drm/i915: Split out i915_vma.c

As a side product, had to split two other files;
- i915_gem_fence_reg.h
- i915_gem_object.h (only parts that needed immediate untanglement)

I tried to move code in as big chunks as possible, to make review
easier. i915_vma_compare was moved to a header temporarily.

v2:
- Use i915_gem_fence_reg.{c,h}

v3:
- Rebased

v4:
- Fix building when DEBUG_GEM is enabled by reordering a bit.

Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1478861034-30643-1-git-send-email-joonas.lahtinen@linux.intel.com
diff --git a/drivers/gpu/drm/i915/i915_gem_object.h b/drivers/gpu/drm/i915/i915_gem_object.h
new file mode 100644
index 0000000..014f803
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_gem_object.h
@@ -0,0 +1,337 @@
+/*
+ * Copyright © 2016 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.
+ *
+ */
+
+#ifndef __I915_GEM_OBJECT_H__
+#define __I915_GEM_OBJECT_H__
+
+#include <linux/reservation.h>
+
+#include <drm/drm_vma_manager.h>
+#include <drm/drm_gem.h>
+#include <drm/drmP.h>
+
+#include <drm/i915_drm.h>
+
+struct drm_i915_gem_object_ops {
+	unsigned int flags;
+#define I915_GEM_OBJECT_HAS_STRUCT_PAGE 0x1
+#define I915_GEM_OBJECT_IS_SHRINKABLE   0x2
+
+	/* Interface between the GEM object and its backing storage.
+	 * get_pages() is called once prior to the use of the associated set
+	 * of pages before to binding them into the GTT, and put_pages() is
+	 * called after we no longer need them. As we expect there to be
+	 * associated cost with migrating pages between the backing storage
+	 * and making them available for the GPU (e.g. clflush), we may hold
+	 * onto the pages after they are no longer referenced by the GPU
+	 * in case they may be used again shortly (for example migrating the
+	 * pages to a different memory domain within the GTT). put_pages()
+	 * will therefore most likely be called when the object itself is
+	 * being released or under memory pressure (where we attempt to
+	 * reap pages for the shrinker).
+	 */
+	struct sg_table *(*get_pages)(struct drm_i915_gem_object *);
+	void (*put_pages)(struct drm_i915_gem_object *, struct sg_table *);
+
+	int (*dmabuf_export)(struct drm_i915_gem_object *);
+	void (*release)(struct drm_i915_gem_object *);
+};
+
+struct drm_i915_gem_object {
+	struct drm_gem_object base;
+
+	const struct drm_i915_gem_object_ops *ops;
+
+	/** List of VMAs backed by this object */
+	struct list_head vma_list;
+	struct rb_root vma_tree;
+
+	/** Stolen memory for this object, instead of being backed by shmem. */
+	struct drm_mm_node *stolen;
+	struct list_head global_link;
+	union {
+		struct rcu_head rcu;
+		struct llist_node freed;
+	};
+
+	/**
+	 * Whether the object is currently in the GGTT mmap.
+	 */
+	struct list_head userfault_link;
+
+	/** Used in execbuf to temporarily hold a ref */
+	struct list_head obj_exec_link;
+
+	struct list_head batch_pool_link;
+
+	unsigned long flags;
+
+	/**
+	 * Have we taken a reference for the object for incomplete GPU
+	 * activity?
+	 */
+#define I915_BO_ACTIVE_REF 0
+
+	/*
+	 * Is the object to be mapped as read-only to the GPU
+	 * Only honoured if hardware has relevant pte bit
+	 */
+	unsigned long gt_ro:1;
+	unsigned int cache_level:3;
+	unsigned int cache_dirty:1;
+
+	atomic_t frontbuffer_bits;
+	unsigned int frontbuffer_ggtt_origin; /* write once */
+
+	/** Current tiling stride for the object, if it's tiled. */
+	unsigned int tiling_and_stride;
+#define FENCE_MINIMUM_STRIDE 128 /* See i915_tiling_ok() */
+#define TILING_MASK (FENCE_MINIMUM_STRIDE-1)
+#define STRIDE_MASK (~TILING_MASK)
+
+	/** Count of VMA actually bound by this object */
+	unsigned int bind_count;
+	unsigned int active_count;
+	unsigned int pin_display;
+
+	struct {
+		struct mutex lock; /* protects the pages and their use */
+		atomic_t pages_pin_count;
+
+		struct sg_table *pages;
+		void *mapping;
+
+		struct i915_gem_object_page_iter {
+			struct scatterlist *sg_pos;
+			unsigned int sg_idx; /* in pages, but 32bit eek! */
+
+			struct radix_tree_root radix;
+			struct mutex lock; /* protects this cache */
+		} get_page;
+
+		/**
+		 * Advice: are the backing pages purgeable?
+		 */
+		unsigned int madv:2;
+
+		/**
+		 * This is set if the object has been written to since the
+		 * pages were last acquired.
+		 */
+		bool dirty:1;
+
+		/**
+		 * This is set if the object has been pinned due to unknown
+		 * swizzling.
+		 */
+		bool quirked:1;
+	} mm;
+
+	/** Breadcrumb of last rendering to the buffer.
+	 * There can only be one writer, but we allow for multiple readers.
+	 * If there is a writer that necessarily implies that all other
+	 * read requests are complete - but we may only be lazily clearing
+	 * the read requests. A read request is naturally the most recent
+	 * request on a ring, so we may have two different write and read
+	 * requests on one ring where the write request is older than the
+	 * read request. This allows for the CPU to read from an active
+	 * buffer by only waiting for the write to complete.
+	 */
+	struct reservation_object *resv;
+
+	/** References from framebuffers, locks out tiling changes. */
+	unsigned long framebuffer_references;
+
+	/** Record of address bit 17 of each page at last unbind. */
+	unsigned long *bit_17;
+
+	struct i915_gem_userptr {
+		uintptr_t ptr;
+		unsigned read_only :1;
+
+		struct i915_mm_struct *mm;
+		struct i915_mmu_object *mmu_object;
+		struct work_struct *work;
+	} userptr;
+
+	/** for phys allocated objects */
+	struct drm_dma_handle *phys_handle;
+
+	struct reservation_object __builtin_resv;
+};
+
+static inline struct drm_i915_gem_object *
+to_intel_bo(struct drm_gem_object *gem)
+{
+	/* Assert that to_intel_bo(NULL) == NULL */
+	BUILD_BUG_ON(offsetof(struct drm_i915_gem_object, base));
+
+	return container_of(gem, struct drm_i915_gem_object, base);
+}
+
+/**
+ * i915_gem_object_lookup_rcu - look up a temporary GEM object from its handle
+ * @filp: DRM file private date
+ * @handle: userspace handle
+ *
+ * Returns:
+ *
+ * A pointer to the object named by the handle if such exists on @filp, NULL
+ * otherwise. This object is only valid whilst under the RCU read lock, and
+ * note carefully the object may be in the process of being destroyed.
+ */
+static inline struct drm_i915_gem_object *
+i915_gem_object_lookup_rcu(struct drm_file *file, u32 handle)
+{
+#ifdef CONFIG_LOCKDEP
+	WARN_ON(debug_locks && !lock_is_held(&rcu_lock_map));
+#endif
+	return idr_find(&file->object_idr, handle);
+}
+
+static inline struct drm_i915_gem_object *
+i915_gem_object_lookup(struct drm_file *file, u32 handle)
+{
+	struct drm_i915_gem_object *obj;
+
+	rcu_read_lock();
+	obj = i915_gem_object_lookup_rcu(file, handle);
+	if (obj && !kref_get_unless_zero(&obj->base.refcount))
+		obj = NULL;
+	rcu_read_unlock();
+
+	return obj;
+}
+
+__deprecated
+extern struct drm_gem_object *
+drm_gem_object_lookup(struct drm_file *file, u32 handle);
+
+__attribute__((nonnull))
+static inline struct drm_i915_gem_object *
+i915_gem_object_get(struct drm_i915_gem_object *obj)
+{
+	drm_gem_object_reference(&obj->base);
+	return obj;
+}
+
+__deprecated
+extern void drm_gem_object_reference(struct drm_gem_object *);
+
+__attribute__((nonnull))
+static inline void
+i915_gem_object_put(struct drm_i915_gem_object *obj)
+{
+	__drm_gem_object_unreference(&obj->base);
+}
+
+__deprecated
+extern void drm_gem_object_unreference(struct drm_gem_object *);
+
+__deprecated
+extern void drm_gem_object_unreference_unlocked(struct drm_gem_object *);
+
+static inline bool
+i915_gem_object_is_dead(const struct drm_i915_gem_object *obj)
+{
+	return atomic_read(&obj->base.refcount.refcount) == 0;
+}
+
+static inline bool
+i915_gem_object_has_struct_page(const struct drm_i915_gem_object *obj)
+{
+	return obj->ops->flags & I915_GEM_OBJECT_HAS_STRUCT_PAGE;
+}
+
+static inline bool
+i915_gem_object_is_shrinkable(const struct drm_i915_gem_object *obj)
+{
+	return obj->ops->flags & I915_GEM_OBJECT_IS_SHRINKABLE;
+}
+
+static inline bool
+i915_gem_object_is_active(const struct drm_i915_gem_object *obj)
+{
+	return obj->active_count;
+}
+
+static inline bool
+i915_gem_object_has_active_reference(const struct drm_i915_gem_object *obj)
+{
+	return test_bit(I915_BO_ACTIVE_REF, &obj->flags);
+}
+
+static inline void
+i915_gem_object_set_active_reference(struct drm_i915_gem_object *obj)
+{
+	lockdep_assert_held(&obj->base.dev->struct_mutex);
+	__set_bit(I915_BO_ACTIVE_REF, &obj->flags);
+}
+
+static inline void
+i915_gem_object_clear_active_reference(struct drm_i915_gem_object *obj)
+{
+	lockdep_assert_held(&obj->base.dev->struct_mutex);
+	__clear_bit(I915_BO_ACTIVE_REF, &obj->flags);
+}
+
+void __i915_gem_object_release_unless_active(struct drm_i915_gem_object *obj);
+
+static inline unsigned int
+i915_gem_object_get_tiling(struct drm_i915_gem_object *obj)
+{
+	return obj->tiling_and_stride & TILING_MASK;
+}
+
+static inline bool
+i915_gem_object_is_tiled(struct drm_i915_gem_object *obj)
+{
+	return i915_gem_object_get_tiling(obj) != I915_TILING_NONE;
+}
+
+static inline unsigned int
+i915_gem_object_get_stride(struct drm_i915_gem_object *obj)
+{
+	return obj->tiling_and_stride & STRIDE_MASK;
+}
+
+static inline struct intel_engine_cs *
+i915_gem_object_last_write_engine(struct drm_i915_gem_object *obj)
+{
+	struct intel_engine_cs *engine = NULL;
+	struct dma_fence *fence;
+
+	rcu_read_lock();
+	fence = reservation_object_get_excl_rcu(obj->resv);
+	rcu_read_unlock();
+
+	if (fence && dma_fence_is_i915(fence) && !dma_fence_is_signaled(fence))
+		engine = to_request(fence)->engine;
+	dma_fence_put(fence);
+
+	return engine;
+}
+
+#endif
+