diff options
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/pci/pci.c | 65 |
1 files changed, 50 insertions, 15 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 766bb13..985df63 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -278,6 +278,38 @@ int pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap) } /** + * pci_pcie_cap2 - query for devices' PCI_CAP_ID_EXP v2 capability structure + * @dev: PCI device to check + * + * Like pci_pcie_cap() but also checks that the PCIe capability version is + * >= 2. Note that v1 capability structures could be sparse in that not + * all register fields were required. v2 requires the entire structure to + * be present size wise, while still allowing for non-implemented registers + * to exist but they must be hardwired to 0. + * + * Due to the differences in the versions of capability structures, one + * must be careful not to try and access non-existant registers that may + * exist in early versions - v1 - of Express devices. + * + * Returns the offset of the PCIe capability structure as long as the + * capability version is >= 2; otherwise 0 is returned. + */ +static int pci_pcie_cap2(struct pci_dev *dev) +{ + u16 flags; + int pos; + + pos = pci_pcie_cap(dev); + if (pos) { + pci_read_config_word(dev, pos + PCI_EXP_FLAGS, &flags); + if ((flags & PCI_EXP_FLAGS_VERS) < 2) + pos = 0; + } + + return pos; +} + +/** * pci_find_ext_capability - Find an extended capability * @dev: PCI device to query * @cap: capability code @@ -1983,7 +2015,7 @@ void pci_enable_ari(struct pci_dev *dev) { int pos; u32 cap; - u16 flags, ctrl; + u16 ctrl; struct pci_dev *bridge; if (pcie_ari_disabled || !pci_is_pcie(dev) || dev->devfn) @@ -1997,15 +2029,11 @@ void pci_enable_ari(struct pci_dev *dev) if (!bridge) return; - pos = pci_pcie_cap(bridge); + /* ARI is a PCIe cap v2 feature */ + pos = pci_pcie_cap2(bridge); 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; @@ -2018,7 +2046,7 @@ void pci_enable_ari(struct pci_dev *dev) } /** - * pci_enable_ido - enable ID-based ordering on a device + * pci_enable_ido - enable ID-based Ordering on a device * @dev: the PCI device * @type: which types of IDO to enable * @@ -2031,7 +2059,8 @@ void pci_enable_ido(struct pci_dev *dev, unsigned long type) int pos; u16 ctrl; - pos = pci_pcie_cap(dev); + /* ID-based Ordering is a PCIe cap v2 feature */ + pos = pci_pcie_cap2(dev); if (!pos) return; @@ -2054,7 +2083,8 @@ void pci_disable_ido(struct pci_dev *dev, unsigned long type) int pos; u16 ctrl; - pos = pci_pcie_cap(dev); + /* ID-based Ordering is a PCIe cap v2 feature */ + pos = pci_pcie_cap2(dev); if (!pos) return; @@ -2093,7 +2123,8 @@ int pci_enable_obff(struct pci_dev *dev, enum pci_obff_signal_type type) u16 ctrl; int ret; - pos = pci_pcie_cap(dev); + /* OBFF is a PCIe cap v2 feature */ + pos = pci_pcie_cap2(dev); if (!pos) return -ENOTSUPP; @@ -2143,7 +2174,8 @@ void pci_disable_obff(struct pci_dev *dev) int pos; u16 ctrl; - pos = pci_pcie_cap(dev); + /* OBFF is a PCIe cap v2 feature */ + pos = pci_pcie_cap2(dev); if (!pos) return; @@ -2165,7 +2197,8 @@ static bool pci_ltr_supported(struct pci_dev *dev) int pos; u32 cap; - pos = pci_pcie_cap(dev); + /* LTR is a PCIe cap v2 feature */ + pos = pci_pcie_cap2(dev); if (!pos) return false; @@ -2193,7 +2226,8 @@ int pci_enable_ltr(struct pci_dev *dev) if (!pci_ltr_supported(dev)) return -ENOTSUPP; - pos = pci_pcie_cap(dev); + /* LTR is a PCIe cap v2 feature */ + pos = pci_pcie_cap2(dev); if (!pos) return -ENOTSUPP; @@ -2228,7 +2262,8 @@ void pci_disable_ltr(struct pci_dev *dev) if (!pci_ltr_supported(dev)) return; - pos = pci_pcie_cap(dev); + /* LTR is a PCIe cap v2 feature */ + pos = pci_pcie_cap2(dev); if (!pos) return; |