Re: [PATCH v3] gpu: drm: gma500: Change return type to vm_fault_t
From: Souptick Joarder
Date: Thu Jun 14 2018 - 15:12:17 EST
On Mon, Jun 4, 2018 at 10:47 AM, Souptick Joarder <jrdr.linux@xxxxxxxxx> wrote:
> On Sun, May 27, 2018 at 6:15 AM, Souptick Joarder <jrdr.linux@xxxxxxxxx> wrote:
>> 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
>>
>
> If no comment, we would like to get this patch
> in 4.18.
Patrik, Is it possible to get this patch in 4.18 ?