[PATCH 34/56] drm/i915: num_pd_pages/num_pd_entries isn't useful

[Ben Widawsky <benjamin.widawsky@intel.com>]

These values are never quite useful for dynamic allocations of the page
tables. Getting rid of them will help prevent later confusion.

TODO: this probably needs to be earlier in the series

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
---
 drivers/gpu/drm/i915/i915_debugfs.c | 11 ++++-----
 drivers/gpu/drm/i915/i915_gem_gtt.c | 45 ++++++++++---------------------------
 drivers/gpu/drm/i915/i915_gem_gtt.h |  7 ++++--
 3 files changed, 21 insertions(+), 42 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 921d898..40aca7f 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1814,13 +1814,12 @@ static int i915_swizzle_info(struct seq_file *m, void *data)
 
 static size_t gen6_ppgtt_count_pt_pages(struct i915_hw_ppgtt *ppgtt)
 {
-	struct i915_pagedir *pd = &ppgtt->pd;
-	struct i915_pagetab **pt = &pd->page_tables[0];
+	struct i915_pagetab *pt;
 	size_t cnt = 0;
-	int i;
+	uint32_t useless;
 
-	for (i = 0; i < ppgtt->num_pd_entries; i++) {
-		if (pt[i] != ppgtt->scratch_pt)
+	gen6_for_all_pdes(pt, ppgtt, useless) {
+		if (pt != ppgtt->scratch_pt)
 			cnt++;
 	}
 
@@ -1844,8 +1843,6 @@ static void gen8_ppgtt_info(struct seq_file *m, struct drm_device *dev, int verb
 	if (!ppgtt)
 		return;
 
-	seq_printf(m, "Page directories: %d\n", ppgtt->num_pd_pages);
-	seq_printf(m, "Page tables: %d\n", ppgtt->num_pd_entries);
 	for_each_ring(ring, dev_priv, unused) {
 		seq_printf(m, "%s\n", ring->name);
 		for (i = 0; i < 4; i++) {
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index a895f4b..a646475 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -617,22 +617,14 @@ static int gen8_ppgtt_alloc_pagedirs(struct i915_pagedirpo *pdp,
 		pdp->pagedirs[pdpe] = alloc_pd_single(ppgtt->base.dev);
 		if (IS_ERR(ppgtt->pdp.pagedirs[pdpe]))
 			goto unwind_out;
-
-		ppgtt->num_pd_pages++;
 	}
 
-	BUG_ON(ppgtt->num_pd_pages > GEN8_LEGACY_PDPES);
-
 	return 0;
 
 unwind_out:
-	while (pdpe--) {
+	while (pdpe--)
 		free_pd_single(ppgtt->pdp.pagedirs[pdpe],
 			       ppgtt->base.dev);
-		ppgtt->num_pd_pages--;
-	}
-
-	WARN_ON(ppgtt->num_pd_pages);
 
 	return -ENOMEM;
 }
@@ -655,12 +647,8 @@ static int gen8_ppgtt_alloc(struct i915_hw_ppgtt *ppgtt,
 						ppgtt->base.dev);
 		if (ret)
 			goto err_out;
-
-		ppgtt->num_pd_entries += I915_PDES_PER_PD;
 	}
 
-	BUG_ON(pdpe > ppgtt->num_pd_pages);
-
 	return 0;
 
 	/* TODO: Check this for all cases */
@@ -682,7 +670,6 @@ err_out:
 static int gen8_ppgtt_init(struct i915_hw_ppgtt *ppgtt, uint64_t size)
 {
 	const int max_pdp = DIV_ROUND_UP(size, 1 << 30);
-	const int min_pt_pages = I915_PDES_PER_PD * max_pdp;
 	int i, j, ret;
 
 	if (size % (1<<30))
@@ -731,27 +718,21 @@ static int gen8_ppgtt_init(struct i915_hw_ppgtt *ppgtt, uint64_t size)
 	ppgtt->base.insert_entries = gen8_ppgtt_insert_entries;
 	ppgtt->base.cleanup = gen8_ppgtt_cleanup;
 
-	DRM_DEBUG_DRIVER("Allocated %d pages for page directories (%d wasted)\n",
-			 ppgtt->num_pd_pages, ppgtt->num_pd_pages - max_pdp);
-	DRM_DEBUG_DRIVER("Allocated %d pages for page tables (%lld wasted)\n",
-			 ppgtt->num_pd_entries,
-			 (ppgtt->num_pd_entries - min_pt_pages) + size % (1<<30));
 	return 0;
 }
 
 static void gen6_dump_ppgtt(struct i915_hw_ppgtt *ppgtt, struct seq_file *m)
 {
 	struct i915_address_space *vm = &ppgtt->base;
+	struct i915_pagetab *unused;
 	gen6_gtt_pte_t scratch_pte;
 	uint32_t pd_entry;
-	int pte, pde;
+	uint32_t  pte, pde, temp;
+	uint32_t start = ppgtt->base.start, length = ppgtt->base.total;
 
 	scratch_pte = vm->pte_encode(vm->scratch.addr, I915_CACHE_LLC, true);
 
-	seq_printf(m, "  VM %p (pd_offset %x-%x):\n", vm,
-		   ppgtt->pd.pd_offset,
-		   ppgtt->pd.pd_offset + ppgtt->num_pd_entries);
-	for (pde = 0; pde < ppgtt->num_pd_entries; pde++) {
+	gen6_for_each_pde(unused, &ppgtt->pd, start, length, temp, pde) {
 		u32 expected;
 		gen6_gtt_pte_t *pt_vaddr;
 		dma_addr_t pt_addr = ppgtt->pd.page_tables[pde]->daddr;
@@ -1229,12 +1210,12 @@ static void gen6_teardown_va_range(struct i915_address_space *vm,
 
 static void gen6_ppgtt_free(struct i915_hw_ppgtt *ppgtt)
 {
-	int i;
+	struct i915_pagetab *pt;
+	uint32_t pde;
 
-	for (i = 0; i < ppgtt->num_pd_entries; i++) {
-		struct i915_pagetab *pt = ppgtt->pd.page_tables[i];
+	gen6_for_all_pdes(pt, ppgtt, pde) {
 		if (pt != ppgtt->scratch_pt)
-			free_pt_single(ppgtt->pd.page_tables[i], ppgtt->base.dev);
+			free_pt_single(pt, ppgtt->base.dev);
 	}
 
 	/* Consider putting this as part of pd free. */
@@ -1293,7 +1274,6 @@ alloc:
 	if (ppgtt->node.start < dev_priv->gtt.mappable_end)
 		DRM_DEBUG("Forced to use aperture for PDEs\n");
 
-	ppgtt->num_pd_entries = I915_PDES_PER_PD;
 	return 0;
 
 err_out:
@@ -1312,8 +1292,7 @@ static int gen6_ppgtt_alloc(struct i915_hw_ppgtt *ppgtt, bool preallocate_pt)
 	if (!preallocate_pt)
 		return 0;
 
-	ret = alloc_pt_range(&ppgtt->pd, 0, ppgtt->num_pd_entries,
-			     ppgtt->base.dev);
+	ret = alloc_pt_range(&ppgtt->pd, 0, I915_PDES_PER_PD, ppgtt->base.dev);
 	if (ret) {
 		free_pt_scratch(ppgtt->scratch_pt, ppgtt->base.dev);
 		drm_mm_remove_node(&ppgtt->node);
@@ -1362,7 +1341,7 @@ static int gen6_ppgtt_init(struct i915_hw_ppgtt *ppgtt, bool aliasing)
 	ppgtt->base.insert_entries = gen6_ppgtt_insert_entries;
 	ppgtt->base.cleanup = gen6_ppgtt_cleanup;
 	ppgtt->base.start = 0;
-	ppgtt->base.total = ppgtt->num_pd_entries * GEN6_PTES_PER_PT * PAGE_SIZE;
+	ppgtt->base.total = I915_PDES_PER_PD * GEN6_PTES_PER_PT * PAGE_SIZE;
 	ppgtt->debug_dump = gen6_dump_ppgtt;
 
 	ppgtt->pd.pd_offset =
@@ -1602,7 +1581,7 @@ void i915_gem_restore_gtt_mappings(struct drm_device *dev)
 		if (i915_is_ggtt(vm))
 			ppgtt = dev_priv->mm.aliasing_ppgtt;
 
-		gen6_map_page_range(dev_priv, &ppgtt->pd, 0, ppgtt->num_pd_entries);
+		gen6_map_page_range(dev_priv, &ppgtt->pd, 0, I915_PDES_PER_PD);
 	}
 
 	i915_gem_chipset_flush(dev);
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
index 5c6db90..a581b33 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.h
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
@@ -260,8 +260,6 @@ struct i915_hw_ppgtt {
 	struct i915_address_space base;
 	struct kref ref;
 	struct drm_mm_node node;
-	unsigned num_pd_entries;
-	unsigned num_pd_pages; /* gen8+ */
 	union {
 		struct i915_pagedirpo pdp;
 		struct i915_pagedir pd;
@@ -328,6 +326,11 @@ struct i915_gtt {
 	     temp = min(temp, (unsigned)length), \
 	     start += temp, length -= temp)
 
+#define gen6_for_all_pdes(pt, ppgtt, iter)  \
+	for (iter = 0, pt = ppgtt->pd.page_tables[iter];			\
+	     iter < gen6_pde_index(ppgtt->base.total);			\
+	     pt =  ppgtt->pd.page_tables[++iter])
+
 static inline uint32_t i915_pte_index(uint64_t address, uint32_t pde_shift)
 {
 	const uint32_t mask = NUM_PTE(pde_shift) - 1;
-- 
1.9.2