1 files changed, 438 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem_evict.c b/drivers/gpu/drm/i915/i915_gem_evict.c
new file mode 100644
index 000000000..02b83a5ed
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_gem_evict.c
@@ -0,0 +1,438 @@
+/*
+ * Copyright © 2008-2010 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.
+ *
+ * Authors:
+ *    Eric Anholt <eric@anholt.net>
+ *    Chris Wilson <chris@chris-wilson.co.uuk>
+ *
+ */
+
+#include <drm/drmP.h>
+#include <drm/i915_drm.h>
+
+#include "i915_drv.h"
+#include "intel_drv.h"
+#include "i915_trace.h"
+
+I915_SELFTEST_DECLARE(static struct igt_evict_ctl {
+	bool fail_if_busy:1;
+} igt_evict_ctl;)
+
+static bool ggtt_is_idle(struct drm_i915_private *i915)
+{
+       struct intel_engine_cs *engine;
+       enum intel_engine_id id;
+
+       if (i915->gt.active_requests)
+	       return false;
+
+       for_each_engine(engine, i915, id) {
+	       if (!intel_engine_has_kernel_context(engine))
+		       return false;
+       }
+
+       return true;
+}
+
+static int ggtt_flush(struct drm_i915_private *i915)
+{
+	int err;
+
+	/* Not everything in the GGTT is tracked via vma (otherwise we
+	 * could evict as required with minimal stalling) so we are forced
+	 * to idle the GPU and explicitly retire outstanding requests in
+	 * the hopes that we can then remove contexts and the like only
+	 * bound by their active reference.
+	 */
+	err = i915_gem_switch_to_kernel_context(i915);
+	if (err)
+		return err;
+
+	err = i915_gem_wait_for_idle(i915,
+				     I915_WAIT_INTERRUPTIBLE |
+				     I915_WAIT_LOCKED,
+				     MAX_SCHEDULE_TIMEOUT);
+	if (err)
+		return err;
+
+	GEM_BUG_ON(!ggtt_is_idle(i915));
+	return 0;
+}
+
+static bool
+mark_free(struct drm_mm_scan *scan,
+	  struct i915_vma *vma,
+	  unsigned int flags,
+	  struct list_head *unwind)
+{
+	if (i915_vma_is_pinned(vma))
+		return false;
+
+	if (flags & PIN_NONFAULT && i915_vma_has_userfault(vma))
+		return false;
+
+	list_add(&vma->evict_link, unwind);
+	return drm_mm_scan_add_block(scan, &vma->node);
+}
+
+/**
+ * i915_gem_evict_something - Evict vmas to make room for binding a new one
+ * @vm: address space to evict from
+ * @min_size: size of the desired free space
+ * @alignment: alignment constraint of the desired free space
+ * @cache_level: cache_level for the desired space
+ * @start: start (inclusive) of the range from which to evict objects
+ * @end: end (exclusive) of the range from which to evict objects
+ * @flags: additional flags to control the eviction algorithm
+ *
+ * This function will try to evict vmas until a free space satisfying the
+ * requirements is found. Callers must check first whether any such hole exists
+ * already before calling this function.
+ *
+ * This function is used by the object/vma binding code.
+ *
+ * Since this function is only used to free up virtual address space it only
+ * ignores pinned vmas, and not object where the backing storage itself is
+ * pinned. Hence obj->pages_pin_count does not protect against eviction.
+ *
+ * To clarify: This is for freeing up virtual address space, not for freeing
+ * memory in e.g. the shrinker.
+ */
+int
+i915_gem_evict_something(struct i915_address_space *vm,
+			 u64 min_size, u64 alignment,
+			 unsigned cache_level,
+			 u64 start, u64 end,
+			 unsigned flags)
+{
+	struct drm_i915_private *dev_priv = vm->i915;
+	struct drm_mm_scan scan;
+	struct list_head eviction_list;
+	struct list_head *phases[] = {
+		&vm->inactive_list,
+		&vm->active_list,
+		NULL,
+	}, **phase;
+	struct i915_vma *vma, *next;
+	struct drm_mm_node *node;
+	enum drm_mm_insert_mode mode;
+	int ret;
+
+	lockdep_assert_held(&vm->i915->drm.struct_mutex);
+	trace_i915_gem_evict(vm, min_size, alignment, flags);
+
+	/*
+	 * The goal is to evict objects and amalgamate space in LRU order.
+	 * The oldest idle objects reside on the inactive list, which is in
+	 * retirement order. The next objects to retire are those in flight,
+	 * on the active list, again in retirement order.
+	 *
+	 * The retirement sequence is thus:
+	 *   1. Inactive objects (already retired)
+	 *   2. Active objects (will stall on unbinding)
+	 *
+	 * On each list, the oldest objects lie at the HEAD with the freshest
+	 * object on the TAIL.
+	 */
+	mode = DRM_MM_INSERT_BEST;
+	if (flags & PIN_HIGH)
+		mode = DRM_MM_INSERT_HIGH;
+	if (flags & PIN_MAPPABLE)
+		mode = DRM_MM_INSERT_LOW;
+	drm_mm_scan_init_with_range(&scan, &vm->mm,
+				    min_size, alignment, cache_level,
+				    start, end, mode);
+
+	/*
+	 * Retire before we search the active list. Although we have
+	 * reasonable accuracy in our retirement lists, we may have
+	 * a stray pin (preventing eviction) that can only be resolved by
+	 * retiring.
+	 */
+	if (!(flags & PIN_NONBLOCK))
+		i915_retire_requests(dev_priv);
+	else
+		phases[1] = NULL;
+
+search_again:
+	INIT_LIST_HEAD(&eviction_list);
+	phase = phases;
+	do {
+		list_for_each_entry(vma, *phase, vm_link)
+			if (mark_free(&scan, vma, flags, &eviction_list))
+				goto found;
+	} while (*++phase);
+
+	/* Nothing found, clean up and bail out! */
+	list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {
+		ret = drm_mm_scan_remove_block(&scan, &vma->node);
+		BUG_ON(ret);
+	}
+
+	/*
+	 * Can we unpin some objects such as idle hw contents,
+	 * or pending flips? But since only the GGTT has global entries
+	 * such as scanouts, rinbuffers and contexts, we can skip the
+	 * purge when inspecting per-process local address spaces.
+	 */
+	if (!i915_is_ggtt(vm) || flags & PIN_NONBLOCK)
+		return -ENOSPC;
+
+	/*
+	 * Not everything in the GGTT is tracked via VMA using
+	 * i915_vma_move_to_active(), otherwise we could evict as required
+	 * with minimal stalling. Instead we are forced to idle the GPU and
+	 * explicitly retire outstanding requests which will then remove
+	 * the pinning for active objects such as contexts and ring,
+	 * enabling us to evict them on the next iteration.
+	 *
+	 * To ensure that all user contexts are evictable, we perform
+	 * a switch to the perma-pinned kernel context. This all also gives
+	 * us a termination condition, when the last retired context is
+	 * the kernel's there is no more we can evict.
+	 */
+	if (!ggtt_is_idle(dev_priv)) {
+		if (I915_SELFTEST_ONLY(igt_evict_ctl.fail_if_busy))
+			return -EBUSY;
+
+		ret = ggtt_flush(dev_priv);
+		if (ret)
+			return ret;
+
+		cond_resched();
+		goto search_again;
+	}
+
+	/*
+	 * If we still have pending pageflip completions, drop
+	 * back to userspace to give our workqueues time to
+	 * acquire our locks and unpin the old scanouts.
+	 */
+	return intel_has_pending_fb_unpin(dev_priv) ? -EAGAIN : -ENOSPC;
+
+found:
+	/* drm_mm doesn't allow any other other operations while
+	 * scanning, therefore store to-be-evicted objects on a
+	 * temporary list and take a reference for all before
+	 * calling unbind (which may remove the active reference
+	 * of any of our objects, thus corrupting the list).
+	 */
+	list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {
+		if (drm_mm_scan_remove_block(&scan, &vma->node))
+			__i915_vma_pin(vma);
+		else
+			list_del(&vma->evict_link);
+	}
+
+	/* Unbinding will emit any required flushes */
+	ret = 0;
+	list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {
+		__i915_vma_unpin(vma);
+		if (ret == 0)
+			ret = i915_vma_unbind(vma);
+	}
+
+	while (ret == 0 && (node = drm_mm_scan_color_evict(&scan))) {
+		vma = container_of(node, struct i915_vma, node);
+		ret = i915_vma_unbind(vma);
+	}
+
+	return ret;
+}
+
+/**
+ * i915_gem_evict_for_vma - Evict vmas to make room for binding a new one
+ * @vm: address space to evict from
+ * @target: range (and color) to evict for
+ * @flags: additional flags to control the eviction algorithm
+ *
+ * This function will try to evict vmas that overlap the target node.
+ *
+ * To clarify: This is for freeing up virtual address space, not for freeing
+ * memory in e.g. the shrinker.
+ */
+int i915_gem_evict_for_node(struct i915_address_space *vm,
+			    struct drm_mm_node *target,
+			    unsigned int flags)
+{
+	LIST_HEAD(eviction_list);
+	struct drm_mm_node *node;
+	u64 start = target->start;
+	u64 end = start + target->size;
+	struct i915_vma *vma, *next;
+	bool check_color;
+	int ret = 0;
+
+	lockdep_assert_held(&vm->i915->drm.struct_mutex);
+	GEM_BUG_ON(!IS_ALIGNED(start, I915_GTT_PAGE_SIZE));
+	GEM_BUG_ON(!IS_ALIGNED(end, I915_GTT_PAGE_SIZE));
+
+	trace_i915_gem_evict_node(vm, target, flags);
+
+	/* Retire before we search the active list. Although we have
+	 * reasonable accuracy in our retirement lists, we may have
+	 * a stray pin (preventing eviction) that can only be resolved by
+	 * retiring.
+	 */
+	if (!(flags & PIN_NONBLOCK))
+		i915_retire_requests(vm->i915);
+
+	check_color = vm->mm.color_adjust;
+	if (check_color) {
+		/* Expand search to cover neighbouring guard pages (or lack!) */
+		if (start)
+			start -= I915_GTT_PAGE_SIZE;
+
+		/* Always look at the page afterwards to avoid the end-of-GTT */
+		end += I915_GTT_PAGE_SIZE;
+	}
+	GEM_BUG_ON(start >= end);
+
+	drm_mm_for_each_node_in_range(node, &vm->mm, start, end) {
+		/* If we find any non-objects (!vma), we cannot evict them */
+		if (node->color == I915_COLOR_UNEVICTABLE) {
+			ret = -ENOSPC;
+			break;
+		}
+
+		GEM_BUG_ON(!node->allocated);
+		vma = container_of(node, typeof(*vma), node);
+
+		/* If we are using coloring to insert guard pages between
+		 * different cache domains within the address space, we have
+		 * to check whether the objects on either side of our range
+		 * abutt and conflict. If they are in conflict, then we evict
+		 * those as well to make room for our guard pages.
+		 */
+		if (check_color) {
+			if (node->start + node->size == target->start) {
+				if (node->color == target->color)
+					continue;
+			}
+			if (node->start == target->start + target->size) {
+				if (node->color == target->color)
+					continue;
+			}
+		}
+
+		if (flags & PIN_NONBLOCK &&
+		    (i915_vma_is_pinned(vma) || i915_vma_is_active(vma))) {
+			ret = -ENOSPC;
+			break;
+		}
+
+		if (flags & PIN_NONFAULT && i915_vma_has_userfault(vma)) {
+			ret = -ENOSPC;
+			break;
+		}
+
+		/* Overlap of objects in the same batch? */
+		if (i915_vma_is_pinned(vma)) {
+			ret = -ENOSPC;
+			if (vma->exec_flags &&
+			    *vma->exec_flags & EXEC_OBJECT_PINNED)
+				ret = -EINVAL;
+			break;
+		}
+
+		/* Never show fear in the face of dragons!
+		 *
+		 * We cannot directly remove this node from within this
+		 * iterator and as with i915_gem_evict_something() we employ
+		 * the vma pin_count in order to prevent the action of
+		 * unbinding one vma from freeing (by dropping its active
+		 * reference) another in our eviction list.
+		 */
+		__i915_vma_pin(vma);
+		list_add(&vma->evict_link, &eviction_list);
+	}
+
+	list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {
+		__i915_vma_unpin(vma);
+		if (ret == 0)
+			ret = i915_vma_unbind(vma);
+	}
+
+	return ret;
+}
+
+/**
+ * i915_gem_evict_vm - Evict all idle vmas from a vm
+ * @vm: Address space to cleanse
+ *
+ * This function evicts all vmas from a vm.
+ *
+ * This is used by the execbuf code as a last-ditch effort to defragment the
+ * address space.
+ *
+ * To clarify: This is for freeing up virtual address space, not for freeing
+ * memory in e.g. the shrinker.
+ */
+int i915_gem_evict_vm(struct i915_address_space *vm)
+{
+	struct list_head *phases[] = {
+		&vm->inactive_list,
+		&vm->active_list,
+		NULL
+	}, **phase;
+	struct list_head eviction_list;
+	struct i915_vma *vma, *next;
+	int ret;
+
+	lockdep_assert_held(&vm->i915->drm.struct_mutex);
+	trace_i915_gem_evict_vm(vm);
+
+	/* Switch back to the default context in order to unpin
+	 * the existing context objects. However, such objects only
+	 * pin themselves inside the global GTT and performing the
+	 * switch otherwise is ineffective.
+	 */
+	if (i915_is_ggtt(vm)) {
+		ret = ggtt_flush(vm->i915);
+		if (ret)
+			return ret;
+	}
+
+	INIT_LIST_HEAD(&eviction_list);
+	phase = phases;
+	do {
+		list_for_each_entry(vma, *phase, vm_link) {
+			if (i915_vma_is_pinned(vma))
+				continue;
+
+			__i915_vma_pin(vma);
+			list_add(&vma->evict_link, &eviction_list);
+		}
+	} while (*++phase);
+
+	ret = 0;
+	list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {
+		__i915_vma_unpin(vma);
+		if (ret == 0)
+			ret = i915_vma_unbind(vma);
+	}
+	return ret;
+}
+
+#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
+#include "selftests/i915_gem_evict.c"
+#endif