From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Mon, 11 Jun 2018 18:18:24 +0100
Subject: drm/i915/gtt: Invalidate GGTT caches after writing the gen6 page
directories
Git-commit: 68a8570375df647cf8b6626d63917b564dd9390e
Patch-mainline: v4.19-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
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 <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180611171825.13678-1-chris@chris-wilson.co.uk
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/i915/i915_gem_gtt.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
--- 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
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
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 i9
if (flush) {
mark_tlbs_dirty(ppgtt);
- wmb();
+ gen6_ggtt_invalidate(ppgtt->vm.i915);
}
return 0;