From 68a8570375df647cf8b6626d63917b564dd9390e Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Mon, 11 Jun 2018 18:18:24 +0100 Subject: [PATCH] drm/i915/gtt: Invalidate GGTT caches after writing the gen6 page directories When we update the gen6 ppgtt page directories, we do so by writing the new address into a reserved slot in the GGTT. It appears that when the GPU reads that entry from the gsm, it uses its small cache and that we need to invalidate that cache after writing. We don't see an issue currently as we prefill the ppgtt page directories on creation; and only create the single aliasing_ppgtt long before we start using the GGTT (and so before the cache may have a conflicting entry). Signed-off-by: Chris Wilson Cc: Joonas Lahtinen Cc: Mika Kuoppala Cc: Matthew Auld Reviewed-by: Joonas Lahtinen Link: https://patchwork.freedesktop.org/patch/msgid/20180611171825.13678-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_gem_gtt.c | 8 ++++---- 1 file 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 ac75e0c..905a58b 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -1693,8 +1693,8 @@ static inline void gen6_write_pde(const struct i915_hw_ppgtt *ppgtt, const struct i915_page_table *pt) { /* Caller needs to make sure the write completes if necessary */ - writel_relaxed(GEN6_PDE_ADDR_ENCODE(px_dma(pt)) | GEN6_PDE_VALID, - ppgtt->pd_addr + pde); + iowrite32(GEN6_PDE_ADDR_ENCODE(px_dma(pt)) | GEN6_PDE_VALID, + ppgtt->pd_addr + pde); } /* Write all the page tables found in the ppgtt structure to incrementing page @@ -1709,7 +1709,7 @@ static void gen6_write_page_range(struct i915_hw_ppgtt *ppgtt, gen6_write_pde(ppgtt, pde, pt); mark_tlbs_dirty(ppgtt); - wmb(); + gen6_ggtt_invalidate(ppgtt->vm.i915); } static void gen8_ppgtt_enable(struct drm_i915_private *dev_priv) @@ -1864,7 +1864,7 @@ static int gen6_alloc_va_range(struct i915_address_space *vm, if (flush) { mark_tlbs_dirty(ppgtt); - wmb(); + gen6_ggtt_invalidate(ppgtt->vm.i915); } return 0; -- 2.7.4