From patchwork Thu Jul 2 16:31:15 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pierre Morel X-Patchwork-Id: 11639597 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 1023A739 for ; Thu, 2 Jul 2020 16:33:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0293B20720 for ; Thu, 2 Jul 2020 16:33:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726615AbgGBQdn (ORCPT ); Thu, 2 Jul 2020 12:33:43 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:31666 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726147AbgGBQdn (ORCPT ); Thu, 2 Jul 2020 12:33:43 -0400 Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 062GXa03131355; Thu, 2 Jul 2020 12:33:43 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 320sk0vqq5-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 02 Jul 2020 12:33:42 -0400 Received: from m0098393.ppops.net (m0098393.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 062GXgx1131844; Thu, 2 Jul 2020 12:33:42 -0400 Received: from ppma05fra.de.ibm.com (6c.4a.5195.ip4.static.sl-reverse.com [149.81.74.108]) by mx0a-001b2d01.pphosted.com with ESMTP id 320sk0vpr7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 02 Jul 2020 12:33:41 -0400 Received: from pps.filterd (ppma05fra.de.ibm.com [127.0.0.1]) by ppma05fra.de.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 062GRlaG027149; Thu, 2 Jul 2020 16:31:27 GMT Received: from b06cxnps4074.portsmouth.uk.ibm.com (d06relay11.portsmouth.uk.ibm.com [9.149.109.196]) by ppma05fra.de.ibm.com with ESMTP id 31wwr8aye5-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 02 Jul 2020 16:31:26 +0000 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 062GVOt326280144 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 2 Jul 2020 16:31:24 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B348811C04A; Thu, 2 Jul 2020 16:31:24 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 41D5011C050; Thu, 2 Jul 2020 16:31:24 +0000 (GMT) Received: from oc3016276355.ibm.com (unknown [9.145.146.43]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 2 Jul 2020 16:31:24 +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 v10 4/9] s390x: clock and delays calculations Date: Thu, 2 Jul 2020 18:31:15 +0200 Message-Id: <1593707480-23921-5-git-send-email-pmorel@linux.ibm.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1593707480-23921-1-git-send-email-pmorel@linux.ibm.com> References: <1593707480-23921-1-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=2020-07-02_09:2020-07-02,2020-07-02 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 cotscore=-2147483648 clxscore=1015 impostorscore=0 mlxlogscore=999 spamscore=0 mlxscore=0 suspectscore=1 phishscore=0 adultscore=0 priorityscore=1501 malwarescore=0 bulkscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2007020111 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