[PATCH] drm/ttm: revert "make TT creation purely optional v3"

[Christian König]

Am 11.08.20 um 14:52 schrieb Christian König:
> Am 11.08.20 um 11:24 schrieb Christian König:
>> This reverts commit 2ddef17678bc2ea1d20517dd2b4ed4aa967ffa8b.
>>
>> As it turned out VMWGFX needs a much wider audit to fix this.
>>
>> Signed-off-by: Christian König <christian.koenig at amd.com>
>
> Dare to give me an rb for this? I already tested on amdgpu and it 
> should be fixing the VMWGFX problems we currently have.

Ups, that was your old AMD address :)

So once more with feeling,
Christian.

>
> Thanks,
> Christian.
>
>> ---
>>   drivers/gpu/drm/ttm/ttm_bo.c      | 19 ++++++++++++++++---
>>   drivers/gpu/drm/ttm/ttm_bo_util.c |  7 ++-----
>>   drivers/gpu/drm/ttm/ttm_bo_vm.c   |  5 -----
>>   drivers/gpu/drm/ttm/ttm_tt.c      |  1 +
>>   4 files changed, 19 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
>> index ad09329b62d3..42386bda32fe 100644
>> --- a/drivers/gpu/drm/ttm/ttm_bo.c
>> +++ b/drivers/gpu/drm/ttm/ttm_bo.c
>> @@ -656,7 +656,7 @@ static int ttm_bo_evict(struct ttm_buffer_object 
>> *bo,
>>           ttm_bo_wait(bo, false, false);
>>             ttm_bo_cleanup_memtype_use(bo);
>> -        return 0;
>> +        return ttm_tt_create(bo, false);
>>       }
>>         evict_mem = bo->mem;
>> @@ -1191,8 +1191,13 @@ int ttm_bo_validate(struct ttm_buffer_object *bo,
>>       /*
>>        * Remove the backing store if no placement is given.
>>        */
>> -    if (!placement->num_placement && !placement->num_busy_placement)
>> -        return ttm_bo_pipeline_gutting(bo);
>> +    if (!placement->num_placement && !placement->num_busy_placement) {
>> +        ret = ttm_bo_pipeline_gutting(bo);
>> +        if (ret)
>> +            return ret;
>> +
>> +        return ttm_tt_create(bo, false);
>> +    }
>>         /*
>>        * Check whether we need to move buffer.
>> @@ -1209,6 +1214,14 @@ int ttm_bo_validate(struct ttm_buffer_object *bo,
>>           ttm_flag_masked(&bo->mem.placement, new_flags,
>>                   ~TTM_PL_MASK_MEMTYPE);
>>       }
>> +    /*
>> +     * We might need to add a TTM.
>> +     */
>> +    if (bo->mem.mem_type == TTM_PL_SYSTEM && bo->ttm == NULL) {
>> +        ret = ttm_tt_create(bo, true);
>> +        if (ret)
>> +            return ret;
>> +    }
>>       return 0;
>>   }
>>   EXPORT_SYMBOL(ttm_bo_validate);
>> diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c 
>> b/drivers/gpu/drm/ttm/ttm_bo_util.c
>> index 496158acd5b9..76376dc71f25 100644
>> --- a/drivers/gpu/drm/ttm/ttm_bo_util.c
>> +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
>> @@ -531,15 +531,12 @@ static int ttm_bo_kmap_ttm(struct 
>> ttm_buffer_object *bo,
>>           .interruptible = false,
>>           .no_wait_gpu = false
>>       };
>> -    struct ttm_tt *ttm;
>> +    struct ttm_tt *ttm = bo->ttm;
>>       pgprot_t prot;
>>       int ret;
>>   -    ret = ttm_tt_create(bo, true);
>> -    if (ret)
>> -        return ret;
>> +    BUG_ON(!ttm);
>>   -    ttm = bo->ttm;
>>       ret = ttm_tt_populate(ttm, &ctx);
>>       if (ret)
>>           return ret;
>> diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c 
>> b/drivers/gpu/drm/ttm/ttm_bo_vm.c
>> index ba2e8bd198ad..e90c5c806645 100644
>> --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
>> +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
>> @@ -347,11 +347,6 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct 
>> vm_fault *vmf,
>>             };
>>   -        if (ttm_tt_create(bo, true)) {
>> -            ret = VM_FAULT_OOM;
>> -            goto out_io_unlock;
>> -        }
>> -
>>           ttm = bo->ttm;
>>           if (ttm_tt_populate(bo->ttm, &ctx)) {
>>               ret = VM_FAULT_OOM;
>> diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
>> index bdd6169cef13..05c9147ac6d3 100644
>> --- a/drivers/gpu/drm/ttm/ttm_tt.c
>> +++ b/drivers/gpu/drm/ttm/ttm_tt.c
>> @@ -70,6 +70,7 @@ int ttm_tt_create(struct ttm_buffer_object *bo, 
>> bool zero_alloc)
>>           page_flags |= TTM_PAGE_FLAG_SG;
>>           break;
>>       default:
>> +        bo->ttm = NULL;
>>           pr_err("Illegal buffer object type\n");
>>           return -EINVAL;
>>       }
>