diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c index 5b78f3b1b918a7f5600c4222b89288481ed985c2..420cd0a578d079371227a1d2f0d13ad89b39ceeb 100644 --- a/drivers/pci/ats.c +++ b/drivers/pci/ats.c @@ -368,6 +368,36 @@ int pci_pasid_features(struct pci_dev *pdev) } EXPORT_SYMBOL_GPL(pci_pasid_features); +/** + * pci_prg_resp_pasid_required - Return PRG Response PASID Required bit + * status. + * @pdev: PCI device structure + * + * Returns 1 if PASID is required in PRG Response Message, 0 otherwise. + * + * Even though the PRG response PASID status is read from PRI Status + * Register, since this API will mainly be used by PASID users, this + * function is defined within #ifdef CONFIG_PCI_PASID instead of + * CONFIG_PCI_PRI. + */ +int pci_prg_resp_pasid_required(struct pci_dev *pdev) +{ + u16 status; + int pos; + + pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI); + if (!pos) + return 0; + + pci_read_config_word(pdev, pos + PCI_PRI_STATUS, &status); + + if (status & PCI_PRI_STATUS_PASID) + return 1; + + return 0; +} +EXPORT_SYMBOL_GPL(pci_prg_resp_pasid_required); + #define PASID_NUMBER_SHIFT 8 #define PASID_NUMBER_MASK (0x1f << PASID_NUMBER_SHIFT) /** diff --git a/include/linux/pci-ats.h b/include/linux/pci-ats.h index 7c4b8e27268c7455c9f13234d0d2790dfb46dfc4..facfd6a18fe184a90b9f2790ca1e79fd496aff1c 100644 --- a/include/linux/pci-ats.h +++ b/include/linux/pci-ats.h @@ -40,6 +40,7 @@ void pci_disable_pasid(struct pci_dev *pdev); void pci_restore_pasid_state(struct pci_dev *pdev); int pci_pasid_features(struct pci_dev *pdev); int pci_max_pasids(struct pci_dev *pdev); +int pci_prg_resp_pasid_required(struct pci_dev *pdev); #else /* CONFIG_PCI_PASID */ @@ -66,6 +67,10 @@ static inline int pci_max_pasids(struct pci_dev *pdev) return -EINVAL; } +static int pci_prg_resp_pasid_required(struct pci_dev *pdev) +{ + return 0; +} #endif /* CONFIG_PCI_PASID */ diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h index e1e9888c85e6810aad2e54ab25cbbaf49b72ba57..898be572b010d65b33c3e55bf6ad2295784a8583 100644 --- a/include/uapi/linux/pci_regs.h +++ b/include/uapi/linux/pci_regs.h @@ -880,6 +880,7 @@ #define PCI_PRI_STATUS_RF 0x001 /* Response Failure */ #define PCI_PRI_STATUS_UPRGI 0x002 /* Unexpected PRG index */ #define PCI_PRI_STATUS_STOPPED 0x100 /* PRI Stopped */ +#define PCI_PRI_STATUS_PASID 0x8000 /* PRG Response PASID Required */ #define PCI_PRI_MAX_REQ 0x08 /* PRI max reqs supported */ #define PCI_PRI_ALLOC_REQ 0x0c /* PRI max reqs allowed */ #define PCI_EXT_CAP_PRI_SIZEOF 16