From 62ce94a7a5a54aac80975f5e6731707225d4077e Mon Sep 17 00:00:00 2001 From: Sinan Kaya Date: Wed, 12 Jul 2017 00:04:14 -0400 Subject: [PATCH] PCI: Mark Broadcom HT2100 Root Port Extended Tags as broken Per PCIe r3.1, sec 2.2.6.2 and 7.8.4, a Requester may not use 8-bit Tags unless its Extended Tag Field Enable is set, but all Receivers/Completers must handle 8-bit Tags correctly regardless of their Extended Tag Field Enable. Some devices do not handle 8-bit Tags as Completers, so add a quirk for them. If we find such a device, we disable Extended Tags for the entire hierarchy to make peer-to-peer DMA possible. The Broadcom HT2100 seems to have issues with handling 8-bit tags. Mark it as broken. The pci_walk_bus() in the quirk handles devices we've enumerated in the past, and pci_configure_device() handles devices we enumerate in the future. Fixes: 60db3a4d8cc9 ("PCI: Enable PCIe Extended Tags if supported") Link: https://bugzilla.redhat.com/show_bug.cgi?id=1467674 Reported-and-tested-by: Wim ten Have Signed-off-by: Sinan Kaya [bhelgaas: changelog, tweak messages, rename bit and quirk] Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.h | 1 + drivers/pci/probe.c | 43 ++++++++++++++++++++++++++++++++++++------- drivers/pci/quirks.c | 16 ++++++++++++++++ include/linux/pci.h | 1 + 4 files changed, 54 insertions(+), 7 deletions(-) diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 22e061738c6f..a6560c9baa52 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -235,6 +235,7 @@ enum pci_bar_type { pci_bar_mem64, /* A 64-bit memory BAR */ }; +int pci_configure_extended_tags(struct pci_dev *dev, void *ign); bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *pl, int crs_timeout); int pci_setup_device(struct pci_dev *dev); diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index c31310db0404..c81c9835f4c7 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1745,21 +1745,50 @@ static void program_hpp_type2(struct pci_dev *dev, struct hpp_type2 *hpp) */ } -static void pci_configure_extended_tags(struct pci_dev *dev) +int pci_configure_extended_tags(struct pci_dev *dev, void *ign) { - u32 dev_cap; + struct pci_host_bridge *host; + u32 cap; + u16 ctl; int ret; if (!pci_is_pcie(dev)) - return; + return 0; - ret = pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &dev_cap); + ret = pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap); if (ret) - return; + return 0; - if (dev_cap & PCI_EXP_DEVCAP_EXT_TAG) + if (!(cap & PCI_EXP_DEVCAP_EXT_TAG)) + return 0; + + ret = pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl); + if (ret) + return 0; + + host = pci_find_host_bridge(dev->bus); + if (!host) + return 0; + + /* + * If some device in the hierarchy doesn't handle Extended Tags + * correctly, make sure they're disabled. + */ + if (host->no_ext_tags) { + if (ctl & PCI_EXP_DEVCTL_EXT_TAG) { + dev_info(&dev->dev, "disabling Extended Tags\n"); + pcie_capability_clear_word(dev, PCI_EXP_DEVCTL, + PCI_EXP_DEVCTL_EXT_TAG); + } + return 0; + } + + if (!(ctl & PCI_EXP_DEVCTL_EXT_TAG)) { + dev_info(&dev->dev, "enabling Extended Tags\n"); pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_EXT_TAG); + } + return 0; } static void pci_configure_device(struct pci_dev *dev) @@ -1768,7 +1797,7 @@ static void pci_configure_device(struct pci_dev *dev) int ret; pci_configure_mps(dev); - pci_configure_extended_tags(dev); + pci_configure_extended_tags(dev, NULL); memset(&hpp, 0, sizeof(hpp)); ret = pci_get_hp_params(dev, &hpp); diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 6967c6b4cf6b..f135765555c9 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -4681,3 +4681,19 @@ static void quirk_intel_no_flr(struct pci_dev *dev) } DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1502, quirk_intel_no_flr); DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1503, quirk_intel_no_flr); + +static void quirk_no_ext_tags(struct pci_dev *pdev) +{ + struct pci_host_bridge *bridge = pci_find_host_bridge(pdev->bus); + + if (!bridge) + return; + + bridge->no_ext_tags = 1; + dev_info(&pdev->dev, "disabling Extended Tags (this device can't handle them)\n"); + + pci_walk_bus(bridge->bus, pci_configure_extended_tags, NULL); +} +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, 0x0140, quirk_no_ext_tags); +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, 0x0142, quirk_no_ext_tags); +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, 0x0144, quirk_no_ext_tags); diff --git a/include/linux/pci.h b/include/linux/pci.h index 4869e66dd659..3b968d435895 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -451,6 +451,7 @@ struct pci_host_bridge { void *release_data; struct msi_controller *msi; unsigned int ignore_reset_delay:1; /* for entire hierarchy */ + unsigned int no_ext_tags:1; /* no Extended Tags */ /* Resource alignment requirements */ resource_size_t (*align_resource)(struct pci_dev *dev, const struct resource *res,