[PATCH] drm/amdgpu: Fix huge page updates with CPU

[Christian König]

Am 18.08.2017 um 17:18 schrieb Felix Kuehling:
> Correctly detect system memory mappings when using CPU and don't use
> huge pages for them.
>
> Avoid incorrectly translating a physical page table GPU address when
> splitting a huge page while mapping system memory.
>
> Signed-off-by: Felix Kuehling <Felix.Kuehling at amd.com>

Reviewed-by: Christian König <christian.koenig at amd.com>

> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 16 +++++++++++++++-
>   1 file changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index 02c64d28..2015bbf 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -1276,7 +1276,7 @@ static void amdgpu_vm_handle_huge_pages(struct amdgpu_pte_update_params *p,
>   	/* In the case of a mixed PT the PDE must point to it*/
>   	if (p->adev->asic_type < CHIP_VEGA10 ||
>   	    nptes != AMDGPU_VM_PTE_COUNT(p->adev) ||
> -	    p->func == amdgpu_vm_do_copy_ptes ||
> +	    p->src ||
>   	    !(flags & AMDGPU_PTE_VALID)) {
>   
>   		dst = amdgpu_bo_gpu_offset(entry->bo);
> @@ -1293,9 +1293,23 @@ static void amdgpu_vm_handle_huge_pages(struct amdgpu_pte_update_params *p,
>   	entry->addr = (dst | flags);
>   
>   	if (use_cpu_update) {
> +		/* In case a huge page is replaced with a system
> +		 * memory mapping, p->pages_addr != NULL and
> +		 * amdgpu_vm_cpu_set_ptes would try to translate dst
> +		 * through amdgpu_vm_map_gart. But dst is already a
> +		 * GPU address (of the page table). Disable
> +		 * amdgpu_vm_map_gart temporarily.
> +		 */
> +		dma_addr_t *tmp;
> +
> +		tmp = p->pages_addr;
> +		p->pages_addr = NULL;
> +
>   		pd_addr = (unsigned long)amdgpu_bo_kptr(parent->bo);
>   		pde = pd_addr + (entry - parent->entries) * 8;
>   		amdgpu_vm_cpu_set_ptes(p, pde, dst, 1, 0, flags);
> +
> +		p->pages_addr = tmp;
>   	} else {
>   		if (parent->bo->shadow) {
>   			pd_addr = amdgpu_bo_gpu_offset(parent->bo->shadow);