drm/i915/gtt: Introduce struct i915_page_dma

All our paging structures have struct page and dma address
for that page.

Add struct for page/dma address pairs and use it to make
the setup and teardown for different paging structures
identical.

Include the page directory offset also in the struct for legacy
gens. Rename it to clearly point out that it is offset into the
ggtt.

v2: Add comment about ggtt_offset (Michel)

Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Michel Thierry <michel.thierry@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_debugfs.c

@@ -2227,7 +2227,7 @@ static void gen6_ppgtt_info(struct seq_file *m, struct drm_device *dev)
 		struct i915_hw_ppgtt *ppgtt = dev_priv->mm.aliasing_ppgtt;
 
 		seq_puts(m, "aliasing PPGTT:\n");
-		seq_printf(m, "pd gtt offset: 0x%08x\n", ppgtt->pd.pd_offset);
+		seq_printf(m, "pd gtt offset: 0x%08x\n", ppgtt->pd.base.ggtt_offset);
 
 		ppgtt->debug_dump(ppgtt, m);
 	}

drivers/gpu/drm/i915/i915_gem_gtt.c

@@ -301,52 +301,39 @@ static gen6_pte_t iris_pte_encode(dma_addr_t addr,
 	return pte;
 }
 
-#define i915_dma_unmap_single(px, dev) \
-	__i915_dma_unmap_single((px)->daddr, dev)
-
-static void __i915_dma_unmap_single(dma_addr_t daddr,
-				    struct drm_device *dev)
+static int setup_page_dma(struct drm_device *dev, struct i915_page_dma *p)
 {
 	struct device *device = &dev->pdev->dev;
 
-	dma_unmap_page(device, daddr, 4096, PCI_DMA_BIDIRECTIONAL);
-}
-
-/**
- * i915_dma_map_single() - Create a dma mapping for a page table/dir/etc.
- * @px:	Page table/dir/etc to get a DMA map for
- * @dev:	drm device
- *
- * Page table allocations are unified across all gens. They always require a
- * single 4k allocation, as well as a DMA mapping. If we keep the structs
- * symmetric here, the simple macro covers us for every page table type.
- *
- * Return: 0 if success.
- */
-#define i915_dma_map_single(px, dev) \
-	i915_dma_map_page_single((px)->page, (dev), &(px)->daddr)
+	p->page = alloc_page(GFP_KERNEL);
+	if (!p->page)
+		return -ENOMEM;
 
-static int i915_dma_map_page_single(struct page *page,
-				    struct drm_device *dev,
-				    dma_addr_t *daddr)
-{
-	struct device *device = &dev->pdev->dev;
+	p->daddr = dma_map_page(device,
+				p->page, 0, 4096, PCI_DMA_BIDIRECTIONAL);
 
-	*daddr = dma_map_page(device, page, 0, 4096, PCI_DMA_BIDIRECTIONAL);
-	if (dma_mapping_error(device, *daddr))
-		return -ENOMEM;
+	if (dma_mapping_error(device, p->daddr)) {
+		__free_page(p->page);
+		return -EINVAL;
+	}
 
 	return 0;
 }
 
-static void unmap_and_free_pt(struct i915_page_table *pt,
-			       struct drm_device *dev)
+static void cleanup_page_dma(struct drm_device *dev, struct i915_page_dma *p)
 {
-	if (WARN_ON(!pt->page))
+	if (WARN_ON(!p->page))
 		return;
 
-	i915_dma_unmap_single(pt, dev);
-	__free_page(pt->page);
+	dma_unmap_page(&dev->pdev->dev, p->daddr, 4096, PCI_DMA_BIDIRECTIONAL);
+	__free_page(p->page);
+	memset(p, 0, sizeof(*p));
+}
+
+static void unmap_and_free_pt(struct i915_page_table *pt,
+			       struct drm_device *dev)
+{
+	cleanup_page_dma(dev, &pt->base);
 	kfree(pt->used_ptes);
 	kfree(pt);
 }
@@ -357,7 +344,7 @@ static void gen8_initialize_pt(struct i915_address_space *vm,
 	gen8_pte_t *pt_vaddr, scratch_pte;
 	int i;
 
-	pt_vaddr = kmap_atomic(pt->page);
+	pt_vaddr = kmap_atomic(pt->base.page);
 	scratch_pte = gen8_pte_encode(vm->scratch.addr,
 				      I915_CACHE_LLC, true);
 
@@ -386,19 +373,13 @@ static struct i915_page_table *alloc_pt(struct drm_device *dev)
 	if (!pt->used_ptes)
 		goto fail_bitmap;
 
-	pt->page = alloc_page(GFP_KERNEL);
-	if (!pt->page)
-		goto fail_page;
-
-	ret = i915_dma_map_single(pt, dev);
+	ret = setup_page_dma(dev, &pt->base);
 	if (ret)
-		goto fail_dma;
+		goto fail_page_m;
 
 	return pt;
 
-fail_dma:
-	__free_page(pt->page);
-fail_page:
+fail_page_m:
 	kfree(pt->used_ptes);
 fail_bitmap:
 	kfree(pt);
@@ -409,9 +390,8 @@ fail_bitmap:
 static void unmap_and_free_pd(struct i915_page_directory *pd,
 			      struct drm_device *dev)
 {
-	if (pd->page) {
-		i915_dma_unmap_single(pd, dev);
-		__free_page(pd->page);
+	if (pd->base.page) {
+		cleanup_page_dma(dev, &pd->base);
 		kfree(pd->used_pdes);
 		kfree(pd);
 	}
@@ -431,18 +411,12 @@ static struct i915_page_directory *alloc_pd(struct drm_device *dev)
 	if (!pd->used_pdes)
 		goto free_pd;
 
-	pd->page = alloc_page(GFP_KERNEL);
-	if (!pd->page)
-		goto free_bitmap;
-
-	ret = i915_dma_map_single(pd, dev);
+	ret = setup_page_dma(dev, &pd->base);
 	if (ret)
-		goto free_page;
+		goto free_bitmap;
 
 	return pd;
 
-free_page:
-	__free_page(pd->page);
 free_bitmap:
 	kfree(pd->used_pdes);
 free_pd:
@@ -524,10 +498,10 @@ static void gen8_ppgtt_clear_range(struct i915_address_space *vm,
 
 		pt = pd->page_table[pde];
 
-		if (WARN_ON(!pt->page))
+		if (WARN_ON(!pt->base.page))
 			continue;
 
-		page_table = pt->page;
+		page_table = pt->base.page;
 
 		last_pte = pte + num_entries;
 		if (last_pte > GEN8_PTES)
@@ -574,7 +548,7 @@ static void gen8_ppgtt_insert_entries(struct i915_address_space *vm,
 		if (pt_vaddr == NULL) {
 			struct i915_page_directory *pd = ppgtt->pdp.page_directory[pdpe];
 			struct i915_page_table *pt = pd->page_table[pde];
-			struct page *page_table = pt->page;
+			struct page *page_table = pt->base.page;
 
 			pt_vaddr = kmap_atomic(page_table);
 		}
@@ -606,7 +580,7 @@ static void __gen8_do_map_pt(gen8_pde_t * const pde,
 			     struct drm_device *dev)
 {
 	gen8_pde_t entry =
-		gen8_pde_encode(dev, pt->daddr, I915_CACHE_LLC);
+		gen8_pde_encode(dev, pt->base.daddr, I915_CACHE_LLC);
 	*pde = entry;
 }
 
@@ -619,7 +593,7 @@ static void gen8_initialize_pd(struct i915_address_space *vm,
 	struct i915_page_table *pt;
 	int i;
 
-	page_directory = kmap_atomic(pd->page);
+	page_directory = kmap_atomic(pd->base.page);
 	pt = ppgtt->scratch_pt;
 	for (i = 0; i < I915_PDES; i++)
 		/* Map the PDE to the page table */
@@ -634,7 +608,7 @@ static void gen8_free_page_tables(struct i915_page_directory *pd, struct drm_dev
 {
 	int i;
 
-	if (!pd->page)
+	if (!pd->base.page)
 		return;
 
 	for_each_set_bit(i, pd->used_pdes, I915_PDES) {
@@ -885,7 +859,7 @@ static int gen8_alloc_va_range(struct i915_address_space *vm,
 	/* Allocations have completed successfully, so set the bitmaps, and do
 	 * the mappings. */
 	gen8_for_each_pdpe(pd, &ppgtt->pdp, start, length, temp, pdpe) {
-		gen8_pde_t *const page_directory = kmap_atomic(pd->page);
+		gen8_pde_t *const page_directory = kmap_atomic(pd->base.page);
 		struct i915_page_table *pt;
 		uint64_t pd_len = gen8_clamp_pd(start, length);
 		uint64_t pd_start = start;
@@ -996,7 +970,7 @@ static void gen6_dump_ppgtt(struct i915_hw_ppgtt *ppgtt, struct seq_file *m)
 	gen6_for_each_pde(unused, &ppgtt->pd, start, length, temp, pde) {
 		u32 expected;
 		gen6_pte_t *pt_vaddr;
-		dma_addr_t pt_addr = ppgtt->pd.page_table[pde]->daddr;
+		dma_addr_t pt_addr = ppgtt->pd.page_table[pde]->base.daddr;
 		pd_entry = readl(ppgtt->pd_addr + pde);
 		expected = (GEN6_PDE_ADDR_ENCODE(pt_addr) | GEN6_PDE_VALID);
 
@@ -1007,7 +981,7 @@ static void gen6_dump_ppgtt(struct i915_hw_ppgtt *ppgtt, struct seq_file *m)
 				   expected);
 		seq_printf(m, "\tPDE: %x\n", pd_entry);
 
-		pt_vaddr = kmap_atomic(ppgtt->pd.page_table[pde]->page);
+		pt_vaddr = kmap_atomic(ppgtt->pd.page_table[pde]->base.page);
 		for (pte = 0; pte < GEN6_PTES; pte+=4) {
 			unsigned long va =
 				(pde * PAGE_SIZE * GEN6_PTES) +
@@ -1042,7 +1016,7 @@ static void gen6_write_pde(struct i915_page_directory *pd,
 		container_of(pd, struct i915_hw_ppgtt, pd);
 	u32 pd_entry;
 
-	pd_entry = GEN6_PDE_ADDR_ENCODE(pt->daddr);
+	pd_entry = GEN6_PDE_ADDR_ENCODE(pt->base.daddr);
 	pd_entry |= GEN6_PDE_VALID;
 
 	writel(pd_entry, ppgtt->pd_addr + pde);
@@ -1067,9 +1041,9 @@ static void gen6_write_page_range(struct drm_i915_private *dev_priv,
 
 static uint32_t get_pd_offset(struct i915_hw_ppgtt *ppgtt)
 {
-	BUG_ON(ppgtt->pd.pd_offset & 0x3f);
+	BUG_ON(ppgtt->pd.base.ggtt_offset & 0x3f);
 
-	return (ppgtt->pd.pd_offset / 64) << 16;
+	return (ppgtt->pd.base.ggtt_offset / 64) << 16;
 }
 
 static int hsw_mm_switch(struct i915_hw_ppgtt *ppgtt,
@@ -1236,7 +1210,7 @@ static void gen6_ppgtt_clear_range(struct i915_address_space *vm,
 		if (last_pte > GEN6_PTES)
 			last_pte = GEN6_PTES;
 
-		pt_vaddr = kmap_atomic(ppgtt->pd.page_table[act_pt]->page);
+		pt_vaddr = kmap_atomic(ppgtt->pd.page_table[act_pt]->base.page);
 
 		for (i = first_pte; i < last_pte; i++)
 			pt_vaddr[i] = scratch_pte;
@@ -1265,7 +1239,7 @@ static void gen6_ppgtt_insert_entries(struct i915_address_space *vm,
 	pt_vaddr = NULL;
 	for_each_sg_page(pages->sgl, &sg_iter, pages->nents, 0) {
 		if (pt_vaddr == NULL)
-			pt_vaddr = kmap_atomic(ppgtt->pd.page_table[act_pt]->page);
+			pt_vaddr = kmap_atomic(ppgtt->pd.page_table[act_pt]->base.page);
 
 		pt_vaddr[act_pte] =
 			vm->pte_encode(sg_page_iter_dma_address(&sg_iter),
@@ -1293,7 +1267,7 @@ static void gen6_initialize_pt(struct i915_address_space *vm,
 	scratch_pte = vm->pte_encode(vm->scratch.addr,
 			I915_CACHE_LLC, true, 0);
 
-	pt_vaddr = kmap_atomic(pt->page);
+	pt_vaddr = kmap_atomic(pt->base.page);
 
 	for (i = 0; i < GEN6_PTES; i++)
 		pt_vaddr[i] = scratch_pte;
@@ -1509,11 +1483,11 @@ static int gen6_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
 	ppgtt->base.total = I915_PDES * GEN6_PTES * PAGE_SIZE;
 	ppgtt->debug_dump = gen6_dump_ppgtt;
 
-	ppgtt->pd.pd_offset =
+	ppgtt->pd.base.ggtt_offset =
 		ppgtt->node.start / PAGE_SIZE * sizeof(gen6_pte_t);
 
 	ppgtt->pd_addr = (gen6_pte_t __iomem *)dev_priv->gtt.gsm +
-		ppgtt->pd.pd_offset / sizeof(gen6_pte_t);
+		ppgtt->pd.base.ggtt_offset / sizeof(gen6_pte_t);
 
 	gen6_scratch_va_range(ppgtt, 0, ppgtt->base.total);
 
@@ -1524,7 +1498,7 @@ static int gen6_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
 			 ppgtt->node.start / PAGE_SIZE);
 
 	DRM_DEBUG("Adding PPGTT at offset %x\n",
-		  ppgtt->pd.pd_offset << 10);
+		  ppgtt->pd.base.ggtt_offset << 10);
 
 	return 0;
 }

drivers/gpu/drm/i915/i915_gem_gtt.h

@@ -207,19 +207,26 @@ struct i915_vma {
 #define DRM_I915_GEM_OBJECT_MAX_PIN_COUNT 0xf
 };
 
-struct i915_page_table {
+struct i915_page_dma {
 	struct page *page;
-	dma_addr_t daddr;
+	union {
+		dma_addr_t daddr;
+
+		/* For gen6/gen7 only. This is the offset in the GGTT
+		 * where the page directory entries for PPGTT begin
+		 */
+		uint32_t ggtt_offset;
+	};
+};
+
+struct i915_page_table {
+	struct i915_page_dma base;
 
 	unsigned long *used_ptes;
 };
 
 struct i915_page_directory {
-	struct page *page; /* NULL for GEN6-GEN7 */
-	union {
-		uint32_t pd_offset;
-		dma_addr_t daddr;
-	};
+	struct i915_page_dma base;
 
 	unsigned long *used_pdes;
 	struct i915_page_table *page_table[I915_PDES]; /* PDEs */
@@ -474,8 +481,8 @@ static inline dma_addr_t
 i915_page_dir_dma_addr(const struct i915_hw_ppgtt *ppgtt, const unsigned n)
 {
 	return test_bit(n, ppgtt->pdp.used_pdpes) ?
-		ppgtt->pdp.page_directory[n]->daddr :
-		ppgtt->scratch_pd->daddr;
+		ppgtt->pdp.page_directory[n]->base.daddr :
+		ppgtt->scratch_pd->base.daddr;
 }
 
 int i915_gem_gtt_init(struct drm_device *dev);