From patchwork Thu Aug 8 15:54:34 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Suwan Kim X-Patchwork-Id: 11084449 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CD80913B1 for ; Thu, 8 Aug 2019 15:55:06 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BAFBC28B92 for ; Thu, 8 Aug 2019 15:55:06 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AF3F6289F0; Thu, 8 Aug 2019 15:55:06 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 437A228B8D for ; Thu, 8 Aug 2019 15:55:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403994AbfHHPzB (ORCPT ); Thu, 8 Aug 2019 11:55:01 -0400 Received: from mail-pf1-f194.google.com ([209.85.210.194]:42437 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732698AbfHHPzB (ORCPT ); Thu, 8 Aug 2019 11:55:01 -0400 Received: by mail-pf1-f194.google.com with SMTP id q10so44321847pff.9; Thu, 08 Aug 2019 08:55:00 -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 :mime-version:content-transfer-encoding; bh=hCmBSrNvfnQh4RGFGxzKU7/e+KnBtf1L1cfQCo9aVVE=; b=jr8Wxz0rO9NjkhVbYLc8a65PdglxPLiMMa1xceUlCaO0VgA9oPkI38ZN6REK63GbXy AOBi/CHTbk9Je6ZRFDzzD2YKtZlAFVpcL644Bxn2A43VklvUr+TXdOLnYcrxEb60wuAU /QjOkRve3Om5AhqNzUOJYfPEj99rNtHto73VKLWCktH9USFFNU2xVAXoz63Yb84xwS1Y 6vBJrbUKOt+03WKFjAFduufjwPvY5j9FSHmFYGPOPNIMLuAQKKw9Y37CSOFhrQ7lH/2d mp7+hgatYUC4vxo6egCL/aoTZ1KNzX9UpqLe8Ib1pMOjSSYoEYvJHcpSQWdwuO1fjHY4 Nw8g== 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:mime-version:content-transfer-encoding; bh=hCmBSrNvfnQh4RGFGxzKU7/e+KnBtf1L1cfQCo9aVVE=; b=JbgcQMpNVYH8XxSOzS/h75y6eYUU31h+eN9OgTbkXVho+9TRnz7ejra0umZLryd5fg sUYwHP8qK6PXQXD3dr/uZcnyxVuRMr6D19PtwUu8vHMB6pRYhZFshd6RYaoNECMKD1ny xYegEDukfrZwySZuL8FN/bObsGkGtzaCfrfiG1Au8gHvCkaVFigMxSYPjsUPINKdxBIz IcOzn4jgRVIzFzu54CM4UZf+XZUSAYdUA45dNglEhzSGNw9RvZDmelHAK8uSn9lwMPNJ d0LqUJ08a04cwJGjHBn2v0oWEozBIS8WDe7UMAIzNfMUKsYMMjA83HBL9CotCTvfdsWG 7SHg== X-Gm-Message-State: APjAAAVTJRi8LrLfnqV52n3evFltrxLCa5+Gvscw2wtFB7SxnslCmkIz lPXcjEuxfnw2SBzXh+4kISY= X-Google-Smtp-Source: APXvYqxs8nTqj7eeCJOR6O+Gah3tlqYLwqVsxJRjBqL6xwJgQ7zMFsqyQIZocYVHTwm7OzsQ0ig9vQ== X-Received: by 2002:a63:58c:: with SMTP id 134mr13926734pgf.106.1565279700330; Thu, 08 Aug 2019 08:55:00 -0700 (PDT) Received: from localhost.localdomain ([125.142.23.13]) by smtp.googlemail.com with ESMTPSA id c98sm3054805pje.1.2019.08.08.08.54.58 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Thu, 08 Aug 2019 08:54:59 -0700 (PDT) From: Suwan Kim To: shuah@kernel.org, valentina.manea.m@gmail.com, gregkh@linuxfoundation.org, stern@rowland.harvard.edu Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Suwan Kim Subject: [PATCH v5 1/2] usbip: Skip DMA mapping and unmapping for urb at vhci Date: Fri, 9 Aug 2019 00:54:34 +0900 Message-Id: <20190808155435.10050-2-suwan.kim027@gmail.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190808155435.10050-1-suwan.kim027@gmail.com> References: <20190808155435.10050-1-suwan.kim027@gmail.com> MIME-Version: 1.0 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP vhci doesn’t do DMA for remote device. Actually, the real DMA operation is done by network card driver. vhci just passes virtual address of the buffer to the network stack, so vhci doesn’t use and need dma address of the buffer of the URB. But HCD provides DMA mapping and unmapping function by default. Moreover, it causes unnecessary DMA mapping and unmapping which will be done again at the NIC driver and it wastes CPU cycles. So, implement map_urb_for_dma and unmap_urb_for_dma function for vhci in order to skip the DMA mapping and unmapping procedure. When it comes to supporting SG for vhci, it is useful to use native SG list (urb->num_sgs) instead of mapped SG list because DMA mapping fnuction can adjust the number of SG list (urb->num_mapped_sgs). And vhci_map_urb_for_dma() prevents isoc pipe from using SG as hcd_map_urb_for_dma() does. Signed-off-by: Suwan Kim Reviewed-by: Shuah Khan Acked-by: Shuah Khan --- v4 - v5 - Replace pr_err() with dev_err() in the error path. v3 - v4 - Replace WARN_ON() with pr_err() in the error path. v2 - v3 - Move setting URB_DMA_MAP_SG flag to the patch 2. - Prevent isoc pipe from using SG buffer. v1 - v2 - Add setting URB_DMA_MAP_SG flag in urb->transfer_flags to tell stub driver to use SG buffer. --- drivers/usb/usbip/vhci_hcd.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c index 000ab7225717..ea82b932a2f9 100644 --- a/drivers/usb/usbip/vhci_hcd.c +++ b/drivers/usb/usbip/vhci_hcd.c @@ -1288,6 +1288,22 @@ static int vhci_free_streams(struct usb_hcd *hcd, struct usb_device *udev, return 0; } +static int vhci_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb, + gfp_t mem_flags) +{ + if (usb_endpoint_xfer_isoc(&urb->ep->desc) && urb->num_sgs) { + dev_err(&urb->dev->dev, "SG is not supported for isochronous transfer\n"); + return -EINVAL; + } + + return 0; +} + +static void vhci_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb) +{ + dev_dbg(hcd->self.controller, "vhci does not unmap urb for dma\n"); +} + static const struct hc_driver vhci_hc_driver = { .description = driver_name, .product_desc = driver_desc, @@ -1304,6 +1320,9 @@ static const struct hc_driver vhci_hc_driver = { .get_frame_number = vhci_get_frame_number, + .map_urb_for_dma = vhci_map_urb_for_dma, + .unmap_urb_for_dma = vhci_unmap_urb_for_dma, + .hub_status_data = vhci_hub_status, .hub_control = vhci_hub_control, .bus_suspend = vhci_bus_suspend,