Re: [PATCH v2 29/37] drm/i915: Introduce DRM_I915_GEM_MMAP_OFFSET

Chris Wilson
2019-06-28T00:12:15Z

Quoting Matthew Auld (2019-06-27 21:56:25)
> From: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
>
> Add a new CPU mmap implementation that allows multiple fault handlers
> that depends on the object's backing pages.
>
> Note that we multiplex mmap_gtt and mmap_offset through the same ioctl,
> and use the zero extending behaviour of drm to differentiate between
> them, when we inspect the flags.
>
> Signed-off-by: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
> Signed-off-by: Matthew Auld <matthew.auld@intel.com>
> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
> ---
> drivers/gpu/drm/i915/gem/i915_gem_ioctls.h | 2 ++
> drivers/gpu/drm/i915/gem/i915_gem_mman.c | 30 ++++++++++++++++++
> .../gpu/drm/i915/gem/i915_gem_object_types.h | 3 ++
> drivers/gpu/drm/i915/i915_drv.c | 3 +-
> include/uapi/drm/i915_drm.h | 31 +++++++++++++++++++
> 5 files changed, 68 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ioctls.h b/drivers/gpu/drm/i915/gem/i915_gem_ioctls.h
> index ddc7f2a52b3e..5abd5b2172f2 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_ioctls.h
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_ioctls.h
> @@ -30,6 +30,8 @@ int i915_gem_mmap_ioctl(struct drm_device *dev, void *data,
> struct drm_file *file);
> int i915_gem_mmap_gtt_ioctl(struct drm_device *dev, void *data,
> struct drm_file *file);
> +int i915_gem_mmap_offset_ioctl(struct drm_device *dev, void *data,
> + struct drm_file *file_priv);
> int i915_gem_pread_ioctl(struct drm_device *dev, void *data,
> struct drm_file *file);
> int i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
> index 7b46f44d9c20..cbf89e80a97b 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
> @@ -536,12 +536,42 @@ i915_gem_mmap_gtt_ioctl(struct drm_device *dev, void *data,
> struct drm_file *file)
> {
> struct drm_i915_gem_mmap_offset *args = data;
> + struct drm_i915_private *i915 = to_i915(dev);
> +
> + if (args->flags & I915_MMAP_OFFSET_FLAGS)
> + return i915_gem_mmap_offset_ioctl(dev, data, file);
> +
> + if (!HAS_MAPPABLE_APERTURE(i915)) {
> + DRM_ERROR("No aperture, cannot mmap via legacy GTT\n");
> + return -ENODEV;
> + }
>
> return __assign_gem_object_mmap_data(file, args->handle,
> I915_MMAP_TYPE_GTT,
> &args->offset);
> }
>
> +int i915_gem_mmap_offset_ioctl(struct drm_device *dev, void *data,
> + struct drm_file *file)

This seems highly redundant and not correctly plugged in.
-Chris