From patchwork Tue Mar 24 18:24:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julian Wiedmann X-Patchwork-Id: 221949 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B7CDC2BAEE for ; Tue, 24 Mar 2020 18:25:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 72BEB2076E for ; Tue, 24 Mar 2020 18:25:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727932AbgCXSZE (ORCPT ); Tue, 24 Mar 2020 14:25:04 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:18328 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727791AbgCXSZD (ORCPT ); Tue, 24 Mar 2020 14:25:03 -0400 Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 02OI4HZ1093909 for ; Tue, 24 Mar 2020 14:25:02 -0400 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 2ywe7tp25g-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 24 Mar 2020 14:25:02 -0400 Received: from localhost by e06smtp02.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 24 Mar 2020 18:24:54 -0000 Received: from b06wcsmtp001.portsmouth.uk.ibm.com (b06wcsmtp001.portsmouth.uk.ibm.com [9.149.105.160]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 02OIOtuP54132910 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 24 Mar 2020 18:24:55 GMT Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 131EBA4060; Tue, 24 Mar 2020 18:24:55 +0000 (GMT) Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D0293A4066; Tue, 24 Mar 2020 18:24:54 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by b06wcsmtp001.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 24 Mar 2020 18:24:54 +0000 (GMT) From: Julian Wiedmann To: David Miller Cc: netdev , linux-s390 , Heiko Carstens , Ursula Braun , Julian Wiedmann Subject: [PATCH net-next 01/11] s390/qeth: simplify RX buffer tracking Date: Tue, 24 Mar 2020 19:24:38 +0100 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200324182448.95362-1-jwi@linux.ibm.com> References: <20200324182448.95362-1-jwi@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 20032418-0008-0000-0000-000003632A3D X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 20032418-0009-0000-0000-00004A849776 Message-Id: <20200324182448.95362-2-jwi@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138, 18.0.645 definitions=2020-03-24_05:2020-03-23,2020-03-24 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxlogscore=999 impostorscore=0 bulkscore=0 phishscore=0 spamscore=0 adultscore=0 mlxscore=0 lowpriorityscore=0 suspectscore=0 malwarescore=0 priorityscore=1501 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2003240090 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Since RX buffers may contain multiple packets, qeth's NAPI poll code can exhaust its budget in the middle of an RX buffer. Thus we keep track of our current position within the active RX buffer, so we can resume processing here in the next NAPI poll period. Clean up that code by tracking the index of the active buffer element, instead of a pointer to it. Also simplify the code that advances to the next RX buffer when the current buffer has been fully processed. Signed-off-by: Julian Wiedmann --- arch/s390/include/asm/qdio.h | 2 ++ drivers/s390/net/qeth_core.h | 2 +- drivers/s390/net/qeth_core_main.c | 30 ++++++++++++------------------ 3 files changed, 15 insertions(+), 19 deletions(-) diff --git a/arch/s390/include/asm/qdio.h b/arch/s390/include/asm/qdio.h index 1e3517b0518b..6ea3a1d5fe7f 100644 --- a/arch/s390/include/asm/qdio.h +++ b/arch/s390/include/asm/qdio.h @@ -222,6 +222,8 @@ struct qdio_buffer { struct qdio_buffer_element element[QDIO_MAX_ELEMENTS_PER_BUFFER]; } __attribute__ ((packed, aligned(256))); +#define QDIO_ELEMENT_NO(buf, element) (element - &buf->element[0]) + /** * struct sl_element - storage list entry * @sbal: absolute SBAL address diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h index 6eb431c194bd..9840d4fab010 100644 --- a/drivers/s390/net/qeth_core.h +++ b/drivers/s390/net/qeth_core.h @@ -752,7 +752,7 @@ enum qeth_addr_disposition { struct qeth_rx { int b_count; int b_index; - struct qdio_buffer_element *b_element; + u8 buf_element; int e_offset; int qdio_err; }; diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c index bd3adbb6ad50..b25d44c83997 100644 --- a/drivers/s390/net/qeth_core_main.c +++ b/drivers/s390/net/qeth_core_main.c @@ -5332,14 +5332,13 @@ static inline int qeth_is_last_sbale(struct qdio_buffer_element *sbale) } static int qeth_extract_skb(struct qeth_card *card, - struct qeth_qdio_buffer *qethbuffer, - struct qdio_buffer_element **__element, + struct qeth_qdio_buffer *qethbuffer, u8 *element_no, int *__offset) { - struct qdio_buffer_element *element = *__element; struct qeth_priv *priv = netdev_priv(card->dev); struct qdio_buffer *buffer = qethbuffer->buffer; struct napi_struct *napi = &card->napi; + struct qdio_buffer_element *element; unsigned int linear_len = 0; bool uses_frags = false; int offset = *__offset; @@ -5349,6 +5348,8 @@ static int qeth_extract_skb(struct qeth_card *card, struct sk_buff *skb; int skb_len = 0; + element = &buffer->element[*element_no]; + next_packet: /* qeth_hdr must not cross element boundaries */ while (element->length < offset + sizeof(struct qeth_hdr)) { @@ -5504,7 +5505,7 @@ static int qeth_extract_skb(struct qeth_card *card, if (!skb) goto next_packet; - *__element = element; + *element_no = QDIO_ELEMENT_NO(buffer, element); *__offset = offset; qeth_receive_skb(card, skb, hdr, uses_frags); @@ -5519,7 +5520,7 @@ static int qeth_extract_skbs(struct qeth_card *card, int budget, *done = false; while (budget) { - if (qeth_extract_skb(card, buf, &card->rx.b_element, + if (qeth_extract_skb(card, buf, &card->rx.buf_element, &card->rx.e_offset)) { *done = true; break; @@ -5550,10 +5551,6 @@ int qeth_poll(struct napi_struct *napi, int budget) card->rx.b_count = 0; break; } - card->rx.b_element = - &card->qdio.in_q->bufs[card->rx.b_index] - .buffer->element[0]; - card->rx.e_offset = 0; } while (card->rx.b_count) { @@ -5572,15 +5569,12 @@ int qeth_poll(struct napi_struct *napi, int budget) buffer->pool_entry); qeth_queue_input_buffer(card, card->rx.b_index); card->rx.b_count--; - if (card->rx.b_count) { - card->rx.b_index = - QDIO_BUFNR(card->rx.b_index + 1); - card->rx.b_element = - &card->qdio.in_q - ->bufs[card->rx.b_index] - .buffer->element[0]; - card->rx.e_offset = 0; - } + + /* Step forward to next buffer: */ + card->rx.b_index = + QDIO_BUFNR(card->rx.b_index + 1); + card->rx.buf_element = 0; + card->rx.e_offset = 0; } if (work_done >= budget)