device-dax: Convert to vmf_insert_mixed and vm_fault_t

Use new return type vm_fault_t for fault and huge_fault handler. For
now, this is just documenting that the function returns a VM_FAULT value
rather than an errno.  Once all instances are converted, vm_fault_t will
become a distinct type.

Commit 1c8f422059ae ("mm: change return type to vm_fault_t")

Previously vm_insert_mixed() returned an error code which driver mapped into
VM_FAULT_* type. The new function vmf_insert_mixed() will replace this
inefficiency by returning VM_FAULT_* type.

Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

1 files changed, 11 insertions, 15 deletions

diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index de2f8297a210..ad5e7b4a15dc 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -244,11 +244,11 @@ __weak phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff,
 	return -1;
 }
 
-static int __dev_dax_pte_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
+static vm_fault_t __dev_dax_pte_fault(struct dev_dax *dev_dax,
+				struct vm_fault *vmf)
 {
 	struct device *dev = &dev_dax->dev;
 	struct dax_region *dax_region;
-	int rc = VM_FAULT_SIGBUS;
 	phys_addr_t phys;
 	pfn_t pfn;
 	unsigned int fault_size = PAGE_SIZE;
@@ -274,17 +274,11 @@ static int __dev_dax_pte_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
 
 	pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
 
-	rc = vm_insert_mixed(vmf->vma, vmf->address, pfn);
-
-	if (rc == -ENOMEM)
-		return VM_FAULT_OOM;
-	if (rc < 0 && rc != -EBUSY)
-		return VM_FAULT_SIGBUS;
-
-	return VM_FAULT_NOPAGE;
+	return vmf_insert_mixed(vmf->vma, vmf->address, pfn);
 }
 
-static int __dev_dax_pmd_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
+static vm_fault_t __dev_dax_pmd_fault(struct dev_dax *dev_dax,
+				struct vm_fault *vmf)
 {
 	unsigned long pmd_addr = vmf->address & PMD_MASK;
 	struct device *dev = &dev_dax->dev;
@@ -334,7 +328,8 @@ static int __dev_dax_pmd_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
 }
 
 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
-static int __dev_dax_pud_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
+static vm_fault_t __dev_dax_pud_fault(struct dev_dax *dev_dax,
+				struct vm_fault *vmf)
 {
 	unsigned long pud_addr = vmf->address & PUD_MASK;
 	struct device *dev = &dev_dax->dev;
@@ -384,13 +379,14 @@ static int __dev_dax_pud_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
 			vmf->flags & FAULT_FLAG_WRITE);
 }
 #else
-static int __dev_dax_pud_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
+static vm_fault_t __dev_dax_pud_fault(struct dev_dax *dev_dax,
+				struct vm_fault *vmf)
 {
 	return VM_FAULT_FALLBACK;
 }
 #endif /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 
-static int dev_dax_huge_fault(struct vm_fault *vmf,
+static vm_fault_t dev_dax_huge_fault(struct vm_fault *vmf,
 		enum page_entry_size pe_size)
 {
 	int rc, id;
@@ -420,7 +416,7 @@ static int dev_dax_huge_fault(struct vm_fault *vmf,
 	return rc;
 }
 
-static int dev_dax_fault(struct vm_fault *vmf)
+static vm_fault_t dev_dax_fault(struct vm_fault *vmf)
 {
 	return dev_dax_huge_fault(vmf, PE_SIZE_PTE);
 }