[PATCH RFC 06/10] device-dax: Introduce pfn_flags helper

[Joao Martins]

Replace PFN_DEV|PFN_MAP check call sites with two helper functions
dax_is_pfn_dev() and dax_is_pfn_map().

Signed-off-by: Joao Martins <joao.m.martins@xxxxxxxxxx>
---
 drivers/dax/device.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index c6a7f5e12c54..113a554de3ee 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -14,6 +14,17 @@
 #include "dax-private.h"
 #include "bus.h"
 
+static int dax_is_pfn_dev(struct dev_dax *dev_dax)
+{
+	return (dev_dax->region->pfn_flags & (PFN_DEV|PFN_MAP)) == PFN_DEV;
+}
+
+static int dax_is_pfn_map(struct dev_dax *dev_dax)
+{
+	return (dev_dax->region->pfn_flags &
+		(PFN_DEV|PFN_MAP)) == (PFN_DEV|PFN_MAP);
+}
+
 static int check_vma_mmap(struct dev_dax *dev_dax, struct vm_area_struct *vma,
 		const char *func)
 {
@@ -60,8 +71,7 @@ static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
 	if (rc < 0)
 		return rc;
 
-	if ((dev_dax->region->pfn_flags & (PFN_DEV|PFN_MAP)) == PFN_DEV
-			&& (vma->vm_flags & VM_DONTCOPY) == 0) {
+	if (dax_is_pfn_dev(dev_dax) && (vma->vm_flags & VM_DONTCOPY) == 0) {
 		dev_info_ratelimited(&dev_dax->dev,
 				"%s: %s: fail, dax range requires MADV_DONTFORK\n",
 				current->comm, func);
@@ -140,7 +150,7 @@ static vm_fault_t __dev_dax_pmd_fault(struct dev_dax *dev_dax,
 	}
 
 	/* dax pmd mappings require pfn_t_devmap() */
-	if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) != (PFN_DEV|PFN_MAP)) {
+	if (!dax_is_pfn_map(dev_dax)) {
 		dev_dbg(dev, "region lacks devmap flags\n");
 		return VM_FAULT_SIGBUS;
 	}
@@ -190,7 +200,7 @@ static vm_fault_t __dev_dax_pud_fault(struct dev_dax *dev_dax,
 	}
 
 	/* dax pud mappings require pfn_t_devmap() */
-	if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) != (PFN_DEV|PFN_MAP)) {
+	if (!dax_is_pfn_map(dev_dax)) {
 		dev_dbg(dev, "region lacks devmap flags\n");
 		return VM_FAULT_SIGBUS;
 	}
-- 
2.17.1