From patchwork Fri Apr 3 07:05:26 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolin Wang X-Patchwork-Id: 211048 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=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 3BD11C43331 for ; Fri, 3 Apr 2020 07:05:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 08A2620787 for ; Fri, 3 Apr 2020 07:05:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="MufWgAWf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389087AbgDCHFq (ORCPT ); Fri, 3 Apr 2020 03:05:46 -0400 Received: from mail-pj1-f67.google.com ([209.85.216.67]:36280 "EHLO mail-pj1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388472AbgDCHFq (ORCPT ); Fri, 3 Apr 2020 03:05:46 -0400 Received: by mail-pj1-f67.google.com with SMTP id nu11so2564110pjb.1; Fri, 03 Apr 2020 00:05:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :in-reply-to:references; bh=CrZe3I4PBsnuaIeN4buPPytwyP1ByhSDiM4SeWiS8VM=; b=MufWgAWfvPyyz50E4MGAbCI4cA4XL24r3qP/DblFxOdU59p/85Lge88T3t66lyfi+F 7R5fKLXAZAGk4aFAUGhBn7tDLKpYGaxtUrw0I2Qe5SZLaK/jmRVGnwEvYdiie0fWppQR wd+k/eGSaD/pk638UPDO32UPEFfrilGKJsWDiBCN4R5PXPehOGuDnsaH9BO4wAKrflc+ pPixaPXAtJD+3FYFLnGpdw6PaheBWbzIzNDd+9/SjGUOALyu8jo7ra/rFdNG9LdlkE6y bXn+4aGMxa425vrfnvkTn6cSMJUOr7Zl6WCzjWphryJhCz5d9OvWyp9Nv5Oq6IVEC4sy 8bGg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:in-reply-to:references; bh=CrZe3I4PBsnuaIeN4buPPytwyP1ByhSDiM4SeWiS8VM=; b=eTk/bvtwWrg2La6SNd2uKJcXx4g8nq6lIH4HHIrvrka636NPYnG3DrMRbjQn5vrO89 g//tEnbi+doV2TzBQkZ2vLElfMRPLSizD0pkzVAvXUNcaB5IMh11PZsNZEJ7cmw1VP1W 9gHCGT4r39Zj49CLnp+YSIMD1dLI07JV+UFgSt0Dfky+WKpPflt9lfiFS+IlCE63CT5C FPgOW0GGV7yN8h3D8gitXVl8wEwuC1nbDEUKzQ5FZWmpOH8twToyDKFTfVSNssn89z1k jxWnUX09y6vFeqaPbCKbPFNWAkDjCmYg+Qq5xuyg/kHGff/5KA9UmRzUmKSaXzw+dWGO XwWQ== X-Gm-Message-State: AGi0PuYyP4xz36Jn0/HGP9WqkKefDowZaFkwYZO/8sjVRvEONf8P325h CkjHZJW3VImQ0KNCBMSDnlk= X-Google-Smtp-Source: APiQypJvf9N/GAQ/pZeL8u+QLoEXYsFUpcobXFllMB4c0bcfvpd7djx+HyVORGQY98kg28CSl8uQSw== X-Received: by 2002:a17:90a:9f09:: with SMTP id n9mr7921682pjp.157.1585897544918; Fri, 03 Apr 2020 00:05:44 -0700 (PDT) Received: from sh03840pcu.spreadtrum.com ([117.18.48.82]) by smtp.gmail.com with ESMTPSA id u18sm5138701pfl.40.2020.04.03.00.05.42 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 03 Apr 2020 00:05:44 -0700 (PDT) From: Baolin Wang To: adrian.hunter@intel.com, ulf.hansson@linaro.org Cc: orsonzhai@gmail.com, zhang.lyra@gmail.com, baolin.wang7@gmail.com, arnd@arndb.de, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 1/3] mmc: host: Introduce the request_atomic() for the host Date: Fri, 3 Apr 2020 15:05:26 +0800 Message-Id: <04c25ff9f9b17d41d734c498e4be61dee745bb30.1585896945.git.baolin.wang7@gmail.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: References: In-Reply-To: References: Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org The SD host controller can process one request in the atomic context if the card is nonremovable, which means we can submit next request in the irq hard handler when using the MMC host software queue to reduce the latency. Thus this patch adds a new API request_atomic() for the host controller, as well as adding support for host software queue to submit a request by the new request_atomic() API. Moreover there is an unusual case that the card is busy when trying to send a command, and we can not polling the card status in interrupt context by using request_atomic() to dispatch requests. Thus we should queue a work to try again in the non-atomic context in case the host releases the busy signal later. Suggested-by: Adrian Hunter Signed-off-by: Baolin Wang --- drivers/mmc/host/mmc_hsq.c | 29 ++++++++++++++++++++++++++++- drivers/mmc/host/mmc_hsq.h | 1 + include/linux/mmc/host.h | 3 +++ 3 files changed, 32 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/host/mmc_hsq.c b/drivers/mmc/host/mmc_hsq.c index b90b2c9..a57f802 100644 --- a/drivers/mmc/host/mmc_hsq.c +++ b/drivers/mmc/host/mmc_hsq.c @@ -16,11 +16,20 @@ #define HSQ_NUM_SLOTS 64 #define HSQ_INVALID_TAG HSQ_NUM_SLOTS +static void mmc_hsq_retry_handler(struct work_struct *work) +{ + struct mmc_hsq *hsq = container_of(work, struct mmc_hsq, retry_work); + struct mmc_host *mmc = hsq->mmc; + + mmc->ops->request(mmc, hsq->mrq); +} + static void mmc_hsq_pump_requests(struct mmc_hsq *hsq) { struct mmc_host *mmc = hsq->mmc; struct hsq_slot *slot; unsigned long flags; + int ret = 0; spin_lock_irqsave(&hsq->lock, flags); @@ -42,7 +51,24 @@ static void mmc_hsq_pump_requests(struct mmc_hsq *hsq) spin_unlock_irqrestore(&hsq->lock, flags); - mmc->ops->request(mmc, hsq->mrq); + if (mmc->ops->request_atomic) + ret = mmc->ops->request_atomic(mmc, hsq->mrq); + else + mmc->ops->request(mmc, hsq->mrq); + + /* + * If returning BUSY from request_atomic(), which means the card + * may be busy now, and we should change to non-atomic context to + * try again for this unusual case, to avoid time-consuming operations + * in the atomic context. + * + * Note: we just give a warning for other error cases, since the host + * driver will handle them. + */ + if (ret == -EBUSY) + schedule_work(&hsq->retry_work); + else + WARN_ON_ONCE(ret && ret != -EBUSY); } static void mmc_hsq_update_next_tag(struct mmc_hsq *hsq, int remains) @@ -325,6 +351,7 @@ int mmc_hsq_init(struct mmc_hsq *hsq, struct mmc_host *mmc) hsq->mmc->cqe_private = hsq; mmc->cqe_ops = &mmc_hsq_ops; + INIT_WORK(&hsq->retry_work, mmc_hsq_retry_handler); spin_lock_init(&hsq->lock); init_waitqueue_head(&hsq->wait_queue); diff --git a/drivers/mmc/host/mmc_hsq.h b/drivers/mmc/host/mmc_hsq.h index 18b9cf5..ffdd9cd 100644 --- a/drivers/mmc/host/mmc_hsq.h +++ b/drivers/mmc/host/mmc_hsq.h @@ -12,6 +12,7 @@ struct mmc_hsq { wait_queue_head_t wait_queue; struct hsq_slot *slot; spinlock_t lock; + struct work_struct retry_work; int next_tag; int num_slots; diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index c318fb5..d4a50e5d 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -92,6 +92,9 @@ struct mmc_host_ops { int err); void (*pre_req)(struct mmc_host *host, struct mmc_request *req); void (*request)(struct mmc_host *host, struct mmc_request *req); + /* Submit one request to host in atomic context. */ + int (*request_atomic)(struct mmc_host *host, + struct mmc_request *req); /* * Avoid calling the next three functions too often or in a "fast