diff options
Diffstat (limited to 'drivers/pci/ats.c')
| -rw-r--r-- | drivers/pci/ats.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c index 420cd0a578d0..97c08146534a 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 |