[PATCH v2] hwrng: histb - Move driver to drivers/char/hw_random/histb-rng.c

From: David Yang
Date: Fri Apr 21 2023 - 13:00:24 EST

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Move to drivers/char/hw_random since histb-(t)rng does not provide
cryptography pseudo rng.

histb-rng is pretty like hisi-rng, but after investigation, we confirm
there is no RNG_PHY_SEED register on histb-rng so a separate driver is
needed.

Still we rename relevant function names to match those in hisi-rng.

Link: https://lore.kernel.org/r/20230401164448.1393336-1-mmyangfl@xxxxxxxxx
Signed-off-by: David Yang <mmyangfl@xxxxxxxxx>
---
v2: drop the dependency on HW_RANDOM
drivers/char/hw_random/Kconfig | 11 +++
drivers/char/hw_random/Makefile | 1 +
.../trng-stb.c => char/hw_random/histb-rng.c} | 83 +++++++++----------
drivers/crypto/hisilicon/Kconfig | 7 --
drivers/crypto/hisilicon/Makefile | 2 +-
drivers/crypto/hisilicon/trng/Makefile | 3 -
6 files changed, 53 insertions(+), 54 deletions(-)
rename drivers/{crypto/hisilicon/trng/trng-stb.c => char/hw_random/histb-rng.c} (53%)

diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 4fdf07ae3c54..c92f146ee89a 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -335,6 +335,17 @@ config HW_RANDOM_HISI

If unsure, say Y.

+config HW_RANDOM_HISTB
+ tristate "Hisilicon STB Random Number Generator support"
+ depends on ARCH_HISI || COMPILE_TEST
+ default ARCH_HISI
+ help
+ This driver provides kernel-side support for the Random Number
+ Generator hardware found on Hisilicon Hi37xx SoC.
+
+ To compile this driver as a module, choose M here: the
+ module will be called histb-rng.
+
config HW_RANDOM_ST
tristate "ST Microelectronics HW Random Number Generator support"
depends on HW_RANDOM && ARCH_STI
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index 09bde4a0f971..32549a1186dc 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_HW_RANDOM_NOMADIK) += nomadik-rng.o
obj-$(CONFIG_HW_RANDOM_PSERIES) += pseries-rng.o
obj-$(CONFIG_HW_RANDOM_POWERNV) += powernv-rng.o
obj-$(CONFIG_HW_RANDOM_HISI) += hisi-rng.o
+obj-$(CONFIG_HW_RANDOM_HISTB) += histb-rng.o
obj-$(CONFIG_HW_RANDOM_BCM2835) += bcm2835-rng.o
obj-$(CONFIG_HW_RANDOM_IPROC_RNG200) += iproc-rng200.o
obj-$(CONFIG_HW_RANDOM_ST) += st-rng.o
diff --git a/drivers/crypto/hisilicon/trng/trng-stb.c b/drivers/char/hw_random/histb-rng.c
similarity index 53%
rename from drivers/crypto/hisilicon/trng/trng-stb.c
rename to drivers/char/hw_random/histb-rng.c
index 29200a7d3d81..f652e1135e4b 100644
--- a/drivers/crypto/hisilicon/trng/trng-stb.c
+++ b/drivers/char/hw_random/histb-rng.c
@@ -1,31 +1,27 @@
// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
/*
- * Device driver for True RNG in HiSTB SoCs
- *
* Copyright (c) 2023 David Yang
*/

-#include <crypto/internal/rng.h>
-#include <linux/device.h>
#include <linux/err.h>
#include <linux/hw_random.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
#include <linux/module.h>
-#include <linux/mutex.h>
-#include <linux/of_device.h>
+#include <linux/platform_device.h>

-#define HISTB_TRNG_CTRL 0x0
+#define RNG_CTRL 0x0
#define RNG_SOURCE GENMASK(1, 0)
#define DROP_ENABLE BIT(5)
#define POST_PROCESS_ENABLE BIT(7)
#define POST_PROCESS_DEPTH GENMASK(15, 8)
-#define HISTB_TRNG_NUMBER 0x4
-#define HISTB_TRNG_STAT 0x8
+#define RNG_NUMBER 0x4
+#define RNG_STAT 0x8
#define DATA_COUNT GENMASK(2, 0) /* max 4 */

-struct histb_trng_priv {
+struct histb_rng_priv {
struct hwrng rng;
void __iomem *base;
};
@@ -35,19 +31,19 @@ struct histb_trng_priv {
* depth = 1 -> ~1ms
* depth = 255 -> ~16ms
*/
-static int histb_trng_wait(void __iomem *base)
+static int histb_rng_wait(void __iomem *base)
{
u32 val;

- return readl_relaxed_poll_timeout(base + HISTB_TRNG_STAT, val,
+ return readl_relaxed_poll_timeout(base + RNG_STAT, val,
val & DATA_COUNT, 1000, 30 * 1000);
}

-static void histb_trng_init(void __iomem *base, unsigned int depth)
+static void histb_rng_init(void __iomem *base, unsigned int depth)
{
u32 val;

- val = readl_relaxed(base + HISTB_TRNG_CTRL);
+ val = readl_relaxed(base + RNG_CTRL);

val &= ~RNG_SOURCE;
val |= 2;
@@ -58,72 +54,72 @@ static void histb_trng_init(void __iomem *base, unsigned int depth)
val |= POST_PROCESS_ENABLE;
val |= DROP_ENABLE;

- writel_relaxed(val, base + HISTB_TRNG_CTRL);
+ writel_relaxed(val, base + RNG_CTRL);
}

-static int histb_trng_read(struct hwrng *rng, void *data, size_t max, bool wait)
+static int histb_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
{
- struct histb_trng_priv *priv = container_of(rng, typeof(*priv), rng);
+ struct histb_rng_priv *priv = container_of(rng, typeof(*priv), rng);
void __iomem *base = priv->base;

for (int i = 0; i < max; i += sizeof(u32)) {
- if (!(readl_relaxed(base + HISTB_TRNG_STAT) & DATA_COUNT)) {
+ if (!(readl_relaxed(base + RNG_STAT) & DATA_COUNT)) {
if (!wait)
return i;
- if (histb_trng_wait(base)) {
+ if (histb_rng_wait(base)) {
pr_err("failed to generate random number, generated %d\n",
i);
return i ? i : -ETIMEDOUT;
}
}
- *(u32 *) (data + i) = readl_relaxed(base + HISTB_TRNG_NUMBER);
+ *(u32 *) (data + i) = readl_relaxed(base + RNG_NUMBER);
}

return max;
}

-static unsigned int histb_trng_get_depth(void __iomem *base)
+static unsigned int histb_rng_get_depth(void __iomem *base)
{
- return (readl_relaxed(base + HISTB_TRNG_CTRL) & POST_PROCESS_DEPTH) >> 8;
+ return (readl_relaxed(base + RNG_CTRL) & POST_PROCESS_DEPTH) >> 8;
}

static ssize_t
depth_show(struct device *dev, struct device_attribute *attr, char *buf)
{
- struct histb_trng_priv *priv = dev_get_drvdata(dev);
+ struct histb_rng_priv *priv = dev_get_drvdata(dev);
void __iomem *base = priv->base;

- return sprintf(buf, "%d\n", histb_trng_get_depth(base));
+ return sprintf(buf, "%d\n", histb_rng_get_depth(base));
}

static ssize_t
depth_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
- struct histb_trng_priv *priv = dev_get_drvdata(dev);
+ struct histb_rng_priv *priv = dev_get_drvdata(dev);
void __iomem *base = priv->base;
unsigned int depth;

if (kstrtouint(buf, 0, &depth))
return -ERANGE;

- histb_trng_init(base, depth);
+ histb_rng_init(base, depth);
return count;
}

static DEVICE_ATTR_RW(depth);

-static struct attribute *histb_trng_attrs[] = {
+static struct attribute *histb_rng_attrs[] = {
&dev_attr_depth.attr,
NULL,
};

-ATTRIBUTE_GROUPS(histb_trng);
+ATTRIBUTE_GROUPS(histb_rng);

-static int histb_trng_probe(struct platform_device *pdev)
+static int histb_rng_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
- struct histb_trng_priv *priv;
+ struct histb_rng_priv *priv;
void __iomem *base;
int ret;

@@ -133,17 +129,17 @@ static int histb_trng_probe(struct platform_device *pdev)

base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(base))
- return -ENOMEM;
+ return PTR_ERR(base);

- histb_trng_init(base, 144);
- if (histb_trng_wait(base)) {
+ histb_rng_init(base, 144);
+ if (histb_rng_wait(base)) {
dev_err(dev, "cannot bring up device\n");
return -ENODEV;
}

priv->base = base;
priv->rng.name = pdev->name;
- priv->rng.read = histb_trng_read;
+ priv->rng.read = histb_rng_read;
ret = devm_hwrng_register(dev, &priv->rng);
if (ret) {
dev_err(dev, "failed to register hwrng: %d\n", ret);
@@ -155,22 +151,23 @@ static int histb_trng_probe(struct platform_device *pdev)
return 0;
}

-static const struct of_device_id histb_trng_of_match[] = {
- { .compatible = "hisilicon,histb-trng", },
+static const struct of_device_id histb_rng_of_match[] = {
+ { .compatible = "hisilicon,histb-rng", },
{ }
};
+MODULE_DEVICE_TABLE(of, histb_rng_of_match);

-static struct platform_driver histb_trng_driver = {
- .probe = histb_trng_probe,
+static struct platform_driver histb_rng_driver = {
+ .probe = histb_rng_probe,
.driver = {
- .name = "histb-trng",
- .of_match_table = histb_trng_of_match,
- .dev_groups = histb_trng_groups,
+ .name = "histb-rng",
+ .of_match_table = histb_rng_of_match,
+ .dev_groups = histb_rng_groups,
},
};

-module_platform_driver(histb_trng_driver);
+module_platform_driver(histb_rng_driver);

-MODULE_DESCRIPTION("HiSTB True RNG");
+MODULE_DESCRIPTION("Hisilicon STB random number generator driver");
MODULE_LICENSE("Dual MIT/GPL");
MODULE_AUTHOR("David Yang <mmyangfl@xxxxxxxxx>");
diff --git a/drivers/crypto/hisilicon/Kconfig b/drivers/crypto/hisilicon/Kconfig
index e8690c223584..4137a8bf131f 100644
--- a/drivers/crypto/hisilicon/Kconfig
+++ b/drivers/crypto/hisilicon/Kconfig
@@ -82,10 +82,3 @@ config CRYPTO_DEV_HISI_TRNG
select CRYPTO_RNG
help
Support for HiSilicon TRNG Driver.
-
-config CRYPTO_DEV_HISTB_TRNG
- tristate "Support for HiSTB TRNG Driver"
- depends on ARCH_HISI || COMPILE_TEST
- select HW_RANDOM
- help
- Support for HiSTB TRNG Driver.
diff --git a/drivers/crypto/hisilicon/Makefile b/drivers/crypto/hisilicon/Makefile
index fc51e0edec69..8595a5a5d228 100644
--- a/drivers/crypto/hisilicon/Makefile
+++ b/drivers/crypto/hisilicon/Makefile
@@ -5,4 +5,4 @@ obj-$(CONFIG_CRYPTO_DEV_HISI_SEC2) += sec2/
obj-$(CONFIG_CRYPTO_DEV_HISI_QM) += hisi_qm.o
hisi_qm-objs = qm.o sgl.o debugfs.o
obj-$(CONFIG_CRYPTO_DEV_HISI_ZIP) += zip/
-obj-y += trng/
+obj-$(CONFIG_CRYPTO_DEV_HISI_TRNG) += trng/
diff --git a/drivers/crypto/hisilicon/trng/Makefile b/drivers/crypto/hisilicon/trng/Makefile
index cf20b057c66b..d909079f351c 100644
--- a/drivers/crypto/hisilicon/trng/Makefile
+++ b/drivers/crypto/hisilicon/trng/Makefile
@@ -1,5 +1,2 @@
obj-$(CONFIG_CRYPTO_DEV_HISI_TRNG) += hisi-trng-v2.o
hisi-trng-v2-objs = trng.o
-
-obj-$(CONFIG_CRYPTO_DEV_HISTB_TRNG) += histb-trng.o
-histb-trng-objs += trng-stb.o
--
2.39.2

Next message: Vipin Sharma: "[PATCH 7/9] KVM: mmu: Move mmu lock/unlock to arch code for clear dirty log"
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