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 "pci=disable_10bit_tag="
parameter to disable 10-Bit Tag Requester if the peer device does not
support the 10-Bit Tag Completer. This will make P2P traffic safe.
Signed-off-by: Dongdong Liu <liudongdong3@xxxxxxxxxx>
---
Documentation/admin-guide/kernel-parameters.txt | 7 ++++
drivers/pci/pci.c | 56 +++++++++++++++++++++++++
drivers/pci/pci.h | 1 +
drivers/pci/pcie/portdrv_pci.c | 13 +++---
drivers/pci/probe.c | 9 ++--
5 files changed, 78 insertions(+), 8 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index bdb2200..c2c4585 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4019,6 +4019,13 @@
bridges without forcing it upstream. Note:
this removes isolation between devices and
may put more devices in an IOMMU group.
+ disable_10bit_tag=<pci_dev>[; ...]
+ Specify one or more PCI devices (in the format
+ specified above) separated by semicolons.
+ Disable 10-Bit Tag Requester if the peer
+ device does not support the 10-Bit Tag
+ Completer.This will make P2P traffic safe.
+
force_floating [S390] Force usage of floating interrupts.
nomio [S390] Do not use MIO instructions.
norid [S390] ignore the RID field and force use of
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index d14c573..8494e4f 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -6568,6 +6568,59 @@ int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent)
}
#endif
+static const char *disable_10bit_tag_param;
+
+void pci_disable_10bit_tag(struct pci_dev *dev)
+{
+ int ret = 0;
+ const char *p;
+#ifdef CONFIG_PCI_IOV
+ struct pci_sriov *iov;
+#endif
+
+ if (!disable_10bit_tag_param)
+ return;
+
+ p = disable_10bit_tag_param;
+ while (*p) {
+ ret = pci_dev_str_match(dev, p, &p);
+ if (ret < 0) {
+ pr_info_once("PCI: Can't parse disable_10bit_tag parameter: %s\n",
+ disable_10bit_tag_param);
+
+ break;
+ } else if (ret == 1) {
+ /* Found a match */
+ break;
+ }
+
+ if (*p != ';' && *p != ',') {
+ /* End of param or invalid format */
+ break;
+ }
+ p++;
+ }
+
+ if (ret != 1)
+ return;
+
+#ifdef CONFIG_PCI_IOV
+ if (dev->is_virtfn) {
+ iov = dev->physfn->sriov;
+ iov->ctrl &= ~PCI_SRIOV_CTRL_VF_10BIT_TAG_REQ_EN;
+ pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL,
+ iov->ctrl);
+ pci_info(dev, "disabled PF SRIOV 10-Bit Tag Requester\n");
+ return;
+#endif
+ }
+
+ pcie_capability_clear_word(dev, PCI_EXP_DEVCTL2,
+ PCI_EXP_DEVCTL2_10BIT_TAG_REQ_EN);
+
+ pci_info(dev, "disabled 10-Bit Tag Requester\n");
+}
+
/**
* pci_ext_cfg_avail - can we access extended PCI config space?
*
@@ -6643,6 +6696,8 @@ static int __init pci_setup(char *str)
pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS);
} else if (!strncmp(str, "disable_acs_redir=", 18)) {
disable_acs_redir_param = str + 18;
+ } else if (!strncmp(str, "disable_10bit_tag=", 18)) {
+ disable_10bit_tag_param = str + 18;
} else {
pr_err("PCI: Unknown option `%s'\n", str);
}
@@ -6667,6 +6722,7 @@ static int __init pci_realloc_setup_params(void)
resource_alignment_param = kstrdup(resource_alignment_param,
GFP_KERNEL);
disable_acs_redir_param = kstrdup(disable_acs_redir_param, GFP_KERNEL);
+ disable_10bit_tag_param = kstrdup(disable_10bit_tag_param, GFP_KERNEL);
return 0;
}
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 93dcdd4..87c8187 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -16,6 +16,7 @@ extern bool pci_early_dump;
bool pcie_cap_has_lnkctl(const struct pci_dev *dev);
bool pcie_cap_has_rtctl(const struct pci_dev *dev);
+void pci_disable_10bit_tag(struct pci_dev *dev);
/* Functions internal to the PCI core code */
diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c
index 2382cd2..747728e 100644
--- a/drivers/pci/pcie/portdrv_pci.c
+++ b/drivers/pci/pcie/portdrv_pci.c
@@ -125,15 +125,15 @@ static void pci_configure_rp_10bit_tag(struct pci_dev *dev)
bool support = true;
if (dev->subordinate == NULL)
- return;
+ goto disable_10bit_tag_req;
/* If no devices under the root port, no need to enable 10-Bit Tag. */
if (list_empty(&dev->subordinate->devices))
- return;
+ goto disable_10bit_tag_req;
pci_10bit_tag_comp_support(dev, &support);
if (!support)
- return;
+ goto disable_10bit_tag_req;
/*
* PCIe spec 5.0r1.0 section 2.2.6.2 implementation note.
@@ -146,14 +146,17 @@ static void pci_configure_rp_10bit_tag(struct pci_dev *dev)
*/
pci_walk_bus(dev->subordinate, pci_10bit_tag_comp_support, &support);
if (!support)
- return;
+ goto disable_10bit_tag_req;
if (!(dev->pcie_devcap2 & PCI_EXP_DEVCAP2_10BIT_TAG_REQ))
- return;
+ goto disable_10bit_tag_req;
pci_dbg(dev, "enabling 10-Bit Tag Requester\n");
pcie_capability_set_word(dev, PCI_EXP_DEVCTL2,
PCI_EXP_DEVCTL2_10BIT_TAG_REQ_EN);
+
+disable_10bit_tag_req:
+ pci_disable_10bit_tag(dev);
}
/*
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 3da7baa..0b7b053 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2034,11 +2034,11 @@ static void pci_configure_10bit_tags(struct pci_dev *dev)
struct pci_dev *bridge;
if (!(dev->pcie_devcap2 & PCI_EXP_DEVCAP2_10BIT_TAG_COMP))
- return;
+ goto disable_10bit_tag_req;
if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) {
dev->ext_10bit_tag = 1;
- return;
+ goto disable_10bit_tag_req;
}
bridge = pci_upstream_bridge(dev);
@@ -2050,7 +2050,7 @@ static void pci_configure_10bit_tags(struct pci_dev *dev)
* for VF.
*/
if (dev->is_virtfn)
- return;
+ goto disable_10bit_tag_req;
if (pci_pcie_type(dev) == PCI_EXP_TYPE_ENDPOINT &&
dev->ext_10bit_tag == 1 &&
@@ -2059,6 +2059,9 @@ static void pci_configure_10bit_tags(struct pci_dev *dev)
pcie_capability_set_word(dev, PCI_EXP_DEVCTL2,
PCI_EXP_DEVCTL2_10BIT_TAG_REQ_EN);
}
+
+disable_10bit_tag_req:
+ pci_disable_10bit_tag(dev);
}
int pci_configure_extended_tags(struct pci_dev *dev, void *ign)
--
2.7.4
