From 12ea6cad1c7d046e21decc18b0e2170c6794dc51 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Mon, 11 Jun 2012 05:26:55 +0000 Subject: PCI: add PCI DMA source ID quirk DMA transactions are tagged with the source ID of the device making the request. Occasionally hardware screws this up and uses the source ID of a different device (often the wrong function number of a multifunction device). A specific Ricoh multifunction device is a prime example of this problem and included in this patch. Given a pci_dev, this function returns the pci_dev to use as the source ID for DMA. When hardware works correctly, this returns the input device. For the components of the Ricoh multifunction device, it returns the pci_dev for function 0. This will be used by IOMMU drivers for determining the boundaries of IOMMU groups as multiple devices using the same source ID must be contained within the same group. This can also be used by existing streaming DMA paths for the same purpose. [bhelgaas: fold in pci_dev_get() for !CONFIG_PCI] Signed-off-by: Alex Williamson Signed-off-by: Bjorn Helgaas --- include/linux/pci.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/linux/pci.h') diff --git a/include/linux/pci.h b/include/linux/pci.h index d8c379dba6ad..39983be7b25b 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1332,6 +1332,9 @@ static inline struct pci_dev *pci_get_bus_and_slot(unsigned int bus, static inline int pci_domain_nr(struct pci_bus *bus) { return 0; } +static inline struct pci_dev *pci_dev_get(struct pci_dev *dev) +{ return NULL; } + #define dev_is_pci(d) (false) #define dev_is_pf(d) (false) #define dev_num_vf(d) (0) @@ -1486,9 +1489,14 @@ enum pci_fixup_pass { #ifdef CONFIG_PCI_QUIRKS void pci_fixup_device(enum pci_fixup_pass pass, struct pci_dev *dev); +struct pci_dev *pci_get_dma_source(struct pci_dev *dev); #else static inline void pci_fixup_device(enum pci_fixup_pass pass, struct pci_dev *dev) {} +static inline struct pci_dev *pci_get_dma_source(struct pci_dev *dev) +{ + return pci_dev_get(dev); +} #endif void __iomem *pcim_iomap(struct pci_dev *pdev, int bar, unsigned long maxlen); -- cgit v1.2.1