ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/drivers/gpu/drm/i915/i915_syncmap.c b/marvell/linux/drivers/gpu/drm/i915/i915_syncmap.c
new file mode 100644
index 0000000..60404db
--- /dev/null
+++ b/marvell/linux/drivers/gpu/drm/i915/i915_syncmap.c
@@ -0,0 +1,412 @@
+/*
+ * Copyright © 2017 Intel Corporation
+ *
+ * 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 (including the next
+ * paragraph) 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.
+ *
+ */
+
+#include <linux/slab.h>
+
+#include "i915_syncmap.h"
+
+#include "i915_gem.h" /* GEM_BUG_ON() */
+#include "i915_selftest.h"
+
+#define SHIFT ilog2(KSYNCMAP)
+#define MASK (KSYNCMAP - 1)
+
+/*
+ * struct i915_syncmap is a layer of a radixtree that maps a u64 fence
+ * context id to the last u32 fence seqno waited upon from that context.
+ * Unlike lib/radixtree it uses a parent pointer that allows traversal back to
+ * the root. This allows us to access the whole tree via a single pointer
+ * to the most recently used layer. We expect fence contexts to be dense
+ * and most reuse to be on the same i915_gem_context but on neighbouring
+ * engines (i.e. on adjacent contexts) and reuse the same leaf, a very
+ * effective lookup cache. If the new lookup is not on the same leaf, we
+ * expect it to be on the neighbouring branch.
+ *
+ * A leaf holds an array of u32 seqno, and has height 0. The bitmap field
+ * allows us to store whether a particular seqno is valid (i.e. allows us
+ * to distinguish unset from 0).
+ *
+ * A branch holds an array of layer pointers, and has height > 0, and always
+ * has at least 2 layers (either branches or leaves) below it.
+ *
+ * For example,
+ * for x in
+ * 0 1 2 0x10 0x11 0x200 0x201
+ * 0x500000 0x500001 0x503000 0x503001
+ * 0xE<<60:
+ * i915_syncmap_set(&sync, x, lower_32_bits(x));
+ * will build a tree like:
+ * 0xXXXXXXXXXXXXXXXX
+ * 0-> 0x0000000000XXXXXX
+ * | 0-> 0x0000000000000XXX
+ * | | 0-> 0x00000000000000XX
+ * | | | 0-> 0x000000000000000X 0:0, 1:1, 2:2
+ * | | | 1-> 0x000000000000001X 0:10, 1:11
+ * | | 2-> 0x000000000000020X 0:200, 1:201
+ * | 5-> 0x000000000050XXXX
+ * | 0-> 0x000000000050000X 0:500000, 1:500001
+ * | 3-> 0x000000000050300X 0:503000, 1:503001
+ * e-> 0xe00000000000000X e:e
+ */
+
+struct i915_syncmap {
+ u64 prefix;
+ unsigned int height;
+ unsigned int bitmap;
+ struct i915_syncmap *parent;
+ /*
+ * Following this header is an array of either seqno or child pointers:
+ * union {
+ * u32 seqno[KSYNCMAP];
+ * struct i915_syncmap *child[KSYNCMAP];
+ * };
+ */
+};
+
+/**
+ * i915_syncmap_init -- initialise the #i915_syncmap
+ * @root: pointer to the #i915_syncmap
+ */
+void i915_syncmap_init(struct i915_syncmap **root)
+{
+ BUILD_BUG_ON_NOT_POWER_OF_2(KSYNCMAP);
+ BUILD_BUG_ON_NOT_POWER_OF_2(SHIFT);
+ BUILD_BUG_ON(KSYNCMAP > BITS_PER_TYPE((*root)->bitmap));
+ *root = NULL;
+}
+
+static inline u32 *__sync_seqno(struct i915_syncmap *p)
+{
+ GEM_BUG_ON(p->height);
+ return (u32 *)(p + 1);
+}
+
+static inline struct i915_syncmap **__sync_child(struct i915_syncmap *p)
+{
+ GEM_BUG_ON(!p->height);
+ return (struct i915_syncmap **)(p + 1);
+}
+
+static inline unsigned int
+__sync_branch_idx(const struct i915_syncmap *p, u64 id)
+{
+ return (id >> p->height) & MASK;
+}
+
+static inline unsigned int
+__sync_leaf_idx(const struct i915_syncmap *p, u64 id)
+{
+ GEM_BUG_ON(p->height);
+ return id & MASK;
+}
+
+static inline u64 __sync_branch_prefix(const struct i915_syncmap *p, u64 id)
+{
+ return id >> p->height >> SHIFT;
+}
+
+static inline u64 __sync_leaf_prefix(const struct i915_syncmap *p, u64 id)
+{
+ GEM_BUG_ON(p->height);
+ return id >> SHIFT;
+}
+
+static inline bool seqno_later(u32 a, u32 b)
+{
+ return (s32)(a - b) >= 0;
+}
+
+/**
+ * i915_syncmap_is_later -- compare against the last know sync point
+ * @root: pointer to the #i915_syncmap
+ * @id: the context id (other timeline) we are synchronising to
+ * @seqno: the sequence number along the other timeline
+ *
+ * If we have already synchronised this @root timeline with another (@id) then
+ * we can omit any repeated or earlier synchronisation requests. If the two
+ * timelines are already coupled, we can also omit the dependency between the
+ * two as that is already known via the timeline.
+ *
+ * Returns true if the two timelines are already synchronised wrt to @seqno,
+ * false if not and the synchronisation must be emitted.
+ */
+bool i915_syncmap_is_later(struct i915_syncmap **root, u64 id, u32 seqno)
+{
+ struct i915_syncmap *p;
+ unsigned int idx;
+
+ p = *root;
+ if (!p)
+ return false;
+
+ if (likely(__sync_leaf_prefix(p, id) == p->prefix))
+ goto found;
+
+ /* First climb the tree back to a parent branch */
+ do {
+ p = p->parent;
+ if (!p)
+ return false;
+
+ if (__sync_branch_prefix(p, id) == p->prefix)
+ break;
+ } while (1);
+
+ /* And then descend again until we find our leaf */
+ do {
+ if (!p->height)
+ break;
+
+ p = __sync_child(p)[__sync_branch_idx(p, id)];
+ if (!p)
+ return false;
+
+ if (__sync_branch_prefix(p, id) != p->prefix)
+ return false;
+ } while (1);
+
+ *root = p;
+found:
+ idx = __sync_leaf_idx(p, id);
+ if (!(p->bitmap & BIT(idx)))
+ return false;
+
+ return seqno_later(__sync_seqno(p)[idx], seqno);
+}
+
+static struct i915_syncmap *
+__sync_alloc_leaf(struct i915_syncmap *parent, u64 id)
+{
+ struct i915_syncmap *p;
+
+ p = kmalloc(sizeof(*p) + KSYNCMAP * sizeof(u32), GFP_KERNEL);
+ if (unlikely(!p))
+ return NULL;
+
+ p->parent = parent;
+ p->height = 0;
+ p->bitmap = 0;
+ p->prefix = __sync_leaf_prefix(p, id);
+ return p;
+}
+
+static inline void __sync_set_seqno(struct i915_syncmap *p, u64 id, u32 seqno)
+{
+ unsigned int idx = __sync_leaf_idx(p, id);
+
+ p->bitmap |= BIT(idx);
+ __sync_seqno(p)[idx] = seqno;
+}
+
+static inline void __sync_set_child(struct i915_syncmap *p,
+ unsigned int idx,
+ struct i915_syncmap *child)
+{
+ p->bitmap |= BIT(idx);
+ __sync_child(p)[idx] = child;
+}
+
+static noinline int __sync_set(struct i915_syncmap **root, u64 id, u32 seqno)
+{
+ struct i915_syncmap *p = *root;
+ unsigned int idx;
+
+ if (!p) {
+ p = __sync_alloc_leaf(NULL, id);
+ if (unlikely(!p))
+ return -ENOMEM;
+
+ goto found;
+ }
+
+ /* Caller handled the likely cached case */
+ GEM_BUG_ON(__sync_leaf_prefix(p, id) == p->prefix);
+
+ /* Climb back up the tree until we find a common prefix */
+ do {
+ if (!p->parent)
+ break;
+
+ p = p->parent;
+
+ if (__sync_branch_prefix(p, id) == p->prefix)
+ break;
+ } while (1);
+
+ /*
+ * No shortcut, we have to descend the tree to find the right layer
+ * containing this fence.
+ *
+ * Each layer in the tree holds 16 (KSYNCMAP) pointers, either fences
+ * or lower layers. Leaf nodes (height = 0) contain the fences, all
+ * other nodes (height > 0) are internal layers that point to a lower
+ * node. Each internal layer has at least 2 descendents.
+ *
+ * Starting at the top, we check whether the current prefix matches. If
+ * it doesn't, we have gone past our target and need to insert a join
+ * into the tree, and a new leaf node for the target as a descendent
+ * of the join, as well as the original layer.
+ *
+ * The matching prefix means we are still following the right branch
+ * of the tree. If it has height 0, we have found our leaf and just
+ * need to replace the fence slot with ourselves. If the height is
+ * not zero, our slot contains the next layer in the tree (unless
+ * it is empty, in which case we can add ourselves as a new leaf).
+ * As descend the tree the prefix grows (and height decreases).
+ */
+ do {
+ struct i915_syncmap *next;
+
+ if (__sync_branch_prefix(p, id) != p->prefix) {
+ unsigned int above;
+
+ /* Insert a join above the current layer */
+ next = kzalloc(sizeof(*next) + KSYNCMAP * sizeof(next),
+ GFP_KERNEL);
+ if (unlikely(!next))
+ return -ENOMEM;
+
+ /* Compute the height at which these two diverge */
+ above = fls64(__sync_branch_prefix(p, id) ^ p->prefix);
+ above = round_up(above, SHIFT);
+ next->height = above + p->height;
+ next->prefix = __sync_branch_prefix(next, id);
+
+ /* Insert the join into the parent */
+ if (p->parent) {
+ idx = __sync_branch_idx(p->parent, id);
+ __sync_child(p->parent)[idx] = next;
+ GEM_BUG_ON(!(p->parent->bitmap & BIT(idx)));
+ }
+ next->parent = p->parent;
+
+ /* Compute the idx of the other branch, not our id! */
+ idx = p->prefix >> (above - SHIFT) & MASK;
+ __sync_set_child(next, idx, p);
+ p->parent = next;
+
+ /* Ascend to the join */
+ p = next;
+ } else {
+ if (!p->height)
+ break;
+ }
+
+ /* Descend into the next layer */
+ GEM_BUG_ON(!p->height);
+ idx = __sync_branch_idx(p, id);
+ next = __sync_child(p)[idx];
+ if (!next) {
+ next = __sync_alloc_leaf(p, id);
+ if (unlikely(!next))
+ return -ENOMEM;
+
+ __sync_set_child(p, idx, next);
+ p = next;
+ break;
+ }
+
+ p = next;
+ } while (1);
+
+found:
+ GEM_BUG_ON(p->prefix != __sync_leaf_prefix(p, id));
+ __sync_set_seqno(p, id, seqno);
+ *root = p;
+ return 0;
+}
+
+/**
+ * i915_syncmap_set -- mark the most recent syncpoint between contexts
+ * @root: pointer to the #i915_syncmap
+ * @id: the context id (other timeline) we have synchronised to
+ * @seqno: the sequence number along the other timeline
+ *
+ * When we synchronise this @root timeline with another (@id), we also know
+ * that we have synchronized with all previous seqno along that timeline. If
+ * we then have a request to synchronise with the same seqno or older, we can
+ * omit it, see i915_syncmap_is_later()
+ *
+ * Returns 0 on success, or a negative error code.
+ */
+int i915_syncmap_set(struct i915_syncmap **root, u64 id, u32 seqno)
+{
+ struct i915_syncmap *p = *root;
+
+ /*
+ * We expect to be called in sequence following is_later(id), which
+ * should have preloaded the root for us.
+ */
+ if (likely(p && __sync_leaf_prefix(p, id) == p->prefix)) {
+ __sync_set_seqno(p, id, seqno);
+ return 0;
+ }
+
+ return __sync_set(root, id, seqno);
+}
+
+static void __sync_free(struct i915_syncmap *p)
+{
+ if (p->height) {
+ unsigned int i;
+
+ while ((i = ffs(p->bitmap))) {
+ p->bitmap &= ~0u << i;
+ __sync_free(__sync_child(p)[i - 1]);
+ }
+ }
+
+ kfree(p);
+}
+
+/**
+ * i915_syncmap_free -- free all memory associated with the syncmap
+ * @root: pointer to the #i915_syncmap
+ *
+ * Either when the timeline is to be freed and we no longer need the sync
+ * point tracking, or when the fences are all known to be signaled and the
+ * sync point tracking is redundant, we can free the #i915_syncmap to recover
+ * its allocations.
+ *
+ * Will reinitialise the @root pointer so that the #i915_syncmap is ready for
+ * reuse.
+ */
+void i915_syncmap_free(struct i915_syncmap **root)
+{
+ struct i915_syncmap *p;
+
+ p = *root;
+ if (!p)
+ return;
+
+ while (p->parent)
+ p = p->parent;
+
+ __sync_free(p);
+ *root = NULL;
+}
+
+#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
+#include "selftests/i915_syncmap.c"
+#endif