From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752663AbaCQXhg (ORCPT ); Mon, 17 Mar 2014 19:37:36 -0400 Received: from mga11.intel.com ([192.55.52.93]:64364 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751860AbaCQXgu (ORCPT ); Mon, 17 Mar 2014 19:36:50 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,673,1389772800"; d="scan'208";a="500757084" From: "H. Peter Anvin" To: "Ted Ts'o" , Linus Torvalds , Ingo Molnar , Thomas Gleixner Cc: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Linux Kernel Mailing List , "H. Peter Anvin" Subject: [PATCH v2 4/4] random: Add arch_has_random[_seed]() Date: Mon, 17 Mar 2014 16:36:30 -0700 Message-Id: <1395099390-807-5-git-send-email-hpa@linux.intel.com> X-Mailer: git-send-email 1.8.5.3 In-Reply-To: <1395099390-807-1-git-send-email-hpa@linux.intel.com> References: <1395099390-807-1-git-send-email-hpa@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add predicate functions for having arch_get_random[_seed]*(). The only current use is to avoid the loop in arch_random_refill() when arch_get_random_seed_long() is unavailable. Signed-off-by: H. Peter Anvin Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman --- arch/powerpc/include/asm/archrandom.h | 9 +++++++++ arch/x86/include/asm/archrandom.h | 3 +++ drivers/char/random.c | 3 +++ include/linux/random.h | 8 ++++++++ 4 files changed, 23 insertions(+) diff --git a/arch/powerpc/include/asm/archrandom.h b/arch/powerpc/include/asm/archrandom.h index 801beba..bde5311 100644 --- a/arch/powerpc/include/asm/archrandom.h +++ b/arch/powerpc/include/asm/archrandom.h @@ -25,6 +25,11 @@ static inline int arch_get_random_int(unsigned int *v) return rc; } +static inline int arch_has_random(void) +{ + return !!ppc_md.get_random_long; +} + int powernv_get_random_long(unsigned long *v); static inline int arch_get_random_seed_long(unsigned long *v) @@ -35,6 +40,10 @@ static inline int arch_get_random_seed_int(unsigned int *v) { return 0; } +static inline int arch_has_random_seed(void) +{ + return 0; +} #endif /* CONFIG_ARCH_RANDOM */ diff --git a/arch/x86/include/asm/archrandom.h b/arch/x86/include/asm/archrandom.h index ba064d5..c7ed4a6 100644 --- a/arch/x86/include/asm/archrandom.h +++ b/arch/x86/include/asm/archrandom.h @@ -100,6 +100,9 @@ GET_SEED(arch_get_random_seed_int, unsigned int, RDSEED_INT, ASM_NOP4); #endif /* CONFIG_X86_64 */ +#define arch_has_random() static_cpu_has(X86_FEATURE_RDRAND) +#define arch_has_random_seed() static_cpu_has(X86_FEATURE_RDSEED) + #endif /* CONFIG_ARCH_RANDOM */ extern void x86_init_rdrand(struct cpuinfo_x86 *c); diff --git a/drivers/char/random.c b/drivers/char/random.c index c35cee2..6b75713 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1307,6 +1307,9 @@ static int arch_random_refill(void) unsigned int i; unsigned long buf[nlongs]; + if (!arch_has_random_seed()) + return 0; + for (i = 0; i < nlongs; i++) { if (arch_get_random_seed_long(&buf[n])) n++; diff --git a/include/linux/random.h b/include/linux/random.h index ddaddec..e7a221a 100644 --- a/include/linux/random.h +++ b/include/linux/random.h @@ -72,6 +72,10 @@ static inline int arch_get_random_int(unsigned int *v) { return 0; } +static inline int arch_has_random(void) +{ + return 0; +} static inline int arch_get_random_seed_long(unsigned long *v) { return 0; @@ -80,6 +84,10 @@ static inline int arch_get_random_seed_int(unsigned int *v) { return 0; } +static inline int arch_has_random_seed(void) +{ + return 0; +} #endif /* Pseudo random number generator from numerical recipes. */ -- 1.8.5.3