Am 29.11.2017 um 01:20 schrieb Samuel Li:
To improve cpu read performance. This is implemented for APUs currently.

And once more a NAK for this approach.

What we could do is migrate the BO to GTT during mmap, but pinning it is out of question.

Regards,
Christian.


Change-Id: I300a7daed8f2b0ba6be71a43196a6b8617ddc62e
---
  drivers/gpu/drm/amd/amdgpu/amdgpu.h               |   2 +
  drivers/gpu/drm/amd/amdgpu/amdgpu_display.c       |  10 +-
  drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c           |   2 +-
  drivers/gpu/drm/amd/amdgpu/amdgpu_prime.c         | 108 ++++++++++++++++++++++
  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c |   8 +-
  5 files changed, 126 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h 
b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index f8657c3..193db70 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -417,6 +417,8 @@ amdgpu_gem_prime_import_sg_table(struct drm_device *dev,
  struct dma_buf *amdgpu_gem_prime_export(struct drm_device *dev,
                                        struct drm_gem_object *gobj,
                                        int flags);
+struct drm_gem_object *amdgpu_gem_prime_import(struct drm_device *dev,
+                                           struct dma_buf *dma_buf);
  int amdgpu_gem_prime_pin(struct drm_gem_object *obj);
  void amdgpu_gem_prime_unpin(struct drm_gem_object *obj);
  struct reservation_object *amdgpu_gem_prime_res_obj(struct drm_gem_object *);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
index d704a45..b5483e4 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
@@ -147,6 +147,7 @@ int amdgpu_crtc_page_flip_target(struct drm_crtc *crtc,
        struct drm_device *dev = crtc->dev;
        struct amdgpu_device *adev = dev->dev_private;
        struct amdgpu_crtc *amdgpu_crtc = to_amdgpu_crtc(crtc);
+       bool gtt_scannable = (adev->asic_type >= CHIP_CARRIZO && adev->flags & 
AMD_IS_APU);
        struct amdgpu_framebuffer *old_amdgpu_fb;
        struct amdgpu_framebuffer *new_amdgpu_fb;
        struct drm_gem_object *obj;
@@ -190,8 +191,13 @@ int amdgpu_crtc_page_flip_target(struct drm_crtc *crtc,
r = amdgpu_bo_pin(new_abo, AMDGPU_GEM_DOMAIN_VRAM, &base);
        if (unlikely(r != 0)) {
-               DRM_ERROR("failed to pin new abo buffer before flip\n");
-               goto unreserve;
+               /* latest APUs support gtt scan out */
+               if (gtt_scannable)
+                       r = amdgpu_bo_pin(new_abo, AMDGPU_GEM_DOMAIN_GTT, 
&base);
+               if (unlikely(r != 0)) {
+                       DRM_ERROR("failed to pin new abo buffer before flip\n");
+                       goto unreserve;
+               }
        }
r = reservation_object_get_fences_rcu(new_abo->tbo.resv, &work->excl,
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
index 31383e0..df30b08 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
@@ -868,7 +868,7 @@ static struct drm_driver kms_driver = {
        .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
        .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
        .gem_prime_export = amdgpu_gem_prime_export,
-       .gem_prime_import = drm_gem_prime_import,
+       .gem_prime_import = amdgpu_gem_prime_import,
        .gem_prime_pin = amdgpu_gem_prime_pin,
        .gem_prime_unpin = amdgpu_gem_prime_unpin,
        .gem_prime_res_obj = amdgpu_gem_prime_res_obj,
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_prime.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_prime.c
index ae9c106..9e1424d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_prime.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_prime.c
@@ -164,6 +164,82 @@ struct reservation_object *amdgpu_gem_prime_res_obj(struct 
drm_gem_object *obj)
        return bo->tbo.resv;
  }
+static int amdgpu_gem_begin_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
+{
+       struct amdgpu_bo *bo = gem_to_amdgpu_bo(dma_buf->priv);
+       struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
+       long i, ret = 0;
+       unsigned old_count;
+       bool reads = (direction == DMA_BIDIRECTIONAL || direction == 
DMA_FROM_DEVICE);
+       bool gtt_scannable = (adev->asic_type >= CHIP_CARRIZO && adev->flags & 
AMD_IS_APU);
+       u32 domain;
+
+       if (!reads || !gtt_scannable)
+               return 0;
+
+       ret = amdgpu_bo_reserve(bo, false);
+       if (unlikely(ret != 0))
+               return ret;
+
+       /*
+        * Wait for all shared fences to complete before we switch to future
+        * use of exclusive fence on this prime shared bo.
+        */
+       ret = reservation_object_wait_timeout_rcu(bo->tbo.resv, true, false,
+                                                 MAX_SCHEDULE_TIMEOUT);
+
+       if (unlikely(ret < 0)) {
+               DRM_DEBUG_PRIME("Fence wait failed: %li\n", ret);
+               amdgpu_bo_unreserve(bo);
+               return ret;
+       }
+
+       ret = 0;
+       /* Pin to gtt */
+       domain = amdgpu_mem_type_to_domain(bo->tbo.mem.mem_type);
+       if (domain == AMDGPU_GEM_DOMAIN_VRAM) {
+               old_count = bo->pin_count;
+               for (i = 0; i < old_count; i++)
+                       amdgpu_bo_unpin(bo);
+               for (i = 0; i < old_count; i++) {
+                       ret = amdgpu_bo_pin(bo, AMDGPU_GEM_DOMAIN_GTT, NULL);
+                       if (unlikely(ret != 0))
+                               break;
+               }
+       }
+       if (ret == 0)
+               ret = amdgpu_bo_pin(bo, AMDGPU_GEM_DOMAIN_GTT, NULL);
+
+       amdgpu_bo_unreserve(bo);
+       return ret;
+}
+
+static int amdgpu_gem_end_cpu_access(struct dma_buf *dma_buf, enum 
dma_data_direction direction)
+{
+       struct amdgpu_bo *bo = gem_to_amdgpu_bo(dma_buf->priv);
+       int ret = 0;
+       bool reads = (direction == DMA_BIDIRECTIONAL || direction == 
DMA_FROM_DEVICE);
+       struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
+       bool gtt_scannable = (adev->asic_type >= CHIP_CARRIZO && adev->flags & 
AMD_IS_APU);
+
+       if (!reads || !gtt_scannable)
+               return 0;
+
+       mb();
+       ret = amdgpu_bo_reserve(bo, true);
+       if (unlikely(ret != 0))
+               return ret;
+
+       amdgpu_bo_unpin(bo);
+
+       amdgpu_bo_unreserve(bo);
+
+       return 0;
+}
+
+static struct dma_buf_ops amdgpu_dmabuf_ops;
+static atomic_t aops_lock;
+
  struct dma_buf *amdgpu_gem_prime_export(struct drm_device *dev,
                                        struct drm_gem_object *gobj,
                                        int flags)
@@ -178,5 +254,37 @@ struct dma_buf *amdgpu_gem_prime_export(struct drm_device 
*dev,
        buf = drm_gem_prime_export(dev, gobj, flags);
        if (!IS_ERR(buf))
                buf->file->f_mapping = dev->anon_inode->i_mapping;
+
+       while (amdgpu_dmabuf_ops.begin_cpu_access != 
amdgpu_gem_begin_cpu_access ||
+               amdgpu_dmabuf_ops.end_cpu_access != amdgpu_gem_end_cpu_access )
+       {
+               if (!atomic_cmpxchg(&aops_lock, 0, 1)) {
+                       amdgpu_dmabuf_ops = *(buf->ops);
+                       amdgpu_dmabuf_ops.begin_cpu_access = 
amdgpu_gem_begin_cpu_access;
+                       amdgpu_dmabuf_ops.end_cpu_access = 
amdgpu_gem_end_cpu_access;
+               }
+       }
+       buf->ops = &amdgpu_dmabuf_ops;
+
        return buf;
  }
+
+struct drm_gem_object *amdgpu_gem_prime_import(struct drm_device *dev,
+                                           struct dma_buf *dma_buf)
+{
+       struct drm_gem_object *obj;
+
+       if (dma_buf->ops == &amdgpu_dmabuf_ops) {
+               obj = dma_buf->priv;
+               if (obj->dev == dev) {
+                       /*
+                        * Importing dmabuf exported from out own gem increases
+                        * refcount on gem itself instead of f_count of dmabuf.
+                        */
+                       drm_gem_object_get(obj);
+                       return obj;
+               }
+       }
+
+       return drm_gem_prime_import(dev, dma_buf);
+ }
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c 
b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index a3bf021..f25b830 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -2987,6 +2987,8 @@ static int dm_plane_helper_prepare_fb(struct drm_plane 
*plane,
        int r;
        struct dm_plane_state *dm_plane_state_new, *dm_plane_state_old;
        unsigned int awidth;
+       struct amdgpu_device *adev = plane->dev->dev_private;
+       bool gtt_scannable = (adev->asic_type >= CHIP_CARRIZO && adev->flags & 
AMD_IS_APU);
dm_plane_state_old = to_dm_plane_state(plane->state);
        dm_plane_state_new = to_dm_plane_state(new_state);
@@ -3005,7 +3007,11 @@ static int dm_plane_helper_prepare_fb(struct drm_plane 
*plane,
                return r;
r = amdgpu_bo_pin(rbo, AMDGPU_GEM_DOMAIN_VRAM, &afb->address);
-
+       if (unlikely(r != 0)) {
+               /* latest APUs support gtt scan out */
+               if (gtt_scannable)
+                       r = amdgpu_bo_pin(rbo, AMDGPU_GEM_DOMAIN_GTT, 
&afb->address);
+       }
amdgpu_bo_unreserve(rbo);

_______________________________________________
amd-gfx mailing list
[email protected]
https://lists.freedesktop.org/mailman/listinfo/amd-gfx

Reply via email to