Am 27.02.2018 um 16:22 schrieb Amber Lin:
> When using CPU to update page table, we need to kmap all the PDs/PTs after
> they are allocated and that requires a TLB shot down on each CPU, which is
> quite heavy.
>
> Instead, we map the whole visible VRAM to a kernel address at once. Pages
> can be obtained from the offset.
>
> Change-Id: I56574bd544dae273da50e8b5dd6894cd5d9454bd
> Signed-off-by: Amber Lin <Amber.Lin at amd.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h | 1 +
> drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 7 +++++++
> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 5 +++++
> 3 files changed, 13 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h
> index 893c249..503672d 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h
> @@ -77,6 +77,7 @@ struct amdgpu_gmc_funcs {
> struct amdgpu_gmc {
> resource_size_t aper_size;
> resource_size_t aper_base;
> + void __iomem *aper_base_kaddr;
That isn't GMC related and belongs into structure struct amdgpu_mman in
amdgpu_ttm.h.
> /* for some chips with <= 32MB we need to lie
> * about vram size near mc fb location */
> u64 mc_vram_size;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> index 216799cc..56c7870 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> @@ -829,6 +829,10 @@ int amdgpu_bo_init(struct amdgpu_device *adev)
> /* Add an MTRR for the VRAM */
> adev->gmc.vram_mtrr = arch_phys_wc_add(adev->gmc.aper_base,
> adev->gmc.aper_size);
> +#ifdef CONFIG_64BIT
> + adev->gmc.aper_base_kaddr = ioremap_wc(adev->gmc.aper_base,
> + adev->gmc.visible_vram_size);
> +#endif
Put that into amdgpu_ttm_init in amdgpu_ttm.c.
> DRM_INFO("Detected VRAM RAM=%lluM, BAR=%lluM\n",
> adev->gmc.mc_vram_size >> 20,
> (unsigned long long)adev->gmc.aper_size >> 20);
> @@ -842,6 +846,9 @@ void amdgpu_bo_fini(struct amdgpu_device *adev)
> amdgpu_ttm_fini(adev);
> arch_phys_wc_del(adev->gmc.vram_mtrr);
> arch_io_free_memtype_wc(adev->gmc.aper_base, adev->gmc.aper_size);
> + if (adev->gmc.aper_base_kaddr)
> + iounmap(adev->gmc.aper_base_kaddr);
> + adev->gmc.aper_base_kaddr = NULL;
And that into amdgpu_ttm_fini.
> }
>
> int amdgpu_bo_fbdev_mmap(struct amdgpu_bo *bo,
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index e38e6db..cde639d 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -621,6 +621,7 @@ static int amdgpu_ttm_io_mem_reserve(struct ttm_bo_device *bdev, struct ttm_mem_
> {
> struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];
> struct amdgpu_device *adev = amdgpu_ttm_adev(bdev);
> + struct drm_mm_node *mm_node = mem->mm_node;
>
> mem->bus.addr = NULL;
> mem->bus.offset = 0;
> @@ -640,6 +641,10 @@ static int amdgpu_ttm_io_mem_reserve(struct ttm_bo_device *bdev, struct ttm_mem_
> /* check if it's visible */
> if ((mem->bus.offset + mem->bus.size) > adev->gmc.visible_vram_size)
> return -EINVAL;
> + if (adev->gmc.aper_base_kaddr &&
> + (mm_node->size == mem->num_pages)) /* contiguous mem */
> + mem->bus.addr = ((u8 *)adev->gmc.aper_base_kaddr +
> + mem->bus.offset);
The coding style isn't correct here. The "(mm_node->size" should be on
the same column as the "adev->gmc" above.
And please put the comment before the if, not on the same line after it.
Regards,
Christian.
> mem->bus.base = adev->gmc.aper_base;
> mem->bus.is_iomem = true;
> break;
