/* * 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. */ kprintf("i915_gem_evict_something: %016llx-%016llx\n", start, end); 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; kprintf("i915_gem_evict_something: Nothing found %d,%d\n", ggtt_is_idle(dev_priv), intel_has_pending_fb_unpin(dev_priv)); /* * 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) { LINUX_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
