I don't see the advantage over just increasing the alignment requirements in the driver side?
That would be a one liner if I'm not completely mistaken.
Regards,
Christian.
Am 27.11.19 um 09:31 schrieb Thomas HellstrÃm (VMware):
From: Thomas Hellstrom <thellstrom@xxxxxxxxxx>
Using huge page-table entries require that the start of a buffer object
is huge page size aligned. So introduce a ttm_bo_man_get_node_huge()
function that attempts to accomplish this for allocations that are larger
than the huge page size, and provide a new range-manager instance that
uses that function.
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Ralph Campbell <rcampbell@xxxxxxxxxx>
Cc: "JÃrÃme Glisse" <jglisse@xxxxxxxxxx>
Cc: "Christian KÃnig" <christian.koenig@xxxxxxx>
Signed-off-by: Thomas Hellstrom <thellstrom@xxxxxxxxxx>
---
 drivers/gpu/drm/ttm/ttm_bo_manager.c | 92 ++++++++++++++++++++++++++++
 include/drm/ttm/ttm_bo_driver.h | 1 +
 2 files changed, 93 insertions(+)
diff --git a/drivers/gpu/drm/ttm/ttm_bo_manager.c b/drivers/gpu/drm/ttm/ttm_bo_manager.c
index 18d3debcc949..26aa1a2ae7f1 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_manager.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_manager.c
@@ -89,6 +89,89 @@ static int ttm_bo_man_get_node(struct ttm_mem_type_manager *man,
ÂÂÂÂÂ return 0;
 }
 +#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static int ttm_bo_insert_aligned(struct drm_mm *mm, struct drm_mm_node *node,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ unsigned long align_pages,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ const struct ttm_place *place,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ struct ttm_mem_reg *mem,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ unsigned long lpfn,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ enum drm_mm_insert_mode mode)
+{
+ÂÂÂ if (align_pages >= mem->page_alignment &&
+ÂÂÂÂÂÂÂ (!mem->page_alignment || align_pages % mem->page_alignment == 0)) {
+ÂÂÂÂÂÂÂ return drm_mm_insert_node_in_range(mm, node,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ mem->num_pages,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ align_pages, 0,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ place->fpfn, lpfn, mode);
+ÂÂÂ }
+
+ÂÂÂ return -ENOSPC;
+}
+
+static int ttm_bo_man_get_node_huge(struct ttm_mem_type_manager *man,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ struct ttm_buffer_object *bo,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ const struct ttm_place *place,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ struct ttm_mem_reg *mem)
+{
+ÂÂÂ struct ttm_range_manager *rman = (struct ttm_range_manager *) man->priv;
+ÂÂÂ struct drm_mm *mm = &rman->mm;
+ÂÂÂ struct drm_mm_node *node;
+ÂÂÂ unsigned long align_pages;
+ÂÂÂ unsigned long lpfn;
+ÂÂÂ enum drm_mm_insert_mode mode = DRM_MM_INSERT_BEST;
+ÂÂÂ int ret;
+
+ÂÂÂ node = kzalloc(sizeof(*node), GFP_KERNEL);
+ÂÂÂ if (!node)
+ÂÂÂÂÂÂÂ return -ENOMEM;
+
+ÂÂÂ lpfn = place->lpfn;
+ÂÂÂ if (!lpfn)
+ÂÂÂÂÂÂÂ lpfn = man->size;
+
+ÂÂÂ mode = DRM_MM_INSERT_BEST;
+ÂÂÂ if (place->flags & TTM_PL_FLAG_TOPDOWN)
+ÂÂÂÂÂÂÂ mode = DRM_MM_INSERT_HIGH;
+
+ÂÂÂ spin_lock(&rman->lock);
+ÂÂÂ if (IS_ENABLED(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD)) {
+ÂÂÂÂÂÂÂ align_pages = (HPAGE_PUD_SIZE >> PAGE_SHIFT);
+ÂÂÂÂÂÂÂ if (mem->num_pages >= align_pages) {
+ÂÂÂÂÂÂÂÂÂÂÂ ret = ttm_bo_insert_aligned(mm, node, align_pages,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ place, mem, lpfn, mode);
+ÂÂÂÂÂÂÂÂÂÂÂ if (!ret)
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ goto found_unlock;
+ÂÂÂÂÂÂÂ }
+ÂÂÂ }
+
+ÂÂÂ align_pages = (HPAGE_PMD_SIZE >> PAGE_SHIFT);
+ÂÂÂ if (mem->num_pages >= align_pages) {
+ÂÂÂÂÂÂÂ ret = ttm_bo_insert_aligned(mm, node, align_pages, place, mem,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ lpfn, mode);
+ÂÂÂÂÂÂÂ if (!ret)
+ÂÂÂÂÂÂÂÂÂÂÂ goto found_unlock;
+ÂÂÂ }
+
+ÂÂÂ ret = drm_mm_insert_node_in_range(mm, node, mem->num_pages,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ mem->page_alignment, 0,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ place->fpfn, lpfn, mode);
+found_unlock:
+ÂÂÂ spin_unlock(&rman->lock);
+
+ÂÂÂ if (unlikely(ret)) {
+ÂÂÂÂÂÂÂ kfree(node);
+ÂÂÂ } else {
+ÂÂÂÂÂÂÂ mem->mm_node = node;
+ÂÂÂÂÂÂÂ mem->start = node->start;
+ÂÂÂ }
+
+ÂÂÂ return 0;
+}
+#else
+#define ttm_bo_man_get_node_huge ttm_bo_man_get_node
+#endif
+
+
 static void ttm_bo_man_put_node(struct ttm_mem_type_manager *man,
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ struct ttm_mem_reg *mem)
 {
@@ -154,3 +237,12 @@ const struct ttm_mem_type_manager_func ttm_bo_manager_func = {
ÂÂÂÂÂ .debug = ttm_bo_man_debug
 };
 EXPORT_SYMBOL(ttm_bo_manager_func);
+
+const struct ttm_mem_type_manager_func ttm_bo_manager_huge_func = {
+ÂÂÂ .init = ttm_bo_man_init,
+ÂÂÂ .takedown = ttm_bo_man_takedown,
+ÂÂÂ .get_node = ttm_bo_man_get_node_huge,
+ÂÂÂ .put_node = ttm_bo_man_put_node,
+ÂÂÂ .debug = ttm_bo_man_debug
+};
+EXPORT_SYMBOL(ttm_bo_manager_huge_func);
diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h
index cac7a8a0825a..868bd0d4be6a 100644
--- a/include/drm/ttm/ttm_bo_driver.h
+++ b/include/drm/ttm/ttm_bo_driver.h
@@ -888,5 +888,6 @@ int ttm_bo_pipeline_gutting(struct ttm_buffer_object *bo);
 pgprot_t ttm_io_prot(uint32_t caching_flags, pgprot_t tmp);
  extern const struct ttm_mem_type_manager_func ttm_bo_manager_func;
+extern const struct ttm_mem_type_manager_func ttm_bo_manager_huge_func;
  #endif