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