On Mon, Mar 13, 2017 at 01:41:36PM +0100, Christian König wrote:
> From: Christian König <christian.koenig@xxxxxxx>
>
> Try to resize BAR0 to let CPU access all of VRAM.
>
> Signed-off-by: Christian König <christian.koenig@xxxxxxx>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu.h | 1 +
> drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 29 +++++++++++++++++++++++++++++
> drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c | 8 +++++---
> drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c | 8 +++++---
> 4 files changed, 40 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index 3b81ded..905ded9 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -1719,6 +1719,7 @@ uint64_t amdgpu_ttm_tt_pte_flags(struct amdgpu_device *adev, struct ttm_tt *ttm,
> struct ttm_mem_reg *mem);
> void amdgpu_vram_location(struct amdgpu_device *adev, struct amdgpu_mc *mc, u64 base);
> void amdgpu_gtt_location(struct amdgpu_device *adev, struct amdgpu_mc *mc);
> +void amdgpu_resize_bar0(struct amdgpu_device *adev);
> void amdgpu_ttm_set_active_vram_size(struct amdgpu_device *adev, u64 size);
> int amdgpu_ttm_init(struct amdgpu_device *adev);
> void amdgpu_ttm_fini(struct amdgpu_device *adev);
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index 118f4e6..92955fe 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -692,6 +692,35 @@ void amdgpu_gtt_location(struct amdgpu_device *adev, struct amdgpu_mc *mc)
> mc->gtt_size >> 20, mc->gtt_start, mc->gtt_end);
> }
>
> +/**
> + * amdgpu_resize_bar0 - try to resize BAR0
> + *
> + * @adev: amdgpu_device pointer
> + *
> + * Try to resize BAR0 to make all VRAM CPU accessible.
> + */
> +void amdgpu_resize_bar0(struct amdgpu_device *adev)
> +{
> + u32 size = max(ilog2(adev->mc.real_vram_size - 1) + 1, 20) - 20;
> + int r;
> +
> + r = pci_resize_resource(adev->pdev, 0, size);
> +
> + if (r == -ENOTSUPP) {
> + /* The hardware don't support the extension. */
> + return;
> +
> + } else if (r == -ENOSPC) {
> + DRM_INFO("Not enoigh PCI address space for a large BAR.");
s/enoigh/enough/
> + } else if (r) {
> + DRM_ERROR("Problem resizing BAR0 (%d).", r);
> + }
> +
> + /* Reinit the doorbell mapping, it is most likely moved as well */
I think you should assume all BARs moved (I don't know how many you have;
maybe this already covers all of them).
> + amdgpu_doorbell_fini(adev);
> + BUG_ON(amdgpu_doorbell_init(adev));
I think things inside BUG_ON() tend to get overlooked, so I avoid things
that have side-effects. But that's just my personal preference.
