1 files changed, 185 insertions, 0 deletions

diff --git a/include/nvgpu/page_allocator.h b/include/nvgpu/page_allocator.h
new file mode 100644
index 0000000..a6e0205
--- /dev/null
+++ b/include/nvgpu/page_allocator.h
@@ -0,0 +1,185 @@
+/*
+ * Copyright (c) 2016-2017, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef PAGE_ALLOCATOR_PRIV_H
+#define PAGE_ALLOCATOR_PRIV_H
+
+#include <nvgpu/allocator.h>
+#include <nvgpu/nvgpu_mem.h>
+#include <nvgpu/kmem.h>
+#include <nvgpu/list.h>
+#include <nvgpu/rbtree.h>
+
+struct nvgpu_allocator;
+
+/*
+ * This allocator implements the ability to do SLAB style allocation since the
+ * GPU has two page sizes available - 4k and 64k/128k. When the default
+ * granularity is the large page size (64k/128k) small allocations become very
+ * space inefficient. This is most notable in PDE and PTE blocks which are 4k
+ * in size.
+ *
+ * Thus we need the ability to suballocate in 64k pages. The way we do this for
+ * the GPU is as follows. We have several buckets for sub-64K allocations:
+ *
+ *   B0 - 4k
+ *   B1 - 8k
+ *   B3 - 16k
+ *   B4 - 32k
+ *   B5 - 64k (for when large pages are 128k)
+ *
+ * When an allocation comes in for less than the large page size (from now on
+ * assumed to be 64k) the allocation is satisfied by one of the buckets.
+ */
+struct page_alloc_slab {
+        struct nvgpu_list_node empty;
+        struct nvgpu_list_node partial;
+        struct nvgpu_list_node full;
+
+        int nr_empty;
+        int nr_partial;
+        int nr_full;
+
+        u32 slab_size;
+};
+
+enum slab_page_state {
+        SP_EMPTY,
+        SP_PARTIAL,
+        SP_FULL,
+        SP_NONE
+};
+
+struct page_alloc_slab_page {
+        unsigned long bitmap;
+        u64 page_addr;
+        u32 slab_size;
+
+        u32 nr_objects;
+        u32 nr_objects_alloced;
+
+        enum slab_page_state state;
+
+        struct page_alloc_slab *owner;
+        struct nvgpu_list_node list_entry;
+};
+
+static inline struct page_alloc_slab_page *
+page_alloc_slab_page_from_list_entry(struct nvgpu_list_node *node)
+{
+        return (struct page_alloc_slab_page *)
+        ((uintptr_t)node - offsetof(struct page_alloc_slab_page, list_entry));
+};
+
+/*
+ * Struct to handle internal management of page allocation. It holds a list
+ * of the chunks of pages that make up the overall allocation - much like a
+ * scatter gather table.
+ */
+struct nvgpu_page_alloc {
+        /*
+         * nvgpu_sgt for describing the actual allocation. Convenient for
+         * GMMU mapping.
+         */
+        struct nvgpu_sgt sgt;
+
+        int nr_chunks;
+        u64 length;
+
+        /*
+         * Only useful for the RB tree - since the alloc may have discontiguous
+         * pages the base is essentially irrelevant except for the fact that it
+         * is guarenteed to be unique.
+         */
+        u64 base;
+
+        struct nvgpu_rbtree_node tree_entry;
+
+        /*
+         * Set if this is a slab alloc. Points back to the slab page that owns
+         * this particular allocation. nr_chunks will always be 1 if this is
+         * set.
+         */
+        struct page_alloc_slab_page *slab_page;
+};
+
+static inline struct nvgpu_page_alloc *
+nvgpu_page_alloc_from_rbtree_node(struct nvgpu_rbtree_node *node)
+{
+        return (struct nvgpu_page_alloc *)
+              ((uintptr_t)node - offsetof(struct nvgpu_page_alloc, tree_entry));
+};
+
+struct nvgpu_page_allocator {
+        struct nvgpu_allocator *owner;  /* Owner of this allocator. */
+
+        /*
+         * Use a buddy allocator to manage the allocation of the underlying
+         * pages. This lets us abstract the discontiguous allocation handling
+         * out of the annoyingly complicated buddy allocator.
+         */
+        struct nvgpu_allocator source_allocator;
+
+        /*
+         * Page params.
+         */
+        u64 base;
+        u64 length;
+        u64 page_size;
+        u32 page_shift;
+
+        struct nvgpu_rbtree_node *allocs;       /* Outstanding allocations. */
+
+        struct page_alloc_slab *slabs;
+        int nr_slabs;
+
+        struct nvgpu_kmem_cache *alloc_cache;
+        struct nvgpu_kmem_cache *slab_page_cache;
+
+        u64 flags;
+
+        /*
+         * Stat tracking.
+         */
+        u64 nr_allocs;
+        u64 nr_frees;
+        u64 nr_fixed_allocs;
+        u64 nr_fixed_frees;
+        u64 nr_slab_allocs;
+        u64 nr_slab_frees;
+        u64 pages_alloced;
+        u64 pages_freed;
+};
+
+static inline struct nvgpu_page_allocator *page_allocator(
+        struct nvgpu_allocator *a)
+{
+        return (struct nvgpu_page_allocator *)(a)->priv;
+}
+
+static inline struct nvgpu_allocator *palloc_owner(
+        struct nvgpu_page_allocator *a)
+{
+        return a->owner;
+}
+
+#endif