Re: [PATCH v2 4/7] drm/i915/gtt/dgfx: place the PD in LMEM

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On 27/04/2021 09:54, Matthew Auld wrote:
It's a requirement that for dgfx we place all the paging structures in
device local-memory.

v2: use i915_coherent_map_type()
v3: improve the shared dma-resv object comment

Signed-off-by: Matthew Auld <matthew.auld@xxxxxxxxx>
Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx>
---
  drivers/gpu/drm/i915/gt/gen8_ppgtt.c |  5 ++++-
  drivers/gpu/drm/i915/gt/intel_gtt.c  | 30 +++++++++++++++++++++++++---
  drivers/gpu/drm/i915/gt/intel_gtt.h  |  1 +
  3 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
index f83496836f0f..11fb5df45a0f 100644
--- a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
+++ b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
@@ -712,7 +712,10 @@ struct i915_ppgtt *gen8_ppgtt_create(struct intel_gt *gt)
  	 */
  	ppgtt->vm.has_read_only = !IS_GEN_RANGE(gt->i915, 11, 12);
- ppgtt->vm.alloc_pt_dma = alloc_pt_dma;
+	if (HAS_LMEM(gt->i915))
+		ppgtt->vm.alloc_pt_dma = alloc_pt_lmem;
+	else
+		ppgtt->vm.alloc_pt_dma = alloc_pt_dma;
err = gen8_init_scratch(&ppgtt->vm);
  	if (err)
diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.c b/drivers/gpu/drm/i915/gt/intel_gtt.c
index d386b89e2758..061c39d2ad51 100644
--- a/drivers/gpu/drm/i915/gt/intel_gtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
@@ -7,10 +7,26 @@
#include <linux/fault-inject.h> +#include "gem/i915_gem_lmem.h"
  #include "i915_trace.h"
  #include "intel_gt.h"
  #include "intel_gtt.h"
+struct drm_i915_gem_object *alloc_pt_lmem(struct i915_address_space *vm, int sz)
+{
+	struct drm_i915_gem_object *obj;
+
+	obj = i915_gem_object_create_lmem(vm->i915, sz, 0);
+	/*
+	 * Ensure all paging structures for this vm share the same dma-resv
+	 * object underneath, with the idea that one object_lock() will lock
+	 * them all at once.

Okay but I am still missing the part about why is this beneficial and not a downside. I suppose it is not a concept added by this patch so not fair to ask for explanation here anyway.

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>

Regards,

Tvrtko

+	 */
+	if (!IS_ERR(obj))
+		obj->base.resv = &vm->resv;
+	return obj;
+}
+
  struct drm_i915_gem_object *alloc_pt_dma(struct i915_address_space *vm, int sz)
  {
  	struct drm_i915_gem_object *obj;
@@ -19,7 +35,11 @@ struct drm_i915_gem_object *alloc_pt_dma(struct i915_address_space *vm, int sz)
  		i915_gem_shrink_all(vm->i915);
obj = i915_gem_object_create_internal(vm->i915, sz);
-	/* ensure all dma objects have the same reservation class */
+	/*
+	 * Ensure all paging structures for this vm share the same dma-resv
+	 * object underneath, with the idea that one object_lock() will lock
+	 * them all at once.
+	 */
  	if (!IS_ERR(obj))
  		obj->base.resv = &vm->resv;
  	return obj;
@@ -27,9 +47,11 @@ struct drm_i915_gem_object *alloc_pt_dma(struct i915_address_space *vm, int sz)
int map_pt_dma(struct i915_address_space *vm, struct drm_i915_gem_object *obj)
  {
+	enum i915_map_type type;
  	void *vaddr;
- vaddr = i915_gem_object_pin_map_unlocked(obj, I915_MAP_WB);
+	type = i915_coherent_map_type(vm->i915, obj, true);
+	vaddr = i915_gem_object_pin_map_unlocked(obj, type);
  	if (IS_ERR(vaddr))
  		return PTR_ERR(vaddr);
@@ -39,9 +61,11 @@ int map_pt_dma(struct i915_address_space *vm, struct drm_i915_gem_object *obj) int map_pt_dma_locked(struct i915_address_space *vm, struct drm_i915_gem_object *obj)
  {
+	enum i915_map_type type;
  	void *vaddr;
- vaddr = i915_gem_object_pin_map(obj, I915_MAP_WB);
+	type = i915_coherent_map_type(vm->i915, obj, true);
+	vaddr = i915_gem_object_pin_map(obj, type);
  	if (IS_ERR(vaddr))
  		return PTR_ERR(vaddr);
diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.h b/drivers/gpu/drm/i915/gt/intel_gtt.h
index 40e486704558..44ce27c51631 100644
--- a/drivers/gpu/drm/i915/gt/intel_gtt.h
+++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
@@ -527,6 +527,7 @@ int setup_scratch_page(struct i915_address_space *vm);
  void free_scratch(struct i915_address_space *vm);
struct drm_i915_gem_object *alloc_pt_dma(struct i915_address_space *vm, int sz);
+struct drm_i915_gem_object *alloc_pt_lmem(struct i915_address_space *vm, int sz);
  struct i915_page_table *alloc_pt(struct i915_address_space *vm);
  struct i915_page_directory *alloc_pd(struct i915_address_space *vm);
  struct i915_page_directory *__alloc_pd(int npde);

_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/dri-devel



[Index of Archives]     [Linux DRI Users]     [Linux Intel Graphics]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux