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-rw-r--r--arch/s390/Kbuild2
-rw-r--r--arch/s390/Kconfig15
-rw-r--r--arch/s390/crypto/Makefile1
-rw-r--r--arch/s390/crypto/arch_random.c31
-rw-r--r--arch/s390/include/asm/archrandom.h69
5 files changed, 117 insertions, 1 deletions
diff --git a/arch/s390/Kbuild b/arch/s390/Kbuild
index e256592eb66e..eae2c64cf69d 100644
--- a/arch/s390/Kbuild
+++ b/arch/s390/Kbuild
@@ -1,7 +1,7 @@
obj-y += kernel/
obj-y += mm/
obj-$(CONFIG_KVM) += kvm/
-obj-$(CONFIG_CRYPTO_HW) += crypto/
+obj-y += crypto/
obj-$(CONFIG_S390_HYPFS_FS) += hypfs/
obj-$(CONFIG_APPLDATA_BASE) += appldata/
obj-y += net/
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 249c2771be0e..ebc0bf7c84d0 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -507,6 +507,21 @@ source kernel/Kconfig.preempt
source kernel/Kconfig.hz
+config ARCH_RANDOM
+ def_bool y
+ prompt "s390 architectural random number generation API"
+ help
+ Enable the s390 architectural random number generation API
+ to provide random data for all consumers within the Linux
+ kernel.
+
+ When enabled the arch_random_* functions declared in linux/random.h
+ are implemented. The implementation is based on the s390 CPACF
+ instruction subfunction TRNG which provides a real true random
+ number generator.
+
+ If unsure, say Y.
+
endmenu
menu "Memory setup"
diff --git a/arch/s390/crypto/Makefile b/arch/s390/crypto/Makefile
index 402c530c6da5..678d9863e3f0 100644
--- a/arch/s390/crypto/Makefile
+++ b/arch/s390/crypto/Makefile
@@ -10,5 +10,6 @@ obj-$(CONFIG_CRYPTO_AES_S390) += aes_s390.o paes_s390.o
obj-$(CONFIG_S390_PRNG) += prng.o
obj-$(CONFIG_CRYPTO_GHASH_S390) += ghash_s390.o
obj-$(CONFIG_CRYPTO_CRC32_S390) += crc32-vx_s390.o
+obj-$(CONFIG_ARCH_RANDOM) += arch_random.o
crc32-vx_s390-y := crc32-vx.o crc32le-vx.o crc32be-vx.o
diff --git a/arch/s390/crypto/arch_random.c b/arch/s390/crypto/arch_random.c
new file mode 100644
index 000000000000..9317b3e645e2
--- /dev/null
+++ b/arch/s390/crypto/arch_random.c
@@ -0,0 +1,31 @@
+/*
+ * s390 arch random implementation.
+ *
+ * Copyright IBM Corp. 2017
+ * Author(s): Harald Freudenberger <freude@de.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License (version 2 only)
+ * as published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/atomic.h>
+#include <linux/static_key.h>
+#include <asm/cpacf.h>
+
+DEFINE_STATIC_KEY_FALSE(s390_arch_random_available);
+
+atomic64_t s390_arch_random_counter = ATOMIC64_INIT(0);
+EXPORT_SYMBOL(s390_arch_random_counter);
+
+static int __init s390_arch_random_init(void)
+{
+ /* check if subfunction CPACF_PRNO_TRNG is available */
+ if (cpacf_query_func(CPACF_PRNO, CPACF_PRNO_TRNG))
+ static_branch_enable(&s390_arch_random_available);
+
+ return 0;
+}
+arch_initcall(s390_arch_random_init);
diff --git a/arch/s390/include/asm/archrandom.h b/arch/s390/include/asm/archrandom.h
new file mode 100644
index 000000000000..6033901a40b2
--- /dev/null
+++ b/arch/s390/include/asm/archrandom.h
@@ -0,0 +1,69 @@
+/*
+ * Kernel interface for the s390 arch_random_* functions
+ *
+ * Copyright IBM Corp. 2017
+ *
+ * Author: Harald Freudenberger <freude@de.ibm.com>
+ *
+ */
+
+#ifndef _ASM_S390_ARCHRANDOM_H
+#define _ASM_S390_ARCHRANDOM_H
+
+#ifdef CONFIG_ARCH_RANDOM
+
+#include <linux/static_key.h>
+#include <linux/atomic.h>
+#include <asm/cpacf.h>
+
+DECLARE_STATIC_KEY_FALSE(s390_arch_random_available);
+extern atomic64_t s390_arch_random_counter;
+
+static void s390_arch_random_generate(u8 *buf, unsigned int nbytes)
+{
+ cpacf_trng(NULL, 0, buf, nbytes);
+ atomic64_add(nbytes, &s390_arch_random_counter);
+}
+
+static inline bool arch_has_random(void)
+{
+ if (static_branch_likely(&s390_arch_random_available))
+ return true;
+ return false;
+}
+
+static inline bool arch_has_random_seed(void)
+{
+ return arch_has_random();
+}
+
+static inline bool arch_get_random_long(unsigned long *v)
+{
+ if (static_branch_likely(&s390_arch_random_available)) {
+ s390_arch_random_generate((u8 *)v, sizeof(*v));
+ return true;
+ }
+ return false;
+}
+
+static inline bool arch_get_random_int(unsigned int *v)
+{
+ if (static_branch_likely(&s390_arch_random_available)) {
+ s390_arch_random_generate((u8 *)v, sizeof(*v));
+ return true;
+ }
+ return false;
+}
+
+static inline bool arch_get_random_seed_long(unsigned long *v)
+{
+ return arch_get_random_long(v);
+}
+
+static inline bool arch_get_random_seed_int(unsigned int *v)
+{
+ return arch_get_random_int(v);
+}
+
+#endif /* CONFIG_ARCH_RANDOM */
+#endif /* _ASM_S390_ARCHRANDOM_H */
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