[Intel-gfx] [PATCH 4/6] drm/i915/gt: Refactor _wa_add to reuse wa_index and wa_list_grow

[Tvrtko Ursulin]

On 12/11/2020 19:44, Chris Wilson wrote:
> Quoting Umesh Nerlige Ramappa (2020-10-10 01:21:03)
>> Switch the search and grow code of the _wa_add to use _wa_index and
>> _wa_list_grow.
>>
>> Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
>> ---
>>   drivers/gpu/drm/i915/gt/intel_workarounds.c | 54 +++++++--------------
>>   1 file changed, 17 insertions(+), 37 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
>> index 801fcb60f46b..e49283bffa33 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
>> +++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
>> @@ -174,53 +174,33 @@ static void _wa_remove(struct i915_wa_list *wal, i915_reg_t reg, u32 flags)
>>   
>>   static void _wa_add(struct i915_wa_list *wal, const struct i915_wa *wa)
>>   {
>> -       unsigned int addr = i915_mmio_reg_offset(wa->reg);
>> -       unsigned int start = 0, end = wal->count;
>> +       int index;
>>          const unsigned int grow = WA_LIST_CHUNK;
>>          struct i915_wa *wa_;
>>   
>>          GEM_BUG_ON(!is_power_of_2(grow));
>>   
>> -       if (IS_ALIGNED(wal->count, grow)) { /* Either uninitialized or full. */
>> -               struct i915_wa *list;
>> -
>> -               list = kmalloc_array(ALIGN(wal->count + 1, grow), sizeof(*wa),
>> -                                    GFP_KERNEL);
>> -               if (!list) {
>> -                       DRM_ERROR("No space for workaround init!\n");
>> +       if (IS_ALIGNED(wal->count, grow)) /* Either uninitialized or full. */
>> +               if (_wa_list_grow(wal, wal->count) < 0)
>>                          return;
>> -               }
>> -
>> -               if (wal->list)
>> -                       memcpy(list, wal->list, sizeof(*wa) * wal->count);
>>   
>> -               wal->list = list;
> 
> An inherited problem, but I'm a little unnerved by the apparent leak of
> wa->list here.
> 
> Paging Tvrtko to see if he can remember if there's a hidden trick.

I don't see any tricks, just a memory leak for all lists with more than 
16 unique registers on the wa list. :(

Regards,

Tvrtko