| Message ID | 20210603210831.1492251-1-daniel.vetter@ffwll.ch (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/shmem-helper: Switch to vmf_insert_pfn | expand |
On Thu, Jun 03, 2021 at 11:08:31PM +0200, Daniel Vetter wrote: > We want to stop gup, which isn't the case if we use vmf_insert_page > and VM_MIXEDMAP, because that does not set pte_special. > > v2: With this shmem gem helpers now definitely need CONFIG_MMU (0day) > > v3: add more depends on MMU. For usb drivers this is a bit awkward, > but really it's correct: To be able to provide a contig mapping of > buffers to userspace on !MMU platforms we'd need to use the cma > helpers for these drivers on those platforms. As-is this wont work. > > Also not exactly sure why vm_insert_page doesn't go boom, because that > definitely wont fly in practice since the pages are non-contig to > begin with. > > Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> > Cc: Maxime Ripard <mripard@kernel.org> > Cc: Thomas Zimmermann <tzimmermann@suse.de> > Cc: David Airlie <airlied@linux.ie> > Cc: Daniel Vetter <daniel@ffwll.ch> Merged to drm-misc-next. Aside, anyone feel like a review on the previous patch? Still not ready to switch vgem over, but I think I've found the next bug that needs fixing in shmem helpers. -Daniel > --- > drivers/gpu/drm/Kconfig | 2 +- > drivers/gpu/drm/drm_gem_shmem_helper.c | 4 ++-- > drivers/gpu/drm/gud/Kconfig | 2 +- > drivers/gpu/drm/tiny/Kconfig | 4 ++-- > drivers/gpu/drm/udl/Kconfig | 1 + > 5 files changed, 7 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig > index 56a55a6e6239..9c21527b791f 100644 > --- a/drivers/gpu/drm/Kconfig > +++ b/drivers/gpu/drm/Kconfig > @@ -206,7 +206,7 @@ config DRM_KMS_CMA_HELPER > > config DRM_GEM_SHMEM_HELPER > bool > - depends on DRM > + depends on DRM && MMU > help > Choose this if you need the GEM shmem helper functions > > diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c > index 6d625cee7a6a..11edd54f0580 100644 > --- a/drivers/gpu/drm/drm_gem_shmem_helper.c > +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c > @@ -542,7 +542,7 @@ static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf) > } else { > page = shmem->pages[page_offset]; > > - ret = vmf_insert_page(vma, vmf->address, page); > + ret = vmf_insert_pfn(vma, vmf->address, page_to_pfn(page)); > } > > mutex_unlock(&shmem->pages_lock); > @@ -612,7 +612,7 @@ int drm_gem_shmem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) > return ret; > } > > - vma->vm_flags |= VM_MIXEDMAP | VM_DONTEXPAND; > + vma->vm_flags |= VM_PFNMAP | VM_DONTEXPAND; > vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); > if (shmem->map_wc) > vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); > diff --git a/drivers/gpu/drm/gud/Kconfig b/drivers/gpu/drm/gud/Kconfig > index 1c8601bf4d91..9c1e61f9eec3 100644 > --- a/drivers/gpu/drm/gud/Kconfig > +++ b/drivers/gpu/drm/gud/Kconfig > @@ -2,7 +2,7 @@ > > config DRM_GUD > tristate "GUD USB Display" > - depends on DRM && USB > + depends on DRM && USB && MMU > select LZ4_COMPRESS > select DRM_KMS_HELPER > select DRM_GEM_SHMEM_HELPER > diff --git a/drivers/gpu/drm/tiny/Kconfig b/drivers/gpu/drm/tiny/Kconfig > index d46f95d9196d..a15f57ace9e7 100644 > --- a/drivers/gpu/drm/tiny/Kconfig > +++ b/drivers/gpu/drm/tiny/Kconfig > @@ -31,7 +31,7 @@ config DRM_CIRRUS_QEMU > > config DRM_GM12U320 > tristate "GM12U320 driver for USB projectors" > - depends on DRM && USB > + depends on DRM && USB && MMU > select DRM_KMS_HELPER > select DRM_GEM_SHMEM_HELPER > help > @@ -40,7 +40,7 @@ config DRM_GM12U320 > > config DRM_SIMPLEDRM > tristate "Simple framebuffer driver" > - depends on DRM > + depends on DRM && MMU > select DRM_GEM_SHMEM_HELPER > select DRM_KMS_HELPER > help > diff --git a/drivers/gpu/drm/udl/Kconfig b/drivers/gpu/drm/udl/Kconfig > index 1f497d8f1ae5..c744175c6992 100644 > --- a/drivers/gpu/drm/udl/Kconfig > +++ b/drivers/gpu/drm/udl/Kconfig > @@ -4,6 +4,7 @@ config DRM_UDL > depends on DRM > depends on USB > depends on USB_ARCH_HAS_HCD > + depends on MMU > select DRM_GEM_SHMEM_HELPER > select DRM_KMS_HELPER > help > -- > 2.31.0 >
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index 56a55a6e6239..9c21527b791f 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -206,7 +206,7 @@ config DRM_KMS_CMA_HELPER config DRM_GEM_SHMEM_HELPER bool - depends on DRM + depends on DRM && MMU help Choose this if you need the GEM shmem helper functions diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c index 6d625cee7a6a..11edd54f0580 100644 --- a/drivers/gpu/drm/drm_gem_shmem_helper.c +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -542,7 +542,7 @@ static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf) } else { page = shmem->pages[page_offset]; - ret = vmf_insert_page(vma, vmf->address, page); + ret = vmf_insert_pfn(vma, vmf->address, page_to_pfn(page)); } mutex_unlock(&shmem->pages_lock); @@ -612,7 +612,7 @@ int drm_gem_shmem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) return ret; } - vma->vm_flags |= VM_MIXEDMAP | VM_DONTEXPAND; + vma->vm_flags |= VM_PFNMAP | VM_DONTEXPAND; vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); if (shmem->map_wc) vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); diff --git a/drivers/gpu/drm/gud/Kconfig b/drivers/gpu/drm/gud/Kconfig index 1c8601bf4d91..9c1e61f9eec3 100644 --- a/drivers/gpu/drm/gud/Kconfig +++ b/drivers/gpu/drm/gud/Kconfig @@ -2,7 +2,7 @@ config DRM_GUD tristate "GUD USB Display" - depends on DRM && USB + depends on DRM && USB && MMU select LZ4_COMPRESS select DRM_KMS_HELPER select DRM_GEM_SHMEM_HELPER diff --git a/drivers/gpu/drm/tiny/Kconfig b/drivers/gpu/drm/tiny/Kconfig index d46f95d9196d..a15f57ace9e7 100644 --- a/drivers/gpu/drm/tiny/Kconfig +++ b/drivers/gpu/drm/tiny/Kconfig @@ -31,7 +31,7 @@ config DRM_CIRRUS_QEMU config DRM_GM12U320 tristate "GM12U320 driver for USB projectors" - depends on DRM && USB + depends on DRM && USB && MMU select DRM_KMS_HELPER select DRM_GEM_SHMEM_HELPER help @@ -40,7 +40,7 @@ config DRM_GM12U320 config DRM_SIMPLEDRM tristate "Simple framebuffer driver" - depends on DRM + depends on DRM && MMU select DRM_GEM_SHMEM_HELPER select DRM_KMS_HELPER help diff --git a/drivers/gpu/drm/udl/Kconfig b/drivers/gpu/drm/udl/Kconfig index 1f497d8f1ae5..c744175c6992 100644 --- a/drivers/gpu/drm/udl/Kconfig +++ b/drivers/gpu/drm/udl/Kconfig @@ -4,6 +4,7 @@ config DRM_UDL depends on DRM depends on USB depends on USB_ARCH_HAS_HCD + depends on MMU select DRM_GEM_SHMEM_HELPER select DRM_KMS_HELPER help
We want to stop gup, which isn't the case if we use vmf_insert_page and VM_MIXEDMAP, because that does not set pte_special. v2: With this shmem gem helpers now definitely need CONFIG_MMU (0day) v3: add more depends on MMU. For usb drivers this is a bit awkward, but really it's correct: To be able to provide a contig mapping of buffers to userspace on !MMU platforms we'd need to use the cma helpers for these drivers on those platforms. As-is this wont work. Also not exactly sure why vm_insert_page doesn't go boom, because that definitely wont fly in practice since the pages are non-contig to begin with. Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <mripard@kernel.org> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: David Airlie <airlied@linux.ie> Cc: Daniel Vetter <daniel@ffwll.ch> --- drivers/gpu/drm/Kconfig | 2 +- drivers/gpu/drm/drm_gem_shmem_helper.c | 4 ++-- drivers/gpu/drm/gud/Kconfig | 2 +- drivers/gpu/drm/tiny/Kconfig | 4 ++-- drivers/gpu/drm/udl/Kconfig | 1 + 5 files changed, 7 insertions(+), 6 deletions(-)