iommu: debug-pagealloc: Use page_ext_get_from_phys()

Instead of calling pfn_valid() and then getting the page, call
the newly added function page_ext_get_from_phys(), which would
also check for MMIO and offline memory and return NULL in that
case.

Signed-off-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

Author: misaleh

drivers/iommu/iommu-debug-pagealloc.c

@@ -30,33 +30,33 @@ struct page_ext_operations page_iommu_debug_ops = {
 	.need = need_iommu_debug,
 };
 
-static struct page_ext *get_iommu_page_ext(phys_addr_t phys)
-{
-	struct page *page = phys_to_page(phys);
-	struct page_ext *page_ext = page_ext_get(page);
-
-	return page_ext;
-}
-
 static struct iommu_debug_metadata *get_iommu_data(struct page_ext *page_ext)
 {
 	return page_ext_data(page_ext, &page_iommu_debug_ops);
 }
 
 static void iommu_debug_inc_page(phys_addr_t phys)
 {
-	struct page_ext *page_ext = get_iommu_page_ext(phys);
-	struct iommu_debug_metadata *d = get_iommu_data(page_ext);
+	struct page_ext *page_ext = page_ext_from_phys(phys);
+	struct iommu_debug_metadata *d;
+
+	if (!page_ext)
+		return;
 
+	d = get_iommu_data(page_ext);
 	WARN_ON(atomic_inc_return_relaxed(&d->ref) <= 0);
 	page_ext_put(page_ext);
 }
 
 static void iommu_debug_dec_page(phys_addr_t phys)
 {
-	struct page_ext *page_ext = get_iommu_page_ext(phys);
-	struct iommu_debug_metadata *d = get_iommu_data(page_ext);
+	struct page_ext *page_ext = page_ext_from_phys(phys);
+	struct iommu_debug_metadata *d;
+
+	if (!page_ext)
+		return;
 
+	d = get_iommu_data(page_ext);
 	WARN_ON(atomic_dec_return_relaxed(&d->ref) < 0);
 	page_ext_put(page_ext);
 }
@@ -104,11 +104,8 @@ void __iommu_debug_map(struct iommu_domain *domain, phys_addr_t phys, size_t siz
 	if (WARN_ON(!phys || check_add_overflow(phys, size, &end)))
 		return;
 
-	for (off = 0 ; off < size ; off += page_size) {
-		if (!pfn_valid(__phys_to_pfn(phys + off)))
-			continue;
+	for (off = 0 ; off < size ; off += page_size)
 		iommu_debug_inc_page(phys + off);
-	}
 }
 
 static void __iommu_debug_update_iova(struct iommu_domain *domain,
@@ -123,7 +120,7 @@ static void __iommu_debug_update_iova(struct iommu_domain *domain,
 	for (off = 0 ; off < size ; off += page_size) {
 		phys_addr_t phys = iommu_iova_to_phys(domain, iova + off);
 
-		if (!phys || !pfn_valid(__phys_to_pfn(phys)))
+		if (!phys)
 			continue;
 
 		if (inc)