drm/etnaviv: change return type to vm_fault_t

Use new return type vm_fault_t for 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.

Ref- commit 1c8f422059ae ("mm: change return type to vm_fault_t")

Previously vm_insert_page() returns err which driver
mapped into VM_FAULT_* type. The new function
vmf_insert_page() will replace this inefficiency by
returning VM_FAULT_* type.

vmf_error() is the newly introduce inline function
in 4.17-rc6.

Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

2 files changed, 11 insertions, 29 deletions

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_drv.h b/drivers/gpu/drm/etnaviv/etnaviv_drv.h
index d36c7bbe66db..8d02d1b7dcf5 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_drv.h
+++ b/drivers/gpu/drm/etnaviv/etnaviv_drv.h
@@ -18,6 +18,7 @@
 #include <linux/time64.h>
 #include <linux/types.h>
 #include <linux/sizes.h>
+#include <linux/mm_types.h>
 
 #include <drm/drmP.h>
 #include <drm/drm_crtc_helper.h>
@@ -53,7 +54,7 @@ int etnaviv_ioctl_gem_submit(struct drm_device *dev, void *data,
                 struct drm_file *file);
 
 int etnaviv_gem_mmap(struct file *filp, struct vm_area_struct *vma);
-int etnaviv_gem_fault(struct vm_fault *vmf);
+vm_fault_t etnaviv_gem_fault(struct vm_fault *vmf);
 int etnaviv_gem_mmap_offset(struct drm_gem_object *obj, u64 *offset);
 struct sg_table *etnaviv_gem_prime_get_sg_table(struct drm_gem_object *obj);
 void *etnaviv_gem_prime_vmap(struct drm_gem_object *obj);
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
index 209ef1274b80..1fa74226db91 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
@@ -169,31 +169,30 @@ int etnaviv_gem_mmap(struct file *filp, struct vm_area_struct *vma)
         return obj->ops->mmap(obj, vma);
 }
 
-int etnaviv_gem_fault(struct vm_fault *vmf)
+vm_fault_t etnaviv_gem_fault(struct vm_fault *vmf)
 {
         struct vm_area_struct *vma = vmf->vma;
         struct drm_gem_object *obj = vma->vm_private_data;
         struct etnaviv_gem_object *etnaviv_obj = to_etnaviv_bo(obj);
         struct page **pages, *page;
         pgoff_t pgoff;
-        int ret;
+        int err;
 
         /*
          * Make sure we don't parallel update on a fault, nor move or remove
-         * something from beneath our feet.  Note that vm_insert_page() is
+         * something from beneath our feet.  Note that vmf_insert_page() is
          * specifically coded to take care of this, so we don't have to.
          */
-        ret = mutex_lock_interruptible(&etnaviv_obj->lock);
-        if (ret)
-                goto out;
-
+        err = mutex_lock_interruptible(&etnaviv_obj->lock);
+        if (err)
+                return VM_FAULT_NOPAGE;
         /* make sure we have pages attached now */
         pages = etnaviv_gem_get_pages(etnaviv_obj);
         mutex_unlock(&etnaviv_obj->lock);
 
         if (IS_ERR(pages)) {
-                ret = PTR_ERR(pages);
-                goto out;
+                err = PTR_ERR(pages);
+                return vmf_error(err);
         }
 
         /* We don't use vmf->pgoff since that has the fake offset: */
@@ -204,25 +203,7 @@ int etnaviv_gem_fault(struct vm_fault *vmf)
         VERB("Inserting %p pfn %lx, pa %lx", (void *)vmf->address,
              page_to_pfn(page), page_to_pfn(page) << PAGE_SHIFT);
 
-        ret = vm_insert_page(vma, vmf->address, page);
-
-out:
-        switch (ret) {
-        case -EAGAIN:
-        case 0:
-        case -ERESTARTSYS:
-        case -EINTR:
-        case -EBUSY:
-                /*
-                 * EBUSY is ok: this just means that another thread
-                 * already did the job.
-                 */
-                return VM_FAULT_NOPAGE;
-        case -ENOMEM:
-                return VM_FAULT_OOM;
-        default:
-                return VM_FAULT_SIGBUS;
-        }
+        return vmf_insert_page(vma, vmf->address, page);
 }
 
 int etnaviv_gem_mmap_offset(struct drm_gem_object *obj, u64 *offset)