From: Dongdong Liu <liudongdong3@huawei.com>
To: <helgaas@kernel.org>, <hch@infradead.org>, <kw@linux.com>,
<logang@deltatee.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: [PATCH V7 9/9] PCI/P2PDMA: Add a 10-Bit Tag check in P2PDMA
Date: Wed, 4 Aug 2021 21:47:08 +0800 [thread overview]
Message-ID: <1628084828-119542-10-git-send-email-liudongdong3@huawei.com> (raw)
In-Reply-To: <1628084828-119542-1-git-send-email-liudongdong3@huawei.com>
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)) {
+ 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));
+ }
+ 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)
--
2.7.4
next prev parent reply other threads:[~2021-08-04 13:49 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 ` Dongdong Liu [this message]
2021-08-04 15:56 ` [PATCH V7 9/9] PCI/P2PDMA: Add a 10-Bit Tag check in P2PDMA 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
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