msm: Add simple APIs to map contiguous buffer

Typicall, most iommu mapping happens through Ion or another
API. There may be other cases when clients need a simple
API to map a contiguous physical address into an iommu.
Add apis to support mapping and unmapping a physical range
into the iommu. The client is responsible for any reference
counting that needs to occur.

Change-Id: Ie5cb330417f7dd967748bb76cfdf9d123c579e04
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
diff --git a/arch/arm/mach-msm/include/mach/iommu_domains.h b/arch/arm/mach-msm/include/mach/iommu_domains.h
index 52e70ec..e232d00 100644
--- a/arch/arm/mach-msm/include/mach/iommu_domains.h
+++ b/arch/arm/mach-msm/include/mach/iommu_domains.h
@@ -77,6 +77,20 @@
 						unsigned long size,
 						int cached);
 
+extern int msm_iommu_map_contig_buffer(unsigned long phys,
+				unsigned int domain_no,
+				unsigned int partition_no,
+				unsigned long size,
+				unsigned long align,
+				unsigned long cached,
+				unsigned long *iova_val);
+
+
+extern void msm_iommu_unmap_contig_buffer(unsigned long iova,
+					unsigned int domain_no,
+					unsigned int partition_no,
+					unsigned long size);
+
 #else
 static inline struct iommu_domain
 	*msm_get_iommu_domain(int subsys_id) { return NULL; }
@@ -104,7 +118,30 @@
 						int cached)
 {
 	return -ENODEV;
+
 }
+
+
+static inline int msm_iommu_map_contig_buffer(unsigned long phys,
+				unsigned int domain_no,
+				unsigned int partition_no,
+				unsigned long size,
+				unsigned long align,
+				unsigned long cached,
+				unsigned long *iova_val)
+{
+	*iova_val = phys;
+	return 0;
+}
+
+static inline void msm_iommu_unmap_contig_buffer(unsigned long iova,
+					unsigned int domain_no,
+					unsigned int partition_no,
+					unsigned long size)
+{
+	return;
+}
+
 #endif
 
 #endif
diff --git a/arch/arm/mach-msm/iommu_domains.c b/arch/arm/mach-msm/iommu_domains.c
index 8f4af3b..4afb9bd 100644
--- a/arch/arm/mach-msm/iommu_domains.c
+++ b/arch/arm/mach-msm/iommu_domains.c
@@ -65,6 +65,76 @@
 	return ret;
 }
 
+static int msm_iommu_map_iova_phys(struct iommu_domain *domain,
+				unsigned long iova,
+				unsigned long phys,
+				unsigned long size,
+				int cached)
+{
+	int ret;
+	struct scatterlist *sglist;
+
+	sglist = vmalloc(sizeof(*sglist));
+	if (!sglist) {
+		ret = -ENOMEM;
+		goto err1;
+	}
+
+	sg_init_table(sglist, 1);
+	sglist->length = size;
+	sglist->offset = 0;
+	sglist->dma_address = phys;
+
+	ret = iommu_map_range(domain, iova, sglist, size, cached);
+	if (ret) {
+		pr_err("%s: could not map extra %lx in domain %p\n",
+			__func__, iova, domain);
+	}
+
+	vfree(sglist);
+err1:
+	return ret;
+
+}
+
+int msm_iommu_map_contig_buffer(unsigned long phys,
+				unsigned int domain_no,
+				unsigned int partition_no,
+				unsigned long size,
+				unsigned long align,
+				unsigned long cached,
+				unsigned long *iova_val)
+{
+	unsigned long iova;
+	int ret;
+
+	if (size & (align - 1))
+		return -EINVAL;
+
+	iova = msm_allocate_iova_address(domain_no, partition_no, size, align);
+
+	if (!iova)
+		return -ENOMEM;
+
+	ret = msm_iommu_map_iova_phys(msm_get_iommu_domain(domain_no), iova,
+					phys, size, cached);
+
+	if (ret)
+		msm_free_iova_address(iova, domain_no, partition_no, size);
+	else
+		*iova_val = iova;
+
+	return ret;
+}
+
+void msm_iommu_unmap_contig_buffer(unsigned long iova,
+					unsigned int domain_no,
+					unsigned int partition_no,
+					unsigned long size)
+{
+	iommu_unmap_range(msm_get_iommu_domain(domain_no), iova, size);
+	msm_free_iova_address(iova, domain_no, partition_no, size);
+}
 
 struct iommu_domain *msm_get_iommu_domain(int domain_num)
 {