[PATCH v2 1/2] drm/amdgpu: Move HDP remapping earlier during init

Lazar, Lijo lijo.lazar at amd.com
Mon Sep 5 05:27:29 UTC 2022



On 9/2/2022 1:09 AM, Alex Deucher wrote:
> How about this?  We should just move HDP remap to gmc hw_init since
> that is mainly what uses it anyway.
> 

Sorry, I missed to R-B the previous version. Did you find any problem 
when common block is initialized first?

I think that patch provides a consistent IP init sequence during cold 
init and resume.

Thanks,
Lijo

> Alex
> 
> On Tue, Aug 30, 2022 at 2:05 PM Alex Deucher <alexdeucher at gmail.com> wrote:
>>
>> On Tue, Aug 30, 2022 at 12:06 PM Lazar, Lijo <lijo.lazar at amd.com> wrote:
>>>
>>>
>>>
>>> On 8/30/2022 8:39 PM, Alex Deucher wrote:
>>>> On Tue, Aug 30, 2022 at 10:45 AM Lazar, Lijo <lijo.lazar at amd.com> wrote:
>>>>>
>>>>>
>>>>>
>>>>> On 8/30/2022 7:18 PM, Alex Deucher wrote:
>>>>>> On Tue, Aug 30, 2022 at 12:05 AM Lazar, Lijo <lijo.lazar at amd.com> wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On 8/29/2022 10:20 PM, Alex Deucher wrote:
>>>>>>>> On Mon, Aug 29, 2022 at 4:18 AM Lijo Lazar <lijo.lazar at amd.com> wrote:
>>>>>>>>>
>>>>>>>>> HDP flush is used early in the init sequence as part of memory controller
>>>>>>>>> block initialization. Hence remapping of HDP registers needed for flush
>>>>>>>>> needs to happen earlier.
>>>>>>>>>
>>>>>>>>> This also fixes the Unsupported Request error reported through AER during
>>>>>>>>> driver load. The error happens as a write happens to the remap offset
>>>>>>>>> before real remapping is done.
>>>>>>>>>
>>>>>>>>> Link: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.kernel.org%2Fshow_bug.cgi%3Fid%3D216373&data=05%7C01%7Clijo.lazar%40amd.com%7C4e59ae0f8ed54aa7c5a208da8c51aa29%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637976579623485975%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=WTcd9ImY7Oba0MT6oQ7%2B7UEBkdS6azvqgYoK%2B%2F4mJPg%3D&reserved=0
>>>>>>>>>
>>>>>>>>> The error was unnoticed before and got visible because of the commit
>>>>>>>>> referenced below. This doesn't fix anything in the commit below, rather
>>>>>>>>> fixes the issue in amdgpu exposed by the commit. The reference is only
>>>>>>>>> to associate this commit with below one so that both go together.
>>>>>>>>>
>>>>>>>>> Fixes: 8795e182b02d ("PCI/portdrv: Don't disable AER reporting in get_port_device_capability()")
>>>>>>>>>
>>>>>>>>> Reported-by: Tom Seewald <tseewald at gmail.com>
>>>>>>>>> Signed-off-by: Lijo Lazar <lijo.lazar at amd.com>
>>>>>>>>> Cc: stable at vger.kernel.org
>>>>>>>>
>>>>>>>> How about something like the attached patch rather than these two
>>>>>>>> patches?  It's a bit bigger but seems cleaner and more defensive in my
>>>>>>>> opinion.
>>>>>>>>
>>>>>>>
>>>>>>> Whenever device goes to suspend/reset and then comes back, remap offset
>>>>>>> has to be set back to 0 to make sure it doesn't use the wrong offset
>>>>>>> when the register assumes default values again.
>>>>>>>
>>>>>>> To avoid the if-check in hdp_flush (which is more frequent), another way
>>>>>>> is to initialize the remap offset to default offset during early init
>>>>>>> and hw fini/suspend sequences. It won't be obvious (even with this
>>>>>>> patch) as to when remap offset vs default offset is used though.
>>>>>>
>>>>>> On resume, the common IP is resumed first so it will always be set.
>>>>>> The only case that is a problem is init because we init GMC out of
>>>>>> order.  We could init common before GMC in amdgpu_device_ip_init().  I
>>>>>> think that should be fine, but I wasn't sure if there might be some
>>>>>> fallout from that on certain cards.
>>>>>>
>>>>>
>>>>> There are other places where an IP order is forced like in
>>>>> amdgpu_device_ip_reinit_early_sriov(). This also may not affect this
>>>>> case as remapping is not done for VF.
>>>>>
>>>>> Agree that a better way is to have the common IP to be inited first.
>>>>
>>>> How about these patches?
>>>>
>>>
>>> Looks good to me. BTW, is nbio 7.7 for an APU (in which case hdp flush
>>> is not expected to be used)?
>>
>> It would be used in some cases, e.g., GPU VM passthrough where we use
>> the BAR rather than the carve out.
>>
>> Alex
>>
>>
>>>
>>> Thanks,
>>> Lijo
>>>
>>>> Alex
>>>>
>>>>
>>>>>
>>>>> Thanks,
>>>>> Lijo
>>>>>
>>>>>> Alex
>>>>>>
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Lijo
>>>>>>>
>>>>>>>> Alex
>>>>>>>>
>>>>>>>>> ---
>>>>>>>>> v2:
>>>>>>>>>             Take care of IP resume cases (Alex Deucher)
>>>>>>>>>             Add NULL check to nbio.funcs to cover older (GFXv8) ASICs (Felix Kuehling)
>>>>>>>>>             Add more details in commit message and associate with AER patch (Bjorn
>>>>>>>>> Helgaas)
>>>>>>>>>
>>>>>>>>>      drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 24 ++++++++++++++++++++++
>>>>>>>>>      drivers/gpu/drm/amd/amdgpu/nv.c            |  6 ------
>>>>>>>>>      drivers/gpu/drm/amd/amdgpu/soc15.c         |  6 ------
>>>>>>>>>      drivers/gpu/drm/amd/amdgpu/soc21.c         |  6 ------
>>>>>>>>>      4 files changed, 24 insertions(+), 18 deletions(-)
>>>>>>>>>
>>>>>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>>>>>>> index ce7d117efdb5..e420118769a5 100644
>>>>>>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>>>>>>> @@ -2334,6 +2334,26 @@ static int amdgpu_device_init_schedulers(struct amdgpu_device *adev)
>>>>>>>>>             return 0;
>>>>>>>>>      }
>>>>>>>>>
>>>>>>>>> +/**
>>>>>>>>> + * amdgpu_device_prepare_ip - prepare IPs for hardware initialization
>>>>>>>>> + *
>>>>>>>>> + * @adev: amdgpu_device pointer
>>>>>>>>> + *
>>>>>>>>> + * Any common hardware initialization sequence that needs to be done before
>>>>>>>>> + * hw init of individual IPs is performed here. This is different from the
>>>>>>>>> + * 'common block' which initializes a set of IPs.
>>>>>>>>> + */
>>>>>>>>> +static void amdgpu_device_prepare_ip(struct amdgpu_device *adev)
>>>>>>>>> +{
>>>>>>>>> +       /* Remap HDP registers to a hole in mmio space, for the purpose
>>>>>>>>> +        * of exposing those registers to process space. This needs to be
>>>>>>>>> +        * done before hw init of ip blocks to take care of HDP flush
>>>>>>>>> +        * operations through registers during hw_init.
>>>>>>>>> +        */
>>>>>>>>> +       if (adev->nbio.funcs && adev->nbio.funcs->remap_hdp_registers &&
>>>>>>>>> +           !amdgpu_sriov_vf(adev))
>>>>>>>>> +               adev->nbio.funcs->remap_hdp_registers(adev);
>>>>>>>>> +}
>>>>>>>>>
>>>>>>>>>      /**
>>>>>>>>>       * amdgpu_device_ip_init - run init for hardware IPs
>>>>>>>>> @@ -2376,6 +2396,8 @@ static int amdgpu_device_ip_init(struct amdgpu_device *adev)
>>>>>>>>>                                     DRM_ERROR("amdgpu_vram_scratch_init failed %d\n", r);
>>>>>>>>>                                     goto init_failed;
>>>>>>>>>                             }
>>>>>>>>> +
>>>>>>>>> +                       amdgpu_device_prepare_ip(adev);
>>>>>>>>>                             r = adev->ip_blocks[i].version->funcs->hw_init((void *)adev);
>>>>>>>>>                             if (r) {
>>>>>>>>>                                     DRM_ERROR("hw_init %d failed %d\n", i, r);
>>>>>>>>> @@ -3058,6 +3080,7 @@ static int amdgpu_device_ip_reinit_early_sriov(struct amdgpu_device *adev)
>>>>>>>>>                     AMD_IP_BLOCK_TYPE_IH,
>>>>>>>>>             };
>>>>>>>>>
>>>>>>>>> +       amdgpu_device_prepare_ip(adev);
>>>>>>>>>             for (i = 0; i < adev->num_ip_blocks; i++) {
>>>>>>>>>                     int j;
>>>>>>>>>                     struct amdgpu_ip_block *block;
>>>>>>>>> @@ -3139,6 +3162,7 @@ static int amdgpu_device_ip_resume_phase1(struct amdgpu_device *adev)
>>>>>>>>>      {
>>>>>>>>>             int i, r;
>>>>>>>>>
>>>>>>>>> +       amdgpu_device_prepare_ip(adev);
>>>>>>>>>             for (i = 0; i < adev->num_ip_blocks; i++) {
>>>>>>>>>                     if (!adev->ip_blocks[i].status.valid || adev->ip_blocks[i].status.hw)
>>>>>>>>>                             continue;
>>>>>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/nv.c b/drivers/gpu/drm/amd/amdgpu/nv.c
>>>>>>>>> index b3fba8dea63c..3ac7fef74277 100644
>>>>>>>>> --- a/drivers/gpu/drm/amd/amdgpu/nv.c
>>>>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/nv.c
>>>>>>>>> @@ -1032,12 +1032,6 @@ static int nv_common_hw_init(void *handle)
>>>>>>>>>             nv_program_aspm(adev);
>>>>>>>>>             /* setup nbio registers */
>>>>>>>>>             adev->nbio.funcs->init_registers(adev);
>>>>>>>>> -       /* remap HDP registers to a hole in mmio space,
>>>>>>>>> -        * for the purpose of expose those registers
>>>>>>>>> -        * to process space
>>>>>>>>> -        */
>>>>>>>>> -       if (adev->nbio.funcs->remap_hdp_registers && !amdgpu_sriov_vf(adev))
>>>>>>>>> -               adev->nbio.funcs->remap_hdp_registers(adev);
>>>>>>>>>             /* enable the doorbell aperture */
>>>>>>>>>             nv_enable_doorbell_aperture(adev, true);
>>>>>>>>>
>>>>>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/soc15.c b/drivers/gpu/drm/amd/amdgpu/soc15.c
>>>>>>>>> index fde6154f2009..a0481e37d7cf 100644
>>>>>>>>> --- a/drivers/gpu/drm/amd/amdgpu/soc15.c
>>>>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/soc15.c
>>>>>>>>> @@ -1240,12 +1240,6 @@ static int soc15_common_hw_init(void *handle)
>>>>>>>>>             soc15_program_aspm(adev);
>>>>>>>>>             /* setup nbio registers */
>>>>>>>>>             adev->nbio.funcs->init_registers(adev);
>>>>>>>>> -       /* remap HDP registers to a hole in mmio space,
>>>>>>>>> -        * for the purpose of expose those registers
>>>>>>>>> -        * to process space
>>>>>>>>> -        */
>>>>>>>>> -       if (adev->nbio.funcs->remap_hdp_registers && !amdgpu_sriov_vf(adev))
>>>>>>>>> -               adev->nbio.funcs->remap_hdp_registers(adev);
>>>>>>>>>
>>>>>>>>>             /* enable the doorbell aperture */
>>>>>>>>>             soc15_enable_doorbell_aperture(adev, true);
>>>>>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/soc21.c b/drivers/gpu/drm/amd/amdgpu/soc21.c
>>>>>>>>> index 55284b24f113..16b447055102 100644
>>>>>>>>> --- a/drivers/gpu/drm/amd/amdgpu/soc21.c
>>>>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/soc21.c
>>>>>>>>> @@ -660,12 +660,6 @@ static int soc21_common_hw_init(void *handle)
>>>>>>>>>             soc21_program_aspm(adev);
>>>>>>>>>             /* setup nbio registers */
>>>>>>>>>             adev->nbio.funcs->init_registers(adev);
>>>>>>>>> -       /* remap HDP registers to a hole in mmio space,
>>>>>>>>> -        * for the purpose of expose those registers
>>>>>>>>> -        * to process space
>>>>>>>>> -        */
>>>>>>>>> -       if (adev->nbio.funcs->remap_hdp_registers)
>>>>>>>>> -               adev->nbio.funcs->remap_hdp_registers(adev);
>>>>>>>>>             /* enable the doorbell aperture */
>>>>>>>>>             soc21_enable_doorbell_aperture(adev, true);
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>> 2.25.1
>>>>>>>>>


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