drm/i915/fb: Factor out functions to remap contiguous FB obj pages

Factor out functions needed to map contiguous FB obj pages to a GTT/DPT
VMA view in the next patch.

While at it s/4096/I915_GTT_PAGE_SIZE/ in add_padding_pages().

No functional changes.

v2: s/4096/I915_GTT_PAGE_SIZE/ (Matthew)

Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211026225105.2783797-4-imre.deak@intel.com

diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c b/drivers/gpu/drm/i915/gt/intel_ggtt.c
index 57c97554393b9a8942c114cf6e96980267c4cfe9..d2f45bca05d162d65a95e82463c0d0dcf10b39c4 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_ggtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c
@@ -1387,6 +1387,25 @@ err_st_alloc:
        return ERR_PTR(ret);
 }
 
+static struct scatterlist *
+add_padding_pages(unsigned int count,
+                 struct sg_table *st, struct scatterlist *sg)
+{
+       st->nents++;
+
+       /*
+        * The DE ignores the PTEs for the padding tiles, the sg entry
+        * here is just a convenience to indicate how many padding PTEs
+        * to insert at this spot.
+        */
+       sg_set_page(sg, NULL, count * I915_GTT_PAGE_SIZE, 0);
+       sg_dma_address(sg) = 0;
+       sg_dma_len(sg) = count * I915_GTT_PAGE_SIZE;
+       sg = sg_next(sg);
+
+       return sg;
+}
+
 static struct scatterlist *
 remap_pages(struct drm_i915_gem_object *obj,
            unsigned int offset, unsigned int alignment_pad,
@@ -1399,19 +1418,8 @@ remap_pages(struct drm_i915_gem_object *obj,
        if (!width || !height)
                return sg;
 
-       if (alignment_pad) {
-               st->nents++;
-
-               /*
-                * The DE ignores the PTEs for the padding tiles, the sg entry
-                * here is just a convenience to indicate how many padding PTEs
-                * to insert at this spot.
-                */
-               sg_set_page(sg, NULL, alignment_pad * 4096, 0);
-               sg_dma_address(sg) = 0;
-               sg_dma_len(sg) = alignment_pad * 4096;
-               sg = sg_next(sg);
-       }
+       if (alignment_pad)
+               sg = add_padding_pages(alignment_pad, st, sg);
 
        for (row = 0; row < height; row++) {
                unsigned int left = width * I915_GTT_PAGE_SIZE;
@@ -1448,22 +1456,45 @@ remap_pages(struct drm_i915_gem_object *obj,
                if (!left)
                        continue;
 
-               st->nents++;
-
-               /*
-                * The DE ignores the PTEs for the padding tiles, the sg entry
-                * here is just a conenience to indicate how many padding PTEs
-                * to insert at this spot.
-                */
-               sg_set_page(sg, NULL, left, 0);
-               sg_dma_address(sg) = 0;
-               sg_dma_len(sg) = left;
-               sg = sg_next(sg);
+               sg = add_padding_pages(left >> PAGE_SHIFT, st, sg);
        }
 
        return sg;
 }
 
+static struct scatterlist *
+remap_contiguous_pages(struct drm_i915_gem_object *obj,
+                      unsigned int obj_offset,
+                      unsigned int count,
+                      struct sg_table *st, struct scatterlist *sg)
+{
+       struct scatterlist *iter;
+       unsigned int offset;
+
+       iter = i915_gem_object_get_sg_dma(obj, obj_offset, &offset);
+       GEM_BUG_ON(!iter);
+
+       do {
+               unsigned int len;
+
+               len = min(sg_dma_len(iter) - (offset << PAGE_SHIFT),
+                         count << PAGE_SHIFT);
+               sg_set_page(sg, NULL, len, 0);
+               sg_dma_address(sg) =
+                       sg_dma_address(iter) + (offset << PAGE_SHIFT);
+               sg_dma_len(sg) = len;
+
+               st->nents++;
+               count -= len >> PAGE_SHIFT;
+               if (count == 0)
+                       return sg;
+
+               sg = __sg_next(sg);
+               iter = __sg_next(iter);
+               offset = 0;
+       } while (1);
+}
+
 static noinline struct sg_table *
 intel_remap_pages(struct intel_remapped_info *rem_info,
                  struct drm_i915_gem_object *obj)
@@ -1524,9 +1555,8 @@ intel_partial_pages(const struct i915_ggtt_view *view,
                    struct drm_i915_gem_object *obj)
 {
        struct sg_table *st;
-       struct scatterlist *sg, *iter;
+       struct scatterlist *sg;
        unsigned int count = view->partial.size;
-       unsigned int offset;
        int ret = -ENOMEM;
 
        st = kmalloc(sizeof(*st), GFP_KERNEL);
@@ -1537,34 +1567,14 @@ intel_partial_pages(const struct i915_ggtt_view *view,
        if (ret)
                goto err_sg_alloc;
 
-       iter = i915_gem_object_get_sg_dma(obj, view->partial.offset, &offset);
-       GEM_BUG_ON(!iter);
-
-       sg = st->sgl;
        st->nents = 0;
-       do {
-               unsigned int len;
 
-               len = min(sg_dma_len(iter) - (offset << PAGE_SHIFT),
-                         count << PAGE_SHIFT);
-               sg_set_page(sg, NULL, len, 0);
-               sg_dma_address(sg) =
-                       sg_dma_address(iter) + (offset << PAGE_SHIFT);
-               sg_dma_len(sg) = len;
+       sg = remap_contiguous_pages(obj, view->partial.offset, count, st, st->sgl);
 
-               st->nents++;
-               count -= len >> PAGE_SHIFT;
-               if (count == 0) {
-                       sg_mark_end(sg);
-                       i915_sg_trim(st); /* Drop any unused tail entries. */
+       sg_mark_end(sg);
+       i915_sg_trim(st); /* Drop any unused tail entries. */
 
-                       return st;
-               }
-
-               sg = __sg_next(sg);
-               iter = __sg_next(iter);
-               offset = 0;
-       } while (1);
+       return st;
 
 err_sg_alloc:
        kfree(st);