From: LeoLiuoc <LeoLiu-oc@xxxxxxxxxxx> Add support for Zhaoxin hardware random number generator. This driver base on rep_xstore instruction and uses the same X86_FEATURE_XSTORE as via-rng driver. Therefore, modify the x86_cpu_id array in the via-rng driver, so that the corresponding driver can be correctly loader on respective platforms. v1 -> v2: 1. Fix assembler code errors 2. Remove redundant CPU model check codes v2 -> v3: 1. Optimize code details based on the kernel style v3 -> v4: 1. Fix a typographical error v4 -> v5: 1. Modified the definition and declaration of the x86_cpu_id table Signed-off-by: LeoLiuoc <LeoLiu-oc@xxxxxxxxxxx> --- drivers/char/hw_random/Kconfig | 12 ++++ drivers/char/hw_random/Makefile | 1 + drivers/char/hw_random/via-rng.c | 10 +-- drivers/char/hw_random/zhaoxin-rng.c | 93 ++++++++++++++++++++++++++++ 4 files changed, 111 insertions(+), 5 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 442c40efb200..3c1c4fa1203c 100644 --- a/drivers/char/hw_random/Kconfig +++ b/drivers/char/hw_random/Kconfig @@ -152,6 +152,18 @@ config HW_RANDOM_VIA If unsure, say Y. +config HW_RANDOM_ZHAOXIN + tristate "Zhaoxin HW Random Number Generator support" + depends on X86 + 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..4288e1114fc9 100644 --- a/drivers/char/hw_random/via-rng.c +++ b/drivers/char/hw_random/via-rng.c @@ -35,7 +35,7 @@ #include <asm/cpufeature.h> #include <asm/fpu/api.h> - +static struct x86_cpu_id via_rng_cpu_id[]; enum { @@ -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"); @@ -196,7 +196,7 @@ static int __init via_rng_mod_init(void) { int err; - if (!boot_cpu_has(X86_FEATURE_XSTORE)) + if (!x86_match_cpu(via_rng_cpu_id)) return -ENODEV; pr_info("VIA RNG detected\n"); @@ -217,8 +217,8 @@ 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), +static struct x86_cpu_id via_rng_cpu_id[] = { + X86_MATCH_VENDOR_FAM_FEATURE(CENTAUR, 6, X86_FEATURE_XSTORE, NULL), {} }; MODULE_DEVICE_TABLE(x86cpu, via_rng_cpu_id); diff --git a/drivers/char/hw_random/zhaoxin-rng.c b/drivers/char/hw_random/zhaoxin-rng.c new file mode 100644 index 000000000000..5b4586c6dc8a --- /dev/null +++ b/drivers/char/hw_random/zhaoxin-rng.c @@ -0,0 +1,93 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * RNG driver for Zhaoxin RNGs + * + * Copyright 2023 (c) Zhaoxin Semiconductor Co., Ltd + */ + +#include <asm/cpu_device_id.h> +#include <asm/fpu/api.h> +#include <crypto/padlock.h> +#include <linux/cpufeature.h> +#include <linux/delay.h> +#include <linux/hw_random.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.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(".byte 0xf3, 0x0f, 0xa7, 0xc0" + : "=m"(*(size_t *)result), "+c"(size), "+d"(factor), "+D"(result)); + + 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 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)) + 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 CPUs"); +MODULE_AUTHOR("YunShen@xxxxxxxxxxx"); +MODULE_LICENSE("GPL"); -- 2.34.1