[PATCH] hwrng: add Zhaoxin HW RNG driver

[PATCH] hwrng: add Zhaoxin HW RNG driver

[LeoLiu-oc]

From: leoliu-oc <leoliu-oc@zhaoxin.com>

Add support for Zhaoxin HW RNG.

Signed-off-by: leoliu-oc <leoliu-oc@zhaoxin.com>
---
 drivers/char/hw_random/Kconfig       |  13 +++
 drivers/char/hw_random/Makefile      |   1 +
 drivers/char/hw_random/via-rng.c     |  17 ++--
 drivers/char/hw_random/zhaoxin-rng.c | 116 +++++++++++++++++++++++++++
 4 files changed, 139 insertions(+), 8 deletions(-)
 create mode 100644 drivers/char/hw_random/zhaoxin-rng.c

diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index e0b3786ca51b..3b3c00e87b7b 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -150,6 +150,19 @@ config HW_RANDOM_VIA
 
 	  If unsure, say Y.
 
+config HW_RANDOM_ZHAOXIN
+	tristate "Zhaoxin HW Random Number Generator support"
+	depends on X86
+	default HW_RANDOM
+	help
+	  This driver provides kernel-side support for the Random Number
+	  Generator hardware found on Zhaoxin based motherboards.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called zhaoxin-rng.
+
+	  If unsure, say Y.
+
 config HW_RANDOM_IXP4XX
 	tristate "Intel IXP4xx NPU HW Pseudo-Random Number Generator support"
 	depends on ARCH_IXP4XX || COMPILE_TEST
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index 32549a1186dc..ef5b3ae0794d 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_HW_RANDOM_GEODE) += geode-rng.o
 obj-$(CONFIG_HW_RANDOM_N2RNG) += n2-rng.o
 n2-rng-y := n2-drv.o n2-asm.o
 obj-$(CONFIG_HW_RANDOM_VIA) += via-rng.o
+obj-$(CONFIG_HW_RANDOM_ZHAOXIN) += zhaoxin-rng.o
 obj-$(CONFIG_HW_RANDOM_EXYNOS) += exynos-trng.o
 obj-$(CONFIG_HW_RANDOM_IXP4XX) += ixp4xx-rng.o
 obj-$(CONFIG_HW_RANDOM_OMAP) += omap-rng.o
diff --git a/drivers/char/hw_random/via-rng.c b/drivers/char/hw_random/via-rng.c
index a9a0a3b09c8b..33a6e2fdacd1 100644
--- a/drivers/char/hw_random/via-rng.c
+++ b/drivers/char/hw_random/via-rng.c
@@ -135,7 +135,7 @@ static int via_rng_init(struct hwrng *rng)
 	 * is always enabled if CPUID rng_en is set.  There is no
 	 * RNG configuration like it used to be the case in this
 	 * register */
-	if (((c->x86 == 6) && (c->x86_model >= 0x0f))  || (c->x86 > 6)){
+	if ((c->x86 == 6) && (c->x86_model >= 0x0f)) {
 		if (!boot_cpu_has(X86_FEATURE_XSTORE_EN)) {
 			pr_err(PFX "can't enable hardware RNG "
 				"if XSTORE is not enabled\n");
@@ -191,13 +191,20 @@ static struct hwrng via_rng = {
 	.data_read	= via_rng_data_read,
 };
 
+static const struct x86_cpu_id via_rng_cpu_ids[] = {
+	X86_MATCH_VENDOR_FAM_FEATURE(CENTAUR, 6, X86_FEATURE_XSTORE, NULL),
+	{}
+};
+MODULE_DEVICE_TABLE(x86cpu, via_rng_cpu_ids);
 
 static int __init via_rng_mod_init(void)
 {
 	int err;
 
-	if (!boot_cpu_has(X86_FEATURE_XSTORE))
+	if (!x86_match_cpu(via_rng_cpu_ids)) {
+		pr_err(PFX "The CPU isn't support XSTORE.\n");
 		return -ENODEV;
+	}
 
 	pr_info("VIA RNG detected\n");
 	err = hwrng_register(&via_rng);
@@ -217,11 +224,5 @@ static void __exit via_rng_mod_exit(void)
 }
 module_exit(via_rng_mod_exit);
 
-static struct x86_cpu_id __maybe_unused via_rng_cpu_id[] = {
-	X86_MATCH_FEATURE(X86_FEATURE_XSTORE, NULL),
-	{}
-};
-MODULE_DEVICE_TABLE(x86cpu, via_rng_cpu_id);
-
 MODULE_DESCRIPTION("H/W RNG driver for VIA CPU with PadLock");
 MODULE_LICENSE("GPL");
diff --git a/drivers/char/hw_random/zhaoxin-rng.c b/drivers/char/hw_random/zhaoxin-rng.c
new file mode 100644
index 000000000000..2e657b227c5b
--- /dev/null
+++ b/drivers/char/hw_random/zhaoxin-rng.c
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * RNG driver for Zhaoxin RNGs
+ *
+ * Copyright 2005 (c) MontaVista Software, Inc.
+ *
+ * with the majority of the code coming from:
+ *
+ * Hardware driver for the Intel/AMD/VIA Random Number Generators (RNG)
+ * (c) Copyright 2003 Red Hat Inc <jgarzik@redhat.com>
+ *
+ * derived from
+ *
+ * Hardware driver for the AMD 768 Random Number Generator (RNG)
+ * (c) Copyright 2001 Red Hat Inc
+ *
+ * derived from
+ *
+ * Hardware driver for Intel i810 Random Number Generator (RNG)
+ * Copyright 2000,2001 Jeff Garzik <jgarzik@pobox.com>
+ * Copyright 2000,2001 Philipp Rumpf <prumpf@mandrakesoft.com>
+ *
+ * This file is licensed under  the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <crypto/padlock.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/hw_random.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/cpufeature.h>
+#include <asm/cpu_device_id.h>
+#include <asm/fpu/api.h>
+
+enum {
+	ZHAOXIN_RNG_CHUNK_8		= 0x00, /* 64 rand bits, 64 stored bits*/
+	ZHAOXIN_RNG_CHUNK_4		= 0x01, /* 32 rand bits, 32 stored bits */
+	ZHAOXIN_RNG_CHUNK_2		= 0x02, /* 16 rand bits, 32 stored bits */
+	ZHAOXIN_RNG_CHUNK_1		= 0x03, /* 8 rand bits, 32 stored bits */
+	ZHAOXIN_RNG_MAX_SIZE		= (128*1024),
+};
+
+static int zhaoxin_rng_init(struct hwrng *rng)
+{
+	if (!boot_cpu_has(X86_FEATURE_XSTORE_EN)) {
+		pr_err(PFX "can't enable hardware RNG if XSTORE is not enabled\n");
+		return -ENODEV;
+	}
+	return 0;
+}
+
+static inline int rep_xstore(size_t size, size_t factor, void *result)
+{
+	__asm__ __volatile__ (
+	"movq %0, %%rcx\n"
+	"movq %1, %%rdx\n"
+	"movq %2, %%rdi\n"
+	".byte 0xf3, 0x0f, 0xa7, 0xc0"
+	:
+	: "r"(size), "r"(factor), "r"(result)
+	: "%rcx", "%rdx", "%rdi", "memory");
+
+	return 0;
+}
+
+static int zhaoxin_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
+{
+	if (max > ZHAOXIN_RNG_MAX_SIZE)
+		max = ZHAOXIN_RNG_MAX_SIZE;
+	rep_xstore(max, ZHAOXIN_RNG_CHUNK_1, data);
+	return max;
+}
+
+static struct hwrng zhaoxin_rng = {
+	.name   = "zhaoxin",
+	.init   = zhaoxin_rng_init,
+	.read   = zhaoxin_rng_read,
+};
+
+static const struct x86_cpu_id zhaoxin_rng_cpu_ids[] = {
+	X86_MATCH_VENDOR_FAM_FEATURE(ZHAOXIN, 6, X86_FEATURE_XSTORE, NULL),
+	X86_MATCH_VENDOR_FAM_FEATURE(ZHAOXIN, 7, X86_FEATURE_XSTORE, NULL),
+	X86_MATCH_VENDOR_FAM_FEATURE(CENTAUR, 7, X86_FEATURE_XSTORE, NULL),
+	{}
+};
+MODULE_DEVICE_TABLE(x86cpu, zhaoxin_rng_cpu_ids);
+
+static int __init zhaoxin_rng_mod_init(void)
+{
+	int err;
+
+	if (!x86_match_cpu(zhaoxin_rng_cpu_ids)) {
+		pr_err(PFX "The CPU isn't support XSTORE.\n");
+		return -ENODEV;
+	}
+
+	pr_info("Zhaoxin RNG detected\n");
+	err = hwrng_register(&zhaoxin_rng);
+	if (err)
+		pr_err(PFX "RNG registering failed (%d)\n", err);
+
+	return err;
+}
+module_init(zhaoxin_rng_mod_init);
+
+static void __exit zhaoxin_rng_mod_exit(void)
+{
+	hwrng_unregister(&zhaoxin_rng);
+}
+module_exit(zhaoxin_rng_mod_exit);
+MODULE_DESCRIPTION("H/W RNG driver for Zhaoxin CPU");
+MODULE_AUTHOR("YunShen@zhaoxin.com");
+MODULE_LICENSE("GPL");
-- 
2.34.1

Re: [PATCH] hwrng: add Zhaoxin HW RNG driver

[Martin Kaiser]

Hi,

some quick remarks. Feel free to correct me if I misunderstood
something.

LeoLiu-oc (LeoLiu-oc@zhaoxin.com) wrote:

> From: leoliu-oc <leoliu-oc@zhaoxin.com>

> Add support for Zhaoxin HW RNG.

> Signed-off-by: leoliu-oc <leoliu-oc@zhaoxin.com>
> ---
>  drivers/char/hw_random/Kconfig       |  13 +++
>  drivers/char/hw_random/Makefile      |   1 +
>  drivers/char/hw_random/via-rng.c     |  17 ++--
>  drivers/char/hw_random/zhaoxin-rng.c | 116 +++++++++++++++++++++++++++
>  4 files changed, 139 insertions(+), 8 deletions(-)
>  create mode 100644 drivers/char/hw_random/zhaoxin-rng.c

> diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
> index e0b3786ca51b..3b3c00e87b7b 100644
> --- a/drivers/char/hw_random/Kconfig
> +++ b/drivers/char/hw_random/Kconfig
> @@ -150,6 +150,19 @@ config HW_RANDOM_VIA

>  	  If unsure, say Y.

> +config HW_RANDOM_ZHAOXIN
> +	tristate "Zhaoxin HW Random Number Generator support"
> +	depends on X86

depends on X86 || COMPILE_TEST

> +	default HW_RANDOM
> +	help
> +	  This driver provides kernel-side support for the Random Number
> +	  Generator hardware found on Zhaoxin based motherboards.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called zhaoxin-rng.
> +
> +	  If unsure, say Y.
> +
>  config HW_RANDOM_IXP4XX
>  	tristate "Intel IXP4xx NPU HW Pseudo-Random Number Generator support"
>  	depends on ARCH_IXP4XX || COMPILE_TEST
> diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
> index 32549a1186dc..ef5b3ae0794d 100644
> --- a/drivers/char/hw_random/Makefile
> +++ b/drivers/char/hw_random/Makefile
> @@ -14,6 +14,7 @@ obj-$(CONFIG_HW_RANDOM_GEODE) += geode-rng.o
>  obj-$(CONFIG_HW_RANDOM_N2RNG) += n2-rng.o
>  n2-rng-y := n2-drv.o n2-asm.o
>  obj-$(CONFIG_HW_RANDOM_VIA) += via-rng.o
> +obj-$(CONFIG_HW_RANDOM_ZHAOXIN) += zhaoxin-rng.o
>  obj-$(CONFIG_HW_RANDOM_EXYNOS) += exynos-trng.o
>  obj-$(CONFIG_HW_RANDOM_IXP4XX) += ixp4xx-rng.o
>  obj-$(CONFIG_HW_RANDOM_OMAP) += omap-rng.o
> diff --git a/drivers/char/hw_random/via-rng.c b/drivers/char/hw_random/via-rng.c
> index a9a0a3b09c8b..33a6e2fdacd1 100644
> --- a/drivers/char/hw_random/via-rng.c
> +++ b/drivers/char/hw_random/via-rng.c
> @@ -135,7 +135,7 @@ static int via_rng_init(struct hwrng *rng)
>  	 * is always enabled if CPUID rng_en is set.  There is no
>  	 * RNG configuration like it used to be the case in this
>  	 * register */
> -	if (((c->x86 == 6) && (c->x86_model >= 0x0f))  || (c->x86 > 6)){
> +	if ((c->x86 == 6) && (c->x86_model >= 0x0f)) {
>  		if (!boot_cpu_has(X86_FEATURE_XSTORE_EN)) {
>  			pr_err(PFX "can't enable hardware RNG "
>  				"if XSTORE is not enabled\n");
> @@ -191,13 +191,20 @@ static struct hwrng via_rng = {
>  	.data_read	= via_rng_data_read,
>  };

> +static const struct x86_cpu_id via_rng_cpu_ids[] = {
> +	X86_MATCH_VENDOR_FAM_FEATURE(CENTAUR, 6, X86_FEATURE_XSTORE, NULL),
> +	{}
> +};
> +MODULE_DEVICE_TABLE(x86cpu, via_rng_cpu_ids);

>  static int __init via_rng_mod_init(void)
>  {
>  	int err;

> -	if (!boot_cpu_has(X86_FEATURE_XSTORE))
> +	if (!x86_match_cpu(via_rng_cpu_ids)) {
> +		pr_err(PFX "The CPU isn't support XSTORE.\n");

doesn't support

Generally: Should we print an error message if our driver doesn't
support this cpu? It seems that most other callers of x86_match_cpu
simply return without an error message.

>  		return -ENODEV;
> +	}

>  	pr_info("VIA RNG detected\n");
>  	err = hwrng_register(&via_rng);
> @@ -217,11 +224,5 @@ static void __exit via_rng_mod_exit(void)
>  }
>  module_exit(via_rng_mod_exit);

> -static struct x86_cpu_id __maybe_unused via_rng_cpu_id[] = {
> -	X86_MATCH_FEATURE(X86_FEATURE_XSTORE, NULL),
> -	{}
> -};
> -MODULE_DEVICE_TABLE(x86cpu, via_rng_cpu_id);
> -
>  MODULE_DESCRIPTION("H/W RNG driver for VIA CPU with PadLock");
>  MODULE_LICENSE("GPL");
> diff --git a/drivers/char/hw_random/zhaoxin-rng.c b/drivers/char/hw_random/zhaoxin-rng.c
> new file mode 100644
> index 000000000000..2e657b227c5b
> --- /dev/null
> +++ b/drivers/char/hw_random/zhaoxin-rng.c
> @@ -0,0 +1,116 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * RNG driver for Zhaoxin RNGs
> + *
> + * Copyright 2005 (c) MontaVista Software, Inc.

Should this be Copyright 2023 by you?

> + *
> + * with the majority of the code coming from:
> + *
> + * Hardware driver for the Intel/AMD/VIA Random Number Generators (RNG)
> + * (c) Copyright 2003 Red Hat Inc <jgarzik@redhat.com>
> + *
> + * derived from
> + *
> + * Hardware driver for the AMD 768 Random Number Generator (RNG)
> + * (c) Copyright 2001 Red Hat Inc
> + *
> + * derived from
> + *
> + * Hardware driver for Intel i810 Random Number Generator (RNG)
> + * Copyright 2000,2001 Jeff Garzik <jgarzik@pobox.com>
> + * Copyright 2000,2001 Philipp Rumpf <prumpf@mandrakesoft.com>
> + *
> + * This file is licensed under  the terms of the GNU General Public
> + * License version 2. This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#include <crypto/padlock.h>
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/hw_random.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/cpufeature.h>
> +#include <asm/cpu_device_id.h>
> +#include <asm/fpu/api.h>
> +
> +enum {
> +	ZHAOXIN_RNG_CHUNK_8		= 0x00, /* 64 rand bits, 64 stored bits*/
> +	ZHAOXIN_RNG_CHUNK_4		= 0x01, /* 32 rand bits, 32 stored bits */
> +	ZHAOXIN_RNG_CHUNK_2		= 0x02, /* 16 rand bits, 32 stored bits */
> +	ZHAOXIN_RNG_CHUNK_1		= 0x03, /* 8 rand bits, 32 stored bits */
> +	ZHAOXIN_RNG_MAX_SIZE		= (128*1024),
> +};
> +
> +static int zhaoxin_rng_init(struct hwrng *rng)
> +{
> +	if (!boot_cpu_has(X86_FEATURE_XSTORE_EN)) {
> +		pr_err(PFX "can't enable hardware RNG if XSTORE is not enabled\n");
> +		return -ENODEV;
> +	}

Can't we check this when the driver is loaded? (This init function here
is called when the rng becomes active.)

> +	return 0;
> +}
> +
> +static inline int rep_xstore(size_t size, size_t factor, void *result)
> +{
> +	__asm__ __volatile__ (
> +	"movq %0, %%rcx\n"
> +	"movq %1, %%rdx\n"
> +	"movq %2, %%rdi\n"
> +	".byte 0xf3, 0x0f, 0xa7, 0xc0"
> +	:
> +	: "r"(size), "r"(factor), "r"(result)
> +	: "%rcx", "%rdx", "%rdi", "memory");
> +
> +	return 0;
> +}
> +
> +static int zhaoxin_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
> +{
> +	if (max > ZHAOXIN_RNG_MAX_SIZE)
> +		max = ZHAOXIN_RNG_MAX_SIZE;
> +	rep_xstore(max, ZHAOXIN_RNG_CHUNK_1, data);
> +	return max;
> +}
> +
> +static struct hwrng zhaoxin_rng = {
> +	.name   = "zhaoxin",
> +	.init   = zhaoxin_rng_init,
> +	.read   = zhaoxin_rng_read,
> +};
> +
> +static const struct x86_cpu_id zhaoxin_rng_cpu_ids[] = {
> +	X86_MATCH_VENDOR_FAM_FEATURE(ZHAOXIN, 6, X86_FEATURE_XSTORE, NULL),
> +	X86_MATCH_VENDOR_FAM_FEATURE(ZHAOXIN, 7, X86_FEATURE_XSTORE, NULL),
> +	X86_MATCH_VENDOR_FAM_FEATURE(CENTAUR, 7, X86_FEATURE_XSTORE, NULL),
> +	{}
> +};
> +MODULE_DEVICE_TABLE(x86cpu, zhaoxin_rng_cpu_ids);
> +
> +static int __init zhaoxin_rng_mod_init(void)
> +{
> +	int err;
> +
> +	if (!x86_match_cpu(zhaoxin_rng_cpu_ids)) {
> +		pr_err(PFX "The CPU isn't support XSTORE.\n");

Yet again, is this really an error?

> +		return -ENODEV;
> +	}
> +
> +	pr_info("Zhaoxin RNG detected\n");
> +	err = hwrng_register(&zhaoxin_rng);
> +	if (err)
> +		pr_err(PFX "RNG registering failed (%d)\n", err);
> +
> +	return err;
> +}
> +module_init(zhaoxin_rng_mod_init);
> +
> +static void __exit zhaoxin_rng_mod_exit(void)
> +{
> +	hwrng_unregister(&zhaoxin_rng);
> +}
> +module_exit(zhaoxin_rng_mod_exit);
> +MODULE_DESCRIPTION("H/W RNG driver for Zhaoxin CPU");
> +MODULE_AUTHOR("YunShen@zhaoxin.com");
> +MODULE_LICENSE("GPL");
> -- 
> 2.34.1

Best regards,
Martin

Re: [PATCH] hwrng: add Zhaoxin HW RNG driver

[LeoLiu-oc]

在 2023/7/26 20:13, Martin Kaiser 写道:
> Hi,
> 
> some quick remarks. Feel free to correct me if I misunderstood
> something.
> 
Thank you very much for your advice, I will fix them in the next version.

> LeoLiu-oc (LeoLiu-oc@zhaoxin.com) wrote:
> 
>> From: leoliu-oc <leoliu-oc@zhaoxin.com>
> 
>> Add support for Zhaoxin HW RNG.
> 
>> Signed-off-by: leoliu-oc <leoliu-oc@zhaoxin.com>
>> ---
>>   drivers/char/hw_random/Kconfig       |  13 +++
>>   drivers/char/hw_random/Makefile      |   1 +
>>   drivers/char/hw_random/via-rng.c     |  17 ++--
>>   drivers/char/hw_random/zhaoxin-rng.c | 116 +++++++++++++++++++++++++++
>>   4 files changed, 139 insertions(+), 8 deletions(-)
>>   create mode 100644 drivers/char/hw_random/zhaoxin-rng.c
> 
>> diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
>> index e0b3786ca51b..3b3c00e87b7b 100644
>> --- a/drivers/char/hw_random/Kconfig
>> +++ b/drivers/char/hw_random/Kconfig
>> @@ -150,6 +150,19 @@ config HW_RANDOM_VIA
> 
>>   	  If unsure, say Y.
> 
>> +config HW_RANDOM_ZHAOXIN
>> +	tristate "Zhaoxin HW Random Number Generator support"
>> +	depends on X86
> 
> depends on X86 || COMPILE_TEST >
Thanks for your advice. I will add it in the next version.

>> +	default HW_RANDOM
>> +	help
>> +	  This driver provides kernel-side support for the Random Number
>> +	  Generator hardware found on Zhaoxin based motherboards.
>> +
>> +	  To compile this driver as a module, choose M here: the
>> +	  module will be called zhaoxin-rng.
>> +
>> +	  If unsure, say Y.
>> +
>>   config HW_RANDOM_IXP4XX
>>   	tristate "Intel IXP4xx NPU HW Pseudo-Random Number Generator support"
>>   	depends on ARCH_IXP4XX || COMPILE_TEST
>> diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
>> index 32549a1186dc..ef5b3ae0794d 100644
>> --- a/drivers/char/hw_random/Makefile
>> +++ b/drivers/char/hw_random/Makefile
>> @@ -14,6 +14,7 @@ obj-$(CONFIG_HW_RANDOM_GEODE) += geode-rng.o
>>   obj-$(CONFIG_HW_RANDOM_N2RNG) += n2-rng.o
>>   n2-rng-y := n2-drv.o n2-asm.o
>>   obj-$(CONFIG_HW_RANDOM_VIA) += via-rng.o
>> +obj-$(CONFIG_HW_RANDOM_ZHAOXIN) += zhaoxin-rng.o
>>   obj-$(CONFIG_HW_RANDOM_EXYNOS) += exynos-trng.o
>>   obj-$(CONFIG_HW_RANDOM_IXP4XX) += ixp4xx-rng.o
>>   obj-$(CONFIG_HW_RANDOM_OMAP) += omap-rng.o
>> diff --git a/drivers/char/hw_random/via-rng.c b/drivers/char/hw_random/via-rng.c
>> index a9a0a3b09c8b..33a6e2fdacd1 100644
>> --- a/drivers/char/hw_random/via-rng.c
>> +++ b/drivers/char/hw_random/via-rng.c
>> @@ -135,7 +135,7 @@ static int via_rng_init(struct hwrng *rng)
>>   	 * is always enabled if CPUID rng_en is set.  There is no
>>   	 * RNG configuration like it used to be the case in this
>>   	 * register */
>> -	if (((c->x86 == 6) && (c->x86_model >= 0x0f))  || (c->x86 > 6)){
>> +	if ((c->x86 == 6) && (c->x86_model >= 0x0f)) {
>>   		if (!boot_cpu_has(X86_FEATURE_XSTORE_EN)) {
>>   			pr_err(PFX "can't enable hardware RNG "
>>   				"if XSTORE is not enabled\n");
>> @@ -191,13 +191,20 @@ static struct hwrng via_rng = {
>>   	.data_read	= via_rng_data_read,
>>   };
> 
>> +static const struct x86_cpu_id via_rng_cpu_ids[] = {
>> +	X86_MATCH_VENDOR_FAM_FEATURE(CENTAUR, 6, X86_FEATURE_XSTORE, NULL),
>> +	{}
>> +};
>> +MODULE_DEVICE_TABLE(x86cpu, via_rng_cpu_ids);
> 
>>   static int __init via_rng_mod_init(void)
>>   {
>>   	int err;
> 
>> -	if (!boot_cpu_has(X86_FEATURE_XSTORE))
>> +	if (!x86_match_cpu(via_rng_cpu_ids)) {
>> +		pr_err(PFX "The CPU isn't support XSTORE.\n");
> 
> doesn't support
> 
> Generally: Should we print an error message if our driver doesn't
> support this cpu? It seems that most other callers of x86_match_cpu
> simply return without an error message.
>Agree with you. I will remove it in the next version.

>>   		return -ENODEV;
>> +	}
> 
>>   	pr_info("VIA RNG detected\n");
>>   	err = hwrng_register(&via_rng);
>> @@ -217,11 +224,5 @@ static void __exit via_rng_mod_exit(void)
>>   }
>>   module_exit(via_rng_mod_exit);
> 
>> -static struct x86_cpu_id __maybe_unused via_rng_cpu_id[] = {
>> -	X86_MATCH_FEATURE(X86_FEATURE_XSTORE, NULL),
>> -	{}
>> -};
>> -MODULE_DEVICE_TABLE(x86cpu, via_rng_cpu_id);
>> -
>>   MODULE_DESCRIPTION("H/W RNG driver for VIA CPU with PadLock");
>>   MODULE_LICENSE("GPL");
>> diff --git a/drivers/char/hw_random/zhaoxin-rng.c b/drivers/char/hw_random/zhaoxin-rng.c
>> new file mode 100644
>> index 000000000000..2e657b227c5b
>> --- /dev/null
>> +++ b/drivers/char/hw_random/zhaoxin-rng.c
>> @@ -0,0 +1,116 @@
>> +// SPDX-License-Identifier: GPL-2.0-or-later
>> +/*
>> + * RNG driver for Zhaoxin RNGs
>> + *
>> + * Copyright 2005 (c) MontaVista Software, Inc.
> 
> Should this be Copyright 2023 by you? >
OK, I will add Copyright information correctly in the next version.

>> + *
>> + * with the majority of the code coming from:
>> + *
>> + * Hardware driver for the Intel/AMD/VIA Random Number Generators (RNG)
>> + * (c) Copyright 2003 Red Hat Inc <jgarzik@redhat.com>
>> + *
>> + * derived from
>> + *
>> + * Hardware driver for the AMD 768 Random Number Generator (RNG)
>> + * (c) Copyright 2001 Red Hat Inc
>> + *
>> + * derived from
>> + *
>> + * Hardware driver for Intel i810 Random Number Generator (RNG)
>> + * Copyright 2000,2001 Jeff Garzik <jgarzik@pobox.com>
>> + * Copyright 2000,2001 Philipp Rumpf <prumpf@mandrakesoft.com>
>> + *
>> + * This file is licensed under  the terms of the GNU General Public
>> + * License version 2. This program is licensed "as is" without any
>> + * warranty of any kind, whether express or implied.
>> + */
>> +
>> +#include <crypto/padlock.h>
>> +#include <linux/module.h>
>> +#include <linux/kernel.h>
>> +#include <linux/hw_random.h>
>> +#include <linux/delay.h>
>> +#include <linux/io.h>
>> +#include <linux/cpufeature.h>
>> +#include <asm/cpu_device_id.h>
>> +#include <asm/fpu/api.h>
>> +
>> +enum {
>> +	ZHAOXIN_RNG_CHUNK_8		= 0x00, /* 64 rand bits, 64 stored bits*/
>> +	ZHAOXIN_RNG_CHUNK_4		= 0x01, /* 32 rand bits, 32 stored bits */
>> +	ZHAOXIN_RNG_CHUNK_2		= 0x02, /* 16 rand bits, 32 stored bits */
>> +	ZHAOXIN_RNG_CHUNK_1		= 0x03, /* 8 rand bits, 32 stored bits */
>> +	ZHAOXIN_RNG_MAX_SIZE		= (128*1024),
>> +};
>> +
>> +static int zhaoxin_rng_init(struct hwrng *rng)
>> +{
>> +	if (!boot_cpu_has(X86_FEATURE_XSTORE_EN)) {
>> +		pr_err(PFX "can't enable hardware RNG if XSTORE is not enabled\n");
>> +		return -ENODEV;
>> +	}
> 
> Can't we check this when the driver is loaded? (This init function here
> is called when the rng becomes active.) >
The XSTORE feature has two related macro definitions,X86_FEATURE_XSTORE 
and X86_FEATURE_XSTORE_EN.Indicates that the XSTORE feature is present 
and enabled,respectively. X86_FEATURE_XSTORE has been checked when the 
driver is loaded. X86_FEATURE_XSTORE_EN is placed in the init function 
to check whether it is enabled.

This is also a reference to other driver, such as via-rng.c.

>> +	return 0;
>> +}
>> +
>> +static inline int rep_xstore(size_t size, size_t factor, void *result)
>> +{
>> +	__asm__ __volatile__ (
>> +	"movq %0, %%rcx\n"
>> +	"movq %1, %%rdx\n"
>> +	"movq %2, %%rdi\n"
>> +	".byte 0xf3, 0x0f, 0xa7, 0xc0"
>> +	:
>> +	: "r"(size), "r"(factor), "r"(result)
>> +	: "%rcx", "%rdx", "%rdi", "memory");
>> +
>> +	return 0;
>> +}
>> +
>> +static int zhaoxin_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
>> +{
>> +	if (max > ZHAOXIN_RNG_MAX_SIZE)
>> +		max = ZHAOXIN_RNG_MAX_SIZE;
>> +	rep_xstore(max, ZHAOXIN_RNG_CHUNK_1, data);
>> +	return max;
>> +}
>> +
>> +static struct hwrng zhaoxin_rng = {
>> +	.name   = "zhaoxin",
>> +	.init   = zhaoxin_rng_init,
>> +	.read   = zhaoxin_rng_read,
>> +};
>> +
>> +static const struct x86_cpu_id zhaoxin_rng_cpu_ids[] = {
>> +	X86_MATCH_VENDOR_FAM_FEATURE(ZHAOXIN, 6, X86_FEATURE_XSTORE, NULL),
>> +	X86_MATCH_VENDOR_FAM_FEATURE(ZHAOXIN, 7, X86_FEATURE_XSTORE, NULL),
>> +	X86_MATCH_VENDOR_FAM_FEATURE(CENTAUR, 7, X86_FEATURE_XSTORE, NULL),
>> +	{}
>> +};
>> +MODULE_DEVICE_TABLE(x86cpu, zhaoxin_rng_cpu_ids);
>> +
>> +static int __init zhaoxin_rng_mod_init(void)
>> +{
>> +	int err;
>> +
>> +	if (!x86_match_cpu(zhaoxin_rng_cpu_ids)) {
>> +		pr_err(PFX "The CPU isn't support XSTORE.\n");
> 
> Yet again, is this really an error?
> 
Yes, as discussed above. I will fix it in the next version.

>> +		return -ENODEV;
>> +	}
>> +
>> +	pr_info("Zhaoxin RNG detected\n");
>> +	err = hwrng_register(&zhaoxin_rng);
>> +	if (err)
>> +		pr_err(PFX "RNG registering failed (%d)\n", err);
>> +
>> +	return err;
>> +}
>> +module_init(zhaoxin_rng_mod_init);
>> +
>> +static void __exit zhaoxin_rng_mod_exit(void)
>> +{
>> +	hwrng_unregister(&zhaoxin_rng);
>> +}
>> +module_exit(zhaoxin_rng_mod_exit);
>> +MODULE_DESCRIPTION("H/W RNG driver for Zhaoxin CPU");
>> +MODULE_AUTHOR("YunShen@zhaoxin.com");
>> +MODULE_LICENSE("GPL");
>> -- 
>> 2.34.1
> 
> Best regards,
> Martin

Re: [PATCH] hwrng: add Zhaoxin HW RNG driver

[kernel test robot]

Hi LeoLiu-oc,

kernel test robot noticed the following build errors:

[auto build test ERROR on char-misc/char-misc-testing]
[also build test ERROR on char-misc/char-misc-next char-misc/char-misc-linus herbert-cryptodev-2.6/master linus/master v6.5-rc3 next-20230726]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/LeoLiu-oc/hwrng-add-Zhaoxin-HW-RNG-driver/20230726-193710
base:   char-misc/char-misc-testing
patch link:    https://lore.kernel.org/r/20230726113553.1965627-1-LeoLiu-oc%40zhaoxin.com
patch subject: [PATCH] hwrng: add Zhaoxin HW RNG driver
config: i386-randconfig-r006-20230726 (https://download.01.org/0day-ci/archive/20230727/202307270707.SlAbd4tx-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce: (https://download.01.org/0day-ci/archive/20230727/202307270707.SlAbd4tx-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202307270707.SlAbd4tx-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/char/hw_random/zhaoxin-rng.c: Assembler messages:
>> drivers/char/hw_random/zhaoxin-rng.c:57: Error: bad register name `%rcx'
>> drivers/char/hw_random/zhaoxin-rng.c:58: Error: bad register name `%rdx'
>> drivers/char/hw_random/zhaoxin-rng.c:59: Error: bad register name `%rdi'


vim +57 drivers/char/hw_random/zhaoxin-rng.c

    54	
    55	static inline int rep_xstore(size_t size, size_t factor, void *result)
    56	{
  > 57		__asm__ __volatile__ (
  > 58		"movq %0, %%rcx\n"
  > 59		"movq %1, %%rdx\n"
    60		"movq %2, %%rdi\n"
    61		".byte 0xf3, 0x0f, 0xa7, 0xc0"
    62		:
    63		: "r"(size), "r"(factor), "r"(result)
    64		: "%rcx", "%rdx", "%rdi", "memory");
    65	
    66		return 0;
    67	}
    68	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH] hwrng: add Zhaoxin HW RNG driver

[kernel test robot]

Hi LeoLiu-oc,

kernel test robot noticed the following build errors:

[auto build test ERROR on char-misc/char-misc-testing]
[also build test ERROR on char-misc/char-misc-next char-misc/char-misc-linus herbert-cryptodev-2.6/master linus/master v6.5-rc3 next-20230726]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/LeoLiu-oc/hwrng-add-Zhaoxin-HW-RNG-driver/20230726-193710
base:   char-misc/char-misc-testing
patch link:    https://lore.kernel.org/r/20230726113553.1965627-1-LeoLiu-oc%40zhaoxin.com
patch subject: [PATCH] hwrng: add Zhaoxin HW RNG driver
config: i386-randconfig-i014-20230726 (https://download.01.org/0day-ci/archive/20230727/202307271008.RbzxDGux-lkp@intel.com/config)
compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07)
reproduce: (https://download.01.org/0day-ci/archive/20230727/202307271008.RbzxDGux-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202307271008.RbzxDGux-lkp@intel.com/

All errors (new ones prefixed by >>):

>> drivers/char/hw_random/zhaoxin-rng.c:58:2: error: register %rcx is only available in 64-bit mode
           "movq %0, %%rcx\n"
           ^
   <inline asm>:1:13: note: instantiated into assembly here
           movq %eax, %rcx
                      ^~~~
>> drivers/char/hw_random/zhaoxin-rng.c:59:3: error: register %rdx is only available in 64-bit mode
           "movq %1, %%rdx\n"
            ^
   <inline asm>:2:12: note: instantiated into assembly here
   movq %ecx, %rdx
              ^~~~
>> drivers/char/hw_random/zhaoxin-rng.c:60:3: error: register %rdi is only available in 64-bit mode
           "movq %2, %%rdi\n"
            ^
   <inline asm>:3:12: note: instantiated into assembly here
   movq %edx, %rdi
              ^~~~
   3 errors generated.


vim +58 drivers/char/hw_random/zhaoxin-rng.c

    54	
    55	static inline int rep_xstore(size_t size, size_t factor, void *result)
    56	{
    57		__asm__ __volatile__ (
  > 58		"movq %0, %%rcx\n"
  > 59		"movq %1, %%rdx\n"
  > 60		"movq %2, %%rdi\n"
    61		".byte 0xf3, 0x0f, 0xa7, 0xc0"
    62		:
    63		: "r"(size), "r"(factor), "r"(result)
    64		: "%rcx", "%rdx", "%rdi", "memory");
    65	
    66		return 0;
    67	}
    68	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH] hwrng: add Zhaoxin HW RNG driver

[Corentin Labbe]

Le Wed, Jul 26, 2023 at 07:35:53PM +0800, LeoLiu-oc a écrit :
> From: leoliu-oc <leoliu-oc@zhaoxin.com>
> 
> Add support for Zhaoxin HW RNG.
> 
> Signed-off-by: leoliu-oc <leoliu-oc@zhaoxin.com>
> ---
>  drivers/char/hw_random/Kconfig       |  13 +++
>  drivers/char/hw_random/Makefile      |   1 +
>  drivers/char/hw_random/via-rng.c     |  17 ++--

Hello

You are doing changes in via-rng without stating why.
If changes are needed in via-rng, you should do this in a separate patch.

Regards

Re: [PATCH] hwrng: add Zhaoxin HW RNG driver

[LeoLiu-oc]

在 2023/7/27 14:48, Corentin Labbe 写道:
> Le Wed, Jul 26, 2023 at 07:35:53PM +0800, LeoLiu-oc a écrit :
>> From: leoliu-oc <leoliu-oc@zhaoxin.com>
>>
>> Add support for Zhaoxin HW RNG.
>>
>> Signed-off-by: leoliu-oc <leoliu-oc@zhaoxin.com>
>> ---
>>   drivers/char/hw_random/Kconfig       |  13 +++
>>   drivers/char/hw_random/Makefile      |   1 +
>>   drivers/char/hw_random/via-rng.c     |  17 ++--
> 
> Hello
> 
> You are doing changes in via-rng without stating why.
> If changes are needed in via-rng, you should do this in a separate patch.
> 
> Regards

OK，Got it.Thanks for your advice,I will modify it in the next version.

Leoliu-oc