[PATCH v3] gpu: drm: gma500: Change return type to vm_fault_t

From: Souptick Joarder
Date: Sat May 26 2018 - 20:49:57 EST


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_{pfn,mixed} returns err which driver
mapped into VM_FAULT_* type. The new function
vmf_insert_{pfn,mixed} 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@xxxxxxxxx>
Reviewed-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
---
v2: updated the change log

v3: Fixed kbuild error

drivers/gpu/drm/gma500/framebuffer.c | 14 +++++---------
drivers/gpu/drm/gma500/gem.c | 27 ++++++++++-----------------
drivers/gpu/drm/gma500/psb_drv.h | 3 ++-
3 files changed, 17 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/gma500/framebuffer.c b/drivers/gpu/drm/gma500/framebuffer.c
index cb0a2ae..632aadb 100644
--- a/drivers/gpu/drm/gma500/framebuffer.c
+++ b/drivers/gpu/drm/gma500/framebuffer.c
@@ -111,7 +111,7 @@ static int psbfb_pan(struct fb_var_screeninfo *var, struct fb_info *info)
return 0;
}

-static int psbfb_vm_fault(struct vm_fault *vmf)
+static vm_fault_t psbfb_vm_fault(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
struct psb_framebuffer *psbfb = vma->vm_private_data;
@@ -120,7 +120,7 @@ static int psbfb_vm_fault(struct vm_fault *vmf)
int page_num;
int i;
unsigned long address;
- int ret;
+ vm_fault_t ret = VM_FAULT_SIGBUS;
unsigned long pfn;
unsigned long phys_addr = (unsigned long)dev_priv->stolen_base +
psbfb->gtt->offset;
@@ -133,18 +133,14 @@ static int psbfb_vm_fault(struct vm_fault *vmf)
for (i = 0; i < page_num; i++) {
pfn = (phys_addr >> PAGE_SHIFT);

- ret = vm_insert_mixed(vma, address,
+ ret = vmf_insert_mixed(vma, address,
__pfn_to_pfn_t(pfn, PFN_DEV));
- if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0)))
+ if (unlikely(ret & VM_FAULT_ERROR))
break;
- else if (unlikely(ret != 0)) {
- ret = (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
- return ret;
- }
address += PAGE_SIZE;
phys_addr += PAGE_SIZE;
}
- return VM_FAULT_NOPAGE;
+ return ret;
}

static void psbfb_vm_open(struct vm_area_struct *vma)
diff --git a/drivers/gpu/drm/gma500/gem.c b/drivers/gpu/drm/gma500/gem.c
index 1312397..e7be5c9 100644
--- a/drivers/gpu/drm/gma500/gem.c
+++ b/drivers/gpu/drm/gma500/gem.c
@@ -134,12 +134,13 @@ int psb_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
* vma->vm_private_data points to the GEM object that is backing this
* mapping.
*/
-int psb_gem_fault(struct vm_fault *vmf)
+vm_fault_t psb_gem_fault(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
struct drm_gem_object *obj;
struct gtt_range *r;
- int ret;
+ int err;
+ vm_fault_t ret;
unsigned long pfn;
pgoff_t page_offset;
struct drm_device *dev;
@@ -158,9 +159,10 @@ int psb_gem_fault(struct vm_fault *vmf)
/* For now the mmap pins the object and it stays pinned. As things
stand that will do us no harm */
if (r->mmapping == 0) {
- ret = psb_gtt_pin(r);
- if (ret < 0) {
- dev_err(dev->dev, "gma500: pin failed: %d\n", ret);
+ err = psb_gtt_pin(r);
+ if (err < 0) {
+ dev_err(dev->dev, "gma500: pin failed: %d\n", err);
+ ret = vmf_error(err);
goto fail;
}
r->mmapping = 1;
@@ -175,18 +177,9 @@ int psb_gem_fault(struct vm_fault *vmf)
pfn = (dev_priv->stolen_base + r->offset) >> PAGE_SHIFT;
else
pfn = page_to_pfn(r->pages[page_offset]);
- ret = vm_insert_pfn(vma, vmf->address, pfn);
-
+ ret = vmf_insert_pfn(vma, vmf->address, pfn);
fail:
mutex_unlock(&dev_priv->mmap_mutex);
- switch (ret) {
- case 0:
- case -ERESTARTSYS:
- case -EINTR:
- return VM_FAULT_NOPAGE;
- case -ENOMEM:
- return VM_FAULT_OOM;
- default:
- return VM_FAULT_SIGBUS;
- }
+
+ return ret;
}
diff --git a/drivers/gpu/drm/gma500/psb_drv.h b/drivers/gpu/drm/gma500/psb_drv.h
index e8300f5..93d2f40 100644
--- a/drivers/gpu/drm/gma500/psb_drv.h
+++ b/drivers/gpu/drm/gma500/psb_drv.h
@@ -21,6 +21,7 @@
#define _PSB_DRV_H_

#include <linux/kref.h>
+#include <linux/mm_types.h>

#include <drm/drmP.h>
#include <drm/drm_global.h>
@@ -749,7 +750,7 @@ extern int psb_gem_get_aperture(struct drm_device *dev, void *data,
struct drm_file *file);
extern int psb_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
struct drm_mode_create_dumb *args);
-extern int psb_gem_fault(struct vm_fault *vmf);
+extern vm_fault_t psb_gem_fault(struct vm_fault *vmf);

/* psb_device.c */
extern const struct psb_ops psb_chip_ops;
--
1.9.1