[PATCH v4 1/6] PCI: Add pci_add_dma_alias() to abstract implementation

[Bjorn Helgaas via iommu]

From: Jacek Lawrynowicz <jacek.lawrynow...@intel.com>

Add a pci_add_dma_alias() interface to encapsulate the details of adding an
alias.  No functional change intended.
---
 drivers/pci/pci.c    |   14 ++++++++++++++
 drivers/pci/pci.h    |    2 ++
 drivers/pci/quirks.c |   19 +++++++------------
 3 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 602eb42..7fccc8a 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4568,6 +4568,20 @@ int pci_set_vga_state(struct pci_dev *dev, bool decode,
        return 0;
 }
 
+/**
+ * pci_add_dma_alias - Add a DMA devfn alias for a device
+ * @dev: the PCI device for which alias is added
+ * @devfn: alias slot and function
+ *
+ * This helper encodes 8-bit devfn as bit number in dma_alias_mask.
+ * It should be called early, preferably as PCI fixup header quirk.
+ */
+void pci_add_dma_alias(struct pci_dev *dev, u8 devfn)
+{
+       dev->dma_alias_devfn = PCI_DEVFN(PCI_SLOT(dev->devfn), 0);
+       dev->dev_flags |= PCI_DEV_FLAGS_DMA_ALIAS_DEVFN;
+}
+
 bool pci_device_is_present(struct pci_dev *pdev)
 {
        u32 v;
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 9a1660f..c5dc8dc 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -335,4 +335,6 @@ static inline int pci_dev_specific_reset(struct pci_dev 
*dev, int probe)
 }
 #endif
 
+void pci_add_dma_alias(struct pci_dev *dev, u8 devfn);
+
 #endif /* DRIVERS_PCI_H */
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 0575a1e..df28dce 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3581,10 +3581,8 @@ int pci_dev_specific_reset(struct pci_dev *dev, int 
probe)
 
 static void quirk_dma_func0_alias(struct pci_dev *dev)
 {
-       if (PCI_FUNC(dev->devfn) != 0) {
-               dev->dma_alias_devfn = PCI_DEVFN(PCI_SLOT(dev->devfn), 0);
-               dev->dev_flags |= PCI_DEV_FLAGS_DMA_ALIAS_DEVFN;
-       }
+       if (PCI_FUNC(dev->devfn) != 0)
+               pci_add_dma_alias(dev, PCI_DEVFN(PCI_SLOT(dev->devfn), 0));
 }
 
 /*
@@ -3597,10 +3595,8 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_RICOH, 0xe476, 
quirk_dma_func0_alias);
 
 static void quirk_dma_func1_alias(struct pci_dev *dev)
 {
-       if (PCI_FUNC(dev->devfn) != 1) {
-               dev->dma_alias_devfn = PCI_DEVFN(PCI_SLOT(dev->devfn), 1);
-               dev->dev_flags |= PCI_DEV_FLAGS_DMA_ALIAS_DEVFN;
-       }
+       if (PCI_FUNC(dev->devfn) != 1)
+               pci_add_dma_alias(dev, PCI_DEVFN(PCI_SLOT(dev->devfn), 1));
 }
 
 /*
@@ -3667,11 +3663,10 @@ static void quirk_fixed_dma_alias(struct pci_dev *dev)
 
        id = pci_match_id(fixed_dma_alias_tbl, dev);
        if (id) {
-               dev->dma_alias_devfn = id->driver_data;
-               dev->dev_flags |= PCI_DEV_FLAGS_DMA_ALIAS_DEVFN;
+               pci_add_dma_alias(dev, id->driver_data);
                dev_info(&dev->dev, "Enabling fixed DMA alias to %02x.%d\n",
-                        PCI_SLOT(dev->dma_alias_devfn),
-                        PCI_FUNC(dev->dma_alias_devfn));
+                        PCI_SLOT(id->driver_data),
+                        PCI_FUNC(id->driver_data));
        }
 }
 

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