SPARC64: Introduce IOMMU BYPASS method

This change adds IOMMU BYPASS HV API that will allow PCIe devices to
bypass IOMMU during DMA map/unmap.

Orabug: 25573557

Signed-off-by: Tushar Dave <tushar.n.dave@oracle.com>
Signed-off-by: Allen Pais <allen.pais@oracle.com>

diff --git a/arch/sparc/kernel/pci_sun4v.c b/arch/sparc/kernel/pci_sun4v.c
index 30ed5d0095ea62a6bde62502a13007833893a921..195fc668daecac496256dae9789cfb99adbf180d 100644 (file)
--- a/arch/sparc/kernel/pci_sun4v.c
+++ b/arch/sparc/kernel/pci_sun4v.c
@@ -292,22 +292,20 @@ static dma_addr_t dma_4v_map_page_bypass(struct device *dev, struct page *page,
        unsigned long prot;
        unsigned long dma_addr;
 
-       BUG_ON(!dev);
-       pbm = dev->archdata.host_controller;
-       BUG_ON(!pbm);
-       devhandle = pbm->devhandle;
-
        if (unlikely(direction == DMA_NONE))
                goto bad;
 
        prot = HV_PCI_MAP_ATTR_READ;
-
        if (direction != DMA_TO_DEVICE)
                prot |= HV_PCI_MAP_ATTR_WRITE;
 
+       /* VPCI maj=2, min=[0,1] or greater supports relax ordering */
+       if (dma_get_attr(DMA_ATTR_WEAK_ORDERING, attrs) && vpci_major >= 2)
+               prot |= HV_PCI_MAP_ATTR_RELAXED_ORDER;
 
+       pbm = dev->archdata.host_controller;
+       devhandle = pbm->devhandle;
        ra = __pa(page_address(page) + offset);
-
        if (pci_sun4v_iommu_getbypass(devhandle, ra, prot, &dma_addr))
                goto bad;
 
@@ -426,21 +424,21 @@ static int dma_4v_map_sg_bypass(struct device *dev, struct scatterlist *sglist,
        struct scatterlist *s;
        int i;
 
-       BUG_ON(!dev);
-       pbm = dev->archdata.host_controller;
-       BUG_ON(!pbm);
-       devhandle = pbm->devhandle;
-
        if (unlikely(direction == DMA_NONE))
                goto bad;
 
        prot = HV_PCI_MAP_ATTR_READ;
-
        if (direction != DMA_TO_DEVICE)
                prot |= HV_PCI_MAP_ATTR_WRITE;
 
+       /* VPCI maj=2, min=[0,1] or greater supports relax ordering */
+       if (dma_get_attr(DMA_ATTR_WEAK_ORDERING, attrs) && vpci_major >= 2)
+               prot |= HV_PCI_MAP_ATTR_RELAXED_ORDER;
+
+       pbm = dev->archdata.host_controller;
+       devhandle = pbm->devhandle;
        for_each_sg(sglist, s, nelems, i) {
-               ra = (unsigned long) SG_ENT_PHYS_ADDRESS(s);
+               ra = (unsigned long)SG_ENT_PHYS_ADDRESS(s);
                if (pci_sun4v_iommu_getbypass(devhandle, ra, prot, &dma_addr))
                        goto bad;
                s->dma_address = dma_addr;