From 302b4215daa0a704c843da40fd2529e5757a72da Mon Sep 17 00:00:00 2001 From: Yu Zhao Date: Mon, 18 May 2009 13:51:32 +0800 Subject: PCI: support the ATS capability The PCIe ATS capability makes the Endpoint be able to request the DMA address translation from the IOMMU and cache the translation in the device side, thus alleviate IOMMU pressure and improve the hardware performance in the I/O virtualization environment. Signed-off-by: Yu Zhao Acked-by: Jesse Barnes Signed-off-by: David Woodhouse --- drivers/pci/pci.h | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) (limited to 'drivers/pci/pci.h') diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index d03f6b99f292..3c2ec64f78e9 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -229,6 +229,13 @@ struct pci_sriov { u8 __iomem *mstate; /* VF Migration State Array */ }; +/* Address Translation Service */ +struct pci_ats { + int pos; /* capability position */ + int stu; /* Smallest Translation Unit */ + int qdep; /* Invalidate Queue Depth */ +}; + #ifdef CONFIG_PCI_IOV extern int pci_iov_init(struct pci_dev *dev); extern void pci_iov_release(struct pci_dev *dev); @@ -236,6 +243,20 @@ extern int pci_iov_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type); extern void pci_restore_iov_state(struct pci_dev *dev); extern int pci_iov_bus_range(struct pci_bus *bus); + +extern int pci_enable_ats(struct pci_dev *dev, int ps); +extern void pci_disable_ats(struct pci_dev *dev); +extern int pci_ats_queue_depth(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; +} #else static inline int pci_iov_init(struct pci_dev *dev) { @@ -257,6 +278,22 @@ static inline int pci_iov_bus_range(struct pci_bus *bus) { return 0; } + +static inline int pci_enable_ats(struct pci_dev *dev, int ps) +{ + return -ENODEV; +} +static inline void pci_disable_ats(struct pci_dev *dev) +{ +} +static inline int pci_ats_queue_depth(struct pci_dev *dev) +{ + return -ENODEV; +} +static inline int pci_ats_enabled(struct pci_dev *dev) +{ + return 0; +} #endif /* CONFIG_PCI_IOV */ #endif /* DRIVERS_PCI_H */ -- cgit v1.2.3 From e277d2fc79d6abb86fafadb58dca0b9c498a9aa7 Mon Sep 17 00:00:00 2001 From: Yu Zhao Date: Mon, 18 May 2009 13:51:33 +0800 Subject: PCI: handle Virtual Function ATS enabling The SR-IOV spec requires that the Smallest Translation Unit and the Invalidate Queue Depth fields in the Virtual Function ATS capability are hardwired to 0. If a function is a Virtual Function, then and set its Physical Function's STU before enabling the ATS. Signed-off-by: Yu Zhao Acked-by: Jesse Barnes Signed-off-by: David Woodhouse --- drivers/pci/pci.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/pci/pci.h') diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 3c2ec64f78e9..f73bcbedf37c 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -234,6 +234,8 @@ struct pci_ats { int pos; /* capability position */ int stu; /* Smallest Translation Unit */ int qdep; /* Invalidate Queue Depth */ + int ref_cnt; /* Physical Function reference count */ + int is_enabled:1; /* Enable bit is set */ }; #ifdef CONFIG_PCI_IOV @@ -255,7 +257,7 @@ extern int pci_ats_queue_depth(struct pci_dev *dev); */ static inline int pci_ats_enabled(struct pci_dev *dev) { - return !!dev->ats; + return dev->ats && dev->ats->is_enabled; } #else static inline int pci_iov_init(struct pci_dev *dev) -- cgit v1.2.3 From 6faf17f6f1ffc586d16efc2f9fa2083a7785ee74 Mon Sep 17 00:00:00 2001 From: Chris Wright Date: Fri, 28 Aug 2009 13:00:06 -0700 Subject: PCI SR-IOV: correct broken resource alignment calculations An SR-IOV capable device includes an SR-IOV PCIe capability which describes the Virtual Function (VF) BAR requirements. A typical SR-IOV device can support multiple VFs whose BARs must be in a contiguous region, effectively an array of VF BARs. The BAR reports the size requirement for a single VF. We calculate the full range needed by simply multiplying the VF BAR size with the number of possible VFs and create a resource spanning the full range. This all seems sane enough except it artificially inflates the alignment requirement for the VF BAR. The VF BAR need only be aligned to the size of a single BAR not the contiguous range of VF BARs. This can cause us to fail to allocate resources for the BAR despite the fact that we actually have enough space. This patch adds a thin PCI specific layer over the generic resource_alignment() function which is aware of the special nature of VF BARs and does sorting and allocation based on the smaller alignment requirement. I recognize that while resource_alignment is generic, it's basically a PCI helper. An alternative to this patch is to add PCI VF BAR specific information to struct resource. I opted for the extra layer rather than adding such PCI specific information to struct resource. This does have the slight downside that we don't cache the BAR size and re-read for each alignment query (happens a small handful of times during boot for each VF BAR). Signed-off-by: Chris Wright Cc: Ivan Kokshaysky Cc: Linus Torvalds Cc: Matthew Wilcox Cc: Yu Zhao Cc: stable@kernel.org Signed-off-by: Jesse Barnes --- drivers/pci/pci.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'drivers/pci/pci.h') diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index f73bcbedf37c..5ff4d25bf0e9 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -243,6 +243,7 @@ extern int pci_iov_init(struct pci_dev *dev); extern void pci_iov_release(struct pci_dev *dev); extern int pci_iov_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type); +extern int pci_sriov_resource_alignment(struct pci_dev *dev, int resno); extern void pci_restore_iov_state(struct pci_dev *dev); extern int pci_iov_bus_range(struct pci_bus *bus); @@ -298,4 +299,16 @@ static inline int pci_ats_enabled(struct pci_dev *dev) } #endif /* CONFIG_PCI_IOV */ +static inline int pci_resource_alignment(struct pci_dev *dev, + struct resource *res) +{ +#ifdef CONFIG_PCI_IOV + int resno = res - dev->resource; + + if (resno >= PCI_IOV_RESOURCES && resno <= PCI_IOV_RESOURCE_END) + return pci_sriov_resource_alignment(dev, resno); +#endif + return resource_alignment(res); +} + #endif /* DRIVERS_PCI_H */ -- cgit v1.2.3