Re: [PATCH 2/2] drm/amdgpu: check the GART table before invalidating TLB

["Christian König" <christian.koenig@amd.com>]

Am 07.02.22 um 07:30 schrieb Huang Rui:
> On Mon, Feb 07, 2022 at 10:41:55AM +0800, Liu, Aaron wrote:
>> Bypass group programming (utcl2_harvest) aims to forbid UTCL2 to send
>> invalidation command to harvested SE/SA. Once invalidation command comes
>> into harvested SE/SA, SE/SA has no response and system hang.
>>
>> This patch is to add checking if the GART table is already allocated before
>> invalidating TLB. The new procedure is as following:
>> 1. Calling amdgpu_gtt_mgr_init() in amdgpu_ttm_init(). After this step GTT
>>     BOs can be allocated, but GART mappings are still ignored.
>> 2. Calling amdgpu_gart_table_vram_alloc() from the GMC code. This allocates
>>     the GART backing store.
>> 3. Initializing the hardware, and programming the backing store into VMID0
>>     for all VMHUBs.
>> 4. Calling amdgpu_gtt_mgr_recover() to make sure the table is updated with
>>     the GTT allocations done before it was allocated.
>>
>> Signed-off-by: Christian König <christian.koenig@amd.com>
>> Signed-off-by: Aaron Liu <aaron.liu@amd.com>
> Acked-by: Huang Rui <ray.huang@amd.com>

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

>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
>> index 91d8207336c1..01cb89ffbd56 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
>> @@ -259,6 +259,9 @@ void amdgpu_gart_invalidate_tlb(struct amdgpu_device *adev)
>>   {
>>   	int i;
>>   
>> +	if (!adev->gart.ptr)
>> +		return;
>> +
>>   	mb();
>>   	amdgpu_device_flush_hdp(adev, NULL);
>>   	for (i = 0; i < adev->num_vmhubs; i++)
>> -- 
>> 2.25.1
>>