| Message ID | e7dddc4f4092764bb5762e8b46c847278a8923ac.1549915780.git.sathyanarayanan.kuppuswamy@linux.intel.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | Add PGR response PASID requirement check in Intel IOMMU. | expand |
On Mon, Feb 11, 2019 at 01:50:31PM -0800, sathyanarayanan.kuppuswamy@linux.intel.com wrote: > From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> > > Return the PRG Response PASID Required bit in the Page Request > Status Register. > > As per PCIe spec r4.0, sec 10.5.2.3, if this bit is Set then the device > expects a PASID TLP Prefix on PRG Response Messages when the > corresponding Page Requests had a PASID TLP Prefix. If Clear, the device > does not expect PASID TLP Prefixes on any PRG Response Message, and the > device behavior is undefined if this bit is Clear and the device > receives a PRG Response Message with a PASID TLP Prefix. Also the device > behavior is undefined in the this bit is Set and the device receives a > PRG Response Message with no PASID TLP Prefix when the corresponding > Page Requests had a PASID TLP Prefix. s/Set then the device/Set, the device/ s/undefined if this bit is Clear and the device/undefined if the device/ s/is undefined in the this/is undefined if this/ > This function will be used by drivers like IOMMU, if it is required to > check the status of the PRG Response PASID Required bit before enabling > the PASID support of the device. > > Cc: Ashok Raj <ashok.raj@intel.com> > Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> > Cc: Keith Busch <keith.busch@intel.com> > Suggested-by: Ashok Raj <ashok.raj@intel.com> > Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> With typos (also below) addressed, Acked-by: Bjorn Helgaas <bhelgaas@google.com> > --- > drivers/pci/ats.c | 31 +++++++++++++++++++++++++++++++ > include/linux/pci-ats.h | 5 +++++ > include/uapi/linux/pci_regs.h | 1 + > 3 files changed, 37 insertions(+) > > diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c > index 5b78f3b1b918..f843cd846dff 100644 > --- a/drivers/pci/ats.c > +++ b/drivers/pci/ats.c > @@ -368,6 +368,37 @@ 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. > + * Remove blank comment line. > + */ > +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 7c4b8e27268c..facfd6a18fe1 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 e1e9888c85e6..898be572b010 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 > -- > 2.20.1 >
diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c index 5b78f3b1b918..f843cd846dff 100644 --- a/drivers/pci/ats.c +++ b/drivers/pci/ats.c @@ -368,6 +368,37 @@ 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 7c4b8e27268c..facfd6a18fe1 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 e1e9888c85e6..898be572b010 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