[Intel-gfx] [PATCH 38/68] drm/i915: Always dma map page table allocations

[Ben Widawsky]

There is never a case where we don't want to do it. Since we've broken
up the allocations into nice clean helper functions, it's both easy and
obvious to do the dma mapping at the same time.

Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
---
 drivers/gpu/drm/i915/i915_gem_gtt.c | 78 ++++++++-----------------------------
 1 file changed, 17 insertions(+), 61 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 4bd1e07..2346cb7 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -207,20 +207,6 @@ static gen6_gtt_pte_t iris_pte_encode(dma_addr_t addr,
 	pci_unmap_page((dev)->pdev, (pt)->daddr, 4096, PCI_DMA_BIDIRECTIONAL); \
 } while (0);
 
-
-static void dma_unmap_pt_range(struct i915_pagedir *pd,
-			       unsigned pde, size_t n,
-			       struct drm_device *dev)
-{
-	if (WARN_ON(pde + n > I915_PDES_PER_PD))
-		n = I915_PDES_PER_PD - pde;
-
-	n += pde;
-
-	for (; pde < n; pde++)
-		dma_unmap_pt_single(pd->page_tables[pde], dev);
-}
-
 /**
  * dma_map_pt_single() - Create a dma mapping for a page table
  * @pt:		Page table to get a DMA map for
@@ -250,33 +236,12 @@ static int dma_map_pt_single(struct i915_pagetab *pt, struct drm_device *dev)
 	return 0;
 }
 
-static int dma_map_pt_range(struct i915_pagedir *pd,
-			    unsigned pde, size_t n,
-			    struct drm_device *dev)
-{
-	const int first = pde;
-
-	if (WARN_ON(pde + n > I915_PDES_PER_PD))
-		n = I915_PDES_PER_PD - pde;
-
-	n += pde;
-
-	for (; pde < n; pde++) {
-		int ret;
-		ret = dma_map_pt_single(pd->page_tables[pde], dev);
-		if (ret) {
-			dma_unmap_pt_range(pd, first, pde, dev);
-			return ret;
-		}
-	}
-
-	return 0;
-}
-
-static void free_pt_single(struct i915_pagetab *pt)
+static void free_pt_single(struct i915_pagetab *pt, struct drm_device *dev)
 {
 	if (WARN_ON(!pt->page))
 		return;
+
+	dma_unmap_pt_single(pt, dev);
 	__free_page(pt->page);
 	kfree(pt);
 }
@@ -284,6 +249,7 @@ static void free_pt_single(struct i915_pagetab *pt)
 static struct i915_pagetab *alloc_pt_single(struct drm_device *dev)
 {
 	struct i915_pagetab *pt;
+	int ret;
 
 	pt = kzalloc(sizeof(*pt), GFP_KERNEL);
 	if (!pt)
@@ -295,6 +261,13 @@ static struct i915_pagetab *alloc_pt_single(struct drm_device *dev)
 		return ERR_PTR(-ENOMEM);
 	}
 
+	ret = dma_map_pt_single(pt, dev);
+	if (ret) {
+		__free_page(pt->page);
+		kfree(pt);
+		return ERR_PTR(ret);
+	}
+
 	return pt;
 }
 
@@ -338,7 +311,7 @@ static int alloc_pt_range(struct i915_pagedir *pd, uint16_t pde, size_t count,
 
 err_out:
 	while (i--)
-		free_pt_single(pd->page_tables[i]);
+		free_pt_single(pd->page_tables[i], dev);
 	return ret;
 }
 
@@ -513,7 +486,7 @@ static void gen8_ppgtt_insert_entries(struct i915_address_space *vm,
 	}
 }
 
-static void gen8_free_page_tables(struct i915_pagedir *pd)
+static void gen8_free_page_tables(struct i915_pagedir *pd, struct drm_device *dev)
 {
 	int i;
 
@@ -521,7 +494,7 @@ static void gen8_free_page_tables(struct i915_pagedir *pd)
 		return;
 
 	for (i = 0; i < I915_PDES_PER_PD; i++) {
-		free_pt_single(pd->page_tables[i]);
+		free_pt_single(pd->page_tables[i], dev);
 		pd->page_tables[i] = NULL;
 	}
 }
@@ -531,7 +504,7 @@ static void gen8_ppgtt_free(struct i915_hw_ppgtt *ppgtt)
 	int i;
 
 	for (i = 0; i < ppgtt->num_pd_pages; i++) {
-		gen8_free_page_tables(ppgtt->pdp.pagedir[i]);
+		gen8_free_page_tables(ppgtt->pdp.pagedir[i], ppgtt->base.dev);
 		free_pd_single(ppgtt->pdp.pagedir[i]);
 	}
 }
@@ -588,7 +561,7 @@ static int gen8_ppgtt_allocate_page_tables(struct i915_hw_ppgtt *ppgtt)
 
 unwind_out:
 	while (i--)
-		gen8_free_page_tables(ppgtt->pdp.pagedir[i]);
+		gen8_free_page_tables(ppgtt->pdp.pagedir[i], ppgtt->base.dev);
 
 	return -ENOMEM;
 }
@@ -686,18 +659,9 @@ static int gen8_ppgtt_init(struct i915_hw_ppgtt *ppgtt, uint64_t size)
 	 * 2. Create DMA mappings for the page directories and page tables.
 	 */
 	for (i = 0; i < max_pdp; i++) {
-		struct i915_pagedir *pd;
 		ret = gen8_ppgtt_setup_page_directories(ppgtt, i);
 		if (ret)
 			goto bail;
-
-		pd = ppgtt->pdp.pagedir[i];
-
-		for (j = 0; j < I915_PDES_PER_PD; j++) {
-			ret = dma_map_pt_single(pd->page_tables[j], ppgtt->base.dev);
-			if (ret)
-				goto bail;
-		}
 	}
 
 	/*
@@ -1117,7 +1081,7 @@ static void gen6_ppgtt_free(struct i915_hw_ppgtt *ppgtt)
 	int i;
 
 	for (i = 0; i < ppgtt->num_pd_entries; i++)
-		free_pt_single(ppgtt->pd.page_tables[i]);
+		free_pt_single(ppgtt->pd.page_tables[i], ppgtt->base.dev);
 
 	free_pd_single(&ppgtt->pd);
 }
@@ -1131,7 +1095,6 @@ static void gen6_ppgtt_cleanup(struct i915_address_space *vm)
 	drm_mm_takedown(&vm->mm);
 	drm_mm_remove_node(&ppgtt->node);
 
-	dma_unmap_pt_range(&ppgtt->pd, 0, ppgtt->num_pd_entries, vm->dev);
 	gen6_ppgtt_free(ppgtt);
 }
 
@@ -1218,13 +1181,6 @@ static int gen6_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
 	if (ret)
 		return ret;
 
-	ret = dma_map_pt_range(&ppgtt->pd, 0, ppgtt->num_pd_entries,
-			       ppgtt->base.dev);
-	if (ret) {
-		gen6_ppgtt_free(ppgtt);
-		return ret;
-	}
-
 	ppgtt->base.clear_range = gen6_ppgtt_clear_range;
 	ppgtt->base.insert_entries = gen6_ppgtt_insert_entries;
 	ppgtt->base.cleanup = gen6_ppgtt_cleanup;
-- 
2.0.4