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>

diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index de2f829..ad5e7b4 100644 (file)
--- 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);
 }

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index a8a1262..d3bbf6b 100644 (file)
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -3,6 +3,7 @@
 #define _LINUX_HUGE_MM_H
 
 #include <linux/sched/coredump.h>
+#include <linux/mm_types.h>
 
 #include <linux/fs.h> /* only for vma_is_dax() */
 
@@ -46,9 +47,9 @@ extern bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
 extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
                        unsigned long addr, pgprot_t newprot,
                        int prot_numa);
-int vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr,
+vm_fault_t vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr,
                        pmd_t *pmd, pfn_t pfn, bool write);
-int vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr,
+vm_fault_t vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr,
                        pud_t *pud, pfn_t pfn, bool write);
 enum transparent_hugepage_flag {
        TRANSPARENT_HUGEPAGE_FLAG,

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 1cd7c1a..feba371 100644 (file)
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -752,7 +752,7 @@ static void insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr,
        spin_unlock(ptl);
 }
 
-int vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr,
+vm_fault_t vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr,
                        pmd_t *pmd, pfn_t pfn, bool write)
 {
        pgprot_t pgprot = vma->vm_page_prot;
@@ -812,7 +812,7 @@ static void insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr,
        spin_unlock(ptl);
 }
 
-int vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr,
+vm_fault_t vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr,
                        pud_t *pud, pfn_t pfn, bool write)
 {
        pgprot_t pgprot = vma->vm_page_prot;