Merge tag 'dma-mapping-5.15' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping updates from Christoph Hellwig:

 - fix debugfs initialization order (Anthony Iliopoulos)

 - use memory_intersects() directly (Kefeng Wang)

 - allow to return specific errors from ->map_sg (Logan Gunthorpe,
   Martin Oliveira)

 - turn the dma_map_sg return value into an unsigned int (me)

 - provide a common global coherent pool іmplementation (me)

* tag 'dma-mapping-5.15' of git://git.infradead.org/users/hch/dma-mapping: (31 commits)
  hexagon: use the generic global coherent pool
  dma-mapping: make the global coherent pool conditional
  dma-mapping: add a dma_init_global_coherent helper
  dma-mapping: simplify dma_init_coherent_memory
  dma-mapping: allow using the global coherent pool for !ARM
  ARM/nommu: use the generic dma-direct code for non-coherent devices
  dma-direct: add support for dma_coherent_default_memory
  dma-mapping: return an unsigned int from dma_map_sg{,_attrs}
  dma-mapping: disallow .map_sg operations from returning zero on error
  dma-mapping: return error code from dma_dummy_map_sg()
  x86/amd_gart: don't set failed sg dma_address to DMA_MAPPING_ERROR
  x86/amd_gart: return error code from gart_map_sg()
  xen: swiotlb: return error code from xen_swiotlb_map_sg()
  parisc: return error code from .map_sg() ops
  sparc/iommu: don't set failed sg dma_address to DMA_MAPPING_ERROR
  sparc/iommu: return error codes from .map_sg() ops
  s390/pci: don't set failed sg dma_address to DMA_MAPPING_ERROR
  s390/pci: return error code from s390_dma_map_sg()
  powerpc/iommu: don't set failed sg dma_address to DMA_MAPPING_ERROR
  powerpc/iommu: return error code from .map_sg() ops
  ...

2 files changed, 22 insertions, 15 deletions

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 6f0df629353f..9b4c025b8871 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -973,7 +973,7 @@ static int iommu_dma_map_sg_swiotlb(struct device *dev, struct scatterlist *sg,
 
 out_unmap:
 	iommu_dma_unmap_sg_swiotlb(dev, sg, i, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC);
-	return 0;
+	return -EIO;
 }
 
 /*
@@ -994,11 +994,13 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
 	dma_addr_t iova;
 	size_t iova_len = 0;
 	unsigned long mask = dma_get_seg_boundary(dev);
+	ssize_t ret;
 	int i;
 
-	if (static_branch_unlikely(&iommu_deferred_attach_enabled) &&
-	    iommu_deferred_attach(dev, domain))
-		return 0;
+	if (static_branch_unlikely(&iommu_deferred_attach_enabled)) {
+		ret = iommu_deferred_attach(dev, domain);
+		goto out;
+	}
 
 	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 		iommu_dma_sync_sg_for_device(dev, sg, nents, dir);
@@ -1046,14 +1048,17 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
 	}
 
 	iova = iommu_dma_alloc_iova(domain, iova_len, dma_get_mask(dev), dev);
-	if (!iova)
+	if (!iova) {
+		ret = -ENOMEM;
 		goto out_restore_sg;
+	}
 
 	/*
 	 * We'll leave any physical concatenation to the IOMMU driver's
 	 * implementation - it knows better than we do.
 	 */
-	if (iommu_map_sg_atomic(domain, iova, sg, nents, prot) < iova_len)
+	ret = iommu_map_sg_atomic(domain, iova, sg, nents, prot);
+	if (ret < iova_len)
 		goto out_free_iova;
 
 	return __finalise_sg(dev, sg, nents, iova);
@@ -1062,7 +1067,10 @@ out_free_iova:
 	iommu_dma_free_iova(cookie, iova, iova_len, NULL);
 out_restore_sg:
 	__invalidate_sg(sg, nents);
-	return 0;
+out:
+	if (ret != -ENOMEM)
+		return -EINVAL;
+	return ret;
 }
 
 static void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 63f0af10c403..5a570d495f8d 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2570,9 +2570,9 @@ size_t iommu_unmap_fast(struct iommu_domain *domain,
 }
 EXPORT_SYMBOL_GPL(iommu_unmap_fast);
 
-static size_t __iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
-			     struct scatterlist *sg, unsigned int nents, int prot,
-			     gfp_t gfp)
+static ssize_t __iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
+		struct scatterlist *sg, unsigned int nents, int prot,
+		gfp_t gfp)
 {
 	const struct iommu_ops *ops = domain->ops;
 	size_t len = 0, mapped = 0;
@@ -2613,19 +2613,18 @@ out_err:
 	/* undo mappings already done */
 	iommu_unmap(domain, iova, mapped);
 
-	return 0;
-
+	return ret;
 }
 
-size_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
-		    struct scatterlist *sg, unsigned int nents, int prot)
+ssize_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
+		     struct scatterlist *sg, unsigned int nents, int prot)
 {
 	might_sleep();
 	return __iommu_map_sg(domain, iova, sg, nents, prot, GFP_KERNEL);
 }
 EXPORT_SYMBOL_GPL(iommu_map_sg);
 
-size_t iommu_map_sg_atomic(struct iommu_domain *domain, unsigned long iova,
+ssize_t iommu_map_sg_atomic(struct iommu_domain *domain, unsigned long iova,
 		    struct scatterlist *sg, unsigned int nents, int prot)
 {
 	return __iommu_map_sg(domain, iova, sg, nents, prot, GFP_ATOMIC);