diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c index 5b78f3b1b918a7f5600c4222b89288481ed985c2..bae74eb90f42f3e6f3d78dd8548ce30ac6964bb1 100644 --- a/drivers/pci/ats.c +++ b/drivers/pci/ats.c @@ -142,6 +142,33 @@ int pci_ats_queue_depth(struct pci_dev *dev) } EXPORT_SYMBOL_GPL(pci_ats_queue_depth); +/** + * pci_ats_page_aligned - Return Page Aligned Request bit status. + * @pdev: the PCI device + * + * Returns 1, if the Untranslated Addresses generated by the device + * are always aligned or 0 otherwise. + * + * Per PCIe spec r4.0, sec 10.5.1.2, if the Page Aligned Request bit + * is set, it indicates the Untranslated Addresses generated by the + * device are always aligned to a 4096 byte boundary. + */ +int pci_ats_page_aligned(struct pci_dev *pdev) +{ + u16 cap; + + if (!pdev->ats_cap) + return 0; + + pci_read_config_word(pdev, pdev->ats_cap + PCI_ATS_CAP, &cap); + + if (cap & PCI_ATS_CAP_PAGE_ALIGNED) + return 1; + + return 0; +} +EXPORT_SYMBOL_GPL(pci_ats_page_aligned); + #ifdef CONFIG_PCI_PRI /** * pci_enable_pri - Enable PRI capability diff --git a/include/linux/pci.h b/include/linux/pci.h index a0db91ff01e9c98bcd41930310c9bd98e6ff3193..46d280d0a1acde82c3e7f2699f23ee74470fec35 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1514,11 +1514,13 @@ void pci_ats_init(struct pci_dev *dev); int pci_enable_ats(struct pci_dev *dev, int ps); void pci_disable_ats(struct pci_dev *dev); int pci_ats_queue_depth(struct pci_dev *dev); +int pci_ats_page_aligned(struct pci_dev *dev); #else static inline void pci_ats_init(struct pci_dev *d) { } static inline int pci_enable_ats(struct pci_dev *d, int ps) { return -ENODEV; } static inline void pci_disable_ats(struct pci_dev *d) { } static inline int pci_ats_queue_depth(struct pci_dev *d) { return -ENODEV; } +static inline int pci_ats_page_aligned(struct pci_dev *dev) { return 0; } #endif #ifdef CONFIG_PCIE_PTM diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h index e1e9888c85e6810aad2e54ab25cbbaf49b72ba57..7973bb02ed4b656510e9af3424613105c0efea53 100644 --- a/include/uapi/linux/pci_regs.h +++ b/include/uapi/linux/pci_regs.h @@ -866,6 +866,7 @@ #define PCI_ATS_CAP 0x04 /* ATS Capability Register */ #define PCI_ATS_CAP_QDEP(x) ((x) & 0x1f) /* Invalidate Queue Depth */ #define PCI_ATS_MAX_QDEP 32 /* Max Invalidate Queue Depth */ +#define PCI_ATS_CAP_PAGE_ALIGNED 0x0020 /* Page Aligned Request */ #define PCI_ATS_CTRL 0x06 /* ATS Control Register */ #define PCI_ATS_CTRL_ENABLE 0x8000 /* ATS Enable */ #define PCI_ATS_CTRL_STU(x) ((x) & 0x1f) /* Smallest Translation Unit */