From patchwork Wed Aug 26 18:05:35 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Vivier X-Patchwork-Id: 510982 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 587DE140338 for ; Thu, 27 Aug 2015 04:08:07 +1000 (AEST) Received: from localhost ([::1]:39858 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZUf7F-00082P-Cu for incoming@patchwork.ozlabs.org; Wed, 26 Aug 2015 14:08:05 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50255) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZUf53-0004OU-SJ for qemu-devel@nongnu.org; Wed, 26 Aug 2015 14:05:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZUf53-0000fM-2i for qemu-devel@nongnu.org; Wed, 26 Aug 2015 14:05:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50063) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZUf52-0000fH-Ui; Wed, 26 Aug 2015 14:05:49 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (Postfix) with ESMTPS id 888F38EA32; Wed, 26 Aug 2015 18:05:48 +0000 (UTC) Received: from thinkpad.redhat.com (vpn1-5-59.ams2.redhat.com [10.36.5.59]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t7QI5cZP026740; Wed, 26 Aug 2015 14:05:47 -0400 From: Laurent Vivier To: qemu-devel@nongnu.org, Peter Maydell , crosthwaitepeter@gmail.com, qemu-trivial@nongnu.org Date: Wed, 26 Aug 2015 20:05:35 +0200 Message-Id: <1440612338-5912-5-git-send-email-lvivier@redhat.com> In-Reply-To: <1440612338-5912-1-git-send-email-lvivier@redhat.com> References: <1440612338-5912-1-git-send-email-lvivier@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v2 4/7] arm: clarify the use of muldiv64() X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org muldiv64() is used to convert microseconds into CPU ticks. But it is not clear and not commented. This patch uses macro to clearly identify what is used: time, CPU frequency and ticks. For an elapsed time and a given frequency, we compute how many ticks we have. Signed-off-by: Laurent Vivier --- v2: replace "arm: remove muldiv64()" target-arm/helper.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/target-arm/helper.c b/target-arm/helper.c index 7df1f06..4455761 100644 --- a/target-arm/helper.c +++ b/target-arm/helper.c @@ -12,6 +12,8 @@ #include /* For crc32 */ #include "exec/semihost.h" +#define ARM_CPU_FREQ 1000000000 /* FIXME: 1 GHz, should be configurable */ + #ifndef CONFIG_USER_ONLY static inline bool get_phys_addr(CPUARMState *env, target_ulong address, int access_type, ARMMMUIdx mmu_idx, @@ -678,8 +680,8 @@ void pmccntr_sync(CPUARMState *env) { uint64_t temp_ticks; - temp_ticks = muldiv64(qemu_clock_get_us(QEMU_CLOCK_VIRTUAL), - get_ticks_per_sec(), 1000000); + temp_ticks = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), + ARM_CPU_FREQ, NANOSECONDS_PER_SECOND); if (env->cp15.c9_pmcr & PMCRD) { /* Increment once every 64 processor clock cycles */ @@ -717,8 +719,8 @@ static uint64_t pmccntr_read(CPUARMState *env, const ARMCPRegInfo *ri) return env->cp15.c15_ccnt; } - total_ticks = muldiv64(qemu_clock_get_us(QEMU_CLOCK_VIRTUAL), - get_ticks_per_sec(), 1000000); + total_ticks = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), + ARM_CPU_FREQ, NANOSECONDS_PER_SECOND); if (env->cp15.c9_pmcr & PMCRD) { /* Increment once every 64 processor clock cycles */ @@ -738,8 +740,8 @@ static void pmccntr_write(CPUARMState *env, const ARMCPRegInfo *ri, return; } - total_ticks = muldiv64(qemu_clock_get_us(QEMU_CLOCK_VIRTUAL), - get_ticks_per_sec(), 1000000); + total_ticks = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), + ARM_CPU_FREQ, NANOSECONDS_PER_SECOND); if (env->cp15.c9_pmcr & PMCRD) { /* Increment once every 64 processor clock cycles */