The ATS spec can be found at http://www.pcisig.com/specifications/iov/ats/ (it requires membership). Signed-off-by: Yu Zhao <yu.zhao@xxxxxxxxx> --- drivers/pci/pci.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 15 ++++++++++ include/linux/pci_regs.h | 10 +++++++ 3 files changed, 93 insertions(+), 0 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 061d1ee..5abab14 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1337,6 +1337,74 @@ void pci_enable_ari(struct pci_dev *dev) bridge->ari_enabled = 1; } +/** + * pci_enable_ats - enable the ATS capability + * @dev: the PCI device + * @ps: the IOMMU page shift + * + * Returns 0 on success, or a negative value on error. + */ +int pci_enable_ats(struct pci_dev *dev, int ps) +{ + int pos; + u16 ctrl; + + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS); + if (!pos) + return -ENODEV; + + if (ps < PCI_ATS_MIN_STU) + return -EINVAL; + + ctrl = PCI_ATS_CTRL_STU(ps - PCI_ATS_MIN_STU) | PCI_ATS_CTRL_ENABLE; + pci_write_config_word(dev, pos + PCI_ATS_CTRL, ctrl); + + dev->ats_enabled = 1; + + return 0; +} + +/** + * pci_disable_ats - disable the ATS capability + * @dev: the PCI device + */ +void pci_disable_ats(struct pci_dev *dev) +{ + int pos; + u16 ctrl; + + if (!dev->ats_enabled) + return; + + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS); + if (!pos) + return; + + pci_read_config_word(dev, pos + PCI_ATS_CTRL, &ctrl); + ctrl &= ~PCI_ATS_CTRL_ENABLE; + pci_write_config_word(dev, pos + PCI_ATS_CTRL, ctrl); +} + +/** + * pci_ats_qdep - query ATS Invalidate Queue Depth + * @dev: the PCI device + * + * Returns the queue depth on success, or 0 on error. + */ +int pci_ats_qdep(struct pci_dev *dev) +{ + int pos; + u16 cap; + + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS); + if (!pos) + return 0; + + pci_read_config_word(dev, pos + PCI_ATS_CAP, &cap); + + return PCI_ATS_CAP_QDEP(cap) ? : PCI_ATS_MAX_QDEP; +} + int pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge) { diff --git a/include/linux/pci.h b/include/linux/pci.h index 4bb156b..e6a1b5a 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -227,6 +227,7 @@ struct pci_dev { unsigned int msi_enabled:1; unsigned int msix_enabled:1; unsigned int ari_enabled:1; /* ARI forwarding */ + unsigned int ats_enabled:1; /* Address Translation Service */ unsigned int is_managed:1; unsigned int is_pcie:1; pci_dev_flags_t dev_flags; @@ -1155,5 +1156,19 @@ static inline void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar) } #endif +extern int pci_enable_ats(struct pci_dev *dev, int ps); +extern void pci_disable_ats(struct pci_dev *dev); +extern int pci_ats_qdep(struct pci_dev *dev); +/** + * pci_ats_enabled - query the ATS status + * @dev: the PCI device + * + * Returns 1 if ATS capability is enabled, or 0 if not. + */ +static inline int pci_ats_enabled(struct pci_dev *dev) +{ + return dev->ats_enabled; +} + #endif /* __KERNEL__ */ #endif /* LINUX_PCI_H */ diff --git a/include/linux/pci_regs.h b/include/linux/pci_regs.h index e5effd4..00c9db5 100644 --- a/include/linux/pci_regs.h +++ b/include/linux/pci_regs.h @@ -436,6 +436,7 @@ #define PCI_EXT_CAP_ID_DSN 3 #define PCI_EXT_CAP_ID_PWR 4 #define PCI_EXT_CAP_ID_ARI 14 +#define PCI_EXT_CAP_ID_ATS 15 /* Advanced Error Reporting */ #define PCI_ERR_UNCOR_STATUS 4 /* Uncorrectable Error Status */ @@ -553,4 +554,13 @@ #define PCI_ARI_CTRL_ACS 0x0002 /* ACS Function Groups Enable */ #define PCI_ARI_CTRL_FG(x) (((x) >> 4) & 7) /* Function Group */ +/* Address Translation Service */ +#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_CTRL 0x06 /* ATS Control Register */ +#define PCI_ATS_CTRL_ENABLE 0x8000 /* ATS Enable */ +#define PCI_ATS_CTRL_STU(x) ((x) & 0x1f) /* Smallest Translation Unit */ +#define PCI_ATS_MIN_STU 12 /* shift of minimum STU block */ + #endif /* LINUX_PCI_REGS_H */ -- 1.5.6.4 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
