[Intel-gfx] [PATCH 41/56] drm/i915/bdw: Optimize PDP loads
Ben Widawsky
benjamin.widawsky at intel.com
Sat May 10 05:59:36 CEST 2014
Don't do them if they're not necessary, which they're not, for the RCS,
in certain conditions.
Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
---
drivers/gpu/drm/i915/i915_gem_gtt.c | 20 ++++++++++++++++++++
drivers/gpu/drm/i915/i915_gem_gtt.h | 1 +
2 files changed, 21 insertions(+)
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index d8bb4dc..3ea0c7d 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -438,8 +438,20 @@ static int gen8_mm_switch(struct i915_hw_ppgtt *ppgtt,
struct intel_ring_buffer *ring,
bool synchronous)
{
+ struct drm_i915_private *dev_priv = ring->dev->dev_private;
int i, ret;
+ /* The RCS ring gets reloaded by the hardware context state. So we only
+ * need to actually reload if one of the page directory pointer have
+ * changed, or it's !RCS
+ *
+ * Aliasing PPGTT remains special, as we do not track it's
+ * reloading needs.
+ */
+ if (ppgtt != dev_priv->mm.aliasing_ppgtt &&
+ ring->id == RCS && !ppgtt->pdp.needs_reload)
+ return 0;
+
for (i = GEN8_LEGACY_PDPES - 1; i >= 0; i--) {
struct i915_pagedir *pd = ppgtt->pdp.pagedirs[i];
dma_addr_t addr = pd ? pd->daddr : ppgtt->scratch_pt->daddr;
@@ -450,6 +462,9 @@ static int gen8_mm_switch(struct i915_hw_ppgtt *ppgtt,
return ret;
}
+
+ ppgtt->pdp.needs_reload = 0;
+
return 0;
}
@@ -651,6 +666,7 @@ static void gen8_teardown_va_range(struct i915_address_space *vm,
free_pd_single(pd, vm->dev);
ppgtt->pdp.pagedirs[pdpe] = NULL;
WARN_ON(!test_and_clear_bit(pdpe, ppgtt->pdp.used_pdpes));
+ ppgtt->pdp.needs_reload = 1;
}
}
}
@@ -901,6 +917,8 @@ static int gen8_alloc_va_range(struct i915_address_space *vm,
}
set_bit(pdpe, ppgtt->pdp.used_pdpes);
+ if (test_and_set_bit(pdpe, ppgtt->pdp.used_pdpes))
+ ppgtt->pdp.needs_reload = 1;
gen8_map_pagetable_range(pd, start, length, ppgtt->base.dev);
}
@@ -937,6 +955,8 @@ static int gen8_ppgtt_init_common(struct i915_hw_ppgtt *ppgtt, uint64_t size)
ppgtt->switch_mm = gen8_mm_switch;
ppgtt->base.insert_entries = gen8_ppgtt_insert_entries;
+ ppgtt->pdp.needs_reload = 1;
+
ppgtt->scratch_pd = alloc_pt_scratch(ppgtt->base.dev);
if (IS_ERR(ppgtt->scratch_pd))
return PTR_ERR(ppgtt->scratch_pd);
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
index b3d0776..dd561f3 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.h
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
@@ -198,6 +198,7 @@ struct i915_pagedirpo {
/* struct page *page; */
DECLARE_BITMAP(used_pdpes, GEN8_LEGACY_PDPES);
struct i915_pagedir *pagedirs[GEN8_LEGACY_PDPES];
+ unsigned needs_reload:1;
};
struct i915_address_space {
--
1.9.2
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