[PATCH v8 14/23] dma-mapping: make dma_pgprot() honor __DMA_ATTR_ALLOC_CC_SHARED

Fold encrypted/decrypted pgprot selection into dma_pgprot() so callers
do not need to adjust the page protection separately.

Update dma_pgprot() to apply pgprot_decrypted() when DMA_ATTR_CC_SHARED or
__DMA_ATTR_ALLOC_CC_SHARED is set and pgprot_encrypted() otherwise Convert
the dma-direct mmap paths to pass DMA_ATTR_CC_SHARED instead of open-coding
force_dma_unencrypted() handling around dma_pgprot().

Reviewed-by: Jason Gunthorpe <[email protected]>
Tested-by: Jiri Pirko <[email protected]>
Tested-by: Michael Kelley <[email protected]>
Tested-by: Mostafa Saleh <[email protected]>
Signed-off-by: Aneesh Kumar K.V (Arm) <[email protected]>
---
 kernel/dma/direct.c  |  8 +++-----
 kernel/dma/mapping.c | 16 ++++++++++++----
 2 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 9f013ff8e0f6..f54c7929b97f 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -286,9 +286,6 @@ void *dma_direct_alloc(struct device *dev, size_t size,
 	if (remap) {
 		pgprot_t prot = dma_pgprot(dev, PAGE_KERNEL, attrs);
 
-		if (force_dma_unencrypted(dev))
-			prot = pgprot_decrypted(prot);
-
 		/* remove any dirty cache lines on the kernel alias */
 		arch_dma_prep_coherent(page, size);
 
@@ -607,9 +604,10 @@ int dma_direct_mmap(struct device *dev, struct vm_area_struct *vma,
 	unsigned long pfn = PHYS_PFN(dma_to_phys(dev, dma_addr));
 	int ret = -ENXIO;
 
-	vma->vm_page_prot = dma_pgprot(dev, vma->vm_page_prot, attrs);
 	if (force_dma_unencrypted(dev))
-		vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
+		attrs |= DMA_ATTR_CC_SHARED;
+
+	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/mapping.c b/kernel/dma/mapping.c
index d2f70b6ccd0f..a628820fd10e 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -537,13 +537,21 @@ EXPORT_SYMBOL(dma_get_sgtable_attrs);
  */
 pgprot_t dma_pgprot(struct device *dev, pgprot_t prot, unsigned long attrs)
 {
+	pgprot_t dma_prot;
+
 	if (dev_is_dma_coherent(dev))
-		return prot;
+		dma_prot = prot;
 #ifdef CONFIG_ARCH_HAS_DMA_WRITE_COMBINE
-	if (attrs & DMA_ATTR_WRITE_COMBINE)
-		return pgprot_writecombine(prot);
+	else if (attrs & DMA_ATTR_WRITE_COMBINE)
+		dma_prot = pgprot_writecombine(prot);
 #endif
-	return pgprot_dmacoherent(prot);
+	else
+		dma_prot = pgprot_dmacoherent(prot);
+
+	if (attrs & (DMA_ATTR_CC_SHARED | __DMA_ATTR_ALLOC_CC_SHARED))
+		return pgprot_decrypted(dma_prot);
+	else
+		return pgprot_encrypted(dma_prot);
 }
 #endif /* CONFIG_MMU */
 
-- 
2.43.0