drm/ttm: Clean up kmap_atomic_prot selection code

Use helpers to perform the kmap_atomic_prot() functionality to
a) Avoid in-function ifdefs that violate the kernel coding policy,
b) Facilitate exporting the functionality.

This commit should not change any functionality.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>

drivers/gpu/drm/ttm/ttm_bo_util.c

@@ -255,6 +255,33 @@ static int ttm_copy_io_page(void *dst, void *src, unsigned long page)
 	return 0;
 }
 
+#ifdef CONFIG_X86
+#define __ttm_kmap_atomic_prot(__page, __prot) kmap_atomic_prot(__page, __prot)
+#define __ttm_kunmap_atomic(__addr) kunmap_atomic(__addr)
+#else
+#define __ttm_kmap_atomic_prot(__page, __prot) vmap(&__page, 1, 0,  __prot)
+#define __ttm_kunmap_atomic(__addr) vunmap(__addr)
+#endif
+
+static void *ttm_kmap_atomic_prot(struct page *page,
+				  pgprot_t prot)
+{
+	if (pgprot_val(prot) == pgprot_val(PAGE_KERNEL))
+		return kmap_atomic(page);
+	else
+		return __ttm_kmap_atomic_prot(page, prot);
+}
+
+
+static void ttm_kunmap_atomic_prot(void *addr,
+				   pgprot_t prot)
+{
+	if (pgprot_val(prot) == pgprot_val(PAGE_KERNEL))
+		kunmap_atomic(addr);
+	else
+		__ttm_kunmap_atomic(addr);
+}
+
 static int ttm_copy_io_ttm_page(struct ttm_tt *ttm, void *src,
 				unsigned long page,
 				pgprot_t prot)
@@ -266,28 +293,13 @@ static int ttm_copy_io_ttm_page(struct ttm_tt *ttm, void *src,
 		return -ENOMEM;
 
 	src = (void *)((unsigned long)src + (page << PAGE_SHIFT));
-
-#ifdef CONFIG_X86
-	dst = kmap_atomic_prot(d, prot);
-#else
-	if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL))
-		dst = vmap(&d, 1, 0, prot);
-	else
-		dst = kmap(d);
-#endif
+	dst = ttm_kmap_atomic_prot(d, prot);
 	if (!dst)
 		return -ENOMEM;
 
 	memcpy_fromio(dst, src, PAGE_SIZE);
 
-#ifdef CONFIG_X86
-	kunmap_atomic(dst);
-#else
-	if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL))
-		vunmap(dst);
-	else
-		kunmap(d);
-#endif
+	ttm_kunmap_atomic_prot(dst, prot);
 
 	return 0;
 }
@@ -303,27 +315,13 @@ static int ttm_copy_ttm_io_page(struct ttm_tt *ttm, void *dst,
 		return -ENOMEM;
 
 	dst = (void *)((unsigned long)dst + (page << PAGE_SHIFT));
-#ifdef CONFIG_X86
-	src = kmap_atomic_prot(s, prot);
-#else
-	if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL))
-		src = vmap(&s, 1, 0, prot);
-	else
-		src = kmap(s);
-#endif
+	src = ttm_kmap_atomic_prot(s, prot);
 	if (!src)
 		return -ENOMEM;
 
 	memcpy_toio(dst, src, PAGE_SIZE);
 
-#ifdef CONFIG_X86
-	kunmap_atomic(src);
-#else
-	if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL))
-		vunmap(src);
-	else
-		kunmap(s);
-#endif
+	ttm_kunmap_atomic_prot(src, prot);
 
 	return 0;
 }