Merge tag 'dma-mapping-5.3-4' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:

 - fix the handling of the bus_dma_mask in dma_get_required_mask, which
   caused a regression in this merge window (Lucas Stach)

 - fix a regression in the handling of DMA_ATTR_NO_KERNEL_MAPPING (me)

 - fix dma_mmap_coherent to not cause page attribute mismatches on
   coherent architectures like x86 (me)

* tag 'dma-mapping-5.3-4' of git://git.infradead.org/users/hch/dma-mapping:
  dma-mapping: fix page attributes for dma_mmap_*
  dma-direct: don't truncate dma_required_mask to bus addressing capabilities
  dma-direct: fix DMA_ATTR_NO_KERNEL_MAPPING

3 files changed, 24 insertions, 7 deletions

diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 59bdceea3737..795c9b095d75 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -47,9 +47,6 @@ u64 dma_direct_get_required_mask(struct device *dev)
 {
 	u64 max_dma = phys_to_dma_direct(dev, (max_pfn - 1) << PAGE_SHIFT);
 
-	if (dev->bus_dma_mask && dev->bus_dma_mask < max_dma)
-		max_dma = dev->bus_dma_mask;
-
 	return (1ULL << (fls64(max_dma) - 1)) * 2 - 1;
 }
 
@@ -130,10 +127,12 @@ void *dma_direct_alloc_pages(struct device *dev, size_t size,
 	if (!page)
 		return NULL;
 
-	if (attrs & DMA_ATTR_NO_KERNEL_MAPPING) {
+	if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) &&
+	    !force_dma_unencrypted(dev)) {
 		/* remove any dirty cache lines on the kernel alias */
 		if (!PageHighMem(page))
 			arch_dma_prep_coherent(page, size);
+		*dma_handle = phys_to_dma(dev, page_to_phys(page));
 		/* return the page pointer as the opaque cookie */
 		return page;
 	}
@@ -178,7 +177,8 @@ void dma_direct_free_pages(struct device *dev, size_t size, void *cpu_addr,
 {
 	unsigned int page_order = get_order(size);
 
-	if (attrs & DMA_ATTR_NO_KERNEL_MAPPING) {
+	if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) &&
+	    !force_dma_unencrypted(dev)) {
 		/* cpu_addr is a struct page cookie, not a kernel address */
 		__dma_direct_free_pages(dev, size, cpu_addr);
 		return;
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index b945239621d8..b0038ca3aa92 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -150,6 +150,23 @@ int dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt,
 }
 EXPORT_SYMBOL(dma_get_sgtable_attrs);
 
+#ifdef CONFIG_MMU
+/*
+ * Return the page attributes used for mapping dma_alloc_* memory, either in
+ * kernel space if remapping is needed, or to userspace through dma_mmap_*.
+ */
+pgprot_t dma_pgprot(struct device *dev, pgprot_t prot, unsigned long attrs)
+{
+	if (dev_is_dma_coherent(dev) ||
+	    (IS_ENABLED(CONFIG_DMA_NONCOHERENT_CACHE_SYNC) &&
+             (attrs & DMA_ATTR_NON_CONSISTENT)))
+		return prot;
+	if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_MMAP_PGPROT))
+		return arch_dma_mmap_pgprot(dev, prot, attrs);
+	return pgprot_noncached(prot);
+}
+#endif /* CONFIG_MMU */
+
 /*
  * Create userspace mapping for the DMA-coherent memory.
  */
@@ -164,7 +181,7 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
 	unsigned long pfn;
 	int ret = -ENXIO;
 
-	vma->vm_page_prot = arch_dma_mmap_pgprot(dev, vma->vm_page_prot, attrs);
+	vma->vm_page_prot = dma_pgprot(dev, vma->vm_page_prot, attrs);
 
 	if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
 		return ret;
diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c
index a594aec07882..ffe78f0b2fe4 100644
--- a/kernel/dma/remap.c
+++ b/kernel/dma/remap.c
@@ -218,7 +218,7 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
 
 	/* create a coherent mapping */
 	ret = dma_common_contiguous_remap(page, size, VM_USERMAP,
-			arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs),
+			dma_pgprot(dev, PAGE_KERNEL, attrs),
 			__builtin_return_address(0));
 	if (!ret) {
 		__dma_direct_free_pages(dev, size, page);