[PATCH 03/14] drm/i915/xehpsdv: enforce min GTT alignment

[Matthew Auld]

On 13/10/2021 14:38, Daniel Vetter wrote:
> On Mon, Oct 11, 2021 at 09:41:44PM +0530, Ramalingam C wrote:
>> From: Matthew Auld <matthew.auld at intel.com>
>>
>> For local-memory objects we need to align the GTT addresses to 64K, both
>> for the ppgtt and ggtt.
>>
>> Signed-off-by: Matthew Auld <matthew.auld at intel.com>
>> Signed-off-by: Stuart Summers <stuart.summers at intel.com>
>> Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
>> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
>> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> 
> Do we still need this with relocations removed? Userspace is picking all
> the addresses for us, so all we have to check is whether userspace got it
> right.

Yeah, for OFFSET_FIXED this just validates that the provided address is 
correctly aligned to 64K, while for the in-kernel insertion stuff we 
still need to allocate an address that is aligned to 64K. Setting the 
alignment here handles both cases.

> -Daniel
> 
> 
>> ---
>>   drivers/gpu/drm/i915/i915_vma.c | 9 +++++++--
>>   1 file changed, 7 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
>> index 4b7fc4647e46..1ea1fa08efdf 100644
>> --- a/drivers/gpu/drm/i915/i915_vma.c
>> +++ b/drivers/gpu/drm/i915/i915_vma.c
>> @@ -670,8 +670,13 @@ i915_vma_insert(struct i915_vma *vma, u64 size, u64 alignment, u64 flags)
>>   	}
>>   
>>   	color = 0;
>> -	if (vma->obj && i915_vm_has_cache_coloring(vma->vm))
>> -		color = vma->obj->cache_level;
>> +	if (vma->obj) {
>> +		if (HAS_64K_PAGES(vma->vm->i915) && i915_gem_object_is_lmem(vma->obj))
>> +			alignment = max(alignment, I915_GTT_PAGE_SIZE_64K);
>> +
>> +		if (i915_vm_has_cache_coloring(vma->vm))
>> +			color = vma->obj->cache_level;
>> +	}
>>   
>>   	if (flags & PIN_OFFSET_FIXED) {
>>   		u64 offset = flags & PIN_OFFSET_MASK;
>> -- 
>> 2.20.1
>>
>