[PATCH v1 1/2] drm/amdgpu: save the reset dump register value for devcoredump

[Somalapuram, Amaranath]

On 5/20/2022 7:36 PM, Sharma, Shashank wrote:
> Hey Amar,
>
> On 5/20/2022 3:49 PM, Somalapuram Amaranath wrote:
>> Allocate memory for register value and use the same values for 
>> devcoredump.
>> Remove dump_stack reset register dumps.
>>
>> Signed-off-by: Somalapuram Amaranath <Amaranath.Somalapuram at amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu.h         | 1 +
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 9 ++++++++-
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c  | 7 +++----
>>   3 files changed, 12 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>> index 76df583663c7..c79d9992b113 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>> @@ -1042,6 +1042,7 @@ struct amdgpu_device {
>>         /* reset dump register */
>>       uint32_t                        *reset_dump_reg_list;
>> +    uint32_t            *reset_dump_reg_value;
>>       int                             num_regs;
>>         struct amdgpu_reset_domain    *reset_domain;
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
>> index eedb12f6b8a3..942fdbd316f4 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
>> @@ -1683,7 +1683,7 @@ static ssize_t 
>> amdgpu_reset_dump_register_list_write(struct file *f,
>>   {
>>       struct amdgpu_device *adev = (struct amdgpu_device 
>> *)file_inode(f)->i_private;
>>       char reg_offset[11];
>> -    uint32_t *new, *tmp = NULL;
>> +    uint32_t *new, *tmp = NULL, *tmp_value = NULL;
>>       int ret, i = 0, len = 0;
>>         do {
>> @@ -1709,17 +1709,24 @@ static ssize_t 
>> amdgpu_reset_dump_register_list_write(struct file *f,
>>           i++;
>>       } while (len < size);
>>   +    new = krealloc_array(tmp_value, i, sizeof(uint32_t), GFP_KERNEL);
>
> tmp_value is initialized to NULL, which means krealloc_array() will 
> behave like kmalloc_array(), is there any particular reason we are 
> adding this variable at all just to use krealloc_array(), and why not 
> use kmalloc_array() directly ?

I thought of using kmalloc_array() (got little confused on next write 
cycle), I agree to use kmalloc_array().

Regards,
S.Amarnath
>
>> +    if (!new) {
>> +        ret = -ENOMEM;
>> +        goto error_free;
>> +    }
>>       ret = down_write_killable(&adev->reset_domain->sem);
>>       if (ret)
>>           goto error_free;
>>         swap(adev->reset_dump_reg_list, tmp);
>> +    swap(adev->reset_dump_reg_value, new);
>>       adev->num_regs = i;
>>       up_write(&adev->reset_domain->sem);
>>       ret = size;
>>     error_free:
>>       kfree(tmp);
>> +    kfree(new);
>>       return ret;
>>   }
>>   diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> index 4daa0e893965..963c897a76e6 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> @@ -4720,15 +4720,14 @@ int amdgpu_device_pre_asic_reset(struct 
>> amdgpu_device *adev,
>>     static int amdgpu_reset_reg_dumps(struct amdgpu_device *adev)
>>   {
>> -    uint32_t reg_value;
>>       int i;
>>         lockdep_assert_held(&adev->reset_domain->sem);
>> -    dump_stack();
> This should be a part of different patch, where you can give some 
> background on why are we removing this.
>>         for (i = 0; i < adev->num_regs; i++) {
>> -        reg_value = RREG32(adev->reset_dump_reg_list[i]);
>> - trace_amdgpu_reset_reg_dumps(adev->reset_dump_reg_list[i], reg_value);
>> +        adev->reset_dump_reg_value[i] = 
>> RREG32(adev->reset_dump_reg_list[i]);
>> + trace_amdgpu_reset_reg_dumps(adev->reset_dump_reg_list[i],
>> +                adev->reset_dump_reg_value[i]);
>>       }
>>         return 0;
>
> - Shashank