When trying to understand our PPAT table definition I noticed that pat_sel is composed by: PAT - Bit 7 of PTE PCD - Bit 4 of PTE (Cache disabled) PWT - Bit 3 of PTE (Write through)
So it seems 010 should indicate Uncached while 011 should indicate Write Through But we are currently doing Index 2 WT for scanout with eLLC Index 3 UC fr uncached objects, mostly for scanout. This patch shouldn't have any real impact because it just change the internal mapping PTE to PAT in a way that makes more sense of Mapping PCD and PWT bits. Cc: Chris Wilson <[email protected]> Cc: Ben Widawsky <[email protected]> Signed-off-by: Rodrigo Vivi <[email protected]> --- drivers/gpu/drm/i915/i915_gem_gtt.c | 4 ++-- drivers/gpu/drm/i915/i915_gem_gtt.h | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index df9f71e..f153cd9 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -2652,8 +2652,8 @@ static void bdw_setup_private_ppat(struct drm_i915_private *dev_priv) pat = GEN8_PPAT(0, GEN8_PPAT_WB | GEN8_PPAT_LLC) | /* for normal objects, no eLLC */ GEN8_PPAT(1, GEN8_PPAT_WC | GEN8_PPAT_LLCELLC) | /* for something pointing to ptes? */ - GEN8_PPAT(2, GEN8_PPAT_WT | GEN8_PPAT_LLCELLC) | /* for scanout with eLLC */ - GEN8_PPAT(3, GEN8_PPAT_UC) | /* Uncached objects, mostly for scanout */ + GEN8_PPAT(2, GEN8_PPAT_UC) | /* Uncached objects, mostly for scanout */ + GEN8_PPAT(3, GEN8_PPAT_WT | GEN8_PPAT_LLCELLC) | /* for scanout with eLLC */ GEN8_PPAT(4, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(0)) | GEN8_PPAT(5, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(1)) | GEN8_PPAT(6, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(2)) | diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h index f7d4e19..2d831ae 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.h +++ b/drivers/gpu/drm/i915/i915_gem_gtt.h @@ -128,10 +128,10 @@ #define I915_PDPES_PER_PDP(dev_priv) (USES_FULL_48BIT_PPGTT(dev_priv) ?\ GEN8_PML4ES_PER_PML4 : GEN8_LEGACY_PDPES) -#define PPAT_UNCACHED_INDEX (_PAGE_PWT | _PAGE_PCD) +#define PPAT_UNCACHED_INDEX _PAGE_PCD #define PPAT_CACHED_PDE_INDEX 0 /* WB LLC */ #define PPAT_CACHED_INDEX _PAGE_PAT /* WB LLCeLLC */ -#define PPAT_DISPLAY_ELLC_INDEX _PAGE_PCD /* WT eLLC */ +#define PPAT_DISPLAY_ELLC_INDEX (_PAGE_PWT | _PAGE_PCD) /* WT eLLC */ #define CHV_PPAT_SNOOP (1<<6) #define GEN8_PPAT_AGE(x) (x<<4) -- 1.9.1 _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
