From: Logan Gunthorpe <logang@deltatee.com>
To: Dongdong Liu <liudongdong3@huawei.com>,
helgaas@kernel.org, hch@infradead.org, kw@linux.com,
leon@kernel.org, linux-pci@vger.kernel.org, rajur@chelsio.com,
hverkuil-cisco@xs4all.nl
Cc: linux-media@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH V7 9/9] PCI/P2PDMA: Add a 10-Bit Tag check in P2PDMA
Date: Wed, 4 Aug 2021 09:56:38 -0600 [thread overview]
Message-ID: <640662ff-e464-2cb5-318b-aa75d1ece1eb@deltatee.com> (raw)
In-Reply-To: <1628084828-119542-10-git-send-email-liudongdong3@huawei.com>
On 2021-08-04 7:47 a.m., Dongdong Liu wrote:
> Add a 10-Bit Tag check in the P2PDMA code to ensure that a device with
> 10-Bit Tag Requester doesn't interact with a device that does not
> support 10-BIT Tag Completer. Before that happens, the kernel should
> emit a warning. "echo 0 > /sys/bus/pci/devices/.../10bit_tag" to
> disable 10-BIT Tag Requester for PF device.
> "echo 0 > /sys/bus/pci/devices/.../sriov_vf_10bit_tag_ctl" to disable
> 10-BIT Tag Requester for VF device.
>
> Signed-off-by: Dongdong Liu <liudongdong3@huawei.com>
> ---
> drivers/pci/p2pdma.c | 40 ++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 40 insertions(+)
>
> diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
> index 50cdde3..948f2be 100644
> --- a/drivers/pci/p2pdma.c
> +++ b/drivers/pci/p2pdma.c
> @@ -19,6 +19,7 @@
> #include <linux/random.h>
> #include <linux/seq_buf.h>
> #include <linux/xarray.h>
> +#include "pci.h"
>
> enum pci_p2pdma_map_type {
> PCI_P2PDMA_MAP_UNKNOWN = 0,
> @@ -410,6 +411,41 @@ static unsigned long map_types_idx(struct pci_dev *client)
> (client->bus->number << 8) | client->devfn;
> }
>
> +static bool check_10bit_tags_vaild(struct pci_dev *a, struct pci_dev *b,
> + bool verbose)
> +{
> + bool req;
> + bool comp;
> + u16 ctl2;
> +
> + if (a->is_virtfn) {
> +#ifdef CONFIG_PCI_IOV
> + req = !!(a->physfn->sriov->ctrl &
> + PCI_SRIOV_CTRL_VF_10BIT_TAG_REQ_EN);
> +#endif
> + } else {
> + pcie_capability_read_word(a, PCI_EXP_DEVCTL2, &ctl2);
> + req = !!(ctl2 & PCI_EXP_DEVCTL2_10BIT_TAG_REQ_EN);
> + }
> +
> + comp = !!(b->pcie_devcap2 & PCI_EXP_DEVCAP2_10BIT_TAG_COMP);
> + if (req && (!comp)) {
I think the brackets around !comp are unnecessary.
> + if (verbose) {
> + pci_warn(a, "cannot be used for peer-to-peer DMA as 10-Bit Tag Requester enable is set in device (%s), but peer device (%s) does not support the 10-Bit Tag Completer\n",
> + pci_name(a), pci_name(b));
> + if (a->is_virtfn)
> + pci_warn(a, "to disable 10-Bit Tag Requester for this device, echo 0 > /sys/bus/pci/devices/%s/sriov_vf_10bit_tag_ctl\n",
> + pci_name(a));
> + else
> + pci_warn(a, "to disable 10-Bit Tag Requester for this device, echo 0 > /sys/bus/pci/devices/%s/10bit_tag\n",
> + pci_name(a));
Can we not simplify this slightly by having a const char * set to the
tag in the above if (a->is_virtfn)?
pci_warn(a, "to disable 10-Bit Tag Requester for this device, echo 0 >
/sys/bus/pci/devices/%s/%s\n", pci_name(a), tag);
> + }
> + return false;
> + }
> +
> + return true;
> +}
> +
> /*
> * Calculate the P2PDMA mapping type and distance between two PCI devices.
> *
> @@ -532,6 +568,10 @@ calc_map_type_and_dist(struct pci_dev *provider, struct pci_dev *client,
> map_type = PCI_P2PDMA_MAP_NOT_SUPPORTED;
> }
> done:
> + if (!check_10bit_tags_vaild(client, provider, verbose) ||
> + !check_10bit_tags_vaild(provider, client, verbose))
> + map_type = PCI_P2PDMA_MAP_NOT_SUPPORTED;
> +
> rcu_read_lock();
> p2pdma = rcu_dereference(provider->p2pdma);
> if (p2pdma)
>
next prev parent reply other threads:[~2021-08-04 15:56 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
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 [this message]
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=640662ff-e464-2cb5-318b-aa75d1ece1eb@deltatee.com \
--to=logang@deltatee.com \
--cc=hch@infradead.org \
--cc=helgaas@kernel.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=netdev@vger.kernel.org \
--cc=rajur@chelsio.com \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
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).