dma-direct: factor out dma_set_{de,en}crypted helpers

Christoph Hellwig · Christoph Hellwig · commit 4d0564785bb0 · 2021-12-07T12:47:05.000+01:00
Factor out helpers the make dealing with memory encryption a little less
cumbersome.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
@@ -75,6 +75,20 @@ static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size)
 		min_not_zero(dev->coherent_dma_mask, dev->bus_dma_limit);
 }
 
+static int dma_set_decrypted(struct device *dev, void *vaddr, size_t size)
+{
+	if (!force_dma_unencrypted(dev))
+		return 0;
+	return set_memory_decrypted((unsigned long)vaddr, 1 << get_order(size));
+}
+
+static int dma_set_encrypted(struct device *dev, void *vaddr, size_t size)
+{
+	if (!force_dma_unencrypted(dev))
+		return 0;
+	return set_memory_encrypted((unsigned long)vaddr, 1 << get_order(size));
+}
+
 static void __dma_direct_free_pages(struct device *dev, struct page *page,
 				    size_t size)
 {
@@ -154,7 +168,6 @@ void *dma_direct_alloc(struct device *dev, size_t size,
 {
 	struct page *page;
 	void *ret;
-	int err;
 
 	size = PAGE_ALIGN(size);
 	if (attrs & DMA_ATTR_NO_WARN)
@@ -216,12 +229,8 @@ void *dma_direct_alloc(struct device *dev, size_t size,
 				__builtin_return_address(0));
 		if (!ret)
 			goto out_free_pages;
-		if (force_dma_unencrypted(dev)) {
-			err = set_memory_decrypted((unsigned long)ret,
-						   1 << get_order(size));
-			if (err)
-				goto out_free_pages;
-		}
+		if (dma_set_decrypted(dev, ret, size))
+			goto out_free_pages;
 		memset(ret, 0, size);
 		goto done;
 	}
@@ -238,13 +247,8 @@ void *dma_direct_alloc(struct device *dev, size_t size,
 	}
 
 	ret = page_address(page);
-	if (force_dma_unencrypted(dev)) {
-		err = set_memory_decrypted((unsigned long)ret,
-					   1 << get_order(size));
-		if (err)
-			goto out_free_pages;
-	}
-
+	if (dma_set_decrypted(dev, ret, size))
+		goto out_free_pages;
 	memset(ret, 0, size);
 
 	if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) &&
@@ -259,13 +263,9 @@ void *dma_direct_alloc(struct device *dev, size_t size,
 	return ret;
 
 out_encrypt_pages:
-	if (force_dma_unencrypted(dev)) {
-		err = set_memory_encrypted((unsigned long)page_address(page),
-					   1 << get_order(size));
-		/* If memory cannot be re-encrypted, it must be leaked */
-		if (err)
-			return NULL;
-	}
+	/* If memory cannot be re-encrypted, it must be leaked */
+	if (dma_set_encrypted(dev, page_address(page), size))
+		return NULL;
 out_free_pages:
 	__dma_direct_free_pages(dev, page, size);
 	return NULL;
@@ -304,8 +304,7 @@ void dma_direct_free(struct device *dev, size_t size,
 	    dma_free_from_pool(dev, cpu_addr, PAGE_ALIGN(size)))
 		return;
 
-	if (force_dma_unencrypted(dev))
-		set_memory_encrypted((unsigned long)cpu_addr, 1 << page_order);
+	dma_set_encrypted(dev, cpu_addr, 1 << page_order);
 
 	if (IS_ENABLED(CONFIG_DMA_REMAP) && is_vmalloc_addr(cpu_addr))
 		vunmap(cpu_addr);
@@ -341,11 +340,8 @@ struct page *dma_direct_alloc_pages(struct device *dev, size_t size,
 	}
 
 	ret = page_address(page);
-	if (force_dma_unencrypted(dev)) {
-		if (set_memory_decrypted((unsigned long)ret,
-				1 << get_order(size)))
-			goto out_free_pages;
-	}
+	if (dma_set_decrypted(dev, ret, size))
+		goto out_free_pages;
 	memset(ret, 0, size);
 	*dma_handle = phys_to_dma_direct(dev, page_to_phys(page));
 	return page;
@@ -366,9 +362,7 @@ void dma_direct_free_pages(struct device *dev, size_t size,
 	    dma_free_from_pool(dev, vaddr, size))
 		return;
 
-	if (force_dma_unencrypted(dev))
-		set_memory_encrypted((unsigned long)vaddr, 1 << page_order);
-
+	dma_set_encrypted(dev, vaddr, 1 << page_order);
 	__dma_direct_free_pages(dev, page, size);
 }
 
