[RFC 05/11] iommu/dma: iommu_dma_(un)map_mixed

[Eric Auger <eric.auger@redhat.com>]

iommu_dma_map_mixed and iommu_dma_unmap_mixed operate on
IOMMU_DOMAIN_MIXED typed domains. On top of standard iommu_map/unmap
they reserve the IOVA window to prevent the iova allocator to
allocate in those areas.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
---
 drivers/iommu/dma-iommu.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/dma-iommu.h | 18 ++++++++++++++++++
 2 files changed, 66 insertions(+)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 04bbc85..db21143 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -759,3 +759,51 @@ int iommu_get_dma_msi_region_cookie(struct iommu_domain *domain,
 	return 0;
 }
 EXPORT_SYMBOL(iommu_get_dma_msi_region_cookie);
+
+int iommu_dma_map_mixed(struct iommu_domain *domain, unsigned long iova,
+			phys_addr_t paddr, size_t size, int prot)
+{
+	struct iova_domain *iovad;
+	unsigned long lo, hi;
+	int ret;
+
+	if (domain->type != IOMMU_DOMAIN_MIXED)
+		return -EINVAL;
+
+	if (!domain->iova_cookie)
+		return -EINVAL;
+
+	iovad = cookie_iovad(domain);
+
+	lo = iova_pfn(iovad, iova);
+	hi = iova_pfn(iovad, iova + size - 1);
+	reserve_iova(iovad, lo, hi);
+	ret = iommu_map(domain, iova, paddr, size, prot);
+	if (ret)
+		free_iova(iovad, lo);
+	return ret;
+}
+EXPORT_SYMBOL(iommu_dma_map_mixed);
+
+size_t iommu_dma_unmap_mixed(struct iommu_domain *domain, unsigned long iova,
+			     size_t size)
+{
+	struct iova_domain *iovad;
+	unsigned long lo;
+	size_t ret;
+
+	if (domain->type != IOMMU_DOMAIN_MIXED)
+		return -EINVAL;
+
+	if (!domain->iova_cookie)
+		return -EINVAL;
+
+	iovad = cookie_iovad(domain);
+	lo = iova_pfn(iovad, iova);
+
+	ret = iommu_unmap(domain, iova, size);
+	if (ret == size)
+		free_iova(iovad, lo);
+	return ret;
+}
+EXPORT_SYMBOL(iommu_dma_unmap_mixed);
diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
index 1c55413..f2aa855 100644
--- a/include/linux/dma-iommu.h
+++ b/include/linux/dma-iommu.h
@@ -70,6 +70,12 @@ void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg);
 int iommu_get_dma_msi_region_cookie(struct iommu_domain *domain,
 		dma_addr_t base, u64 size);
 
+int iommu_dma_map_mixed(struct iommu_domain *domain, unsigned long iova,
+			phys_addr_t paddr, size_t size, int prot);
+
+size_t iommu_dma_unmap_mixed(struct iommu_domain *domain, unsigned long iova,
+			     size_t size);
+
 #else
 
 struct iommu_domain;
@@ -99,6 +105,18 @@ static inline int iommu_get_dma_msi_region_cookie(struct iommu_domain *domain,
 	return -ENODEV;
 }
 
+int iommu_dma_map_mixed(struct iommu_domain *domain, unsigned long iova,
+			phys_addr_t paddr, size_t size, int prot)
+{
+	return -ENODEV;
+}
+
+size_t iommu_dma_unmap_mixed(struct iommu_domain *domain, unsigned long iova,
+			     size_t size)
+{
+	return -ENODEV;
+}
+
 #endif	/* CONFIG_IOMMU_DMA */
 #endif	/* __KERNEL__ */
 #endif	/* __DMA_IOMMU_H */
-- 
1.9.1