DRI clients really should be using MOCS to get fine grained streaming cache controls. With that note, I *hope* that this patch doesn't improve performance overwhelmingly, because if it does - it means there is a problem elsewhere. In any case, the kernel, and old userspace should get some benefit from this, so let's do it. eLLC is always a good default, and really not using it is the special case for MOCS. References: http://www.intel.com/newsroom/kits/restricted/ha$well!/pdfs/4th_Gen_Intel_Core_PressBriefing_5-29.pdf (page 57) Signed-off-by: Ben Widawsky <ben at bwidawsk.net> --- drivers/gpu/drm/i915/i915_gem_gtt.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index 42262d0..0ff8073 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -53,6 +53,7 @@ #define HSW_CACHEABILITY_CONTROL(bits) ((((bits) & 0x7) << 1) | \ (((bits) & 0x8) << (11 - 3))) #define HSW_WB_LLC_AGE0 HSW_CACHEABILITY_CONTROL(0x3) +#define HSW_WB_ELLC_LLC_AGE0 HSW_CACHEABILITY_CONTROL(0xb) static gen6_gtt_pte_t gen6_pte_encode(dma_addr_t addr, enum i915_cache_level level) @@ -109,6 +110,18 @@ static gen6_gtt_pte_t hsw_pte_encode(dma_addr_t addr, return pte; } +static gen6_gtt_pte_t iris_pte_encode(dma_addr_t addr, + enum i915_cache_level level) +{ + gen6_gtt_pte_t pte = GEN6_PTE_VALID; + pte |= HSW_PTE_ADDR_ENCODE(addr); + + if (level != I915_CACHE_NONE) + pte |= HSW_WB_ELLC_LLC_AGE0; + + return pte; +} + static void gen6_write_pdes(struct i915_hw_ppgtt *ppgtt) { struct drm_i915_private *dev_priv = ppgtt->dev->dev_private; @@ -860,7 +873,9 @@ int i915_gem_gtt_init(struct drm_device *dev) } else { gtt->gtt_probe = gen6_gmch_probe; gtt->gtt_remove = gen6_gmch_remove; - if (IS_HASWELL(dev)) + if (IS_HASWELL(dev) && dev_priv->ellc_size) + gtt->pte_encode = iris_pte_encode; + else if (IS_HASWELL(dev)) gtt->pte_encode = hsw_pte_encode; else if (IS_VALLEYVIEW(dev)) gtt->pte_encode = byt_pte_encode; -- 1.8.3
