From patchwork Wed Nov 6 08:32:58 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guan-Yu Lin X-Patchwork-Id: 841356 Received: from mail-yw1-f202.google.com (mail-yw1-f202.google.com [209.85.128.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B58CE1D61B1 for ; Wed, 6 Nov 2024 08:35:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730882139; cv=none; b=kkIlCa6wTxJGi5HCLhvYzeoG7+Hqlgp/E6iOTU++ut0MmDPbxhBP6CWr1pHk/z+v8wDZZ35dBiEK4uP1Qb6ZJxNumpjGTK9iR1F/FDx55Fe+ow3QfRcoxy0QATp6t/dKXNVjyKIkGXJz74i8oT5TxyXbzsH57Rx9+aKr8UoVRWE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730882139; c=relaxed/simple; bh=JqrI/y417lO2lfXhgkqQF0tA66aDyMukgTr/nW0zek4=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=hezes8H+IejMsvIonHebiFgNd95btXS4bUONGVZm7RzaS0h+vI30M+n67C3zpWpYhMn9JM7F/4DfW1poTV3ZEW5J6dgeJ5HX4rv5C4VGalGYxdcb5JWIeXdUWsaQ7lxQyV0B/u3ZXvd25gpBFmmDkjcLL612D0JhJ2H+y1HVWw8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--guanyulin.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=Or3QXsTW; arc=none smtp.client-ip=209.85.128.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--guanyulin.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Or3QXsTW" Received: by mail-yw1-f202.google.com with SMTP id 00721157ae682-6e35a643200so115692017b3.0 for ; Wed, 06 Nov 2024 00:35:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1730882137; x=1731486937; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=moU1umJAlwIcW6CJtpZmFEP7kB4MQYjSX3i6CUT0ojI=; b=Or3QXsTWeRKEM28x30Ctib6SHqH5QUGcRtVogjyNcMArO9bL+6exmgRTxkCBF835xB 2Xy3yw08Ims3gG8Bx2TVsvmCuefF/LR9fVmHFsJnnzPq6cAyrOvuCUATcP8ktjjq0vfD TbjpDLAfoM/arp6S60/xSXaIJ0y5sULW3RYX3ZKd7WhlzUL4GHUblr91yClv3eRC8p3U +XhOJh93O1VxhrFeLZFzsnq+xw7khjMyR6K06oEDlfl5yPUNiG6OcbEbusercgGhhhOp SvsBAgbQhED4vBVPPB035CySi1fApOPx1Szdg8NnSR16f9aNG53nAsREo54zQAYH6vxP PstA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1730882137; x=1731486937; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=moU1umJAlwIcW6CJtpZmFEP7kB4MQYjSX3i6CUT0ojI=; b=bcQY9Bv3ODTB5Zav+yDuRjjQhy9jzkwL2g1TsytucDND0aLAUCxnjdlBJqYXafe2Rw dMUDkQh3sDdfcKfHJvctZm3izCQff2fCyt3vHpgtom12JzO5IM1hyw8l9v1kJ8ctYHXv sekheslM9B8Etc0XuRDdStHtVdAgAEo4kps3sIiRqUw8grsY87gmpFKE6w7zT0IW1ZbL CgJVG0DRZsoGND4N+v+jRS32ZhCqMVWGzaKfDEo7vKdf5UafGw7m182flAoi6yxTfdIK SVIaLPW4KNhCTKoh0/KUwkr2JlMXhRYBuO8w31xnp6lQAlNFcuJ/NmDP4Xp69HfQWiaJ R5nw== X-Gm-Message-State: AOJu0Yx/aPw2cO/lpsStPZcN9MNvAxhKJjKFx6LLuuPpdVeeSjDUva6f auIJd2DiNksQDRwfB8asevJxKJQfMCIe8NQ8hFe+bxRFCRE/fD9w7aoGX3fy6KNHnmFw0EDRV8R An9YHHnxDH6Edzw== X-Google-Smtp-Source: AGHT+IFQFnkuCf/v6ladehVoYM1WJRWgfBTSx9mlAsCcKpaQ0AKHa0ncYilNBiCFgL2E3rDcTyqyBpTqWkJJUvQ= X-Received: from guanyulin.c.googlers.com ([fda3:e722:ac3:cc00:131:cd17:ac11:19c7]) (user=guanyulin job=sendgmr) by 2002:a05:690c:6481:b0:6de:19f:34d7 with SMTP id 00721157ae682-6ea5231763cmr1418007b3.2.1730882136853; Wed, 06 Nov 2024 00:35:36 -0800 (PST) Date: Wed, 6 Nov 2024 08:32:58 +0000 In-Reply-To: <20241106083501.408074-1-guanyulin@google.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20241106083501.408074-1-guanyulin@google.com> X-Mailer: git-send-email 2.47.0.199.ga7371fff76-goog Message-ID: <20241106083501.408074-5-guanyulin@google.com> Subject: [PATCH v6 4/5] xhci: sideband: add api to trace sideband usage From: Guan-Yu Lin To: gregkh@linuxfoundation.org, Thinh.Nguyen@synopsys.com, mathias.nyman@intel.com, stern@rowland.harvard.edu, sumit.garg@linaro.org, dianders@chromium.org, kekrby@gmail.com, oneukum@suse.com, yajun.deng@linux.dev, niko.mauno@vaisala.com, christophe.jaillet@wanadoo.fr, tj@kernel.org, stanley_chang@realtek.com, andreyknvl@gmail.com, quic_jjohnson@quicinc.com, ricardo@marliere.net Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Guan-Yu Lin The existing sideband driver only registers sidebands without tracking their active usage. To address this, new apis are introduced to: - mark sideband usage: record the sideband usage information in the USB host controller driver and USB device driver. - query sideband status: provide a means for other drivers to fetch sideband activity information on a USB host controller. Signed-off-by: Guan-Yu Lin --- drivers/usb/core/hcd.c | 4 ++ drivers/usb/host/xhci-sideband.c | 92 +++++++++++++++++++++++++++++++ include/linux/usb/hcd.h | 6 ++ include/linux/usb/xhci-sideband.h | 5 ++ 4 files changed, 107 insertions(+) diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 1ff7d901fede..6aca6c69bf74 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -2595,6 +2595,10 @@ struct usb_hcd *__usb_create_hcd(const struct hc_driver *driver, INIT_WORK(&hcd->wakeup_work, hcd_resume_work); #endif +#ifdef CONFIG_USB_XHCI_SIDEBAND + refcount_set(&hcd->sb_usage_count, 0); +#endif + INIT_WORK(&hcd->died_work, hcd_died_work); hcd->driver = driver; diff --git a/drivers/usb/host/xhci-sideband.c b/drivers/usb/host/xhci-sideband.c index d04cf0af57ae..bd0fc1564052 100644 --- a/drivers/usb/host/xhci-sideband.c +++ b/drivers/usb/host/xhci-sideband.c @@ -334,6 +334,98 @@ xhci_sideband_interrupter_id(struct xhci_sideband *sb) } EXPORT_SYMBOL_GPL(xhci_sideband_interrupter_id); +/** + * xhci_sideband_get - inform related drivers there's a new active sideband + * @sb: sideband instance for this usb device + * + * An active sideband indicates that another entity is currently using the host + * controller. Inform the host controller and related usb devices by increasing + * their sb_usage_count. This allows the corresponding drivers to dynamically + * adjust power management actions based on current sideband activity. + * + * Returns 0 on success, negative error otherwise + */ +int xhci_sideband_get(struct xhci_sideband *sb) +{ + struct usb_device *udev; + struct usb_hcd *hcd; + int ret; + + if (!sb || !sb->xhci) + return -ENODEV; + + hcd = xhci_to_hcd(sb->xhci); + refcount_inc(&hcd->sb_usage_count); + + udev = sb->vdev->udev; + + device_lock(&udev->dev); + ret = usb_sideband_get(udev); + device_unlock(&udev->dev); + + if (ret) { + refcount_dec(&hcd->sb_usage_count); + return ret; + } + + return 0; +} +EXPORT_SYMBOL_GPL(xhci_sideband_get); + +/** + * xhci_sideband_put - inform related drivers there's a sideband deactivated + * @sb: sideband instance for this usb device + * + * The inverse operation of xhci_sideband_get, which informs the host + * controller and related usb devices by decreasing their sb_usage_count. This + * allows the corresponding drivers to dynamically adjust power management + * actions based on current sideband activity. + * + * Returns 0 on success, negative error otherwise + */ +int xhci_sideband_put(struct xhci_sideband *sb) +{ + struct usb_device *udev; + struct usb_hcd *hcd; + int ret; + + if (!sb || !sb->xhci) + return -ENODEV; + + hcd = xhci_to_hcd(sb->xhci); + refcount_dec(&hcd->sb_usage_count); + + udev = sb->vdev->udev; + + device_lock(&udev->dev); + ret = usb_sideband_put(udev); + device_unlock(&udev->dev); + + if (ret) { + refcount_inc(&hcd->sb_usage_count); + return ret; + } + + return 0; +} +EXPORT_SYMBOL_GPL(xhci_sideband_put); + +/** + * xhci_sideband_check - check sideband activities on the host controller + * @hcd: the host controller driver associated with the target host controller + * + * Allow other drivers, such as usb controller driver, to check if there are + * any sideband activity on the host controller right now. This information + * could be used for power management or other forms or resource management. + * + * Returns true on any active sideband existence, false otherwise + */ +bool xhci_sideband_check(struct usb_hcd *hcd) +{ + return !!refcount_read(&hcd->sb_usage_count); +} +EXPORT_SYMBOL_GPL(xhci_sideband_check); + /** * xhci_sideband_register - register a sideband for a usb device * @udev: usb device to be accessed via sideband diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h index ac95e7c89df5..9867c178d188 100644 --- a/include/linux/usb/hcd.h +++ b/include/linux/usb/hcd.h @@ -85,6 +85,12 @@ struct usb_hcd { #ifdef CONFIG_PM struct work_struct wakeup_work; /* for remote wakeup */ #endif + +#ifdef CONFIG_USB_XHCI_SIDEBAND + /* Number of active sideband accessing the host controller. */ + refcount_t sb_usage_count; +#endif + struct work_struct died_work; /* for when the device dies */ /* diff --git a/include/linux/usb/xhci-sideband.h b/include/linux/usb/xhci-sideband.h index f0223c5535e0..4850fc826e00 100644 --- a/include/linux/usb/xhci-sideband.h +++ b/include/linux/usb/xhci-sideband.h @@ -12,6 +12,7 @@ #include #include +#include #define EP_CTX_PER_DEV 31 /* FIXME defined twice, from xhci.h */ @@ -57,6 +58,10 @@ xhci_sideband_get_endpoint_buffer(struct xhci_sideband *sb, struct sg_table * xhci_sideband_get_event_buffer(struct xhci_sideband *sb); +int xhci_sideband_get(struct xhci_sideband *sb); +int xhci_sideband_put(struct xhci_sideband *sb); +bool xhci_sideband_check(struct usb_hcd *hcd); + int xhci_sideband_create_interrupter(struct xhci_sideband *sb, int num_seg, bool ip_autoclear, u32 imod_interval, int intr_num);