From: Allen Pais <allen.pais@oracle.com>
Date: Tue, 16 May 2017 07:08:38 +0000 (+0530)
Subject: SPARC64: Introduce IOMMU BYPASS method
X-Git-Tag: v4.1.12-98.0.20170517_2143~10
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=615d721f4a13bee8bd4c9445ff6d9f8a90ed9410;p=users%2Fjedix%2Flinux-maple.git

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 30ed5d0095ea6..195fc668daeca 100644
--- 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;