From patchwork Tue Apr 12 17:27:54 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Jason A. Donenfeld" X-Patchwork-Id: 12811015 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7843FC433EF for ; Tue, 12 Apr 2022 17:30:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243245AbiDLRdO (ORCPT ); Tue, 12 Apr 2022 13:33:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41016 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358186AbiDLRdL (ORCPT ); Tue, 12 Apr 2022 13:33:11 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D132D2F003; Tue, 12 Apr 2022 10:30:51 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id B5659B81F5D; Tue, 12 Apr 2022 17:30:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 28CC1C385A8; Tue, 12 Apr 2022 17:30:45 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="T/o5MTm4" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1649784644; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=gMuiTScdp7c+tPntikHvEFRo+YYqSeslWu8YJFI7ND8=; b=T/o5MTm4nPPUUHDTZbOx4bZYhhv1IWhyqAYPcEo30+zAtqeCY9MBgw2oz3E9hK+K97B+LX VzJafAUAE8rt36dyZn/uE6s64UaWvyzjbQ8gM4Zwrq3eq3GpRUCgDsLvHbbybJqL+1VMHd 8XCdSDUrNtcVHntc/zmYVpWb8/d62Vw= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 987d3c63 (TLSv1.3:AEAD-AES256-GCM-SHA384:256:NO); Tue, 12 Apr 2022 17:30:43 +0000 (UTC) From: "Jason A. Donenfeld" To: linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, tglx@linutronix.de, arnd@arndb.de Cc: "Jason A. Donenfeld" , Theodore Ts'o , Dominik Brodowski , Russell King , Catalin Marinas , Will Deacon , Geert Uytterhoeven , Thomas Bogendoerfer , Paul Walmsley , Palmer Dabbelt , Albert Ou , "David S . Miller" , Richard Weinberger , Anton Ivanov , Johannes Berg , Ingo Molnar , Borislav Petkov , Dave Hansen , "H . Peter Anvin" , Chris Zankel , Max Filippov , John Stultz , Stephen Boyd , Dinh Nguyen , linux-arm-kernel@lists.infradead.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, x86@kernel.org, linux-xtensa@linux-xtensa.org Subject: [PATCH v3 10/10] xtensa: use fallback for random_get_entropy() instead of zero Date: Tue, 12 Apr 2022 19:27:54 +0200 Message-Id: <20220412172754.149498-11-Jason@zx2c4.com> In-Reply-To: <20220412172754.149498-1-Jason@zx2c4.com> References: <20220412172754.149498-1-Jason@zx2c4.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org In the event that random_get_entropy() can't access a cycle counter or similar, falling back to returning 0 is really not the best we can do. Instead, at least calling random_get_entropy_fallback() would be preferable, because that always needs to return _something_, even falling back to jiffies eventually. It's not as though random_get_entropy_fallback() is super high precision or guaranteed to be entropic, but basically anything that's not zero all the time is better than returning zero all the time. This is accomplished by just including the asm-generic code like on other architectures, which means we can get rid of the empty stub function here. Cc: Thomas Gleixner Cc: Arnd Bergmann Cc: Max Filippov Signed-off-by: Jason A. Donenfeld --- arch/xtensa/include/asm/timex.h | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/xtensa/include/asm/timex.h b/arch/xtensa/include/asm/timex.h index 233ec75e60c6..3f2462f2d027 100644 --- a/arch/xtensa/include/asm/timex.h +++ b/arch/xtensa/include/asm/timex.h @@ -29,10 +29,6 @@ extern unsigned long ccount_freq; -typedef unsigned long long cycles_t; - -#define get_cycles() (0) - void local_timer_setup(unsigned cpu); /* @@ -59,4 +55,6 @@ static inline void set_linux_timer (unsigned long ccompare) xtensa_set_sr(ccompare, SREG_CCOMPARE + LINUX_TIMER); } +#include + #endif /* _XTENSA_TIMEX_H */