heinrich Schuchardt to read all the
  bytes requested in the individual drivers.

Changes since V4:
* Get the read functions of individual drivers to return number of
  bytes read on successful read, and a -ve value on error.
* Handle review comments from Heinrich Schuchardt.

Changes since V3:
* Handle review comments from Patrick Delaunay

Changes since V2:
* Add a driver for the virtio-rng device on qemu platform

Changes since V1:
* Add a SPDX header in rng.h
* Change the UCLASS_DRIVER name from hwrng to rng, consistent with the
  rest of the naming convention
* Handle review comment from Patrice Chotard


Sughosh Ganu (8):
  dm: rng: Add random number generator(rng) uclass
  clk: stm32mp1: Add a clock entry for RNG1 device
  stm32mp1: rng: Add a driver for random number generator(rng) device
  configs: stm32mp15: Enable random number generator(rng) device
  sandbox: rng: Add a random number generator(rng) driver
  configs: sandbox: Enable random number generator(rng) device
  test: rng: Add basic test for random number generator(rng) uclass
  virtio: rng: Add a random number generator(rng) driver

 arch/sandbox/dts/test.dts           |   4 +
 configs/sandbox64_defconfig         |   2 +
 configs/sandbox_defconfig           |   2 +
 configs/stm32mp15_basic_defconfig   |   2 +
 configs/stm32mp15_optee_defconfig   |   2 +
 configs/stm32mp15_trusted_defconfig |   2 +
 drivers/Kconfig                     |   2 +
 drivers/Makefile                    |   1 +
 drivers/clk/clk_stm32mp1.c          |   1 +
 drivers/rng/Kconfig                 |  22 +++++
 drivers/rng/Makefile                |   8 ++
 drivers/rng/rng-uclass.c            |  23 ++++++
 drivers/rng/sandbox_rng.c           |  56 +++++++++++++
 drivers/rng/stm32mp1_rng.c          | 161 ++++++++++++++++++++++++++++++++++++
 drivers/virtio/Kconfig              |   6 ++
 drivers/virtio/Makefile             |   1 +
 drivers/virtio/virtio-uclass.c      |   1 +
 drivers/virtio/virtio_rng.c         |  87 +++++++++++++++++++
 include/dm/uclass-id.h              |   1 +
 include/rng.h                       |  33 ++++++++
 include/virtio.h                    |   4 +-
 test/dm/Makefile                    |   1 +
 test/dm/rng.c                       |  26 ++++++
 23 files changed, 447 insertions(+), 1 deletion(-)
 create mode 100644 drivers/rng/Kconfig
 create mode 100644 drivers/rng/Makefile
 create mode 100644 drivers/rng/rng-uclass.c
 create mode 100644 drivers/rng/sandbox_rng.c
 create mode 100644 drivers/rng/stm32mp1_rng.c
 create mode 100644 drivers/virtio/virtio_rng.c
 create mode 100644 include/rng.h
 create mode 100644 test/dm/rng.c

-- 
2.7.4

[PATCH v6 1/8] dm: rng: Add random number generator(rng) uclass

[Sughosh Ganu]

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>
---
Changes since V5:
* Handle review comments from Heinrich Schuchardt to read all the
  bytes requested in the individual drivers.

 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..d54e3e0
--- /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_
+
+#include <dm.h>
+
+/**
+ * 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_ */
-- 
2.7.4

[PATCH v6 2/8] clk: stm32mp1: Add a clock entry for RNG1 device

[Sughosh Ganu]

Add an entry for allowing clock enablement for the random number
generator peripheral, RNG1.

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/clk/clk_stm32mp1.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/clk/clk_stm32mp1.c b/drivers/clk/clk_stm32mp1.c
index 3718970..da66bde 100644
--- a/drivers/clk/clk_stm32mp1.c
+++ b/drivers/clk/clk_stm32mp1.c
@@ -563,6 +563,7 @@ static const struct stm32mp1_clk_gate stm32mp1_clk_gate[] = {
 	STM32MP1_CLK_SET_CLR(RCC_MP_AHB4ENSETR, 10, GPIOK, _UNKNOWN_SEL),
 
 	STM32MP1_CLK_SET_CLR(RCC_MP_AHB5ENSETR, 0, GPIOZ, _UNKNOWN_SEL),
+	STM32MP1_CLK_SET_CLR(RCC_MP_AHB5ENSETR, 6, RNG1_K, _UNKNOWN_SEL),
 
 	STM32MP1_CLK_SET_CLR(RCC_MP_AHB6ENSETR, 7, ETHCK_K, _ETH_SEL),
 	STM32MP1_CLK_SET_CLR(RCC_MP_AHB6ENSETR, 8, ETHTX, _UNKNOWN_SEL),
-- 
2.7.4

[PATCH v6 3/8] stm32mp1: rng: Add a driver for random number generator(rng) device

[Sughosh Ganu]

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>
---
Changes since V5:
* Handle review comments from Heinrich Schuchardt to read all the
  bytes requested in the individual drivers.

 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,
+};
-- 
2.7.4

[PATCH v6 4/8] configs: stm32mp15: Enable random number generator(rng) device

[Sughosh Ganu]

Enable support for the rng device on the stm32mp15 configs.

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>
---
 configs/stm32mp15_basic_defconfig   | 2 ++
 configs/stm32mp15_optee_defconfig   | 2 ++
 configs/stm32mp15_trusted_defconfig | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/configs/stm32mp15_basic_defconfig b/configs/stm32mp15_basic_defconfig
index 713a7e6..c85369c 100644
--- a/configs/stm32mp15_basic_defconfig
+++ b/configs/stm32mp15_basic_defconfig
@@ -143,3 +143,5 @@ CONFIG_VIDEO_STM32_DSI=y
 CONFIG_VIDEO_STM32_MAX_XRES=1280
 CONFIG_VIDEO_STM32_MAX_YRES=800
 CONFIG_FDT_FIXUP_PARTITIONS=y
+CONFIG_DM_RNG=y
+CONFIG_RNG_STM32MP1=y
diff --git a/configs/stm32mp15_optee_defconfig b/configs/stm32mp15_optee_defconfig
index f9161fd..c192d8d 100644
--- a/configs/stm32mp15_optee_defconfig
+++ b/configs/stm32mp15_optee_defconfig
@@ -127,3 +127,5 @@ CONFIG_VIDEO_STM32_DSI=y
 CONFIG_VIDEO_STM32_MAX_XRES=1280
 CONFIG_VIDEO_STM32_MAX_YRES=800
 CONFIG_FDT_FIXUP_PARTITIONS=y
+CONFIG_DM_RNG=y
+CONFIG_RNG_STM32MP1=y
diff --git a/configs/stm32mp15_trusted_defconfig b/configs/stm32mp15_trusted_defconfig
index a5ea528..a846962 100644
--- a/configs/stm32mp15_trusted_defconfig
+++ b/configs/stm32mp15_trusted_defconfig
@@ -126,3 +126,5 @@ CONFIG_VIDEO_STM32_DSI=y
 CONFIG_VIDEO_STM32_MAX_XRES=1280
 CONFIG_VIDEO_STM32_MAX_YRES=800
 CONFIG_FDT_FIXUP_PARTITIONS=y
+CONFIG_DM_RNG=y
+CONFIG_RNG_STM32MP1=y
-- 
2.7.4

[PATCH v6 5/8] sandbox: rng: Add a random number generator(rng) driver

[Sughosh Ganu]

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>
---
Changes since V5:
* Handle review comments from Heinrich Schuchardt to read all the
  bytes requested in the individual drivers.

 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..2c85540 100644
--- a/arch/sandbox/dts/test.dts
+++ b/arch/sandbox/dts/test.dts
@@ -599,6 +599,10 @@
 		reset-names = "other", "test";
 	};
 
+	rng at 0 {
+		compatible = "sandbox,sandbox-rng";
+	};
+
 	rproc_1: rproc at 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,
+};
-- 
2.7.4

[PATCH v6 6/8] configs: sandbox: Enable random number generator(rng) device

[Sughosh Ganu]

Enable support for random number generator on sandbox configs. This is
aimed primarily at adding unit test support for rng uclass.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@st.com>
---
 configs/sandbox64_defconfig | 2 ++
 configs/sandbox_defconfig   | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/configs/sandbox64_defconfig b/configs/sandbox64_defconfig
index cc536ff..a21d832 100644
--- a/configs/sandbox64_defconfig
+++ b/configs/sandbox64_defconfig
@@ -158,6 +158,8 @@ CONFIG_REGULATOR_RK8XX=y
 CONFIG_REGULATOR_S5M8767=y
 CONFIG_DM_REGULATOR_SANDBOX=y
 CONFIG_REGULATOR_TPS65090=y
+CONFIG_DM_RNG=y
+CONFIG_RNG_SANDBOX=y
 CONFIG_DM_PWM=y
 CONFIG_PWM_SANDBOX=y
 CONFIG_RAM=y
diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
index 64245f7..9bdc0f5 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -179,6 +179,8 @@ CONFIG_REGULATOR_RK8XX=y
 CONFIG_REGULATOR_S5M8767=y
 CONFIG_DM_REGULATOR_SANDBOX=y
 CONFIG_REGULATOR_TPS65090=y
+CONFIG_DM_RNG=y
+CONFIG_RNG_SANDBOX=y
 CONFIG_DM_PWM=y
 CONFIG_PWM_SANDBOX=y
 CONFIG_RAM=y
-- 
2.7.4

[PATCH v6 7/8] test: rng: Add basic test for random number generator(rng) uclass

[Sughosh Ganu]

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>
---
* Change the test checking logic based on changes made in the sandbox
  rng driver, which returns 0 on a successful read.

 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);
-- 
2.7.4

[PATCH v6 8/8] virtio: rng: Add a random number generator(rng) driver

[Sughosh Ganu]

Add a driver for the virtio-rng device on the qemu platform. The
device uses pci as a transport medium. The driver can be enabled with
the following configs

CONFIG_VIRTIO
CONFIG_DM_RNG
CONFIG_VIRTIO_PCI
CONFIG_VIRTIO_RNG

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
---
* Handle review comments from Heinrich Schuchardt to read all the
  bytes requested in the individual drivers.

 drivers/virtio/Kconfig         |  6 +++
 drivers/virtio/Makefile        |  1 +
 drivers/virtio/virtio-uclass.c |  1 +
 drivers/virtio/virtio_rng.c    | 87 ++++++++++++++++++++++++++++++++++++++++++
 include/virtio.h               |  4 +-
 5 files changed, 98 insertions(+), 1 deletion(-)
 create mode 100644 drivers/virtio/virtio_rng.c

diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
index a9d5fd0..2e3dd3b 100644
--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
@@ -59,4 +59,10 @@ config VIRTIO_BLK
 	  This is the virtual block driver for virtio. It can be used with
 	  QEMU based targets.
 
+config VIRTIO_RNG
+       bool "virtio rng driver"
+       depends on VIRTIO
+       help
+         This is the virtual random number generator driver. It can be used
+	 with Qemu based targets.
 endmenu
diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile
index 4579044..dc88809 100644
--- a/drivers/virtio/Makefile
+++ b/drivers/virtio/Makefile
@@ -9,3 +9,4 @@ obj-$(CONFIG_VIRTIO_PCI) += virtio_pci_legacy.o virtio_pci_modern.o
 obj-$(CONFIG_VIRTIO_SANDBOX) += virtio_sandbox.o
 obj-$(CONFIG_VIRTIO_NET) += virtio_net.o
 obj-$(CONFIG_VIRTIO_BLK) += virtio_blk.o
+obj-$(CONFIG_VIRTIO_RNG) += virtio_rng.o
diff --git a/drivers/virtio/virtio-uclass.c b/drivers/virtio/virtio-uclass.c
index 34397d7..436faa4 100644
--- a/drivers/virtio/virtio-uclass.c
+++ b/drivers/virtio/virtio-uclass.c
@@ -24,6 +24,7 @@
 static const char *const virtio_drv_name[VIRTIO_ID_MAX_NUM] = {
 	[VIRTIO_ID_NET]		= VIRTIO_NET_DRV_NAME,
 	[VIRTIO_ID_BLOCK]	= VIRTIO_BLK_DRV_NAME,
+	[VIRTIO_ID_RNG]		= VIRTIO_RNG_DRV_NAME,
 };
 
 int virtio_get_config(struct udevice *vdev, unsigned int offset,
diff --git a/drivers/virtio/virtio_rng.c b/drivers/virtio/virtio_rng.c
new file mode 100644
index 0000000..f8c10bf
--- /dev/null
+++ b/drivers/virtio/virtio_rng.c
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2019, Linaro Limited
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <rng.h>
+#include <virtio_types.h>
+#include <virtio.h>
+#include <virtio_ring.h>
+
+struct virtio_rng_priv {
+	struct virtqueue *rng_vq;
+};
+
+static int virtio_rng_read(struct udevice *dev, void *data, size_t len)
+{
+	int ret;
+	unsigned int rsize = 0;
+	size_t nbytes = len;
+	unsigned char *buf = data;
+	struct virtio_sg sg;
+	struct virtio_sg *sgs[1];
+	struct virtio_rng_priv *priv = dev_get_priv(dev);
+
+	if (!len)
+		return 0;
+
+	do {
+		sg.addr = buf;
+		sg.length = nbytes;
+		sgs[0] = &sg;
+
+		ret = virtqueue_add(priv->rng_vq, sgs, 0, 1);
+		if (ret)
+			return ret;
+
+		virtqueue_kick(priv->rng_vq);
+
+		while (!virtqueue_get_buf(priv->rng_vq, &rsize))
+			;
+		nbytes -= rsize;
+		buf += rsize;
+	} while (nbytes != 0);
+
+	return 0;
+}
+
+static int virtio_rng_bind(struct udevice *dev)
+{
+	struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(dev->parent);
+
+	/* Indicate what driver features we support */
+	virtio_driver_features_init(uc_priv, NULL, 0, NULL, 0);
+
+	return 0;
+}
+
+static int virtio_rng_probe(struct udevice *dev)
+{
+	struct virtio_rng_priv *priv = dev_get_priv(dev);
+	int ret;
+
+	ret = virtio_find_vqs(dev, 1, &priv->rng_vq);
+	if (ret < 0) {
+		debug("%s: virtio_find_vqs failed\n", __func__);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct dm_rng_ops virtio_rng_ops = {
+	.read	= virtio_rng_read,
+};
+
+U_BOOT_DRIVER(virtio_rng) = {
+	.name	= VIRTIO_RNG_DRV_NAME,
+	.id	= UCLASS_RNG,
+	.bind	= virtio_rng_bind,
+	.probe	= virtio_rng_probe,
+	.remove = virtio_reset,
+	.ops	= &virtio_rng_ops,
+	.priv_auto_alloc_size = sizeof(struct virtio_rng_priv),
+	.flags	= DM_FLAG_ACTIVE_DMA,
+};
diff --git a/include/virtio.h b/include/virtio.h
index 654fdf1..561dcc3 100644
--- a/include/virtio.h
+++ b/include/virtio.h
@@ -22,10 +22,12 @@
 
 #define VIRTIO_ID_NET		1 /* virtio net */
 #define VIRTIO_ID_BLOCK		2 /* virtio block */
-#define VIRTIO_ID_MAX_NUM	3
+#define VIRTIO_ID_RNG		4 /* virtio rng */
+#define VIRTIO_ID_MAX_NUM	5
 
 #define VIRTIO_NET_DRV_NAME	"virtio-net"
 #define VIRTIO_BLK_DRV_NAME	"virtio-blk"
+#define VIRTIO_RNG_DRV_NAME	"virtio-rng"
 
 /* Status byte for guest to report progress, and synchronize features */
 
-- 
2.7.4

[PATCH v6 8/8] virtio: rng: Add a random number generator(rng) driver

[Heinrich Schuchardt]

On 12/27/19 3:23 PM, Sughosh Ganu wrote:
> Add a driver for the virtio-rng device on the qemu platform. The
> device uses pci as a transport medium. The driver can be enabled with
> the following configs
>
> CONFIG_VIRTIO
> CONFIG_DM_RNG
> CONFIG_VIRTIO_PCI
> CONFIG_VIRTIO_RNG
>
> Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> ---
> * Handle review comments from Heinrich Schuchardt to read all the
>    bytes requested in the individual drivers.
>
>   drivers/virtio/Kconfig         |  6 +++
>   drivers/virtio/Makefile        |  1 +
>   drivers/virtio/virtio-uclass.c |  1 +
>   drivers/virtio/virtio_rng.c    | 87 ++++++++++++++++++++++++++++++++++++++++++
>   include/virtio.h               |  4 +-
>   5 files changed, 98 insertions(+), 1 deletion(-)
>   create mode 100644 drivers/virtio/virtio_rng.c
>
> diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
> index a9d5fd0..2e3dd3b 100644
> --- a/drivers/virtio/Kconfig
> +++ b/drivers/virtio/Kconfig
> @@ -59,4 +59,10 @@ config VIRTIO_BLK
>   	  This is the virtual block driver for virtio. It can be used with
>   	  QEMU based targets.
>
> +config VIRTIO_RNG
> +       bool "virtio rng driver"
> +       depends on VIRTIO
> +       help
> +         This is the virtual random number generator driver. It can be used
> +	 with Qemu based targets.
>   endmenu
> diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile
> index 4579044..dc88809 100644
> --- a/drivers/virtio/Makefile
> +++ b/drivers/virtio/Makefile
> @@ -9,3 +9,4 @@ obj-$(CONFIG_VIRTIO_PCI) += virtio_pci_legacy.o virtio_pci_modern.o
>   obj-$(CONFIG_VIRTIO_SANDBOX) += virtio_sandbox.o
>   obj-$(CONFIG_VIRTIO_NET) += virtio_net.o
>   obj-$(CONFIG_VIRTIO_BLK) += virtio_blk.o
> +obj-$(CONFIG_VIRTIO_RNG) += virtio_rng.o
> diff --git a/drivers/virtio/virtio-uclass.c b/drivers/virtio/virtio-uclass.c
> index 34397d7..436faa4 100644
> --- a/drivers/virtio/virtio-uclass.c
> +++ b/drivers/virtio/virtio-uclass.c
> @@ -24,6 +24,7 @@
>   static const char *const virtio_drv_name[VIRTIO_ID_MAX_NUM] = {
>   	[VIRTIO_ID_NET]		= VIRTIO_NET_DRV_NAME,
>   	[VIRTIO_ID_BLOCK]	= VIRTIO_BLK_DRV_NAME,
> +	[VIRTIO_ID_RNG]		= VIRTIO_RNG_DRV_NAME,
>   };
>
>   int virtio_get_config(struct udevice *vdev, unsigned int offset,
> diff --git a/drivers/virtio/virtio_rng.c b/drivers/virtio/virtio_rng.c
> new file mode 100644
> index 0000000..f8c10bf
> --- /dev/null
> +++ b/drivers/virtio/virtio_rng.c
> @@ -0,0 +1,87 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (c) 2019, Linaro Limited
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <rng.h>
> +#include <virtio_types.h>
> +#include <virtio.h>
> +#include <virtio_ring.h>
> +
> +struct virtio_rng_priv {
> +	struct virtqueue *rng_vq;
> +};
> +
> +static int virtio_rng_read(struct udevice *dev, void *data, size_t len)
> +{
> +	int ret;
> +	unsigned int rsize = 0;
> +	size_t nbytes = len;
> +	unsigned char *buf = data;
> +	struct virtio_sg sg;
> +	struct virtio_sg *sgs[1];
> +	struct virtio_rng_priv *priv = dev_get_priv(dev);
> +
> +	if (!len)
> +		return 0;
> +
> +	do {
> +		sg.addr = buf;

As described in the response to an earlier version of the patch the
address passed as sg.addr has to be 4 byte aligned because
virtqueue_get_buf() internally copies u32.

With

     qemu-system-aarch64 -M virt \
     -device virtio-rng-pci,disable-legacy=on,max-bytes=15,period=1000

sg.addr will not even be 4 byte aligned if data is 4 byte aligned.

So if QEMU some day will correctly emulate alignment traps this function
may lead to a crash.

So I would prefer to use a local variable as buffer and then copy the
random bytes from the buffer to data. See suggestion below.

Best regards

Heinrich

#define BUFFER_SIZE 16UL

static int virtio_rng_read(struct udevice *dev, void *data, size_t len)
{
	int ret;
	unsigned int rsize = 0;
	unsigned char buf[BUFFER_SIZE];
	unsigned char *ptr = data;
	struct virtio_sg sg;
	struct virtio_sg *sgs = sg;
	struct virtio_rng_priv *priv = dev_get_priv(dev);

	while (len) {
		sg.addr = buf;
		sg.length = min(BUFFER_SIZE, len);

		ret = virtqueue_add(priv->rng_vq, &sgs, 0, 1);
		if (ret)
			return ret;

		virtqueue_kick(priv->rng_vq);

		while (!virtqueue_get_buf(priv->rng_vq, &rsize))
			;
		memcpy(ptr, buf, rsize);
		len -= rsize;
		ptr += rsize;
	}

	return 0;
}

> +		sg.length = nbytes;
> +		sgs[0] = &sg;
> +
> +		ret = virtqueue_add(priv->rng_vq, sgs, 0, 1);
> +		if (ret)
> +			return ret;
> +
> +		virtqueue_kick(priv->rng_vq);
> +
> +		while (!virtqueue_get_buf(priv->rng_vq, &rsize))
> +			;
> +		nbytes -= rsize;
> +		buf += rsize;
> +	} while (nbytes != 0);
> +
> +	return 0;
> +}
> +
> +static int virtio_rng_bind(struct udevice *dev)
> +{
> +	struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(dev->parent);
> +
> +	/* Indicate what driver features we support */
> +	virtio_driver_features_init(uc_priv, NULL, 0, NULL, 0);
> +
> +	return 0;
> +}
> +
> +static int virtio_rng_probe(struct udevice *dev)
> +{
> +	struct virtio_rng_priv *priv = dev_get_priv(dev);
> +	int ret;
> +
> +	ret = virtio_find_vqs(dev, 1, &priv->rng_vq);
> +	if (ret < 0) {
> +		debug("%s: virtio_find_vqs failed\n", __func__);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct dm_rng_ops virtio_rng_ops = {
> +	.read	= virtio_rng_read,
> +};
> +
> +U_BOOT_DRIVER(virtio_rng) = {
> +	.name	= VIRTIO_RNG_DRV_NAME,
> +	.id	= UCLASS_RNG,
> +	.bind	= virtio_rng_bind,
> +	.probe	= virtio_rng_probe,
> +	.remove = virtio_reset,
> +	.ops	= &virtio_rng_ops,
> +	.priv_auto_alloc_size = sizeof(struct virtio_rng_priv),
> +	.flags	= DM_FLAG_ACTIVE_DMA,
> +};
> diff --git a/include/virtio.h b/include/virtio.h
> index 654fdf1..561dcc3 100644
> --- a/include/virtio.h
> +++ b/include/virtio.h
> @@ -22,10 +22,12 @@
>
>   #define VIRTIO_ID_NET		1 /* virtio net */
>   #define VIRTIO_ID_BLOCK		2 /* virtio block */
> -#define VIRTIO_ID_MAX_NUM	3
> +#define VIRTIO_ID_RNG		4 /* virtio rng */
> +#define VIRTIO_ID_MAX_NUM	5
>
>   #define VIRTIO_NET_DRV_NAME	"virtio-net"
>   #define VIRTIO_BLK_DRV_NAME	"virtio-blk"
> +#define VIRTIO_RNG_DRV_NAME	"virtio-rng"
>
>   /* Status byte for guest to report progress, and synchronize features */
>
>

[PATCH v6 7/8] test: rng: Add basic test for random number generator(rng) uclass

[Heinrich Schuchardt]

On 12/27/19 3:23 PM, Sughosh Ganu wrote:
> 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: Heinrich Schuchardt <xypron.glpk@gmx.de>

[PATCH v6 6/8] configs: sandbox: Enable random number generator(rng) device

[Heinrich Schuchardt]

On 12/27/19 3:23 PM, Sughosh Ganu wrote:
> Enable support for random number generator on sandbox configs. This is
> aimed primarily at adding unit test support for rng uclass.
>
> Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
> Reviewed-by: Patrick Delaunay <patrick.delaunay@st.com>

Why do you exclude:

* configs/sandbox_flattree_defconfig,
* configs/sandbox_spl_defconfig?

Best regards

Heinrich

> ---
>   configs/sandbox64_defconfig | 2 ++
>   configs/sandbox_defconfig   | 2 ++
>   2 files changed, 4 insertions(+)
>
> diff --git a/configs/sandbox64_defconfig b/configs/sandbox64_defconfig
> index cc536ff..a21d832 100644
> --- a/configs/sandbox64_defconfig
> +++ b/configs/sandbox64_defconfig
> @@ -158,6 +158,8 @@ CONFIG_REGULATOR_RK8XX=y
>   CONFIG_REGULATOR_S5M8767=y
>   CONFIG_DM_REGULATOR_SANDBOX=y
>   CONFIG_REGULATOR_TPS65090=y
> +CONFIG_DM_RNG=y
> +CONFIG_RNG_SANDBOX=y
>   CONFIG_DM_PWM=y
>   CONFIG_PWM_SANDBOX=y
>   CONFIG_RAM=y
> diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
> index 64245f7..9bdc0f5 100644
> --- a/configs/sandbox_defconfig
> +++ b/configs/sandbox_defconfig
> @@ -179,6 +179,8 @@ CONFIG_REGULATOR_RK8XX=y
>   CONFIG_REGULATOR_S5M8767=y
>   CONFIG_DM_REGULATOR_SANDBOX=y
>   CONFIG_REGULATOR_TPS65090=y
> +CONFIG_DM_RNG=y
> +CONFIG_RNG_SANDBOX=y
>   CONFIG_DM_PWM=y
>   CONFIG_PWM_SANDBOX=y
>   CONFIG_RAM=y
>

[PATCH v6 5/8] sandbox: rng: Add a random number generator(rng) driver

[Heinrich Schuchardt]

On 12/27/19 3:23 PM, Sughosh Ganu wrote:
> 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>
> ---
> Changes since V5:
> * Handle review comments from Heinrich Schuchardt to read all the
>    bytes requested in the individual drivers.
>
>   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..2c85540 100644
> --- a/arch/sandbox/dts/test.dts
> +++ b/arch/sandbox/dts/test.dts

I would suggest to add the RNG to the other sandbox device trees as well.

> @@ -599,6 +599,10 @@
>   		reset-names = "other", "test";
>   	};
>
> +	rng at 0 {
> +		compatible = "sandbox,sandbox-rng";

The device tree compiler complains about this:

$ dtc -I dtb -O dts ./arch/sandbox/dts/test.dtb

<stdout>: Warning (unit_address_vs_reg):
/rng at 0: node has a unit name, but no reg property
<stdout>: Warning (unique_unit_address):
/rng at 0: duplicate unit-address (also used in node /usb at 0)

Best regards

Heinrich

> +	};
> +
>   	rproc_1: rproc at 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,
> +};
>

[PATCH v6 1/8] dm: rng: Add random number generator(rng) uclass

[Heinrich Schuchardt]

On 12/27/19 3:23 PM, Sughosh Ganu wrote:
> 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>

[PATCH v6 0/8] Add a random number generator uclass

[Heinrich Schuchardt]

On 12/27/19 3:23 PM, Sughosh Ganu wrote:
> Add a random number generator(rng) uclass to facilitate adding drivers
> for rng devices. I plan to add an implementation of the
> EFI_RNG_PROTOCOL, which would get the random number from the rng
> uclass -- the protocol would be used by the efi stub for getting a
> random number for the kaslr feature.
>
> The patch series also adds a driver for the rng device found on the
> stm32mp1 and qemu platforms. A dummy rng driver for sandbox has also
> been added, along with the unit test for the rng uclass.

Who shall be the maintainer for the RNG sub-system of U-Boot?

Sughosh do you want to volunteer?

Otherwise as this development is driven by the wish to implement the
EFI_RNG_PROTOCOL I could pick it up.

Best regards

Heinrich

[PATCH v6 8/8] virtio: rng: Add a random number generator(rng) driver

[Heinrich Schuchardt]

On 12/28/19 7:09 AM, Heinrich Schuchardt wrote:
> #define BUFFER_SIZE 16UL
> 
> static int virtio_rng_read(struct udevice *dev, void *data, size_t len)
> {
>      int ret;
>      unsigned int rsize = 0;
>      unsigned char buf[BUFFER_SIZE];

This should be
	unsigned char buf[BUFFER_SIZE] __aligned(4);

>      unsigned char *ptr = data;
>      struct virtio_sg sg;
>      struct virtio_sg *sgs = sg;
>      struct virtio_rng_priv *priv = dev_get_priv(dev);
> 
>      while (len) {
>          sg.addr = buf;
>          sg.length = min(BUFFER_SIZE, len);
> 
>          ret = virtqueue_add(priv->rng_vq, &sgs, 0, 1);
>          if (ret)
>              return ret;
> 
>          virtqueue_kick(priv->rng_vq);
> 
>          while (!virtqueue_get_buf(priv->rng_vq, &rsize))
>              ;
>          memcpy(ptr, buf, rsize);
>          len -= rsize;
>          ptr += rsize;
>      }
> 
>      return 0;
> }

[PATCH v6 6/8] configs: sandbox: Enable random number generator(rng) device

[Sughosh Ganu]

On Sat, 28 Dec 2019 at 11:55, Heinrich Schuchardt <xypron.glpk@gmx.de>
wrote:

> On 12/27/19 3:23 PM, Sughosh Ganu wrote:
> > Enable support for random number generator on sandbox configs. This is
> > aimed primarily at adding unit test support for rng uclass.
> >
> > Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> > Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
> > Reviewed-by: Patrick Delaunay <patrick.delaunay@st.com>
>
> Why do you exclude:
>
> * configs/sandbox_flattree_defconfig,
> * configs/sandbox_spl_defconfig?
>

This was primarily aimed at adding a unit test for rng on a 32 bit and 64
bit target. Do you think adding support for rng on the two additional
targets is adding any value. I don't have a strong opinion on this. If you
think that i should enable rng on the two additional targets as well, i
will do so.

Also, can you also review the patch for adding efi_rng_protocol support on
qemu arm64 platform[1]. Once you have, i will make the changes and send
the updated version.

-sughosh

[1] - https://lists.denx.de/pipermail/u-boot/2019-December/394665.html

[PATCH v6 5/8] sandbox: rng: Add a random number generator(rng) driver

[Sughosh Ganu]

On Sat, 28 Dec 2019 at 12:53, Heinrich Schuchardt <xypron.glpk@gmx.de>
wrote:

> On 12/27/19 3:23 PM, Sughosh Ganu wrote:
> > 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>
> > ---
> > Changes since V5:
> > * Handle review comments from Heinrich Schuchardt to read all the
> >    bytes requested in the individual drivers.
> >
> >   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..2c85540 100644
> > --- a/arch/sandbox/dts/test.dts
> > +++ b/arch/sandbox/dts/test.dts
>
> I would suggest to add the RNG to the other sandbox device trees as well.
>

Can this not be added when there is an actual use of the rng device on any
sandbox targets. Currently, the only use on sandbox is for running a unit
test for rng uclass.


> > @@ -599,6 +599,10 @@
> >               reset-names = "other", "test";
> >       };
> >
> > +     rng at 0 {
> > +             compatible = "sandbox,sandbox-rng";
>
> The device tree compiler complains about this:
>
> $ dtc -I dtb -O dts ./arch/sandbox/dts/test.dtb
>
> <stdout>: Warning (unit_address_vs_reg):
> /rng at 0: node has a unit name, but no reg property
> <stdout>: Warning (unique_unit_address):
> /rng at 0: duplicate unit-address (also used in node /usb at 0)
>

Will take a look.

-sughosh

[PATCH v6 6/8] configs: sandbox: Enable random number generator(rng) device

[Heinrich Schuchardt]

On 12/28/19 12:07 PM, Sughosh Ganu wrote:
>
> On Sat, 28 Dec 2019 at 11:55, Heinrich Schuchardt <xypron.glpk@gmx.de
> <mailto:xypron.glpk@gmx.de>> wrote:
>
>     On 12/27/19 3:23 PM, Sughosh Ganu wrote:
>      > Enable support for random number generator on sandbox configs.
>     This is
>      > aimed primarily at adding unit test support for rng uclass.
>      >
>      > Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org
>     <mailto:sughosh.ganu@linaro.org>>
>      > Reviewed-by: Patrice Chotard <patrice.chotard@st.com
>     <mailto:patrice.chotard@st.com>>
>      > Reviewed-by: Patrick Delaunay <patrick.delaunay@st.com
>     <mailto:patrick.delaunay@st.com>>
>
>     Why do you exclude:
>
>     * configs/sandbox_flattree_defconfig,
>     * configs/sandbox_spl_defconfig?
>
>
> This was primarily aimed at adding a unit test for rng on a 32 bit and
> 64 bit target. Do you think adding support for rng on the two additional
> targets is adding any value. I don't have a strong opinion on this. If
> you think that i should enable rng on the two additional targets as
> well, i will do so.
>
> Also, can you also review the patch for adding efi_rng_protocol support
> on qemu arm64 platform[1]. Once you have, i will make the changes and
> send  the updated version.
>
> -sughosh

I think we should add the RNT device to all configs so that we can test
in any of the contexts. But is nothing that would stop me from accepting
the patch series. We can add this later too.

Best regards

Heinrich

>
> [1] - https://lists.denx.de/pipermail/u-boot/2019-December/394665.html

[PATCH v6 6/8] configs: sandbox: Enable random number generator(rng) device

[Simon Glass]

Hi,

On Sat, 28 Dec 2019 at 06:21, Heinrich Schuchardt <xypron.glpk@gmx.de> wrote:
>
> On 12/28/19 12:07 PM, Sughosh Ganu wrote:
> >
> > On Sat, 28 Dec 2019 at 11:55, Heinrich Schuchardt <xypron.glpk@gmx.de
> > <mailto:xypron.glpk@gmx.de>> wrote:
> >
> >     On 12/27/19 3:23 PM, Sughosh Ganu wrote:
> >      > Enable support for random number generator on sandbox configs.
> >     This is
> >      > aimed primarily at adding unit test support for rng uclass.
> >      >
> >      > Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org
> >     <mailto:sughosh.ganu@linaro.org>>
> >      > Reviewed-by: Patrice Chotard <patrice.chotard@st.com
> >     <mailto:patrice.chotard@st.com>>
> >      > Reviewed-by: Patrick Delaunay <patrick.delaunay@st.com
> >     <mailto:patrick.delaunay@st.com>>
> >
> >     Why do you exclude:
> >
> >     * configs/sandbox_flattree_defconfig,
> >     * configs/sandbox_spl_defconfig?
> >
> >
> > This was primarily aimed at adding a unit test for rng on a 32 bit and
> > 64 bit target. Do you think adding support for rng on the two additional
> > targets is adding any value. I don't have a strong opinion on this. If
> > you think that i should enable rng on the two additional targets as
> > well, i will do so.
> >
> > Also, can you also review the patch for adding efi_rng_protocol support
> > on qemu arm64 platform[1]. Once you have, i will make the changes and
> > send  the updated version.
> >
> > -sughosh
>
> I think we should add the RNT device to all configs so that we can test
> in any of the contexts. But is nothing that would stop me from accepting
> the patch series. We can add this later too.

I don't really mind either way. But sandbox_flattree and sandbox_spl
are there to check specific things:

sandbox_flattree - checks operation without live device tree
sandbox_spl - checks a few SPL-related things

They are often excluded when new options are added.

Regards,
Simon

[PATCH v6 0/8] Add a random number generator uclass

[Sughosh Ganu]

On Sat, 28 Dec 2019 at 13:22, Heinrich Schuchardt <xypron.glpk@gmx.de>
wrote:

> On 12/27/19 3:23 PM, Sughosh Ganu wrote:
> > Add a random number generator(rng) uclass to facilitate adding drivers
> > for rng devices. I plan to add an implementation of the
> > EFI_RNG_PROTOCOL, which would get the random number from the rng
> > uclass -- the protocol would be used by the efi stub for getting a
> > random number for the kaslr feature.
> >
> > The patch series also adds a driver for the rng device found on the
> > stm32mp1 and qemu platforms. A dummy rng driver for sandbox has also
> > been added, along with the unit test for the rng uclass.
>
> Who shall be the maintainer for the RNG sub-system of U-Boot?
>
> Sughosh do you want to volunteer?
>

How about i co-maintain this with you. Do you think this is fine. Please
let me know.

-sughosh

[PATCH v6 0/8] Add a random number generator uclass

[Heinrich Schuchardt]

On 12/31/19 3:56 AM, Sughosh Ganu wrote:
>
> On Sat, 28 Dec 2019 at 13:22, Heinrich Schuchardt <xypron.glpk@gmx.de
> <mailto:xypron.glpk@gmx.de>> wrote:
>
>     On 12/27/19 3:23 PM, Sughosh Ganu wrote:
>      > Add a random number generator(rng) uclass to facilitate adding
>     drivers
>      > for rng devices. I plan to add an implementation of the
>      > EFI_RNG_PROTOCOL, which would get the random number from the rng
>      > uclass -- the protocol would be used by the efi stub for getting a
>      > random number for the kaslr feature.
>      >
>      > The patch series also adds a driver for the rng device found on the
>      > stm32mp1 and qemu platforms. A dummy rng driver for sandbox has also
>      > been added, along with the unit test for the rng uclass.
>
>     Who shall be the maintainer for the RNG sub-system of U-Boot?
>
>     Sughosh do you want to volunteer?
>
>
> How about i co-maintain this with you. Do you think this is fine. Please
> let me know.

I think one maintainer is enough and I am fine if you volunteer.

Wolfgang can create a repository for you on gitlab.denx.de.

Afterwards you can create a patch to add the information to the
MAINTAINERS file, e.g.

RNG
M:      Sughosh Ganu <sughosh.ganu@linaro.org>
S:      Maintained
T:      git https://gitlab.denx.de/u-boot/custodians/u-boot-rng.git
F:      drivers/rng/
F:      drivers/virtio/virtio_rng.c

If you want me to review:

RNG
M:      Sughosh Ganu <sughosh.ganu@linaro.org>
R:	Heinrich Schuchardt <xypron.glpk@gmx.de>
S:      Maintained
T:      git https://gitlab.denx.de/u-boot/custodians/u-boot-rng.git
F:      drivers/rng/
F:      drivers/virtio/virtio_rng.c

Best regards

Heinrich

[PATCH v6 0/8] Add a random number generator uclass

[Sughosh Ganu]

On Tue, 31 Dec 2019 at 12:38, Heinrich Schuchardt <xypron.glpk@gmx.de>
wrote:

> On 12/31/19 3:56 AM, Sughosh Ganu wrote:
> >
> > On Sat, 28 Dec 2019 at 13:22, Heinrich Schuchardt <xypron.glpk@gmx.de
> > <mailto:xypron.glpk@gmx.de>> wrote:
> >
> >     On 12/27/19 3:23 PM, Sughosh Ganu wrote:
> >      > Add a random number generator(rng) uclass to facilitate adding
> >     drivers
> >      > for rng devices. I plan to add an implementation of the
> >      > EFI_RNG_PROTOCOL, which would get the random number from the rng
> >      > uclass -- the protocol would be used by the efi stub for getting a
> >      > random number for the kaslr feature.
> >      >
> >      > The patch series also adds a driver for the rng device found on
> the
> >      > stm32mp1 and qemu platforms. A dummy rng driver for sandbox has
> also
> >      > been added, along with the unit test for the rng uclass.
> >
> >     Who shall be the maintainer for the RNG sub-system of U-Boot?
> >
> >     Sughosh do you want to volunteer?
> >
> >
> > How about i co-maintain this with you. Do you think this is fine. Please
> > let me know.
>
> I think one maintainer is enough and I am fine if you volunteer.
>
> Wolfgang can create a repository for you on gitlab.denx.de.
>
> Afterwards you can create a patch to add the information to the
> MAINTAINERS file, e.g.
>
> RNG
> M:      Sughosh Ganu <sughosh.ganu@linaro.org>
> S:      Maintained
> T:      git https://gitlab.denx.de/u-boot/custodians/u-boot-rng.git
> F:      drivers/rng/
> F:      drivers/virtio/virtio_rng.c
>
> If you want me to review:
>
> RNG
> M:      Sughosh Ganu <sughosh.ganu@linaro.org>
> R:      Heinrich Schuchardt <xypron.glpk@gmx.de>
> S:      Maintained
> T:      git https://gitlab.denx.de/u-boot/custodians/u-boot-rng.git
> F:      drivers/rng/
> F:      drivers/virtio/virtio_rng.c
>

Ok. Will take it up then, with you as the reviewer.

-sughosh