Re: [PATCH v7 2/9] drm/i915/gt: Use XY_FAST_COLOR_BLT to clear obj on graphics ver 12+

["Thomas Hellström" <thomas.hellstrom@linux.intel.com>]

On Tue, 2022-03-29 at 00:37 +0530, Ramalingam C wrote:
> Use faster XY_FAST_COLOR_BLT cmd on graphics version of 12 and more,
> for clearing (Zero out) the pages of the newly allocated object.
> 
> XY_FAST_COLOR_BLT is faster than the older XY_COLOR_BLT.
> 
> v2:
>   Typo fix at title [Thomas]
> v3:
>   XY_FAST_COLOR_BLT is used only for FLAT_CCS capable gen12+

Hm. It's a huge benefit also for DG1. But we can do that as a follow up
patch.

> 
> Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> Reviewed-by: Thomas Hellstrom <thomas.hellstrom@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/gt/intel_gpu_commands.h |  5 +++
>  drivers/gpu/drm/i915/gt/intel_migrate.c      | 43 +++++++++++++++++-
> --
>  2 files changed, 43 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gt/intel_gpu_commands.h
> b/drivers/gpu/drm/i915/gt/intel_gpu_commands.h
> index d112ffd56418..925e55b6a94f 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gpu_commands.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gpu_commands.h
> @@ -205,6 +205,11 @@
>  
>  #define COLOR_BLT_CMD                  (2 << 29 | 0x40 << 22 | (5 -
> 2))
>  #define XY_COLOR_BLT_CMD               (2 << 29 | 0x50 << 22)
> +#define XY_FAST_COLOR_BLT_CMD          (2 << 29 | 0x44 << 22)
> +#define   XY_FAST_COLOR_BLT_DEPTH_32   (2 << 19)
> +#define   XY_FAST_COLOR_BLT_DW         16
> +#define   XY_FAST_COLOR_BLT_MOCS_MASK  GENMASK(27, 21)
> +#define   XY_FAST_COLOR_BLT_MEM_TYPE_SHIFT 31
>  #define SRC_COPY_BLT_CMD               (2 << 29 | 0x43 << 22)
>  #define GEN9_XY_FAST_COPY_BLT_CMD      (2 << 29 | 0x42 << 22)
>  #define XY_SRC_COPY_BLT_CMD            (2 << 29 | 0x53 << 22)
> diff --git a/drivers/gpu/drm/i915/gt/intel_migrate.c
> b/drivers/gpu/drm/i915/gt/intel_migrate.c
> index 9e6c98a17441..17dd372a47d1 100644
> --- a/drivers/gpu/drm/i915/gt/intel_migrate.c
> +++ b/drivers/gpu/drm/i915/gt/intel_migrate.c
> @@ -614,18 +614,51 @@ intel_context_migrate_copy(struct intel_context
> *ce,
>         return err;
>  }
>  
> -static int emit_clear(struct i915_request *rq, u32 offset, int size,
> u32 value)
> +static int emit_clear(struct i915_request *rq, u32 offset, int size,
> +                     u32 value, bool is_lmem)
>  {
> -       const int ver = GRAPHICS_VER(rq->engine->i915);
> +       struct drm_i915_private *i915 = rq->engine->i915;
> +       int mocs = rq->engine->gt->mocs.uc_index << 1;
> +       const int ver = GRAPHICS_VER(i915);
> +       int ring_sz;
>         u32 *cs;
>  
>         GEM_BUG_ON(size >> PAGE_SHIFT > S16_MAX);
>  
> -       cs = intel_ring_begin(rq, ver >= 8 ? 8 : 6);
> +       if (HAS_FLAT_CCS(i915) && ver >= 12)
> +               ring_sz = XY_FAST_COLOR_BLT_DW;
> +       else if (ver >= 8)
> +               ring_sz = 8;
> +       else
> +               ring_sz = 6;
> +
> +       cs = intel_ring_begin(rq, ring_sz);
>         if (IS_ERR(cs))
>                 return PTR_ERR(cs);
>  
> -       if (ver >= 8) {
> +       if (HAS_FLAT_CCS(i915) && ver >= 12) {
> +               *cs++ = XY_FAST_COLOR_BLT_CMD |
> XY_FAST_COLOR_BLT_DEPTH_32 |
> +                       (XY_FAST_COLOR_BLT_DW - 2);
> +               *cs++ = FIELD_PREP(XY_FAST_COLOR_BLT_MOCS_MASK, mocs)
> |
> +                       (PAGE_SIZE - 1);
> +               *cs++ = 0;
> +               *cs++ = size >> PAGE_SHIFT << 16 | PAGE_SIZE / 4;
> +               *cs++ = offset;
> +               *cs++ = rq->engine->instance;
> +               *cs++ = !is_lmem << XY_FAST_COLOR_BLT_MEM_TYPE_SHIFT;
> +               /* BG7 */
> +               *cs++ = value;
> +               *cs++ = 0;
> +               *cs++ = 0;
> +               *cs++ = 0;
> +               /* BG11 */
> +               *cs++ = 0;
> +               *cs++ = 0;
> +               /* BG13 */
> +               *cs++ = 0;
> +               *cs++ = 0;
> +               *cs++ = 0;
> +       } else if (ver >= 8) {
>                 *cs++ = XY_COLOR_BLT_CMD | BLT_WRITE_RGBA | (7 - 2);
>                 *cs++ = BLT_DEPTH_32 | BLT_ROP_COLOR_COPY |
> PAGE_SIZE;
>                 *cs++ = 0;
> @@ -708,7 +741,7 @@ intel_context_migrate_clear(struct intel_context
> *ce,
>                 if (err)
>                         goto out_rq;
>  
> -               err = emit_clear(rq, offset, len, value);
> +               err = emit_clear(rq, offset, len, value, is_lmem);
>  
>                 /* Arbitration is re-enabled between requests. */
>  out_rq: