From 864d296cf948aef0fa32b81407541572583f7572 Mon Sep 17 00:00:00 2001 From: Chris Wright Date: Wed, 13 Jul 2011 10:14:33 -0700 Subject: PCI: ARI is a PCIe v2 feature The function pci_enable_ari() may mistakenly set the downstream port of a v1 PCIe switch in ARI Forwarding mode. This is a PCIe v2 feature, and with an SR-IOV device on that switch port believing the switch above is ARI capable it may attempt to use functions 8-255, translating into invalid (non-zero) device numbers for that bus. This has been seen to cause Completion Timeouts and general misbehaviour including hangs and panics. Cc: stable@kernel.org Acked-by: Don Dutile Tested-by: Don Dutile Signed-off-by: Chris Wright Signed-off-by: Jesse Barnes --- drivers/pci/pci.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'drivers/pci/pci.c') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 692671b11667..d549bbc93cdd 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1905,7 +1905,7 @@ void pci_enable_ari(struct pci_dev *dev) { int pos; u32 cap; - u16 ctrl; + u16 flags, ctrl; struct pci_dev *bridge; if (!pci_is_pcie(dev) || dev->devfn) @@ -1923,6 +1923,11 @@ void pci_enable_ari(struct pci_dev *dev) if (!pos) return; + /* ARI is a PCIe v2 feature */ + pci_read_config_word(bridge, pos + PCI_EXP_FLAGS, &flags); + if ((flags & PCI_EXP_FLAGS_VERS) < 2) + return; + pci_read_config_dword(bridge, pos + PCI_EXP_DEVCAP2, &cap); if (!(cap & PCI_EXP_DEVCAP2_ARI)) return; -- cgit v1.2.3 From c9b378c7cbf623649e4ca64f955f2afd12ef01b2 Mon Sep 17 00:00:00 2001 From: Jon Mason Date: Tue, 28 Jun 2011 18:26:25 -0500 Subject: PCI: correct pcie_set_readrq write size When setting the PCI-E MRRS, pcie_set_readrq queries the current settings via a pci_read_config_word call but writes the modified result via a pci_write_config_dword. This results in writing 16 more bits than were queried. Also, the function description comment is slightly incorrect. Signed-off-by: Jon Mason Signed-off-by: Jesse Barnes --- drivers/pci/pci.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/pci/pci.c') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index d549bbc93cdd..08a95b369d85 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3191,7 +3191,7 @@ EXPORT_SYMBOL(pcie_get_readrq); * @rq: maximum memory read count in bytes * valid values are 128, 256, 512, 1024, 2048, 4096 * - * If possible sets maximum read byte count + * If possible sets maximum memory read request in bytes */ int pcie_set_readrq(struct pci_dev *dev, int rq) { @@ -3214,7 +3214,7 @@ int pcie_set_readrq(struct pci_dev *dev, int rq) if ((ctl & PCI_EXP_DEVCTL_READRQ) != v) { ctl &= ~PCI_EXP_DEVCTL_READRQ; ctl |= v; - err = pci_write_config_dword(dev, cap + PCI_EXP_DEVCTL, ctl); + err = pci_write_config_word(dev, cap + PCI_EXP_DEVCTL, ctl); } out: -- cgit v1.2.3