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From:   Souptick Joarder <jrdr.linux@gmail.com>
Date:   Wed, 23 May 2018 15:24:12 +0530
Message-ID: <CAFqt6zaav_OHxxBP6T=SHmXKeYQzG_HJzJRkuFDq0A_H6-mgfA@mail.gmail.com>
Subject: Re: [PATCH v2] gpu: drm: udl: Adding new typedef vm_fault_t
To:     Souptick Joarder <jrdr.linux@gmail.com>, airlied@redhat.com,
        =?UTF-8?Q?Christian_K=C3=B6nig?= <christian.koenig@amd.com>,
        =?UTF-8?Q?Cihangir_Akt=C3=BCrk?= <cakturk@gmail.com>,
        Sean Paul <seanpaul@chromium.org>,
        Michal Hocko <mhocko@kernel.org>,
        dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
        Matthew Wilcox <willy@infradead.org>
Cc:     Daniel Vetter <daniel.vetter@ffwll.ch>
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On Wed, May 23, 2018 at 2:19 PM, Daniel Vetter <daniel@ffwll.ch> wrote:
> On Mon, May 21, 2018 at 10:27:44AM +0530, Souptick Joarder wrote:
>> On Thu, May 10, 2018 at 7:18 PM, Souptick Joarder <jrdr.linux@gmail.com> wrote:
>> > On Wed, Apr 25, 2018 at 10:29 AM, Souptick Joarder <jrdr.linux@gmail.com> wrote:
>> >> 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_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.
>> >>
>> >> Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
>> >> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
>> >> ---
>> >> v2: Updated the change log
>> >>
>> >>  drivers/gpu/drm/udl/udl_drv.h |  3 ++-
>> >>  drivers/gpu/drm/udl/udl_gem.c | 15 ++-------------
>> >>  2 files changed, 4 insertions(+), 14 deletions(-)
>> >>
>> >> diff --git a/drivers/gpu/drm/udl/udl_drv.h b/drivers/gpu/drm/udl/udl_drv.h
>> >> index 2a75ab8..11151c4 100644
>> >> --- a/drivers/gpu/drm/udl/udl_drv.h
>> >> +++ b/drivers/gpu/drm/udl/udl_drv.h
>> >> @@ -16,6 +16,7 @@
>> >>
>> >>  #include <linux/usb.h>
>> >>  #include <drm/drm_gem.h>
>> >> +#include <linux/mm_types.h>
>> >>
>> >>  #define DRIVER_NAME            "udl"
>> >>  #define DRIVER_DESC            "DisplayLink"
>> >> @@ -134,7 +135,7 @@ struct drm_gem_object *udl_gem_prime_import(struct drm_device *dev,
>> >>  int udl_gem_vmap(struct udl_gem_object *obj);
>> >>  void udl_gem_vunmap(struct udl_gem_object *obj);
>> >>  int udl_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma);
>> >> -int udl_gem_fault(struct vm_fault *vmf);
>> >> +vm_fault_t udl_gem_fault(struct vm_fault *vmf);
>> >>
>> >>  int udl_handle_damage(struct udl_framebuffer *fb, int x, int y,
>> >>                       int width, int height);
>> >> diff --git a/drivers/gpu/drm/udl/udl_gem.c b/drivers/gpu/drm/udl/udl_gem.c
>> >> index dee6bd9..cf5fe35 100644
>> >> --- a/drivers/gpu/drm/udl/udl_gem.c
>> >> +++ b/drivers/gpu/drm/udl/udl_gem.c
>> >> @@ -100,13 +100,12 @@ int udl_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
>> >>         return ret;
>> >>  }
>> >>
>> >> -int udl_gem_fault(struct vm_fault *vmf)
>> >> +vm_fault_t udl_gem_fault(struct vm_fault *vmf)
>> >>  {
>> >>         struct vm_area_struct *vma = vmf->vma;
>> >>         struct udl_gem_object *obj = to_udl_bo(vma->vm_private_data);
>> >>         struct page *page;
>> >>         unsigned int page_offset;
>> >> -       int ret = 0;
>> >>
>> >>         page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
>> >>
>> >> @@ -114,17 +113,7 @@ int udl_gem_fault(struct vm_fault *vmf)
>> >>                 return VM_FAULT_SIGBUS;
>> >>
>> >>         page = obj->pages[page_offset];
>> >> -       ret = vm_insert_page(vma, vmf->address, page);
>> >> -       switch (ret) {
>> >> -       case -EAGAIN:
>> >> -       case 0:
>> >> -       case -ERESTARTSYS:
>> >> -               return VM_FAULT_NOPAGE;
>> >> -       case -ENOMEM:
>> >> -               return VM_FAULT_OOM;
>> >> -       default:
>> >> -               return VM_FAULT_SIGBUS;
>> >> -       }
>> >> +       return vmf_insert_page(vma, vmf->address, page);
>> >>  }
>> >>
>> >>  int udl_gem_get_pages(struct udl_gem_object *obj)
>> >> --
>> >> 1.9.1
>> >>
>> >
>> > Any comment on this patch ?
>>
>> If no comment, we would like to get this patch in queue
>> for 4.18.
>
> 4.18 is done already, queued up for 4.19 in drm-misc-next.
>
> Thanks, Daniel
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch

Thanks :)