[Intel-xe] [RFC v2 3/6] drm/xe/xe2: Allocate extra pages for ccs during bo create.

[Thomas Hellström]

On 11/27/23 04:19, Ghimiray, Himal Prasad wrote:
>
>
> On 24-11-2023 16:39, Thomas Hellström wrote:
>> On Tue, 2023-11-21 at 15:39 +0530, Himal Prasad Ghimiray wrote:
>>> Each byte of CCS data now represents 512 bytes of main memory data.
>>> Allocate extra pages to handle ccs region for igfx too.
>>>
>>> Bspec:58796
>>>
>>> Cc: Thomas Hellström<thomas.hellstrom at linux.intel.com>
>>> Signed-off-by: Himal Prasad Ghimiray
>>> <himal.prasad.ghimiray at intel.com>
>>> ---
>>>   drivers/gpu/drm/xe/regs/xe_gpu_commands.h |  2 +-
>>>   drivers/gpu/drm/xe/xe_bo.c                | 15 ++++++---------
>>>   drivers/gpu/drm/xe/xe_device.c            |  2 +-
>>>   3 files changed, 8 insertions(+), 11 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/xe/regs/xe_gpu_commands.h
>>> b/drivers/gpu/drm/xe/regs/xe_gpu_commands.h
>>> index 4402f72481dc..7f74592f99ce 100644
>>> --- a/drivers/gpu/drm/xe/regs/xe_gpu_commands.h
>>> +++ b/drivers/gpu/drm/xe/regs/xe_gpu_commands.h
>>> @@ -16,7 +16,7 @@
>>>   #define   XY_CTRL_SURF_MOCS_MASK       GENMASK(31, 26)
>>>   #define   XE2_XY_CTRL_SURF_MOCS_INDEX_MASK     GENMASK(31, 28)
>>>   #define   NUM_CCS_BYTES_PER_BLOCK      256
>>> -#define   NUM_BYTES_PER_CCS_BYTE       256
>>> +#define   NUM_BYTES_PER_CCS_BYTE(_xe)  (GRAPHICS_VER(_xe) >= 20 ?
>>> 512 : 256)
>>>   #define   NUM_CCS_BLKS_PER_XFER                1024
>>>   
>>>   #define XY_FAST_COLOR_BLT_CMD          (2 << 29 | 0x44 << 22)
>>> diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
>>> index 4305f5cbc2ab..4730ee3c1012 100644
>>> --- a/drivers/gpu/drm/xe/xe_bo.c
>>> +++ b/drivers/gpu/drm/xe/xe_bo.c
>>> @@ -2074,19 +2074,16 @@ int xe_bo_evict(struct xe_bo *bo, bool
>>> force_alloc)
>>>    * placed in system memory.
>>>    * @bo: The xe_bo
>>>    *
>>> - * If a bo has an allowable placement in XE_PL_TT memory, it can't
>>> use
>>> - * flat CCS compression, because the GPU then has no way to access
>>> the
>>> - * CCS metadata using relevant commands. For the opposite case, we
>>> need to
>>> - * allocate storage for the CCS metadata when the BO is not resident
>>> in
>>> - * VRAM memory.
>> Please extend modify this comment rather than deleting it
> Sure. Will address in next patch.
>>> - *
>>>    * Return: true if extra pages need to be allocated, false
>>> otherwise.
>>>    */
>>>   bool xe_bo_needs_ccs_pages(struct xe_bo *bo)
>>>   {
>>> -       return bo->ttm.type == ttm_bo_type_device &&
>>> -               !(bo->flags & XE_BO_CREATE_SYSTEM_BIT) &&
>>> -               (bo->flags & XE_BO_CREATE_VRAM_MASK);
>>> +       struct xe_device *xe = xe_bo_device(bo);
>>> +
>>> +       return (xe_device_has_flat_ccs(xe) &&
>>> +               bo->ttm.type == ttm_bo_type_device &&
>>> +               ((IS_DGFX(xe) && (bo->flags &
>>> XE_BO_CREATE_VRAM_MASK)) ||
>> It looks like you have removed a restriction for DGFX here: If the BO
>> has SYSTEM set, then ccs pages are not needed.
>
> Is ((IS_DGFX(xe) && (bo->flags & XE_BO_CREATE_VRAM_MASK)) not suffice 
> to ensure
>
> that for DGFX BO is only in VRAM region ?
>
No. It can also has the the CREATE_SYSTEM_BIT set, and then the content 
can't be compressed.

/Thomas



>>> +               (!IS_DGFX(xe) && (bo->flags &
>>> XE_BO_CREATE_SYSTEM_BIT))));
>>>   }
>>>   
>>>   /**
>>> diff --git a/drivers/gpu/drm/xe/xe_device.c
>>> b/drivers/gpu/drm/xe/xe_device.c
>>> index 07a3e4cf48d1..265f9ffc5323 100644
>>> --- a/drivers/gpu/drm/xe/xe_device.c
>>> +++ b/drivers/gpu/drm/xe/xe_device.c
>>> @@ -551,7 +551,7 @@ void xe_device_wmb(struct xe_device *xe)
>>>   u32 xe_device_ccs_bytes(struct xe_device *xe, u64 size)
>>>   {
>>>          return xe_device_has_flat_ccs(xe) ?
>>> -               DIV_ROUND_UP(size, NUM_BYTES_PER_CCS_BYTE) : 0;
>>> +               DIV_ROUND_UP(size, NUM_BYTES_PER_CCS_BYTE(xe)) : 0;
>>>   }
>>>   
>>>   bool xe_device_mem_access_ongoing(struct xe_device *xe)
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