[Intel-gfx] [PATCH 12/19] drm/i915/lmem: Bypass aperture when lmem is available
Tvrtko Ursulin
tvrtko.ursulin at linux.intel.com
Wed Apr 14 15:33:36 UTC 2021
On 12/04/2021 10:05, Matthew Auld wrote:
> From: Anusha Srivatsa <anusha.srivatsa at intel.com>
>
> In the scenario where local memory is available, we have
> rely on CPU access via lmem directly instead of aperture.
>
> v2:
> gmch is only relevant for much older hw, therefore we can drop the
> has_aperture check since it should always be present on such platforms.
> (Chris)
>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Cc: Chris P Wilson <chris.p.wilson at intel.com>
> Cc: Daniel Vetter <daniel.vetter at intel.com>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> Cc: CQ Tang <cq.tang at intel.com>
> Signed-off-by: Anusha Srivatsa <anusha.srivatsa at intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_fbdev.c | 22 +++++++++++++++-------
> drivers/gpu/drm/i915/gem/i915_gem_lmem.c | 15 +++++++++++++++
> drivers/gpu/drm/i915/gem/i915_gem_lmem.h | 5 +++++
> drivers/gpu/drm/i915/i915_vma.c | 19 +++++++++++++------
> 4 files changed, 48 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_fbdev.c b/drivers/gpu/drm/i915/display/intel_fbdev.c
> index 2b37959da747..4af40229f5ec 100644
> --- a/drivers/gpu/drm/i915/display/intel_fbdev.c
> +++ b/drivers/gpu/drm/i915/display/intel_fbdev.c
> @@ -139,14 +139,22 @@ static int intelfb_alloc(struct drm_fb_helper *helper,
> size = mode_cmd.pitches[0] * mode_cmd.height;
> size = PAGE_ALIGN(size);
>
> - /* If the FB is too big, just don't use it since fbdev is not very
> - * important and we should probably use that space with FBC or other
> - * features. */
> obj = ERR_PTR(-ENODEV);
> - if (size * 2 < dev_priv->stolen_usable_size)
> - obj = i915_gem_object_create_stolen(dev_priv, size);
> - if (IS_ERR(obj))
> - obj = i915_gem_object_create_shmem(dev_priv, size);
> + if (HAS_LMEM(dev_priv)) {
> + obj = i915_gem_object_create_lmem(dev_priv, size,
> + I915_BO_ALLOC_CONTIGUOUS);
Has to be contiguous? Question for display experts I guess.
[Comes back later.] Ah for iomap? Put a comment to that effect perhaps?
> + } else {
> + /*
> + * If the FB is too big, just don't use it since fbdev is not very
> + * important and we should probably use that space with FBC or other
> + * features.
> + */
> + if (size * 2 < dev_priv->stolen_usable_size)
> + obj = i915_gem_object_create_stolen(dev_priv, size);
> + if (IS_ERR(obj))
> + obj = i915_gem_object_create_shmem(dev_priv, size);
> + }
Could we keep the IS_ERR ordered allocation order to save having to
re-indent? Bike shed so optional..
> +
> if (IS_ERR(obj)) {
> drm_err(&dev_priv->drm, "failed to allocate framebuffer\n");
> return PTR_ERR(obj);
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_lmem.c b/drivers/gpu/drm/i915/gem/i915_gem_lmem.c
> index 017db8f71130..f44bdd08f7cb 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_lmem.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_lmem.c
> @@ -17,6 +17,21 @@ const struct drm_i915_gem_object_ops i915_gem_lmem_obj_ops = {
> .release = i915_gem_object_release_memory_region,
> };
>
> +void __iomem *
> +i915_gem_object_lmem_io_map(struct drm_i915_gem_object *obj,
> + unsigned long n,
> + unsigned long size)
> +{
> + resource_size_t offset;
> +
> + GEM_BUG_ON(!i915_gem_object_is_contiguous(obj));
> +
> + offset = i915_gem_object_get_dma_address(obj, n);
> + offset -= obj->mm.region->region.start;
> +
> + return io_mapping_map_wc(&obj->mm.region->iomap, offset, size);
> +}
> +
> bool i915_gem_object_is_lmem(struct drm_i915_gem_object *obj)
> {
> struct intel_memory_region *mr = obj->mm.region;
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_lmem.h b/drivers/gpu/drm/i915/gem/i915_gem_lmem.h
> index 036d53c01de9..fac6bc5a5ebb 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_lmem.h
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_lmem.h
> @@ -14,6 +14,11 @@ struct intel_memory_region;
>
> extern const struct drm_i915_gem_object_ops i915_gem_lmem_obj_ops;
>
> +void __iomem *
> +i915_gem_object_lmem_io_map(struct drm_i915_gem_object *obj,
> + unsigned long n,
> + unsigned long size);
> +
> bool i915_gem_object_is_lmem(struct drm_i915_gem_object *obj);
>
> struct drm_i915_gem_object *
> diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
> index 07490db51cdc..e24d33aecac4 100644
> --- a/drivers/gpu/drm/i915/i915_vma.c
> +++ b/drivers/gpu/drm/i915/i915_vma.c
> @@ -27,6 +27,7 @@
>
> #include "display/intel_frontbuffer.h"
>
> +#include "gem/i915_gem_lmem.h"
> #include "gt/intel_engine.h"
> #include "gt/intel_engine_heartbeat.h"
> #include "gt/intel_gt.h"
> @@ -448,9 +449,11 @@ void __iomem *i915_vma_pin_iomap(struct i915_vma *vma)
> void __iomem *ptr;
> int err;
>
> - if (GEM_WARN_ON(!i915_vma_is_map_and_fenceable(vma))) {
> - err = -ENODEV;
> - goto err;
> + if (!i915_gem_object_is_lmem(vma->obj)) {
> + if (GEM_WARN_ON(!i915_vma_is_map_and_fenceable(vma))) {
> + err = -ENODEV;
> + goto err;
> + }
> }
>
> GEM_BUG_ON(!i915_vma_is_ggtt(vma));
> @@ -458,9 +461,13 @@ void __iomem *i915_vma_pin_iomap(struct i915_vma *vma)
>
> ptr = READ_ONCE(vma->iomap);
> if (ptr == NULL) {
> - ptr = io_mapping_map_wc(&i915_vm_to_ggtt(vma->vm)->iomap,
> - vma->node.start,
> - vma->node.size);
> + if (i915_gem_object_is_lmem(vma->obj))
> + ptr = i915_gem_object_lmem_io_map(vma->obj, 0,
> + vma->obj->base.size);
Can the vma size be bigger than the object here? Given how below works
of vma->node.size.
> + else
> + ptr = io_mapping_map_wc(&i915_vm_to_ggtt(vma->vm)->iomap,
> + vma->node.start,
> + vma->node.size);
Looks a bit odd that this calls the same io_mapping_map_wc as
i915_gem_object_lmem_io_map ends up doing. Perhaps that suggests there
should be a single helper here but I am not sure what would be elegant.
Regards,
Tvrtko
> if (ptr == NULL) {
> err = -ENOMEM;
> goto err;
>
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