Netdev Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Bjorn Helgaas <helgaas@kernel.org>
To: Dongdong Liu <liudongdong3@huawei.com>
Cc: hch@infradead.org, kw@linux.com, logang@deltatee.com,
	leon@kernel.org, linux-pci@vger.kernel.org, rajur@chelsio.com,
	hverkuil-cisco@xs4all.nl, linux-media@vger.kernel.org,
	netdev@vger.kernel.org
Subject: Re: [PATCH V7 8/9] PCI/IOV: Add 10-Bit Tag sysfs files for VF devices
Date: Wed, 4 Aug 2021 19:05:25 -0500	[thread overview]
Message-ID: <20210805000525.GA1693795@bjorn-Precision-5520> (raw)
In-Reply-To: <1628084828-119542-9-git-send-email-liudongdong3@huawei.com>

On Wed, Aug 04, 2021 at 09:47:07PM +0800, Dongdong Liu wrote:
> PCIe spec 5.0 r1.0 section 2.2.6.2 says that if an Endpoint supports
> sending Requests to other Endpoints (as opposed to host memory), the
> Endpoint must not send 10-Bit Tag Requests to another given Endpoint
> unless an implementation-specific mechanism determines that the
> Endpoint supports 10-Bit Tag Completer capability.
> Add sriov_vf_10bit_tag file to query the status of VF 10-Bit Tag
> Requester Enable. Add sriov_vf_10bit_tag_ctl file to disable the VF
> 10-Bit Tag Requester. The typical use case is for p2pdma when the peer
> device does not support 10-BIT Tag Completer.

Fix the usual spec quoting issue.  Or maybe this is not actually
quoted but is missing blank lines between paragraphs.

s/10-BIT/10-Bit/

> Signed-off-by: Dongdong Liu <liudongdong3@huawei.com>
> ---
>  Documentation/ABI/testing/sysfs-bus-pci | 20 +++++++++++++
>  drivers/pci/iov.c                       | 50 +++++++++++++++++++++++++++++++++
>  2 files changed, 70 insertions(+)
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
> index 0e0c97d..8fdbfae 100644
> --- a/Documentation/ABI/testing/sysfs-bus-pci
> +++ b/Documentation/ABI/testing/sysfs-bus-pci
> @@ -421,3 +421,23 @@ Description:
>  		to disable 10-Bit Tag Requester when the driver does not bind
>  		the deivce. The typical use case is for p2pdma when the peer
>  		device does not support 10-BIT Tag Completer.
> +
> +What:		/sys/bus/pci/devices/.../sriov_vf_10bit_tag
> +Date:		August 2021
> +Contact:	Dongdong Liu <liudongdong3@huawei.com>
> +Description:
> +		This file is associated with a SR-IOV physical function (PF).
> +		It is visible when the device has VF 10-Bit Tag Requester
> +		Supported. It contains the status of VF 10-Bit Tag Requester
> +		Enable. The file is only readable.

s/only readable/read-only/

> +What:		/sys/bus/pci/devices/.../sriov_vf_10bit_tag_ctl

Why does this file have "_ctl" on the end when the one in patch 7/9
does not?

> +Date:		August 2021
> +Contact:	Dongdong Liu <liudongdong3@huawei.com>
> +Description:
> +		This file is associated with a SR-IOV virtual function (VF).
> +		It is visible when the device has VF 10-Bit Tag Requester
> +		Supported. It only allows to write 0 to disable VF 10-Bit
> +		Tag Requester. The file is only writeable when the vf driver
> +		does not bind to a dirver. The typical use case is for p2pdma
> +		when the peer device does not support 10-BIT Tag Completer.

s/vf/VF/
s/dirver/driver/
s/10-BIT/10-Bit/

"when the vr driver does not bind to a driver"?  Not quite right.
Must be a "device" in there somewhere.

So IIUC this file is associated with a VF, but the bit it writes is
actually in the *PF*?  So writing 0 to any VF's file disables 10-bit
tags for *all* VFs?  That's worth mentioning here.

> diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
> index 0d0bed1..04c1298 100644
> --- a/drivers/pci/iov.c
> +++ b/drivers/pci/iov.c
> @@ -220,10 +220,38 @@ static ssize_t sriov_vf_msix_count_store(struct device *dev,
>  static DEVICE_ATTR_WO(sriov_vf_msix_count);
>  #endif
>  
> +static ssize_t sriov_vf_10bit_tag_ctl_store(struct device *dev,
> +					    struct device_attribute *attr,
> +					    const char *buf, size_t count)
> +{
> +	struct pci_dev *vf_dev = to_pci_dev(dev);
> +	struct pci_dev *pdev = pci_physfn(vf_dev);
> +	struct pci_sriov *iov;
> +	bool enable;
> +
> +	if (kstrtobool(buf, &enable) < 0)
> +		return -EINVAL;
> +
> +	if (enable != false)
> +		return -EINVAL;

Is this "if (enable)" again?

> +	if (vf_dev->driver)
> +		return -EBUSY;
> +
> +	iov = pdev->sriov;
> +	iov->ctrl &= ~PCI_SRIOV_CTRL_VF_10BIT_TAG_REQ_EN;
> +	pci_write_config_word(pdev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
> +	pci_info(pdev, "disabled SRIOV 10-Bit Tag Requester\n");

s/SRIOV/SR-IOV/ to match spec and other usages.

> +
> +	return count;
> +}
> +static DEVICE_ATTR_WO(sriov_vf_10bit_tag_ctl);
> +
>  static struct attribute *sriov_vf_dev_attrs[] = {
>  #ifdef CONFIG_PCI_MSI
>  	&dev_attr_sriov_vf_msix_count.attr,
>  #endif
> +	&dev_attr_sriov_vf_10bit_tag_ctl.attr,
>  	NULL,
>  };
>  
> @@ -236,6 +264,11 @@ static umode_t sriov_vf_attrs_are_visible(struct kobject *kobj,
>  	if (!pdev->is_virtfn)
>  		return 0;
>  
> +	pdev = pci_physfn(pdev);
> +	if ((a == &dev_attr_sriov_vf_10bit_tag_ctl.attr) &&
> +	     !(pdev->sriov->cap & PCI_SRIOV_CAP_VF_10BIT_TAG_REQ))
> +		return 0;
> +
>  	return a->mode;
>  }
>  
> @@ -487,12 +520,23 @@ static ssize_t sriov_drivers_autoprobe_store(struct device *dev,
>  	return count;
>  }
>  
> +static ssize_t sriov_vf_10bit_tag_show(struct device *dev,
> +				       struct device_attribute *attr,
> +				       char *buf)
> +{
> +	struct pci_dev *pdev = to_pci_dev(dev);
> +
> +	return sysfs_emit(buf, "%u\n",
> +		!!(pdev->sriov->ctrl & PCI_SRIOV_CTRL_VF_10BIT_TAG_REQ_EN));
> +}
> +
>  static DEVICE_ATTR_RO(sriov_totalvfs);
>  static DEVICE_ATTR_RW(sriov_numvfs);
>  static DEVICE_ATTR_RO(sriov_offset);
>  static DEVICE_ATTR_RO(sriov_stride);
>  static DEVICE_ATTR_RO(sriov_vf_device);
>  static DEVICE_ATTR_RW(sriov_drivers_autoprobe);
> +static DEVICE_ATTR_RO(sriov_vf_10bit_tag);
>  
>  static struct attribute *sriov_pf_dev_attrs[] = {
>  	&dev_attr_sriov_totalvfs.attr,
> @@ -501,6 +545,7 @@ static struct attribute *sriov_pf_dev_attrs[] = {
>  	&dev_attr_sriov_stride.attr,
>  	&dev_attr_sriov_vf_device.attr,
>  	&dev_attr_sriov_drivers_autoprobe.attr,
> +	&dev_attr_sriov_vf_10bit_tag.attr,
>  #ifdef CONFIG_PCI_MSI
>  	&dev_attr_sriov_vf_total_msix.attr,
>  #endif
> @@ -511,10 +556,15 @@ static umode_t sriov_pf_attrs_are_visible(struct kobject *kobj,
>  					  struct attribute *a, int n)
>  {
>  	struct device *dev = kobj_to_dev(kobj);
> +	struct pci_dev *pdev = to_pci_dev(dev);
>  
>  	if (!dev_is_pf(dev))
>  		return 0;
>  
> +	if ((a == &dev_attr_sriov_vf_10bit_tag.attr) &&
> +	     !(pdev->sriov->cap & PCI_SRIOV_CAP_VF_10BIT_TAG_REQ))
> +		return 0;
> +
>  	return a->mode;
>  }
>  
> -- 
> 2.7.4
> 

  reply	other threads:[~2021-08-05  0:05 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-04 13:46 [PATCH V7 0/9] PCI: Enable 10-Bit tag support for PCIe devices Dongdong Liu
2021-08-04 13:47 ` [PATCH V7 1/9] PCI: Use cached Device Capabilities Register Dongdong Liu
2021-08-04 13:47 ` [PATCH V7 2/9] PCI: Use cached Device Capabilities 2 Register Dongdong Liu
2021-08-04 13:47 ` [PATCH V7 3/9] PCI: Add 10-Bit Tag register definitions Dongdong Liu
2021-08-04 13:47 ` [PATCH V7 4/9] PCI: Enable 10-Bit Tag support for PCIe Endpoint devices Dongdong Liu
2021-08-04 23:17   ` Bjorn Helgaas
2021-08-05  7:47     ` Dongdong Liu
2021-08-05 19:54       ` Bjorn Helgaas
2021-08-07  6:19         ` Dongdong Liu
2021-08-04 13:47 ` [PATCH V7 5/9] PCI/IOV: Enable 10-Bit tag support for PCIe VF devices Dongdong Liu
2021-08-04 23:29   ` Bjorn Helgaas
2021-08-05  8:03     ` Dongdong Liu
2021-08-06 22:59       ` Bjorn Helgaas
2021-08-07  7:46         ` Dongdong Liu
2021-08-04 13:47 ` [PATCH V7 6/9] PCI: Enable 10-Bit Tag support for PCIe RP devices Dongdong Liu
2021-08-04 23:38   ` Bjorn Helgaas
2021-08-05  8:25     ` Dongdong Liu
2021-08-09 17:26       ` Bjorn Helgaas
2021-08-10 11:59         ` Dongdong Liu
2021-08-04 13:47 ` [PATCH V7 7/9] PCI/sysfs: Add a 10-Bit Tag sysfs file Dongdong Liu
2021-08-04 15:51   ` Logan Gunthorpe
2021-08-05 13:14     ` Dongdong Liu
2021-08-05 13:53       ` Leon Romanovsky
2021-08-05 15:36       ` Logan Gunthorpe
2021-08-04 23:49   ` Bjorn Helgaas
2021-08-05  8:37     ` Dongdong Liu
2021-08-05 15:31       ` Bjorn Helgaas
2021-08-07  7:01         ` Dongdong Liu
2021-08-09 17:37           ` Bjorn Helgaas
2021-08-10 12:16             ` Dongdong Liu
2021-08-04 23:52   ` Bjorn Helgaas
2021-08-05  8:38     ` Dongdong Liu
2021-08-04 13:47 ` [PATCH V7 8/9] PCI/IOV: Add 10-Bit Tag sysfs files for VF devices Dongdong Liu
2021-08-05  0:05   ` Bjorn Helgaas [this message]
2021-08-05  8:47     ` Dongdong Liu
2021-08-05  9:39     ` Dongdong Liu
2021-08-04 13:47 ` [PATCH V7 9/9] PCI/P2PDMA: Add a 10-Bit Tag check in P2PDMA Dongdong Liu
2021-08-04 15:56   ` Logan Gunthorpe
2021-08-05  8:49     ` Dongdong Liu
2021-08-05 18:12   ` Bjorn Helgaas
2021-08-07  7:11     ` Dongdong Liu
2021-08-09 17:31       ` Bjorn Helgaas
2021-08-10 12:31         ` Dongdong Liu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210805000525.GA1693795@bjorn-Precision-5520 \
    --to=helgaas@kernel.org \
    --cc=hch@infradead.org \
    --cc=hverkuil-cisco@xs4all.nl \
    --cc=kw@linux.com \
    --cc=leon@kernel.org \
    --cc=linux-media@vger.kernel.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=liudongdong3@huawei.com \
    --cc=logang@deltatee.com \
    --cc=netdev@vger.kernel.org \
    --cc=rajur@chelsio.com \
    --subject='Re: [PATCH V7 8/9] PCI/IOV: Add 10-Bit Tag sysfs files for VF devices' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).