diff options
| -rw-r--r-- | drivers/pci/pci.c | 69 | ||||
| -rw-r--r-- | drivers/pci/quirks.c | 33 | ||||
| -rw-r--r-- | include/linux/pci.h | 10 |
3 files changed, 111 insertions, 1 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 447e83472c0..1ccf7d49f52 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -2360,6 +2360,75 @@ void pci_enable_acs(struct pci_dev *dev) } /** + * pci_acs_enabled - test ACS against required flags for a given device + * @pdev: device to test + * @acs_flags: required PCI ACS flags + * + * Return true if the device supports the provided flags. Automatically + * filters out flags that are not implemented on multifunction devices. + */ +bool pci_acs_enabled(struct pci_dev *pdev, u16 acs_flags) +{ + int pos, ret; + u16 ctrl; + + ret = pci_dev_specific_acs_enabled(pdev, acs_flags); + if (ret >= 0) + return ret > 0; + + if (!pci_is_pcie(pdev)) + return false; + + /* Filter out flags not applicable to multifunction */ + if (pdev->multifunction) + acs_flags &= (PCI_ACS_RR | PCI_ACS_CR | + PCI_ACS_EC | PCI_ACS_DT); + + if (pdev->pcie_type == PCI_EXP_TYPE_DOWNSTREAM || + pdev->pcie_type == PCI_EXP_TYPE_ROOT_PORT || + pdev->multifunction) { + pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ACS); + if (!pos) + return false; + + pci_read_config_word(pdev, pos + PCI_ACS_CTRL, &ctrl); + if ((ctrl & acs_flags) != acs_flags) + return false; + } + + return true; +} + +/** + * pci_acs_path_enable - test ACS flags from start to end in a hierarchy + * @start: starting downstream device + * @end: ending upstream device or NULL to search to the root bus + * @acs_flags: required flags + * + * Walk up a device tree from start to end testing PCI ACS support. If + * any step along the way does not support the required flags, return false. + */ +bool pci_acs_path_enabled(struct pci_dev *start, + struct pci_dev *end, u16 acs_flags) +{ + struct pci_dev *pdev, *parent = start; + + do { + pdev = parent; + + if (!pci_acs_enabled(pdev, acs_flags)) + return false; + + if (pci_is_root_bus(pdev->bus)) + return (end == NULL); + + parent = pdev->bus->self; + } while (pdev != end); + + return true; +} + +/** * pci_swizzle_interrupt_pin - swizzle INTx for device behind bridge * @dev: the PCI device * @pin: the INTx pin (1=INTA, 2=INTB, 3=INTD, 4=INTD) diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index acd3956b44b..27e2c8f4ec7 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -3230,3 +3230,36 @@ struct pci_dev *pci_get_dma_source(struct pci_dev *dev) return pci_dev_get(dev); } + +static const struct pci_dev_acs_enabled { + u16 vendor; + u16 device; + int (*acs_enabled)(struct pci_dev *dev, u16 acs_flags); +} pci_dev_acs_enabled[] = { + { 0 } +}; + +int pci_dev_specific_acs_enabled(struct pci_dev *dev, u16 acs_flags) +{ + const struct pci_dev_acs_enabled *i; + int ret; + + /* + * Allow devices that do not expose standard PCIe ACS capabilities + * or control to indicate their support here. Multi-function express + * devices which do not allow internal peer-to-peer between functions, + * but do not implement PCIe ACS may wish to return true here. + */ + for (i = pci_dev_acs_enabled; i->acs_enabled; i++) { + if ((i->vendor == dev->vendor || + i->vendor == (u16)PCI_ANY_ID) && + (i->device == dev->device || + i->device == (u16)PCI_ANY_ID)) { + ret = i->acs_enabled(dev, acs_flags); + if (ret >= 0) + return ret; + } + } + + return -ENOTTY; +} diff --git a/include/linux/pci.h b/include/linux/pci.h index 39983be7b25..dd7af0f37b3 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1490,6 +1490,7 @@ enum pci_fixup_pass { #ifdef CONFIG_PCI_QUIRKS void pci_fixup_device(enum pci_fixup_pass pass, struct pci_dev *dev); struct pci_dev *pci_get_dma_source(struct pci_dev *dev); +int pci_dev_specific_acs_enabled(struct pci_dev *dev, u16 acs_flags); #else static inline void pci_fixup_device(enum pci_fixup_pass pass, struct pci_dev *dev) {} @@ -1497,6 +1498,11 @@ static inline struct pci_dev *pci_get_dma_source(struct pci_dev *dev) { return pci_dev_get(dev); } +static inline int pci_dev_specific_acs_enabled(struct pci_dev *dev, + u16 acs_flags) +{ + return -ENOTTY; +} #endif void __iomem *pcim_iomap(struct pci_dev *pdev, int bar, unsigned long maxlen); @@ -1599,7 +1605,9 @@ static inline bool pci_is_pcie(struct pci_dev *dev) } void pci_request_acs(void); - +bool pci_acs_enabled(struct pci_dev *pdev, u16 acs_flags); +bool pci_acs_path_enabled(struct pci_dev *start, + struct pci_dev *end, u16 acs_flags); #define PCI_VPD_LRDT 0x80 /* Large Resource Data Type */ #define PCI_VPD_LRDT_ID(x) (x | PCI_VPD_LRDT) |