Re: [Intel-gfx] [PATCH] gen8_ppgtt: Use correct huge page manager for MTL

[Matthew Auld <matthew.auld@intel.com>]

On 21/02/2023 16:06, Matthew Auld wrote:
> On 17/02/2023 19:18, Jonathan Cavitt wrote:
>> MTL currently uses gen8_ppgtt_insert_huge when managing huge pages.  
>> This is because
>> MTL reports as not supporting 64K pages, or more accurately, the 
>> system that reports
>> whether a platform has 64K pages reports false for MTL.  This is only 
>> half correct,
>> as the 64K page support reporting system only cares about 64K page 
>> support for LMEM,
>> which MTL doesn't have.
>>
>> MTL should be using xehpsdv_ppgtt_insert_huge.  However, simply 
>> changing over to
>> using that manager doesn't resolve the issue because MTL is expecting 
>> the virtual
>> address space for the page table to be flushed after initialization, 
>> so we must also
>> add a flush statement there.
>>
>> Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
> Reviewed-by: Matthew Auld <matthew.auld@intel.com>

Also make sure we use "drm/i915:" prefix for commit title.

> 
> Although it looks like the hugepage mock tests are failing with this. I 
> assume the mock device just uses some "max" gen version or so, which now 
> triggers this path. Any ideas for that?
> 
>> ---
>>   drivers/gpu/drm/i915/gt/gen8_ppgtt.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c 
>> b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
>> index 4daaa6f55668..9c571185395f 100644
>> --- a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
>> +++ b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
>> @@ -570,6 +570,7 @@ xehpsdv_ppgtt_insert_huge(struct 
>> i915_address_space *vm,
>>               }
>>           } while (rem >= page_size && index < max);
>> +        drm_clflush_virt_range(vaddr, PAGE_SIZE);
>>           vma_res->page_sizes_gtt |= page_size;
>>       } while (iter->sg && sg_dma_len(iter->sg));
>>   }
>> @@ -707,7 +708,7 @@ static void gen8_ppgtt_insert(struct 
>> i915_address_space *vm,
>>       struct sgt_dma iter = sgt_dma(vma_res);
>>       if (vma_res->bi.page_sizes.sg > I915_GTT_PAGE_SIZE) {
>> -        if (HAS_64K_PAGES(vm->i915))
>> +        if (GRAPHICS_VER_FULL(vm->i915) >= IP_VER(12, 50))
>>               xehpsdv_ppgtt_insert_huge(vm, vma_res, &iter, 
>> cache_level, flags);
>>           else
>>               gen8_ppgtt_insert_huge(vm, vma_res, &iter, cache_level, 
>> flags);