[PATCH 10/19] AMD IOMMU: add checks for dma_ops domain to dma_ops functions

[Joerg Roedel <joerg.roedel@amd.com>]

Impact: detect when a driver uses a device assigned otherwise

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
---
 arch/x86/kernel/amd_iommu.c |   21 +++++++++++++++++++++
 1 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 07ef5e9..be626ad 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -786,6 +786,15 @@ free_dma_dom:
 }
 
 /*
+ * little helper function to check whether a given protection domain is a
+ * dma_ops domain
+ */
+static bool dma_ops_domain(struct protection_domain *domain)
+{
+	return domain->flags & PD_DMA_OPS_MASK;
+}
+
+/*
  * Find out the protection domain structure for a given PCI device. This
  * will give us the pointer to the page table root for example.
  */
@@ -1089,6 +1098,8 @@ static dma_addr_t map_single(struct device *dev, phys_addr_t paddr,
 		/* device not handled by any AMD IOMMU */
 		return (dma_addr_t)paddr;
 
+	BUG_ON(!dma_ops_domain(domain));
+
 	spin_lock_irqsave(&domain->lock, flags);
 	addr = __map_single(dev, iommu, domain->priv, paddr, size, dir, false,
 			    dma_mask);
@@ -1120,6 +1131,8 @@ static void unmap_single(struct device *dev, dma_addr_t dma_addr,
 		/* device not handled by any AMD IOMMU */
 		return;
 
+	BUG_ON(!dma_ops_domain(domain));
+
 	spin_lock_irqsave(&domain->lock, flags);
 
 	__unmap_single(iommu, domain->priv, dma_addr, size, dir);
@@ -1175,6 +1188,8 @@ static int map_sg(struct device *dev, struct scatterlist *sglist,
 	if (!iommu || !domain)
 		return map_sg_no_iommu(dev, sglist, nelems, dir);
 
+	BUG_ON(!dma_ops_domain(domain));
+
 	spin_lock_irqsave(&domain->lock, flags);
 
 	for_each_sg(sglist, s, nelems, i) {
@@ -1229,6 +1244,8 @@ static void unmap_sg(struct device *dev, struct scatterlist *sglist,
 	    !get_device_resources(dev, &iommu, &domain, &devid))
 		return;
 
+	BUG_ON(!dma_ops_domain(domain));
+
 	spin_lock_irqsave(&domain->lock, flags);
 
 	for_each_sg(sglist, s, nelems, i) {
@@ -1275,6 +1292,8 @@ static void *alloc_coherent(struct device *dev, size_t size,
 		return virt_addr;
 	}
 
+	BUG_ON(!dma_ops_domain(domain));
+
 	if (!dma_mask)
 		dma_mask = *dev->dma_mask;
 
@@ -1317,6 +1336,8 @@ static void free_coherent(struct device *dev, size_t size,
 	if (!iommu || !domain)
 		goto free_mem;
 
+	BUG_ON(!dma_ops_domain(domain));
+
 	spin_lock_irqsave(&domain->lock, flags);
 
 	__unmap_single(iommu, domain->priv, dma_addr, size, DMA_BIDIRECTIONAL);
-- 
1.5.6.4