drm/i915: vfuncs for ppgtt

Like for the global gtt we want a notch more flexibility here. Only
big change (besides a few tiny function parameter adjustments) was to
move gen6_ppgtt_insert_entries up (and remove _sg_ from its name, we
only have one kind of insert_entries since the last gtt cleanup).

We could also extract the platform ppgtt setup/teardown code a bit
better, but I don't care that much.

With this we have the hw details of pte writing nicely hidden away
behind a bit of abstraction. Which should pave the way for
different/multiple ppgtts (e.g. what we need for real ppgtt support).

Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

2 files changed, 65 insertions, 56 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index fb0815bebe0f..4be7c68bf5fd 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -412,6 +412,15 @@ struct i915_hw_ppgtt {
         uint32_t pd_offset;
         dma_addr_t *pt_dma_addr;
         dma_addr_t scratch_page_dma_addr;
+
+        /* pte functions, mirroring the interface of the global gtt. */
+        void (*clear_range)(struct i915_hw_ppgtt *ppgtt,
+                            unsigned int first_entry,
+                            unsigned int num_entries);
+        void (*insert_entries)(struct i915_hw_ppgtt *ppgtt,
+                               struct sg_table *st,
+                               unsigned int pg_start,
+                               enum i915_cache_level cache_level);
 };
 
 
@@ -1662,7 +1671,6 @@ int i915_gem_context_destroy_ioctl(struct drm_device *dev, void *data,
                                    struct drm_file *file);
 
 /* i915_gem_gtt.c */
-int __must_check i915_gem_init_aliasing_ppgtt(struct drm_device *dev);
 void i915_gem_cleanup_aliasing_ppgtt(struct drm_device *dev);
 void i915_ppgtt_bind_object(struct i915_hw_ppgtt *ppgtt,
                             struct drm_i915_gem_object *obj,
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 4712626f8dc1..f63dbc7a89ce 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -77,7 +77,7 @@ static inline gtt_pte_t pte_encode(struct drm_device *dev,
 }
 
 /* PPGTT support for Sandybdrige/Gen6 and later */
-static void i915_ppgtt_clear_range(struct i915_hw_ppgtt *ppgtt,
+static void gen6_ppgtt_clear_range(struct i915_hw_ppgtt *ppgtt,
                                    unsigned first_entry,
                                    unsigned num_entries)
 {
@@ -108,7 +108,51 @@ static void i915_ppgtt_clear_range(struct i915_hw_ppgtt *ppgtt,
         }
 }
 
-int i915_gem_init_aliasing_ppgtt(struct drm_device *dev)
+static void gen6_ppgtt_insert_entries(struct i915_hw_ppgtt *ppgtt,
+                                      struct sg_table *pages,
+                                      unsigned first_entry,
+                                      enum i915_cache_level cache_level)
+{
+        gtt_pte_t *pt_vaddr;
+        unsigned act_pd = first_entry / I915_PPGTT_PT_ENTRIES;
+        unsigned first_pte = first_entry % I915_PPGTT_PT_ENTRIES;
+        unsigned i, j, m, segment_len;
+        dma_addr_t page_addr;
+        struct scatterlist *sg;
+
+        /* init sg walking */
+        sg = pages->sgl;
+        i = 0;
+        segment_len = sg_dma_len(sg) >> PAGE_SHIFT;
+        m = 0;
+
+        while (i < pages->nents) {
+                pt_vaddr = kmap_atomic(ppgtt->pt_pages[act_pd]);
+
+                for (j = first_pte; j < I915_PPGTT_PT_ENTRIES; j++) {
+                        page_addr = sg_dma_address(sg) + (m << PAGE_SHIFT);
+                        pt_vaddr[j] = pte_encode(ppgtt->dev, page_addr,
+                                                 cache_level);
+
+                        /* grab the next page */
+                        if (++m == segment_len) {
+                                if (++i == pages->nents)
+                                        break;
+
+                                sg = sg_next(sg);
+                                segment_len = sg_dma_len(sg) >> PAGE_SHIFT;
+                                m = 0;
+                        }
+                }
+
+                kunmap_atomic(pt_vaddr);
+
+                first_pte = 0;
+                act_pd++;
+        }
+}
+
+static int i915_gem_init_aliasing_ppgtt(struct drm_device *dev)
 {
         struct drm_i915_private *dev_priv = dev->dev_private;
         struct i915_hw_ppgtt *ppgtt;
@@ -127,6 +171,8 @@ int i915_gem_init_aliasing_ppgtt(struct drm_device *dev)
 
         ppgtt->dev = dev;
         ppgtt->num_pd_entries = I915_PPGTT_PD_ENTRIES;
+        ppgtt->clear_range = gen6_ppgtt_clear_range;
+        ppgtt->insert_entries = gen6_ppgtt_insert_entries;
         ppgtt->pt_pages = kzalloc(sizeof(struct page *)*ppgtt->num_pd_entries,
                                   GFP_KERNEL);
         if (!ppgtt->pt_pages)
@@ -159,8 +205,8 @@ int i915_gem_init_aliasing_ppgtt(struct drm_device *dev)
 
         ppgtt->scratch_page_dma_addr = dev_priv->gtt.scratch_page_dma;
 
-        i915_ppgtt_clear_range(ppgtt, 0,
-                               ppgtt->num_pd_entries*I915_PPGTT_PT_ENTRIES);
+        ppgtt->clear_range(ppgtt, 0,
+                           ppgtt->num_pd_entries*I915_PPGTT_PT_ENTRIES);
 
         ppgtt->pd_offset = (first_pd_entry_in_global_pt)*sizeof(gtt_pte_t);
 
@@ -209,66 +255,21 @@ void i915_gem_cleanup_aliasing_ppgtt(struct drm_device *dev)
         kfree(ppgtt);
 }
 
-static void i915_ppgtt_insert_sg_entries(struct i915_hw_ppgtt *ppgtt,
-                                         const struct sg_table *pages,
-                                         unsigned first_entry,
-                                         enum i915_cache_level cache_level)
-{
-        gtt_pte_t *pt_vaddr;
-        unsigned act_pd = first_entry / I915_PPGTT_PT_ENTRIES;
-        unsigned first_pte = first_entry % I915_PPGTT_PT_ENTRIES;
-        unsigned i, j, m, segment_len;
-        dma_addr_t page_addr;
-        struct scatterlist *sg;
-
-        /* init sg walking */
-        sg = pages->sgl;
-        i = 0;
-        segment_len = sg_dma_len(sg) >> PAGE_SHIFT;
-        m = 0;
-
-        while (i < pages->nents) {
-                pt_vaddr = kmap_atomic(ppgtt->pt_pages[act_pd]);
-
-                for (j = first_pte; j < I915_PPGTT_PT_ENTRIES; j++) {
-                        page_addr = sg_dma_address(sg) + (m << PAGE_SHIFT);
-                        pt_vaddr[j] = pte_encode(ppgtt->dev, page_addr,
-                                                 cache_level);
-
-                        /* grab the next page */
-                        if (++m == segment_len) {
-                                if (++i == pages->nents)
-                                        break;
-
-                                sg = sg_next(sg);
-                                segment_len = sg_dma_len(sg) >> PAGE_SHIFT;
-                                m = 0;
-                        }
-                }
-
-                kunmap_atomic(pt_vaddr);
-
-                first_pte = 0;
-                act_pd++;
-        }
-}
-
 void i915_ppgtt_bind_object(struct i915_hw_ppgtt *ppgtt,
                             struct drm_i915_gem_object *obj,
                             enum i915_cache_level cache_level)
 {
-        i915_ppgtt_insert_sg_entries(ppgtt,
-                                     obj->pages,
-                                     obj->gtt_space->start >> PAGE_SHIFT,
-                                     cache_level);
+        ppgtt->insert_entries(ppgtt, obj->pages,
+                              obj->gtt_space->start >> PAGE_SHIFT,
+                              cache_level);
 }
 
 void i915_ppgtt_unbind_object(struct i915_hw_ppgtt *ppgtt,
                               struct drm_i915_gem_object *obj)
 {
-        i915_ppgtt_clear_range(ppgtt,
-                               obj->gtt_space->start >> PAGE_SHIFT,
-                               obj->base.size >> PAGE_SHIFT);
+        ppgtt->clear_range(ppgtt,
+                           obj->gtt_space->start >> PAGE_SHIFT,
+                           obj->base.size >> PAGE_SHIFT);
 }
 
 void i915_gem_init_ppgtt(struct drm_device *dev)