Add support for new Intel on-CPU Bull Mountain random number

generator, found on IvyBridge and supposedly later CPUs, accessible
with RDRAND instruction.

From the Intel whitepapers and articles about Bull Mountain, it seems
that we do not need to perform post-processing of RDRAND results, like
AES-encryption of the data with random IV and keys, which was done for
Padlock. Intel claims that sanitization is performed in hardware.

Make both Padlock and Bull Mountain random generators support code
covered by kernel config options, for the benefit of people who prefer
minimal kernels. Also add the tunables to disable hardware generator
even if detected.

Reviewed by:	markm, secteam (simon)
Tested by:	bapt, Michael Moll <kvedulv@kvedulv.de>
MFC after:	3 weeks

11 files changed, 174 insertions, 35 deletions

diff --git a/sys/amd64/conf/GENERIC b/sys/amd64/conf/GENERIC
index 7f814fc..95f9d9b 100644
--- a/sys/amd64/conf/GENERIC
+++ b/sys/amd64/conf/GENERIC
@@ -292,6 +292,8 @@ device		wpi		# Intel 3945ABG wireless NICs.
 # Pseudo devices.
 device		loop		# Network loopback
 device		random		# Entropy device
+options 	PADLOCK_RNG	# VIA Padlock RNG
+options 	IVY_RNG		# Intel Bull Mountain RNG
 device		ether		# Ethernet support
 device		vlan		# 802.1Q VLAN support
 device		tun		# Packet tunnel.
diff --git a/sys/conf/files.amd64 b/sys/conf/files.amd64
index 9aa61e2..374afcb 100644
--- a/sys/conf/files.amd64
+++ b/sys/conf/files.amd64
@@ -213,7 +213,8 @@ dev/lindev/lindev.c		optional	lindev
 dev/nfe/if_nfe.c		optional	nfe pci
 dev/nve/if_nve.c		optional	nve pci
 dev/nvram/nvram.c		optional	nvram isa
-dev/random/nehemiah.c		optional	random
+dev/random/ivy.c		optional	random ivy_rng
+dev/random/nehemiah.c		optional	random padlock_rng
 dev/qlxgb/qla_dbg.c		optional	qlxgb pci
 dev/qlxgb/qla_hw.c		optional	qlxgb pci
 dev/qlxgb/qla_ioctl.c		optional	qlxgb pci
diff --git a/sys/conf/files.i386 b/sys/conf/files.i386
index f3de163..b592437 100644
--- a/sys/conf/files.i386
+++ b/sys/conf/files.i386
@@ -226,7 +226,8 @@ dev/nfe/if_nfe.c		optional nfe pci
 dev/nve/if_nve.c		optional nve pci
 dev/nvram/nvram.c		optional nvram isa
 dev/pcf/pcf_isa.c		optional pcf
-dev/random/nehemiah.c		optional random
+dev/random/ivy.c		optional random ivy_rng
+dev/random/nehemiah.c		optional random padlock_rng
 dev/sbni/if_sbni.c		optional sbni
 dev/sbni/if_sbni_isa.c		optional sbni isa
 dev/sbni/if_sbni_pci.c		optional sbni pci
diff --git a/sys/conf/options.amd64 b/sys/conf/options.amd64
index 31d1650..7db409c 100644
--- a/sys/conf/options.amd64
+++ b/sys/conf/options.amd64
@@ -68,3 +68,7 @@ XENHVM			opt_global.h
 
 # options for the Intel C600 SAS driver (isci)
 ISCI_LOGGING	opt_isci.h
+
+# hw random number generators for random(4)
+PADLOCK_RNG		opt_cpu.h
+IVY_RNG			opt_cpu.h
diff --git a/sys/conf/options.i386 b/sys/conf/options.i386
index 3638266..9ce7b8c 100644
--- a/sys/conf/options.i386
+++ b/sys/conf/options.i386
@@ -123,3 +123,7 @@ XENHVM			opt_global.h
 
 # options for the Intel C600 SAS driver (isci)
 ISCI_LOGGING	opt_isci.h
+
+# hw random number generators for random(4)
+PADLOCK_RNG		opt_cpu.h
+IVY_RNG			opt_cpu.h
diff --git a/sys/dev/random/ivy.c b/sys/dev/random/ivy.c
new file mode 100644
index 0000000..3f9de2d
--- /dev/null
+++ b/sys/dev/random/ivy.c
@@ -0,0 +1,117 @@
+/*-
+ * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer
+ *    in this position and unchanged.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include "opt_cpu.h"
+
+#ifdef IVY_RNG
+
+#include <sys/param.h>
+#include <sys/time.h>
+#include <sys/lock.h>
+#include <sys/mutex.h>
+#include <sys/selinfo.h>
+#include <sys/systm.h>
+#include <dev/random/randomdev.h>
+
+#define	RETRY_COUNT	10
+
+static void random_ivy_init(void);
+static void random_ivy_deinit(void);
+static int random_ivy_read(void *, int);
+
+struct random_systat random_ivy = {
+	.ident = "Hardware, Intel IvyBridge+ RNG",
+	.init = random_ivy_init,
+	.deinit = random_ivy_deinit,
+	.read = random_ivy_read,
+	.write = (random_write_func_t *)random_null_func,
+	.reseed = (random_reseed_func_t *)random_null_func,
+	.seeded = 1,
+};
+
+static inline int
+ivy_rng_store(long *tmp)
+{
+#ifdef __GNUCLIKE_ASM
+	uint32_t count;
+
+	__asm __volatile(
+#ifdef __amd64__
+	    ".byte\t0x48,0x0f,0xc7,0xf0\n\t" /* rdrand %rax */
+	    "jnc\t1f\n\t"
+	    "movq\t%%rax,%1\n\t"
+	    "movl\t$8,%%eax\n"
+#else /* i386 */
+	    ".byte\t0x0f,0xc7,0xf0\n\t" /* rdrand %eax */
+	    "jnc\t1f\n\t"
+	    "movl\t%%eax,%1\n\t"
+	    "movl\t$4,%%eax\n"
+#endif
+	    "1:\n"	/* %eax is cleared by processor on failure */
+	    : "=a" (count), "=g" (*tmp) : "a" (0) : "cc");
+	return (count);
+#else /* __GNUCLIKE_ASM */
+	return (0);
+#endif
+}
+
+static void
+random_ivy_init(void)
+{
+}
+
+void
+random_ivy_deinit(void)
+{
+}
+
+static int
+random_ivy_read(void *buf, int c)
+{
+	char *b;
+	long tmp;
+	int count, res, retry;
+
+	for (count = c, b = buf; count > 0; count -= res, b += res) {
+		for (retry = 0; retry < RETRY_COUNT; retry++) {
+			res = ivy_rng_store(&tmp);
+			if (res != 0)
+				break;
+		}
+		if (res == 0)
+			break;
+		if (res > count)
+			res = count;
+		memcpy(b, &tmp, res);
+	}
+	return (c - count);
+}
+
+#endif
diff --git a/sys/dev/random/nehemiah.c b/sys/dev/random/nehemiah.c
index b9f52e7..f3afa89 100644
--- a/sys/dev/random/nehemiah.c
+++ b/sys/dev/random/nehemiah.c
@@ -28,6 +28,10 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
+#include "opt_cpu.h"
+
+#ifdef PADLOCK_RNG
+
 #include <sys/param.h>
 #include <sys/time.h>
 #include <sys/lock.h>
@@ -203,3 +207,5 @@ random_nehemiah_read(void *buf, int c)
 	mtx_unlock(&random_nehemiah_mtx);
 	return (c);
 }
+
+#endif
diff --git a/sys/dev/random/nehemiah.h b/sys/dev/random/nehemiah.h
deleted file mode 100644
index b35fb3f..0000000
--- a/sys/dev/random/nehemiah.h
+++ /dev/null
@@ -1,29 +0,0 @@
-/*-
- * Copyright (c) 2000-2004 Mark R V Murray
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer
- *    in this position and unchanged.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
- * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
- * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * $FreeBSD$
- */
-
-extern struct random_systat random_nehemiah;
diff --git a/sys/dev/random/probe.c b/sys/dev/random/probe.c
index 0bbfd95..3edfe09 100644
--- a/sys/dev/random/probe.c
+++ b/sys/dev/random/probe.c
@@ -28,12 +28,17 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
+#if defined(__amd64__) || (defined(__i386__) && !defined(PC98))
+#include "opt_cpu.h"
+#endif
+
 #include <sys/types.h>
 #include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
 #include <sys/malloc.h>
 #include <sys/random.h>
 #include <sys/selinfo.h>
-#include <sys/stdint.h>
 #include <sys/sysctl.h>
 
 #if defined(__amd64__) || (defined(__i386__) && !defined(PC98))
@@ -45,7 +50,15 @@ __FBSDID("$FreeBSD$");
 
 #include <dev/random/randomdev.h>
 #include <dev/random/randomdev_soft.h>
-#include <dev/random/nehemiah.h>
+
+#if defined(__amd64__) || (defined(__i386__) && !defined(PC98))
+#ifdef PADLOCK_RNG
+extern struct random_systat random_nehemiah;
+#endif
+#ifdef IVY_RNG
+extern struct random_systat random_ivy;
+#endif
+#endif
 
 void
 random_ident_hardware(struct random_systat *systat)
@@ -56,8 +69,25 @@ random_ident_hardware(struct random_systat *systat)
 
 	/* Then go looking for hardware */
 #if defined(__amd64__) || (defined(__i386__) && !defined(PC98))
+#ifdef PADLOCK_RNG
 	if (via_feature_rng & VIA_HAS_RNG) {
-		*systat = random_nehemiah;
+		int enable;
+
+		enable = 1;
+		TUNABLE_INT_FETCH("hw.nehemiah_rng_enable", &enable);
+		if (enable)
+			*systat = random_nehemiah;
+	}
+#endif
+#ifdef IVY_RNG
+	if (cpu_feature2 & CPUID2_RDRAND) {
+		int enable;
+
+		enable = 1;
+		TUNABLE_INT_FETCH("hw.ivy_rng_enable", &enable);
+		if (enable)
+			*systat = random_ivy;
 	}
 #endif
+#endif
 }
diff --git a/sys/i386/conf/GENERIC b/sys/i386/conf/GENERIC
index b542e1c..74829b8 100644
--- a/sys/i386/conf/GENERIC
+++ b/sys/i386/conf/GENERIC
@@ -305,6 +305,8 @@ device		wpi		# Intel 3945ABG wireless NICs.
 # Pseudo devices.
 device		loop		# Network loopback
 device		random		# Entropy device
+options 	PADLOCK_RNG	# VIA Padlock RNG
+options 	IVY_RNG		# Intel Bull Mountain RNG
 device		ether		# Ethernet support
 device		vlan		# 802.1Q VLAN support
 device		tun		# Packet tunnel.
diff --git a/sys/modules/random/Makefile b/sys/modules/random/Makefile
index 746f45a..ad14899 100644
--- a/sys/modules/random/Makefile
+++ b/sys/modules/random/Makefile
@@ -8,10 +8,11 @@ KMOD=	random
 SRCS=	randomdev.c probe.c
 .if ${MACHINE} == "amd64" || ${MACHINE} == "i386"
 SRCS+=	nehemiah.c
+SRCS+=	ivy.c
 .endif
 SRCS+=	randomdev_soft.c yarrow.c hash.c
 SRCS+=	rijndael-alg-fst.c rijndael-api-fst.c sha2.c
-SRCS+=	bus_if.h device_if.h vnode_if.h
+SRCS+=	bus_if.h device_if.h vnode_if.h opt_cpu.h
 
 CFLAGS+= -I${.CURDIR}/../..