| Message ID | 20180601192724.GA2001@jordon-HP-15-Notebook-PC (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, Jun 2, 2018 at 12:57 AM, Souptick Joarder <jrdr.linux@gmail.com> 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_{mixed,pfn} returns err which driver > mapped into VM_FAULT_* type. The new function > vmf_insert_{mixed,pfn} will replace this inefficiency by > returning VM_FAULT_* type. > > Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> > --- > v2: Address christian's comment. Put reverse > xmas tree order for variable declarations. > > drivers/gpu/drm/ttm/ttm_bo_vm.c | 45 ++++++++++++++++++++--------------------- > 1 file changed, 22 insertions(+), 23 deletions(-) > > diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c > index 8eba95b..9de8b4f 100644 > --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c > +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c > @@ -43,10 +43,11 @@ > > #define TTM_BO_VM_NUM_PREFAULT 16 > > -static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo, > +static vm_fault_t ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo, > struct vm_fault *vmf) > { > - int ret = 0; > + vm_fault_t ret = 0; > + int err = 0; > > if (likely(!bo->moving)) > goto out_unlock; > @@ -77,9 +78,9 @@ static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo, > /* > * Ordinary wait. > */ > - ret = dma_fence_wait(bo->moving, true); > - if (unlikely(ret != 0)) { > - ret = (ret != -ERESTARTSYS) ? VM_FAULT_SIGBUS : > + err = dma_fence_wait(bo->moving, true); > + if (unlikely(err != 0)) { > + ret = (err != -ERESTARTSYS) ? VM_FAULT_SIGBUS : > VM_FAULT_NOPAGE; > goto out_unlock; > } > @@ -104,7 +105,7 @@ static unsigned long ttm_bo_io_mem_pfn(struct ttm_buffer_object *bo, > + page_offset; > } > > -static int ttm_bo_vm_fault(struct vm_fault *vmf) > +static vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf) > { > struct vm_area_struct *vma = vmf->vma; > struct ttm_buffer_object *bo = (struct ttm_buffer_object *) > @@ -115,8 +116,9 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) > unsigned long pfn; > struct ttm_tt *ttm = NULL; > struct page *page; > - int ret; > + int err; > int i; > + vm_fault_t ret = VM_FAULT_NOPAGE; > unsigned long address = vmf->address; > struct ttm_mem_type_manager *man = > &bdev->man[bo->mem.mem_type]; > @@ -128,9 +130,9 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) > * for reserve, and if it fails, retry the fault after waiting > * for the buffer to become unreserved. > */ > - ret = ttm_bo_reserve(bo, true, true, NULL); > - if (unlikely(ret != 0)) { > - if (ret != -EBUSY) > + err = ttm_bo_reserve(bo, true, true, NULL); > + if (unlikely(err != 0)) { > + if (err != -EBUSY) > return VM_FAULT_NOPAGE; > > if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) { > @@ -162,8 +164,8 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) > } > > if (bdev->driver->fault_reserve_notify) { > - ret = bdev->driver->fault_reserve_notify(bo); > - switch (ret) { > + err = bdev->driver->fault_reserve_notify(bo); > + switch (err) { > case 0: > break; > case -EBUSY: > @@ -191,13 +193,13 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) > goto out_unlock; > } > > - ret = ttm_mem_io_lock(man, true); > - if (unlikely(ret != 0)) { > + err = ttm_mem_io_lock(man, true); > + if (unlikely(err != 0)) { > ret = VM_FAULT_NOPAGE; > goto out_unlock; > } > - ret = ttm_mem_io_reserve_vm(bo); > - if (unlikely(ret != 0)) { > + err = ttm_mem_io_reserve_vm(bo); > + if (unlikely(err != 0)) { > ret = VM_FAULT_SIGBUS; > goto out_io_unlock; > } > @@ -265,23 +267,20 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) > } > > if (vma->vm_flags & VM_MIXEDMAP) > - ret = vm_insert_mixed(&cvma, address, > + ret = vmf_insert_mixed(&cvma, address, > __pfn_to_pfn_t(pfn, PFN_DEV)); > else > - ret = vm_insert_pfn(&cvma, address, pfn); > + ret = vmf_insert_pfn(&cvma, address, pfn); > > /* > * Somebody beat us to this PTE or prefaulting to > * an already populated PTE, or prefaulting error. > */ > > - if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0))) > + if (unlikely((ret == VM_FAULT_NOPAGE && i > 0))) > break; > - else if (unlikely(ret != 0)) { > - ret = > - (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS; > + else if (unlikely(ret & VM_FAULT_ERROR)) > goto out_io_unlock; > - } > > address += PAGE_SIZE; > if (unlikely(++page_offset >= page_last)) > -- > 1.9.1 > If no further comment, we would like get this patch in 4.18 / 4.18-rc-x.
Am 08.06.2018 um 06:36 schrieb Souptick Joarder: > On Sat, Jun 2, 2018 at 12:57 AM, Souptick Joarder <jrdr.linux@gmail.com> 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_{mixed,pfn} returns err which driver >> mapped into VM_FAULT_* type. The new function >> vmf_insert_{mixed,pfn} will replace this inefficiency by >> returning VM_FAULT_* type. >> >> Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> >> --- >> v2: Address christian's comment. Put reverse >> xmas tree order for variable declarations. >> >> drivers/gpu/drm/ttm/ttm_bo_vm.c | 45 ++++++++++++++++++++--------------------- >> 1 file changed, 22 insertions(+), 23 deletions(-) >> >> diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c >> index 8eba95b..9de8b4f 100644 >> --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c >> +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c >> @@ -43,10 +43,11 @@ >> >> #define TTM_BO_VM_NUM_PREFAULT 16 >> >> -static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo, >> +static vm_fault_t ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo, >> struct vm_fault *vmf) >> { >> - int ret = 0; >> + vm_fault_t ret = 0; >> + int err = 0; >> >> if (likely(!bo->moving)) >> goto out_unlock; >> @@ -77,9 +78,9 @@ static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo, >> /* >> * Ordinary wait. >> */ >> - ret = dma_fence_wait(bo->moving, true); >> - if (unlikely(ret != 0)) { >> - ret = (ret != -ERESTARTSYS) ? VM_FAULT_SIGBUS : >> + err = dma_fence_wait(bo->moving, true); >> + if (unlikely(err != 0)) { >> + ret = (err != -ERESTARTSYS) ? VM_FAULT_SIGBUS : >> VM_FAULT_NOPAGE; >> goto out_unlock; >> } >> @@ -104,7 +105,7 @@ static unsigned long ttm_bo_io_mem_pfn(struct ttm_buffer_object *bo, >> + page_offset; >> } >> >> -static int ttm_bo_vm_fault(struct vm_fault *vmf) >> +static vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf) >> { >> struct vm_area_struct *vma = vmf->vma; >> struct ttm_buffer_object *bo = (struct ttm_buffer_object *) >> @@ -115,8 +116,9 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) >> unsigned long pfn; >> struct ttm_tt *ttm = NULL; >> struct page *page; >> - int ret; >> + int err; >> int i; >> + vm_fault_t ret = VM_FAULT_NOPAGE; >> unsigned long address = vmf->address; >> struct ttm_mem_type_manager *man = >> &bdev->man[bo->mem.mem_type]; >> @@ -128,9 +130,9 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) >> * for reserve, and if it fails, retry the fault after waiting >> * for the buffer to become unreserved. >> */ >> - ret = ttm_bo_reserve(bo, true, true, NULL); >> - if (unlikely(ret != 0)) { >> - if (ret != -EBUSY) >> + err = ttm_bo_reserve(bo, true, true, NULL); >> + if (unlikely(err != 0)) { >> + if (err != -EBUSY) >> return VM_FAULT_NOPAGE; >> >> if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) { >> @@ -162,8 +164,8 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) >> } >> >> if (bdev->driver->fault_reserve_notify) { >> - ret = bdev->driver->fault_reserve_notify(bo); >> - switch (ret) { >> + err = bdev->driver->fault_reserve_notify(bo); >> + switch (err) { >> case 0: >> break; >> case -EBUSY: >> @@ -191,13 +193,13 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) >> goto out_unlock; >> } >> >> - ret = ttm_mem_io_lock(man, true); >> - if (unlikely(ret != 0)) { >> + err = ttm_mem_io_lock(man, true); >> + if (unlikely(err != 0)) { >> ret = VM_FAULT_NOPAGE; >> goto out_unlock; >> } >> - ret = ttm_mem_io_reserve_vm(bo); >> - if (unlikely(ret != 0)) { >> + err = ttm_mem_io_reserve_vm(bo); >> + if (unlikely(err != 0)) { >> ret = VM_FAULT_SIGBUS; >> goto out_io_unlock; >> } >> @@ -265,23 +267,20 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) >> } >> >> if (vma->vm_flags & VM_MIXEDMAP) >> - ret = vm_insert_mixed(&cvma, address, >> + ret = vmf_insert_mixed(&cvma, address, >> __pfn_to_pfn_t(pfn, PFN_DEV)); >> else >> - ret = vm_insert_pfn(&cvma, address, pfn); >> + ret = vmf_insert_pfn(&cvma, address, pfn); >> >> /* >> * Somebody beat us to this PTE or prefaulting to >> * an already populated PTE, or prefaulting error. >> */ >> >> - if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0))) >> + if (unlikely((ret == VM_FAULT_NOPAGE && i > 0))) >> break; >> - else if (unlikely(ret != 0)) { >> - ret = >> - (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS; >> + else if (unlikely(ret & VM_FAULT_ERROR)) >> goto out_io_unlock; >> - } >> >> address += PAGE_SIZE; >> if (unlikely(++page_offset >= page_last)) >> -- >> 1.9.1 >> > If no further comment, we would like get this patch in 4.18 / 4.18-rc-x. The patch looks good to me and I will pick it up for the next TTM pull request. I don't think it will make it into 4.18-rc-1, but 4.18-rc-x sounds realistic. Christian.
Am 08.06.2018 um 08:44 schrieb Christian König: > Am 08.06.2018 um 06:36 schrieb Souptick Joarder: >> On Sat, Jun 2, 2018 at 12:57 AM, Souptick Joarder >> <jrdr.linux@gmail.com> 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_{mixed,pfn} returns err which driver >>> mapped into VM_FAULT_* type. The new function >>> vmf_insert_{mixed,pfn} will replace this inefficiency by >>> returning VM_FAULT_* type. >>> >>> Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> >>> --- >>> v2: Address christian's comment. Put reverse >>> xmas tree order for variable declarations. >>> >>> drivers/gpu/drm/ttm/ttm_bo_vm.c | 45 >>> ++++++++++++++++++++--------------------- >>> 1 file changed, 22 insertions(+), 23 deletions(-) >>> >>> diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c >>> b/drivers/gpu/drm/ttm/ttm_bo_vm.c >>> index 8eba95b..9de8b4f 100644 >>> --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c >>> +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c >>> @@ -43,10 +43,11 @@ >>> >>> #define TTM_BO_VM_NUM_PREFAULT 16 >>> >>> -static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo, >>> +static vm_fault_t ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo, >>> struct vm_fault *vmf) >>> { >>> - int ret = 0; >>> + vm_fault_t ret = 0; >>> + int err = 0; >>> >>> if (likely(!bo->moving)) >>> goto out_unlock; >>> @@ -77,9 +78,9 @@ static int ttm_bo_vm_fault_idle(struct >>> ttm_buffer_object *bo, >>> /* >>> * Ordinary wait. >>> */ >>> - ret = dma_fence_wait(bo->moving, true); >>> - if (unlikely(ret != 0)) { >>> - ret = (ret != -ERESTARTSYS) ? VM_FAULT_SIGBUS : >>> + err = dma_fence_wait(bo->moving, true); >>> + if (unlikely(err != 0)) { >>> + ret = (err != -ERESTARTSYS) ? VM_FAULT_SIGBUS : >>> VM_FAULT_NOPAGE; >>> goto out_unlock; >>> } >>> @@ -104,7 +105,7 @@ static unsigned long ttm_bo_io_mem_pfn(struct >>> ttm_buffer_object *bo, >>> + page_offset; >>> } >>> >>> -static int ttm_bo_vm_fault(struct vm_fault *vmf) >>> +static vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf) >>> { >>> struct vm_area_struct *vma = vmf->vma; >>> struct ttm_buffer_object *bo = (struct ttm_buffer_object *) >>> @@ -115,8 +116,9 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) >>> unsigned long pfn; >>> struct ttm_tt *ttm = NULL; >>> struct page *page; >>> - int ret; >>> + int err; >>> int i; >>> + vm_fault_t ret = VM_FAULT_NOPAGE; >>> unsigned long address = vmf->address; >>> struct ttm_mem_type_manager *man = >>> &bdev->man[bo->mem.mem_type]; >>> @@ -128,9 +130,9 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) >>> * for reserve, and if it fails, retry the fault after waiting >>> * for the buffer to become unreserved. >>> */ >>> - ret = ttm_bo_reserve(bo, true, true, NULL); >>> - if (unlikely(ret != 0)) { >>> - if (ret != -EBUSY) >>> + err = ttm_bo_reserve(bo, true, true, NULL); >>> + if (unlikely(err != 0)) { >>> + if (err != -EBUSY) >>> return VM_FAULT_NOPAGE; >>> >>> if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) { >>> @@ -162,8 +164,8 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) >>> } >>> >>> if (bdev->driver->fault_reserve_notify) { >>> - ret = bdev->driver->fault_reserve_notify(bo); >>> - switch (ret) { >>> + err = bdev->driver->fault_reserve_notify(bo); >>> + switch (err) { >>> case 0: >>> break; >>> case -EBUSY: >>> @@ -191,13 +193,13 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) >>> goto out_unlock; >>> } >>> >>> - ret = ttm_mem_io_lock(man, true); >>> - if (unlikely(ret != 0)) { >>> + err = ttm_mem_io_lock(man, true); >>> + if (unlikely(err != 0)) { >>> ret = VM_FAULT_NOPAGE; >>> goto out_unlock; >>> } >>> - ret = ttm_mem_io_reserve_vm(bo); >>> - if (unlikely(ret != 0)) { >>> + err = ttm_mem_io_reserve_vm(bo); >>> + if (unlikely(err != 0)) { >>> ret = VM_FAULT_SIGBUS; >>> goto out_io_unlock; >>> } >>> @@ -265,23 +267,20 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) >>> } >>> >>> if (vma->vm_flags & VM_MIXEDMAP) >>> - ret = vm_insert_mixed(&cvma, address, >>> + ret = vmf_insert_mixed(&cvma, address, >>> __pfn_to_pfn_t(pfn, PFN_DEV)); >>> else >>> - ret = vm_insert_pfn(&cvma, address, pfn); >>> + ret = vmf_insert_pfn(&cvma, address, pfn); >>> >>> /* >>> * Somebody beat us to this PTE or prefaulting to >>> * an already populated PTE, or prefaulting error. >>> */ >>> >>> - if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0))) >>> + if (unlikely((ret == VM_FAULT_NOPAGE && i > 0))) >>> break; >>> - else if (unlikely(ret != 0)) { >>> - ret = >>> - (ret == -ENOMEM) ? VM_FAULT_OOM : >>> VM_FAULT_SIGBUS; >>> + else if (unlikely(ret & VM_FAULT_ERROR)) >>> goto out_io_unlock; >>> - } >>> >>> address += PAGE_SIZE; >>> if (unlikely(++page_offset >= page_last)) >>> -- >>> 1.9.1 >>> >> If no further comment, we would like get this patch in 4.18 / 4.18-rc-x. > The patch looks good to me and I will pick it up for the next TTM pull > request. I don't think it will make it into 4.18-rc-1, but 4.18-rc-x > sounds realistic. The kernel is still compiling, but as soon as I know that this works I'm going to push it into our internal branch which brings it on the way to 4.18-rc-2. Regards, Christian. > > Christian.
diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c index 8eba95b..9de8b4f 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c @@ -43,10 +43,11 @@ #define TTM_BO_VM_NUM_PREFAULT 16 -static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo, +static vm_fault_t ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo, struct vm_fault *vmf) { - int ret = 0; + vm_fault_t ret = 0; + int err = 0; if (likely(!bo->moving)) goto out_unlock; @@ -77,9 +78,9 @@ static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo, /* * Ordinary wait. */ - ret = dma_fence_wait(bo->moving, true); - if (unlikely(ret != 0)) { - ret = (ret != -ERESTARTSYS) ? VM_FAULT_SIGBUS : + err = dma_fence_wait(bo->moving, true); + if (unlikely(err != 0)) { + ret = (err != -ERESTARTSYS) ? VM_FAULT_SIGBUS : VM_FAULT_NOPAGE; goto out_unlock; } @@ -104,7 +105,7 @@ static unsigned long ttm_bo_io_mem_pfn(struct ttm_buffer_object *bo, + page_offset; } -static int ttm_bo_vm_fault(struct vm_fault *vmf) +static vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; struct ttm_buffer_object *bo = (struct ttm_buffer_object *) @@ -115,8 +116,9 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) unsigned long pfn; struct ttm_tt *ttm = NULL; struct page *page; - int ret; + int err; int i; + vm_fault_t ret = VM_FAULT_NOPAGE; unsigned long address = vmf->address; struct ttm_mem_type_manager *man = &bdev->man[bo->mem.mem_type]; @@ -128,9 +130,9 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) * for reserve, and if it fails, retry the fault after waiting * for the buffer to become unreserved. */ - ret = ttm_bo_reserve(bo, true, true, NULL); - if (unlikely(ret != 0)) { - if (ret != -EBUSY) + err = ttm_bo_reserve(bo, true, true, NULL); + if (unlikely(err != 0)) { + if (err != -EBUSY) return VM_FAULT_NOPAGE; if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) { @@ -162,8 +164,8 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) } if (bdev->driver->fault_reserve_notify) { - ret = bdev->driver->fault_reserve_notify(bo); - switch (ret) { + err = bdev->driver->fault_reserve_notify(bo); + switch (err) { case 0: break; case -EBUSY: @@ -191,13 +193,13 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) goto out_unlock; } - ret = ttm_mem_io_lock(man, true); - if (unlikely(ret != 0)) { + err = ttm_mem_io_lock(man, true); + if (unlikely(err != 0)) { ret = VM_FAULT_NOPAGE; goto out_unlock; } - ret = ttm_mem_io_reserve_vm(bo); - if (unlikely(ret != 0)) { + err = ttm_mem_io_reserve_vm(bo); + if (unlikely(err != 0)) { ret = VM_FAULT_SIGBUS; goto out_io_unlock; } @@ -265,23 +267,20 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) } if (vma->vm_flags & VM_MIXEDMAP) - ret = vm_insert_mixed(&cvma, address, + ret = vmf_insert_mixed(&cvma, address, __pfn_to_pfn_t(pfn, PFN_DEV)); else - ret = vm_insert_pfn(&cvma, address, pfn); + ret = vmf_insert_pfn(&cvma, address, pfn); /* * Somebody beat us to this PTE or prefaulting to * an already populated PTE, or prefaulting error. */ - if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0))) + if (unlikely((ret == VM_FAULT_NOPAGE && i > 0))) break; - else if (unlikely(ret != 0)) { - ret = - (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS; + else if (unlikely(ret & VM_FAULT_ERROR)) goto out_io_unlock; - } address += PAGE_SIZE; if (unlikely(++page_offset >= page_last))
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_{mixed,pfn} returns err which driver mapped into VM_FAULT_* type. The new function vmf_insert_{mixed,pfn} will replace this inefficiency by returning VM_FAULT_* type. Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> --- v2: Address christian's comment. Put reverse xmas tree order for variable declarations. drivers/gpu/drm/ttm/ttm_bo_vm.c | 45 ++++++++++++++++++++--------------------- 1 file changed, 22 insertions(+), 23 deletions(-)