From mboxrd@z Thu Jan 1 00:00:00 1970 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=-17.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 F21F6C433E6 for ; Sun, 14 Mar 2021 05:11:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C7DBA64EC6 for ; Sun, 14 Mar 2021 05:11:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233188AbhCNFLE (ORCPT ); Sun, 14 Mar 2021 00:11:04 -0500 Received: from mail.kernel.org ([198.145.29.99]:54084 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232854AbhCNFKy (ORCPT ); Sun, 14 Mar 2021 00:10:54 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id E111C64E33; Sun, 14 Mar 2021 05:10:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1615698654; bh=sHT4pNllXwbmu1pa2C2GAmEhwcyj5rsbGVi7SDbrN2g=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=DGkHqWOMHfR8VzS5/F8lpqsBeEPuRLo/mBa58u4TZaBDDbUN5fTN9d0dVFIuYyU/L 1zsLqSGzRLA8zQNshWLI6wNncn1JNy/nna26G/bCDYXANhLjBR3rxkCZ4ZGuYnN/aL vhW7aLuU8CtS0cMG1T7tKewAF83uzEENZVuotYkwOojpQ8g+qXiEM7KiWA0po11Zio DLeC2Qn+AUXcxfBGwXlVrPVjUMBpq1TuIXwXHjqAEZD/w0wEeeAQhpxFVljWHlRpCb voEvH8GvLHlpPM8kvx7yV+vZ/KpAXpMgqsbKz6mvEA1o5HlQYqFcGN1h9RVQDB0dcT RgkNrtp3gv+UA== Date: Sun, 14 Mar 2021 13:10:48 +0800 From: Peter Chen To: Sanket Parmar Cc: pawell@cadence.com, a-govindraju@ti.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, kurahul@cadence.com, gregkh@linuxfoundation.org, kishon@ti.com Subject: Re: [PATCH 2/2] usb: cdns3: Optimize DMA request buffer allocation Message-ID: <20210314051048.GA30122@b29397-desktop> References: <1615267180-9289-1-git-send-email-sparmar@cadence.com> <1615267180-9289-2-git-send-email-sparmar@cadence.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1615267180-9289-2-git-send-email-sparmar@cadence.com> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On 21-03-09 06:19:40, Sanket Parmar wrote: > dma_alloc_coherent() might fail on the platform with a small DMA region. > > To avoid such failure in cdns3_prepare_aligned_request_buf(), > dma_alloc_coherent() is replaced with kmalloc and dma_map API to > allocate aligned request buffer of dynamic length. > > Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver") The comment with the 1st patch, it is not a bug-fix. > Reported-by: Aswath Govindraju > Signed-off-by: Sanket Parmar > --- > drivers/usb/cdns3/cdns3-gadget.c | 73 +++++++++++++++++++++++++------------ > drivers/usb/cdns3/cdns3-gadget.h | 2 + > 2 files changed, 51 insertions(+), 24 deletions(-) > > diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c > index 5f51215..b4955ce 100644 > --- a/drivers/usb/cdns3/cdns3-gadget.c > +++ b/drivers/usb/cdns3/cdns3-gadget.c > @@ -818,10 +818,26 @@ void cdns3_gadget_giveback(struct cdns3_endpoint *priv_ep, > usb_gadget_unmap_request_by_dev(priv_dev->sysdev, request, > priv_ep->dir); > > - if ((priv_req->flags & REQUEST_UNALIGNED) && > - priv_ep->dir == USB_DIR_OUT && !request->status) > - memcpy(request->buf, priv_req->aligned_buf->buf, > - request->length); > + if ((priv_req->flags & REQUEST_UNALIGNED) && priv_req->aligned_buf) { > + struct cdns3_aligned_buf *buf; > + > + buf = priv_req->aligned_buf; > + dma_unmap_single(priv_dev->sysdev, buf->dma, buf->size, > + buf->dir); > + priv_req->flags &= ~REQUEST_UNALIGNED; > + > + if (priv_ep->dir == USB_DIR_OUT && !request->status) { > + memcpy(request->buf, priv_req->aligned_buf->buf, > + request->length); > + } > + > + trace_cdns3_free_aligned_request(priv_req); > + priv_req->aligned_buf->in_use = 0; > + queue_work(system_freezable_wq, > + &priv_dev->aligned_buf_wq); > + priv_req->aligned_buf = NULL; > + > + } > > priv_req->flags &= ~(REQUEST_PENDING | REQUEST_UNALIGNED); > /* All TRBs have finished, clear the counter */ > @@ -883,8 +899,7 @@ static void cdns3_free_aligned_request_buf(struct work_struct *work) > * interrupts. > */ > spin_unlock_irqrestore(&priv_dev->lock, flags); > - dma_free_coherent(priv_dev->sysdev, buf->size, > - buf->buf, buf->dma); > + kfree(buf->buf); > kfree(buf); > spin_lock_irqsave(&priv_dev->lock, flags); > } > @@ -910,27 +925,16 @@ static int cdns3_prepare_aligned_request_buf(struct cdns3_request *priv_req) > if (!buf) > return -ENOMEM; > > - buf->size = priv_req->request.length; > + buf->size = usb_endpoint_dir_out(priv_ep->endpoint.desc) ? > + usb_ep_align(&(priv_ep->endpoint), priv_req->request.length) > + : priv_req->request.length; > > - buf->buf = dma_alloc_coherent(priv_dev->sysdev, > - buf->size, > - &buf->dma, > - GFP_ATOMIC); > + buf->buf = kmalloc(buf->size, GFP_ATOMIC); > if (!buf->buf) { > kfree(buf); > return -ENOMEM; > } > > - if (priv_req->aligned_buf) { > - trace_cdns3_free_aligned_request(priv_req); > - priv_req->aligned_buf->in_use = 0; > - queue_work(system_freezable_wq, > - &priv_dev->aligned_buf_wq); > - } > - > - buf->in_use = 1; > - priv_req->aligned_buf = buf; > - > list_add_tail(&buf->list, > &priv_dev->aligned_buf_list); > } > @@ -940,6 +944,27 @@ static int cdns3_prepare_aligned_request_buf(struct cdns3_request *priv_req) > priv_req->request.length); > } > > + if (priv_req->aligned_buf) { > + trace_cdns3_free_aligned_request(priv_req); > + priv_req->aligned_buf->in_use = 0; > + queue_work(system_freezable_wq, > + &priv_dev->aligned_buf_wq); @Pawel, do you remember when this condition is met? > + } > + > + buf->dir = priv_ep->dir ? DMA_TO_DEVICE : DMA_FROM_DEVICE; > + buf->in_use = 1; > + priv_req->aligned_buf = buf; > + > + buf->dma = dma_map_single(priv_dev->sysdev, buf->buf, buf->size, > + buf->dir); > + > + if (dma_mapping_error(priv_dev->sysdev, buf->dma)) { > + dev_err(priv_dev->dev, "Failed to map buffer\n"); > + kfree(buf->buf); > + kfree(buf); > + return -EFAULT; > + } > + > priv_req->flags |= REQUEST_UNALIGNED; > trace_cdns3_prepare_aligned_request(priv_req); > > @@ -3088,11 +3113,11 @@ static void cdns3_gadget_exit(struct cdns *cdns) > struct cdns3_aligned_buf *buf; > > buf = cdns3_next_align_buf(&priv_dev->aligned_buf_list); > - dma_free_coherent(priv_dev->sysdev, buf->size, > - buf->buf, > - buf->dma); > + dma_unmap_single(priv_dev->sysdev, buf->dma, buf->size, > + buf->dir); It only needs to DMA unmap after DMA has completed, this buf will not be used, otherwise, the kfree below will cause issue. > > list_del(&buf->list); > + kfree(buf->buf); > kfree(buf); > } > > diff --git a/drivers/usb/cdns3/cdns3-gadget.h b/drivers/usb/cdns3/cdns3-gadget.h > index ecf9b91..c5660f2 100644 > --- a/drivers/usb/cdns3/cdns3-gadget.h > +++ b/drivers/usb/cdns3/cdns3-gadget.h > @@ -12,6 +12,7 @@ > #ifndef __LINUX_CDNS3_GADGET > #define __LINUX_CDNS3_GADGET > #include > +#include > > /* > * USBSS-DEV register interface. > @@ -1205,6 +1206,7 @@ struct cdns3_aligned_buf { > void *buf; > dma_addr_t dma; > u32 size; > + enum dma_data_direction dir; > unsigned in_use:1; > struct list_head list; > }; > -- > 1.7.1 > -- Thanks, Peter Chen