Add support for the rdrand instruction found in recent Intel processors.

Joint work with naddy@

ok naddy@ deraadt@

6 files changed, 88 insertions, 6 deletions

diff --git a/sys/arch/amd64/amd64/autoconf.c b/sys/arch/amd64/amd64/autoconf.c
index 4cab84c0534..55f241ffe90 100644
--- a/sys/arch/amd64/amd64/autoconf.c
+++ b/sys/arch/amd64/amd64/autoconf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: autoconf.c,v 1.38 2012/07/13 14:43:28 mlarkin Exp $	*/
+/*	$OpenBSD: autoconf.c,v 1.39 2012/09/19 20:19:31 jsg Exp $	*/
 /*	$NetBSD: autoconf.c,v 1.1 2003/04/26 18:39:26 fvdl Exp $	*/
 
 /*-
@@ -97,6 +97,10 @@ extern struct timeout viac3_rnd_tmo;
 extern int	viac3_rnd_present;
 void		viac3_rnd(void *);
 
+extern struct timeout rdrand_tmo;
+extern int	has_rdrand;
+void		rdrand(void *);
+
 #ifdef CRYPTO
 void		viac3_crypto_setup(void);
 extern int	amd64_has_xcrypt;
@@ -143,6 +147,10 @@ cpu_configure(void)
 		timeout_set(&viac3_rnd_tmo, viac3_rnd, &viac3_rnd_tmo);
 		viac3_rnd(&viac3_rnd_tmo);
 	}
+	if (has_rdrand) {
+		timeout_set(&rdrand_tmo, rdrand, &rdrand_tmo);
+		rdrand(&rdrand_tmo);
+	}
 #ifdef CRYPTO
 	/*
 	 * Also, if the chip has crypto available, enable it.
diff --git a/sys/arch/amd64/amd64/cpu.c b/sys/arch/amd64/amd64/cpu.c
index 493dbc99706..213923825b6 100644
--- a/sys/arch/amd64/amd64/cpu.c
+++ b/sys/arch/amd64/amd64/cpu.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.c,v 1.50 2012/07/09 15:25:39 deraadt Exp $	*/
+/*	$OpenBSD: cpu.c,v 1.51 2012/09/19 20:19:31 jsg Exp $	*/
 /* $NetBSD: cpu.c,v 1.1 2003/04/26 18:39:26 fvdl Exp $ */
 
 /*-
@@ -101,6 +101,7 @@
 #include <dev/ic/mc146818reg.h>
 #include <amd64/isa/nvram.h>
 #include <dev/isa/isareg.h>
+#include <dev/rndvar.h>
 
 int     cpu_match(struct device *, void *, void *);
 void    cpu_attach(struct device *, struct device *, void *);
@@ -725,3 +726,33 @@ patinit(struct cpu_info *ci)
 	wrmsr(MSR_CR_PAT, reg);
 	pmap_pg_wc = PG_WC;
 }
+
+struct timeout rdrand_tmo;
+void rdrand(void *);
+
+void
+rdrand(void *v)
+{
+	struct timeout *tmo = v;
+	union {
+		uint64_t u64;
+		uint32_t u32[2];
+	} r;
+	uint64_t valid;
+	int i;
+
+	for (i = 0; i < 2; i++) {
+		__asm __volatile(
+		    "xor	%1, %1\n\t"
+		    "rdrand	%0\n\t"
+		    "rcl	$1, %1\n"
+		    : "=r" (r.u64), "=r" (valid) );
+
+		if (valid) {
+			add_true_randomness(r.u32[0]);
+			add_true_randomness(r.u32[1]);
+		}
+	}
+
+	timeout_add_msec(tmo, 10);
+}
diff --git a/sys/arch/amd64/amd64/identcpu.c b/sys/arch/amd64/amd64/identcpu.c
index 84806873a76..f6fc27f61b9 100644
--- a/sys/arch/amd64/amd64/identcpu.c
+++ b/sys/arch/amd64/amd64/identcpu.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: identcpu.c,v 1.38 2012/09/07 22:02:34 naddy Exp $	*/
+/*	$OpenBSD: identcpu.c,v 1.39 2012/09/19 20:19:31 jsg Exp $	*/
 /*	$NetBSD: identcpu.c,v 1.1 2003/04/26 18:39:28 fvdl Exp $	*/
 
 /*
@@ -52,6 +52,7 @@ int amd64_has_xcrypt;
 #ifdef CRYPTO
 int amd64_has_aesni;
 #endif
+int has_rdrand;
 
 const struct {
 	u_int32_t	bit;
@@ -432,6 +433,9 @@ identifycpu(struct cpu_info *ci)
 
 		if (cpu_ecxfeature & CPUIDECX_AES)
 			amd64_has_aesni = 1;
+
+		if (cpu_ecxfeature & CPUIDECX_RDRAND)
+			has_rdrand = 1;
 	}
 	if (!strncmp(mycpu_model, "Intel", 5)) {
 		u_int32_t cflushsz;
diff --git a/sys/arch/i386/i386/autoconf.c b/sys/arch/i386/i386/autoconf.c
index 1ce58a3fec2..f5429788cf6 100644
--- a/sys/arch/i386/i386/autoconf.c
+++ b/sys/arch/i386/i386/autoconf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: autoconf.c,v 1.90 2012/07/13 14:50:10 mlarkin Exp $	*/
+/*	$OpenBSD: autoconf.c,v 1.91 2012/09/19 20:19:31 jsg Exp $	*/
 /*	$NetBSD: autoconf.c,v 1.20 1996/05/03 19:41:56 christos Exp $	*/
 
 /*-
@@ -89,6 +89,10 @@ extern struct timeout viac3_rnd_tmo;
 extern int	viac3_rnd_present;
 void		viac3_rnd(void *);
 
+extern struct timeout rdrand_tmo;
+extern int	has_rdrand;
+void		rdrand(void *);
+
 #ifdef CRYPTO
 void		viac3_crypto_setup(void);
 extern int	i386_has_xcrypt;
@@ -143,6 +147,11 @@ cpu_configure(void)
 		timeout_set(&viac3_rnd_tmo, viac3_rnd, &viac3_rnd_tmo);
 		viac3_rnd(&viac3_rnd_tmo);
 	}
+	if (has_rdrand) {
+		timeout_set(&rdrand_tmo, rdrand, &rdrand_tmo);
+		rdrand(&rdrand_tmo);
+	}
+
 #ifdef CRYPTO
 	/*
 	 * Also, if the chip has crypto available, enable it.
diff --git a/sys/arch/i386/i386/cpu.c b/sys/arch/i386/i386/cpu.c
index 40840056c30..d3cd2a90e13 100644
--- a/sys/arch/i386/i386/cpu.c
+++ b/sys/arch/i386/i386/cpu.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.c,v 1.44 2012/07/09 15:25:37 deraadt Exp $	*/
+/*	$OpenBSD: cpu.c,v 1.45 2012/09/19 20:19:31 jsg Exp $	*/
 /* $NetBSD: cpu.c,v 1.1.2.7 2000/06/26 02:04:05 sommerfeld Exp $ */
 
 /*-
@@ -102,6 +102,7 @@
 #include <dev/ic/mc146818reg.h>
 #include <i386/isa/nvram.h>
 #include <dev/isa/isareg.h>
+#include <dev/rndvar.h>
 
 int     cpu_match(struct device *, void *, void *);
 void    cpu_attach(struct device *, struct device *, void *);
@@ -384,6 +385,28 @@ patinit(struct cpu_info *ci)
 	pmap_pg_wc = PG_WC;
 }
 
+struct timeout rdrand_tmo;
+void rdrand(void *);
+
+void
+rdrand(void *v)
+{
+	struct timeout *tmo = v;
+	uint32_t r, valid;
+	int i;
+
+	for (i = 0; i < 4; i++) {
+		__asm __volatile(
+		    "xor        %1, %1\n\t"
+		    "rdrand     %0\n\t"
+		    "rcl        $1, %1\n"
+		    : "=r" (r), "=r" (valid) );
+		if (valid)
+			add_true_randomness(r);
+	}
+
+	timeout_add_msec(tmo, 10);
+}
 
 #ifdef MULTIPROCESSOR
 void
diff --git a/sys/arch/i386/i386/machdep.c b/sys/arch/i386/i386/machdep.c
index e76449d9090..97591d87adb 100644
--- a/sys/arch/i386/i386/machdep.c
+++ b/sys/arch/i386/i386/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.511 2012/08/24 02:49:23 guenther Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.512 2012/09/19 20:19:31 jsg Exp $	*/
 /*	$NetBSD: machdep.c,v 1.214 1996/11/10 03:16:17 thorpej Exp $	*/
 
 /*-
@@ -306,6 +306,8 @@ int allowaperture = 0;
 #endif
 #endif
 
+int has_rdrand;
+
 void	winchip_cpu_setup(struct cpu_info *);
 void	amd_family5_setperf_setup(struct cpu_info *);
 void	amd_family5_setup(struct cpu_info *);
@@ -1906,6 +1908,11 @@ identifycpu(struct cpu_info *ci)
 		}
 	}
 
+	if (ci->ci_flags & CPUF_PRIMARY) {
+		if (cpu_ecxfeature & CPUIDECX_RDRAND)
+			has_rdrand = 1;
+	}
+
 #ifndef SMALL_KERNEL
 	if (cpuspeed != 0 && cpu_cpuspeed == NULL)
 		cpu_cpuspeed = pentium_cpuspeed;