From patchwork Tue Jul 14 11:15:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pierre Morel X-Patchwork-Id: 11662351 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 717CB13A4 for ; Tue, 14 Jul 2020 11:17:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5FCEE2220D for ; Tue, 14 Jul 2020 11:17:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728023AbgGNLRI (ORCPT ); Tue, 14 Jul 2020 07:17:08 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:38282 "EHLO mx0b-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727812AbgGNLQO (ORCPT ); Tue, 14 Jul 2020 07:16:14 -0400 Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 06EB2TIr096600; Tue, 14 Jul 2020 07:16:13 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 3279du4dja-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 14 Jul 2020 07:16:13 -0400 Received: from m0098421.ppops.net (m0098421.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 06EBGDmu147889; Tue, 14 Jul 2020 07:16:13 -0400 Received: from ppma06fra.de.ibm.com (48.49.7a9f.ip4.static.sl-reverse.com [159.122.73.72]) by mx0a-001b2d01.pphosted.com with ESMTP id 3279du4dhg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 14 Jul 2020 07:16:13 -0400 Received: from pps.filterd (ppma06fra.de.ibm.com [127.0.0.1]) by ppma06fra.de.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 06EBAmo2016633; Tue, 14 Jul 2020 11:16:11 GMT Received: from b06avi18878370.portsmouth.uk.ibm.com (b06avi18878370.portsmouth.uk.ibm.com [9.149.26.194]) by ppma06fra.de.ibm.com with ESMTP id 328rbqrfr3-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 14 Jul 2020 11:16:11 +0000 Received: from b06wcsmtp001.portsmouth.uk.ibm.com (b06wcsmtp001.portsmouth.uk.ibm.com [9.149.105.160]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 06EBG9OL46399848 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 14 Jul 2020 11:16:09 GMT Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 649E8A4065; Tue, 14 Jul 2020 11:16:08 +0000 (GMT) Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BBF7EA405F; Tue, 14 Jul 2020 11:16:07 +0000 (GMT) Received: from oc3016276355.ibm.com (unknown [9.145.162.148]) by b06wcsmtp001.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 14 Jul 2020 11:16:07 +0000 (GMT) From: Pierre Morel To: kvm@vger.kernel.org Cc: linux-s390@vger.kernel.org, frankja@linux.ibm.com, david@redhat.com, thuth@redhat.com, cohuck@redhat.com, drjones@redhat.com Subject: [kvm-unit-tests PATCH v12 4/9] s390x: clock and delays calculations Date: Tue, 14 Jul 2020 13:15:43 +0200 Message-Id: <1594725348-10034-5-git-send-email-pmorel@linux.ibm.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1594725348-10034-1-git-send-email-pmorel@linux.ibm.com> References: <1594725348-10034-1-git-send-email-pmorel@linux.ibm.com> X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-07-14_02:2020-07-14,2020-07-14 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxlogscore=999 lowpriorityscore=0 clxscore=1015 phishscore=0 mlxscore=0 adultscore=0 bulkscore=0 spamscore=0 malwarescore=0 priorityscore=1501 suspectscore=1 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007140081 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org The hardware gives us a good definition of the microsecond, let's keep this information and let the routine accessing the hardware keep all the information and return microseconds. Calculate delays in microseconds and take care about wrapping around zero. Define values with macros and use inlines to keep the milliseconds interface. Signed-off-by: Pierre Morel Reviewed-by: Thomas Huth Acked-by: Cornelia Huck Reviewed-by: Janosch Frank --- lib/s390x/asm/time.h | 30 +++++++++++++++++++++++++++--- 1 file changed, 27 insertions(+), 3 deletions(-) diff --git a/lib/s390x/asm/time.h b/lib/s390x/asm/time.h index 1791380..7375aa2 100644 --- a/lib/s390x/asm/time.h +++ b/lib/s390x/asm/time.h @@ -13,14 +13,38 @@ #ifndef ASM_S390X_TIME_H #define ASM_S390X_TIME_H -static inline uint64_t get_clock_ms(void) +#define STCK_SHIFT_US (63 - 51) +#define STCK_MAX ((1UL << 52) - 1) + +static inline uint64_t get_clock_us(void) { uint64_t clk; asm volatile(" stck %0 " : : "Q"(clk) : "memory"); - /* Bit 51 is incrememented each microsecond */ - return (clk >> (63 - 51)) / 1000; + return clk >> STCK_SHIFT_US; +} + +static inline uint64_t get_clock_ms(void) +{ + return get_clock_us() / 1000; +} + +static inline void udelay(unsigned long us) +{ + unsigned long startclk = get_clock_us(); + unsigned long c; + + do { + c = get_clock_us(); + if (c < startclk) + c += STCK_MAX; + } while (c < startclk + us); +} + +static inline void mdelay(unsigned long ms) +{ + udelay(ms * 1000); } #endif