From: LeoLiuoc <[email protected]>
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
Signed-off-by: LeoLiuoc <[email protected]>
---
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 | 95 ++++++++++++++++++++++++++++
4 files changed, 113 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..285505b4d620 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 const struct x86_cpu_id via_rng_cpu_ids[];
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_ids))
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..3e5770df9948
--- /dev/null
+++ b/drivers/char/hw_random/zhaoxin-rng.c
@@ -0,0 +1,95 @@
+// 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 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 CPUs");
+MODULE_AUTHOR("[email protected]");
+MODULE_LICENSE("GPL");
--
2.34.1
Hi LeoLiu-oc,
kernel test robot noticed the following build warnings:
[auto build test WARNING on char-misc/char-misc-testing]
[also build test WARNING on char-misc/char-misc-next char-misc/char-misc-linus herbert-cryptodev-2.6/master linus/master v6.7-rc6 next-20231222]
[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-rng-driver-base-on-rep_xstore-instruction/20231222-174625
base: char-misc/char-misc-testing
patch link: https://lore.kernel.org/r/20231221062602.799432-1-LeoLiu-oc%40zhaoxin.com
patch subject: [PATCH v3] hwrng: add Zhaoxin rng driver base on rep_xstore instruction
config: i386-buildonly-randconfig-003-20231223 (https://download.01.org/0day-ci/archive/20231223/[email protected]/config)
compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231223/[email protected]/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 <[email protected]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
All warnings (new ones prefixed by >>):
drivers/char/hw_random/via-rng.c:38:32: warning: tentative array definition assumed to have one element
static const struct x86_cpu_id via_rng_cpu_ids[];
^
>> drivers/char/hw_random/via-rng.c:220:26: warning: unused variable 'via_rng_cpu_id' [-Wunused-variable]
static struct x86_cpu_id via_rng_cpu_id[] = {
^
2 warnings generated.
vim +/via_rng_cpu_id +220 drivers/char/hw_random/via-rng.c
219
> 220 static struct x86_cpu_id via_rng_cpu_id[] = {
221 X86_MATCH_VENDOR_FAM_FEATURE(CENTAUR, 6, X86_FEATURE_XSTORE, NULL),
222 {}
223 };
224 MODULE_DEVICE_TABLE(x86cpu, via_rng_cpu_id);
225
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Hi LeoLiu-oc,
kernel test robot noticed the following build warnings:
[auto build test WARNING on char-misc/char-misc-testing]
[also build test WARNING on char-misc/char-misc-next char-misc/char-misc-linus herbert-cryptodev-2.6/master linus/master v6.7-rc6 next-20231222]
[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-rng-driver-base-on-rep_xstore-instruction/20231222-174625
base: char-misc/char-misc-testing
patch link: https://lore.kernel.org/r/20231221062602.799432-1-LeoLiu-oc%40zhaoxin.com
patch subject: [PATCH v3] hwrng: add Zhaoxin rng driver base on rep_xstore instruction
config: x86_64-defconfig (https://download.01.org/0day-ci/archive/20231223/[email protected]/config)
compiler: gcc-11 (Debian 11.3.0-12) 11.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231223/[email protected]/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 <[email protected]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
All warnings (new ones prefixed by >>):
>> drivers/char/hw_random/via-rng.c:38:32: warning: array 'via_rng_cpu_ids' assumed to have one element
38 | static const struct x86_cpu_id via_rng_cpu_ids[];
| ^~~~~~~~~~~~~~~
>> drivers/char/hw_random/via-rng.c:220:26: warning: 'via_rng_cpu_id' defined but not used [-Wunused-variable]
220 | static struct x86_cpu_id via_rng_cpu_id[] = {
| ^~~~~~~~~~~~~~
vim +/via_rng_cpu_ids +38 drivers/char/hw_random/via-rng.c
37
> 38 static const struct x86_cpu_id via_rng_cpu_ids[];
39
40
41 enum {
42 VIA_STRFILT_CNT_SHIFT = 16,
43 VIA_STRFILT_FAIL = (1 << 15),
44 VIA_STRFILT_ENABLE = (1 << 14),
45 VIA_RAWBITS_ENABLE = (1 << 13),
46 VIA_RNG_ENABLE = (1 << 6),
47 VIA_NOISESRC1 = (1 << 8),
48 VIA_NOISESRC2 = (1 << 9),
49 VIA_XSTORE_CNT_MASK = 0x0F,
50
51 VIA_RNG_CHUNK_8 = 0x00, /* 64 rand bits, 64 stored bits */
52 VIA_RNG_CHUNK_4 = 0x01, /* 32 rand bits, 32 stored bits */
53 VIA_RNG_CHUNK_4_MASK = 0xFFFFFFFF,
54 VIA_RNG_CHUNK_2 = 0x02, /* 16 rand bits, 32 stored bits */
55 VIA_RNG_CHUNK_2_MASK = 0xFFFF,
56 VIA_RNG_CHUNK_1 = 0x03, /* 8 rand bits, 32 stored bits */
57 VIA_RNG_CHUNK_1_MASK = 0xFF,
58 };
59
60 /*
61 * Investigate using the 'rep' prefix to obtain 32 bits of random data
62 * in one insn. The upside is potentially better performance. The
63 * downside is that the instruction becomes no longer atomic. Due to
64 * this, just like familiar issues with /dev/random itself, the worst
65 * case of a 'rep xstore' could potentially pause a cpu for an
66 * unreasonably long time. In practice, this condition would likely
67 * only occur when the hardware is failing. (or so we hope :))
68 *
69 * Another possible performance boost may come from simply buffering
70 * until we have 4 bytes, thus returning a u32 at a time,
71 * instead of the current u8-at-a-time.
72 *
73 * Padlock instructions can generate a spurious DNA fault, but the
74 * kernel doesn't use CR0.TS, so this doesn't matter.
75 */
76
77 static inline u32 xstore(u32 *addr, u32 edx_in)
78 {
79 u32 eax_out;
80
81 asm(".byte 0x0F,0xA7,0xC0 /* xstore %%edi (addr=%0) */"
82 : "=m" (*addr), "=a" (eax_out), "+d" (edx_in), "+D" (addr));
83
84 return eax_out;
85 }
86
87 static int via_rng_data_present(struct hwrng *rng, int wait)
88 {
89 char buf[16 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
90 ((aligned(STACK_ALIGN)));
91 u32 *via_rng_datum = (u32 *)PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
92 u32 bytes_out;
93 int i;
94
95 /* We choose the recommended 1-byte-per-instruction RNG rate,
96 * for greater randomness at the expense of speed. Larger
97 * values 2, 4, or 8 bytes-per-instruction yield greater
98 * speed at lesser randomness.
99 *
100 * If you change this to another VIA_CHUNK_n, you must also
101 * change the ->n_bytes values in rng_vendor_ops[] tables.
102 * VIA_CHUNK_8 requires further code changes.
103 *
104 * A copy of MSR_VIA_RNG is placed in eax_out when xstore
105 * completes.
106 */
107
108 for (i = 0; i < 20; i++) {
109 *via_rng_datum = 0; /* paranoia, not really necessary */
110 bytes_out = xstore(via_rng_datum, VIA_RNG_CHUNK_1);
111 bytes_out &= VIA_XSTORE_CNT_MASK;
112 if (bytes_out || !wait)
113 break;
114 udelay(10);
115 }
116 rng->priv = *via_rng_datum;
117 return bytes_out ? 1 : 0;
118 }
119
120 static int via_rng_data_read(struct hwrng *rng, u32 *data)
121 {
122 u32 via_rng_datum = (u32)rng->priv;
123
124 *data = via_rng_datum;
125
126 return 1;
127 }
128
129 static int via_rng_init(struct hwrng *rng)
130 {
131 struct cpuinfo_x86 *c = &cpu_data(0);
132 u32 lo, hi, old_lo;
133
134 /* VIA Nano CPUs don't have the MSR_VIA_RNG anymore. The RNG
135 * is always enabled if CPUID rng_en is set. There is no
136 * RNG configuration like it used to be the case in this
137 * register */
138 if ((c->x86 == 6) && (c->x86_model >= 0x0f)) {
139 if (!boot_cpu_has(X86_FEATURE_XSTORE_EN)) {
140 pr_err(PFX "can't enable hardware RNG "
141 "if XSTORE is not enabled\n");
142 return -ENODEV;
143 }
144 return 0;
145 }
146
147 /* Control the RNG via MSR. Tread lightly and pay very close
148 * attention to values written, as the reserved fields
149 * are documented to be "undefined and unpredictable"; but it
150 * does not say to write them as zero, so I make a guess that
151 * we restore the values we find in the register.
152 */
153 rdmsr(MSR_VIA_RNG, lo, hi);
154
155 old_lo = lo;
156 lo &= ~(0x7f << VIA_STRFILT_CNT_SHIFT);
157 lo &= ~VIA_XSTORE_CNT_MASK;
158 lo &= ~(VIA_STRFILT_ENABLE | VIA_STRFILT_FAIL | VIA_RAWBITS_ENABLE);
159 lo |= VIA_RNG_ENABLE;
160 lo |= VIA_NOISESRC1;
161
162 /* Enable secondary noise source on CPUs where it is present. */
163
164 /* Nehemiah stepping 8 and higher */
165 if ((c->x86_model == 9) && (c->x86_stepping > 7))
166 lo |= VIA_NOISESRC2;
167
168 /* Esther */
169 if (c->x86_model >= 10)
170 lo |= VIA_NOISESRC2;
171
172 if (lo != old_lo)
173 wrmsr(MSR_VIA_RNG, lo, hi);
174
175 /* perhaps-unnecessary sanity check; remove after testing if
176 unneeded */
177 rdmsr(MSR_VIA_RNG, lo, hi);
178 if ((lo & VIA_RNG_ENABLE) == 0) {
179 pr_err(PFX "cannot enable VIA C3 RNG, aborting\n");
180 return -ENODEV;
181 }
182
183 return 0;
184 }
185
186
187 static struct hwrng via_rng = {
188 .name = "via",
189 .init = via_rng_init,
190 .data_present = via_rng_data_present,
191 .data_read = via_rng_data_read,
192 };
193
194
195 static int __init via_rng_mod_init(void)
196 {
197 int err;
198
199 if (!x86_match_cpu(via_rng_cpu_ids))
200 return -ENODEV;
201
202 pr_info("VIA RNG detected\n");
203 err = hwrng_register(&via_rng);
204 if (err) {
205 pr_err(PFX "RNG registering failed (%d)\n",
206 err);
207 goto out;
208 }
209 out:
210 return err;
211 }
212 module_init(via_rng_mod_init);
213
214 static void __exit via_rng_mod_exit(void)
215 {
216 hwrng_unregister(&via_rng);
217 }
218 module_exit(via_rng_mod_exit);
219
> 220 static struct x86_cpu_id via_rng_cpu_id[] = {
221 X86_MATCH_VENDOR_FAM_FEATURE(CENTAUR, 6, X86_FEATURE_XSTORE, NULL),
222 {}
223 };
224 MODULE_DEVICE_TABLE(x86cpu, via_rng_cpu_id);
225
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
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 v6.7-rc6 next-20231222]
[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-rng-driver-base-on-rep_xstore-instruction/20231222-174625
base: char-misc/char-misc-testing
patch link: https://lore.kernel.org/r/20231221062602.799432-1-LeoLiu-oc%40zhaoxin.com
patch subject: [PATCH v3] hwrng: add Zhaoxin rng driver base on rep_xstore instruction
config: i386-defconfig (https://download.01.org/0day-ci/archive/20231223/[email protected]/config)
compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231223/[email protected]/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 <[email protected]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
All errors (new ones prefixed by >>):
ld: drivers/char/hw_random/via-rng.o: in function `via_rng_mod_init':
>> via-rng.c:(.init.text+0x2): undefined reference to `via_rng_cpu_ids'
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki