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