diff options
Diffstat (limited to 'drivers/gpu/drm/i915/gem/i915_gem_domain.c')
| -rw-r--r-- | drivers/gpu/drm/i915/gem/i915_gem_domain.c | 796 |
1 files changed, 796 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_domain.c b/drivers/gpu/drm/i915/gem/i915_gem_domain.c new file mode 100644 index 000000000000..2e3ce2a69653 --- /dev/null +++ b/drivers/gpu/drm/i915/gem/i915_gem_domain.c @@ -0,0 +1,796 @@ +/* + * SPDX-License-Identifier: MIT + * + * Copyright © 2014-2016 Intel Corporation + */ + +#include "display/intel_frontbuffer.h" + +#include "i915_drv.h" +#include "i915_gem_clflush.h" +#include "i915_gem_gtt.h" +#include "i915_gem_ioctls.h" +#include "i915_gem_object.h" +#include "i915_vma.h" + +static void __i915_gem_object_flush_for_display(struct drm_i915_gem_object *obj) +{ + /* + * We manually flush the CPU domain so that we can override and + * force the flush for the display, and perform it asyncrhonously. + */ + i915_gem_object_flush_write_domain(obj, ~I915_GEM_DOMAIN_CPU); + if (obj->cache_dirty) + i915_gem_clflush_object(obj, I915_CLFLUSH_FORCE); + obj->write_domain = 0; +} + +void i915_gem_object_flush_if_display(struct drm_i915_gem_object *obj) +{ + if (!READ_ONCE(obj->pin_global)) + return; + + i915_gem_object_lock(obj); + __i915_gem_object_flush_for_display(obj); + i915_gem_object_unlock(obj); +} + +/** + * Moves a single object to the WC read, and possibly write domain. + * @obj: object to act on + * @write: ask for write access or read only + * + * This function returns when the move is complete, including waiting on + * flushes to occur. + */ +int +i915_gem_object_set_to_wc_domain(struct drm_i915_gem_object *obj, bool write) +{ + int ret; + + assert_object_held(obj); + + ret = i915_gem_object_wait(obj, + I915_WAIT_INTERRUPTIBLE | + (write ? I915_WAIT_ALL : 0), + MAX_SCHEDULE_TIMEOUT); + if (ret) + return ret; + + if (obj->write_domain == I915_GEM_DOMAIN_WC) + return 0; + + /* Flush and acquire obj->pages so that we are coherent through + * direct access in memory with previous cached writes through + * shmemfs and that our cache domain tracking remains valid. + * For example, if the obj->filp was moved to swap without us + * being notified and releasing the pages, we would mistakenly + * continue to assume that the obj remained out of the CPU cached + * domain. + */ + ret = i915_gem_object_pin_pages(obj); + if (ret) + return ret; + + i915_gem_object_flush_write_domain(obj, ~I915_GEM_DOMAIN_WC); + + /* Serialise direct access to this object with the barriers for + * coherent writes from the GPU, by effectively invalidating the + * WC domain upon first access. + */ + if ((obj->read_domains & I915_GEM_DOMAIN_WC) == 0) + mb(); + + /* It should now be out of any other write domains, and we can update + * the domain values for our changes. + */ + GEM_BUG_ON((obj->write_domain & ~I915_GEM_DOMAIN_WC) != 0); + obj->read_domains |= I915_GEM_DOMAIN_WC; + if (write) { + obj->read_domains = I915_GEM_DOMAIN_WC; + obj->write_domain = I915_GEM_DOMAIN_WC; + obj->mm.dirty = true; + } + + i915_gem_object_unpin_pages(obj); + return 0; +} + +/** + * Moves a single object to the GTT read, and possibly write domain. + * @obj: object to act on + * @write: ask for write access or read only + * + * This function returns when the move is complete, including waiting on + * flushes to occur. + */ +int +i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj, bool write) +{ + int ret; + + assert_object_held(obj); + + ret = i915_gem_object_wait(obj, + I915_WAIT_INTERRUPTIBLE | + (write ? I915_WAIT_ALL : 0), + MAX_SCHEDULE_TIMEOUT); + if (ret) + return ret; + + if (obj->write_domain == I915_GEM_DOMAIN_GTT) + return 0; + + /* Flush and acquire obj->pages so that we are coherent through + * direct access in memory with previous cached writes through + * shmemfs and that our cache domain tracking remains valid. + * For example, if the obj->filp was moved to swap without us + * being notified and releasing the pages, we would mistakenly + * continue to assume that the obj remained out of the CPU cached + * domain. + */ + ret = i915_gem_object_pin_pages(obj); + if (ret) + return ret; + + i915_gem_object_flush_write_domain(obj, ~I915_GEM_DOMAIN_GTT); + + /* Serialise direct access to this object with the barriers for + * coherent writes from the GPU, by effectively invalidating the + * GTT domain upon first access. + */ + if ((obj->read_domains & I915_GEM_DOMAIN_GTT) == 0) + mb(); + + /* It should now be out of any other write domains, and we can update + * the domain values for our changes. + */ + GEM_BUG_ON((obj->write_domain & ~I915_GEM_DOMAIN_GTT) != 0); + obj->read_domains |= I915_GEM_DOMAIN_GTT; + if (write) { + obj->read_domains = I915_GEM_DOMAIN_GTT; + obj->write_domain = I915_GEM_DOMAIN_GTT; + obj->mm.dirty = true; + } + + i915_gem_object_unpin_pages(obj); + return 0; +} + +/** + * Changes the cache-level of an object across all VMA. + * @obj: object to act on + * @cache_level: new cache level to set for the object + * + * After this function returns, the object will be in the new cache-level + * across all GTT and the contents of the backing storage will be coherent, + * with respect to the new cache-level. In order to keep the backing storage + * coherent for all users, we only allow a single cache level to be set + * globally on the object and prevent it from being changed whilst the + * hardware is reading from the object. That is if the object is currently + * on the scanout it will be set to uncached (or equivalent display + * cache coherency) and all non-MOCS GPU access will also be uncached so + * that all direct access to the scanout remains coherent. + */ +int i915_gem_object_set_cache_level(struct drm_i915_gem_object *obj, + enum i915_cache_level cache_level) +{ + struct i915_vma *vma; + int ret; + + assert_object_held(obj); + + if (obj->cache_level == cache_level) + return 0; + + /* Inspect the list of currently bound VMA and unbind any that would + * be invalid given the new cache-level. This is principally to + * catch the issue of the CS prefetch crossing page boundaries and + * reading an invalid PTE on older architectures. + */ +restart: + list_for_each_entry(vma, &obj->vma.list, obj_link) { + if (!drm_mm_node_allocated(&vma->node)) + continue; + + if (i915_vma_is_pinned(vma)) { + DRM_DEBUG("can not change the cache level of pinned objects\n"); + return -EBUSY; + } + + if (!i915_vma_is_closed(vma) && + i915_gem_valid_gtt_space(vma, cache_level)) + continue; + + ret = i915_vma_unbind(vma); + if (ret) + return ret; + + /* As unbinding may affect other elements in the + * obj->vma_list (due to side-effects from retiring + * an active vma), play safe and restart the iterator. + */ + goto restart; + } + + /* We can reuse the existing drm_mm nodes but need to change the + * cache-level on the PTE. We could simply unbind them all and + * rebind with the correct cache-level on next use. However since + * we already have a valid slot, dma mapping, pages etc, we may as + * rewrite the PTE in the belief that doing so tramples upon less + * state and so involves less work. + */ + if (atomic_read(&obj->bind_count)) { + /* Before we change the PTE, the GPU must not be accessing it. + * If we wait upon the object, we know that all the bound + * VMA are no longer active. + */ + ret = i915_gem_object_wait(obj, + I915_WAIT_INTERRUPTIBLE | + I915_WAIT_ALL, + MAX_SCHEDULE_TIMEOUT); + if (ret) + return ret; + + if (!HAS_LLC(to_i915(obj->base.dev)) && + cache_level != I915_CACHE_NONE) { + /* Access to snoopable pages through the GTT is + * incoherent and on some machines causes a hard + * lockup. Relinquish the CPU mmaping to force + * userspace to refault in the pages and we can + * then double check if the GTT mapping is still + * valid for that pointer access. + */ + i915_gem_object_release_mmap(obj); + + /* As we no longer need a fence for GTT access, + * we can relinquish it now (and so prevent having + * to steal a fence from someone else on the next + * fence request). Note GPU activity would have + * dropped the fence as all snoopable access is + * supposed to be linear. + */ + for_each_ggtt_vma(vma, obj) { + ret = i915_vma_put_fence(vma); + if (ret) + return ret; + } + } else { + /* We either have incoherent backing store and + * so no GTT access or the architecture is fully + * coherent. In such cases, existing GTT mmaps + * ignore the cache bit in the PTE and we can + * rewrite it without confusing the GPU or having + * to force userspace to fault back in its mmaps. + */ + } + + list_for_each_entry(vma, &obj->vma.list, obj_link) { + if (!drm_mm_node_allocated(&vma->node)) + continue; + + ret = i915_vma_bind(vma, cache_level, PIN_UPDATE); + if (ret) + return ret; + } + } + + list_for_each_entry(vma, &obj->vma.list, obj_link) + vma->node.color = cache_level; + i915_gem_object_set_cache_coherency(obj, cache_level); + obj->cache_dirty = true; /* Always invalidate stale cachelines */ + + return 0; +} + +int i915_gem_get_caching_ioctl(struct drm_device *dev, void *data, + struct drm_file *file) +{ + struct drm_i915_gem_caching *args = data; + struct drm_i915_gem_object *obj; + int err = 0; + + rcu_read_lock(); + obj = i915_gem_object_lookup_rcu(file, args->handle); + if (!obj) { + err = -ENOENT; + goto out; + } + + switch (obj->cache_level) { + case I915_CACHE_LLC: + case I915_CACHE_L3_LLC: + args->caching = I915_CACHING_CACHED; + break; + + case I915_CACHE_WT: + args->caching = I915_CACHING_DISPLAY; + break; + + default: + args->caching = I915_CACHING_NONE; + break; + } +out: + rcu_read_unlock(); + return err; +} + +int i915_gem_set_caching_ioctl(struct drm_device *dev, void *data, + struct drm_file *file) +{ + struct drm_i915_private *i915 = to_i915(dev); + struct drm_i915_gem_caching *args = data; + struct drm_i915_gem_object *obj; + enum i915_cache_level level; + int ret = 0; + + switch (args->caching) { + case I915_CACHING_NONE: + level = I915_CACHE_NONE; + break; + case I915_CACHING_CACHED: + /* + * Due to a HW issue on BXT A stepping, GPU stores via a + * snooped mapping may leave stale data in a corresponding CPU + * cacheline, whereas normally such cachelines would get + * invalidated. + */ + if (!HAS_LLC(i915) && !HAS_SNOOP(i915)) + return -ENODEV; + + level = I915_CACHE_LLC; + break; + case I915_CACHING_DISPLAY: + level = HAS_WT(i915) ? I915_CACHE_WT : I915_CACHE_NONE; + break; + default: + return -EINVAL; + } + + obj = i915_gem_object_lookup(file, args->handle); + if (!obj) + return -ENOENT; + + /* + * The caching mode of proxy object is handled by its generator, and + * not allowed to be changed by userspace. + */ + if (i915_gem_object_is_proxy(obj)) { + ret = -ENXIO; + goto out; + } + + if (obj->cache_level == level) + goto out; + + ret = i915_gem_object_wait(obj, + I915_WAIT_INTERRUPTIBLE, + MAX_SCHEDULE_TIMEOUT); + if (ret) + goto out; + + ret = mutex_lock_interruptible(&i915->drm.struct_mutex); + if (ret) + goto out; + + ret = i915_gem_object_lock_interruptible(obj); + if (ret == 0) { + ret = i915_gem_object_set_cache_level(obj, level); + i915_gem_object_unlock(obj); + } + mutex_unlock(&i915->drm.struct_mutex); + +out: + i915_gem_object_put(obj); + return ret; +} + +/* + * Prepare buffer for display plane (scanout, cursors, etc). Can be called from + * an uninterruptible phase (modesetting) and allows any flushes to be pipelined + * (for pageflips). We only flush the caches while preparing the buffer for + * display, the callers are responsible for frontbuffer flush. + */ +struct i915_vma * +i915_gem_object_pin_to_display_plane(struct drm_i915_gem_object *obj, + u32 alignment, + const struct i915_ggtt_view *view, + unsigned int flags) +{ + struct i915_vma *vma; + int ret; + + assert_object_held(obj); + + /* Mark the global pin early so that we account for the + * display coherency whilst setting up the cache domains. + */ + obj->pin_global++; + + /* The display engine is not coherent with the LLC cache on gen6. As + * a result, we make sure that the pinning that is about to occur is + * done with uncached PTEs. This is lowest common denominator for all + * chipsets. + * + * However for gen6+, we could do better by using the GFDT bit instead + * of uncaching, which would allow us to flush all the LLC-cached data + * with that bit in the PTE to main memory with just one PIPE_CONTROL. + */ + ret = i915_gem_object_set_cache_level(obj, + HAS_WT(to_i915(obj->base.dev)) ? + I915_CACHE_WT : I915_CACHE_NONE); + if (ret) { + vma = ERR_PTR(ret); + goto err_unpin_global; + } + + /* As the user may map the buffer once pinned in the display plane + * (e.g. libkms for the bootup splash), we have to ensure that we + * always use map_and_fenceable for all scanout buffers. However, + * it may simply be too big to fit into mappable, in which case + * put it anyway and hope that userspace can cope (but always first + * try to preserve the existing ABI). + */ + vma = ERR_PTR(-ENOSPC); + if ((flags & PIN_MAPPABLE) == 0 && + (!view || view->type == I915_GGTT_VIEW_NORMAL)) + vma = i915_gem_object_ggtt_pin(obj, view, 0, alignment, + flags | + PIN_MAPPABLE | + PIN_NONBLOCK); + if (IS_ERR(vma)) + vma = i915_gem_object_ggtt_pin(obj, view, 0, alignment, flags); + if (IS_ERR(vma)) + goto err_unpin_global; + + vma->display_alignment = max_t(u64, vma->display_alignment, alignment); + + __i915_gem_object_flush_for_display(obj); + + /* It should now be out of any other write domains, and we can update + * the domain values for our changes. + */ + obj->read_domains |= I915_GEM_DOMAIN_GTT; + + return vma; + +err_unpin_global: + obj->pin_global--; + return vma; +} + +static void i915_gem_object_bump_inactive_ggtt(struct drm_i915_gem_object *obj) +{ + struct drm_i915_private *i915 = to_i915(obj->base.dev); + struct i915_vma *vma; + + GEM_BUG_ON(!i915_gem_object_has_pinned_pages(obj)); + + mutex_lock(&i915->ggtt.vm.mutex); + for_each_ggtt_vma(vma, obj) { + if (!drm_mm_node_allocated(&vma->node)) + continue; + + list_move_tail(&vma->vm_link, &vma->vm->bound_list); + } + mutex_unlock(&i915->ggtt.vm.mutex); + + if (i915_gem_object_is_shrinkable(obj)) { + unsigned long flags; + + spin_lock_irqsave(&i915->mm.obj_lock, flags); + + if (obj->mm.madv == I915_MADV_WILLNEED) + list_move_tail(&obj->mm.link, &i915->mm.shrink_list); + + spin_unlock_irqrestore(&i915->mm.obj_lock, flags); + } +} + +void +i915_gem_object_unpin_from_display_plane(struct i915_vma *vma) +{ + struct drm_i915_gem_object *obj = vma->obj; + + assert_object_held(obj); + + if (WARN_ON(obj->pin_global == 0)) + return; + + if (--obj->pin_global == 0) + vma->display_alignment = I915_GTT_MIN_ALIGNMENT; + + /* Bump the LRU to try and avoid premature eviction whilst flipping */ + i915_gem_object_bump_inactive_ggtt(obj); + + i915_vma_unpin(vma); +} + +/** + * Moves a single object to the CPU read, and possibly write domain. + * @obj: object to act on + * @write: requesting write or read-only access + * + * This function returns when the move is complete, including waiting on + * flushes to occur. + */ +int +i915_gem_object_set_to_cpu_domain(struct drm_i915_gem_object *obj, bool write) +{ + int ret; + + assert_object_held(obj); + + ret = i915_gem_object_wait(obj, + I915_WAIT_INTERRUPTIBLE | + (write ? I915_WAIT_ALL : 0), + MAX_SCHEDULE_TIMEOUT); + if (ret) + return ret; + + i915_gem_object_flush_write_domain(obj, ~I915_GEM_DOMAIN_CPU); + + /* Flush the CPU cache if it's still invalid. */ + if ((obj->read_domains & I915_GEM_DOMAIN_CPU) == 0) { + i915_gem_clflush_object(obj, I915_CLFLUSH_SYNC); + obj->read_domains |= I915_GEM_DOMAIN_CPU; + } + + /* It should now be out of any other write domains, and we can update + * the domain values for our changes. + */ + GEM_BUG_ON(obj->write_domain & ~I915_GEM_DOMAIN_CPU); + + /* If we're writing through the CPU, then the GPU read domains will + * need to be invalidated at next use. + */ + if (write) + __start_cpu_write(obj); + + return 0; +} + +static inline enum fb_op_origin +fb_write_origin(struct drm_i915_gem_object *obj, unsigned int domain) +{ + return (domain == I915_GEM_DOMAIN_GTT ? + obj->frontbuffer_ggtt_origin : ORIGIN_CPU); +} + +/** + * Called when user space prepares to use an object with the CPU, either + * through the mmap ioctl's mapping or a GTT mapping. + * @dev: drm device + * @data: ioctl data blob + * @file: drm file + */ +int +i915_gem_set_domain_ioctl(struct drm_device *dev, void *data, + struct drm_file *file) +{ + struct drm_i915_gem_set_domain *args = data; + struct drm_i915_gem_object *obj; + u32 read_domains = args->read_domains; + u32 write_domain = args->write_domain; + int err; + + /* Only handle setting domains to types used by the CPU. */ + if ((write_domain | read_domains) & I915_GEM_GPU_DOMAINS) + return -EINVAL; + + /* + * Having something in the write domain implies it's in the read + * domain, and only that read domain. Enforce that in the request. + */ + if (write_domain && read_domains != write_domain) + return -EINVAL; + + if (!read_domains) + return 0; + + obj = i915_gem_object_lookup(file, args->handle); + if (!obj) + return -ENOENT; + + /* + * Already in the desired write domain? Nothing for us to do! + * + * We apply a little bit of cunning here to catch a broader set of + * no-ops. If obj->write_domain is set, we must be in the same + * obj->read_domains, and only that domain. Therefore, if that + * obj->write_domain matches the request read_domains, we are + * already in the same read/write domain and can skip the operation, + * without having to further check the requested write_domain. + */ + if (READ_ONCE(obj->write_domain) == read_domains) { + err = 0; + goto out; + } + + /* + * Try to flush the object off the GPU without holding the lock. + * We will repeat the flush holding the lock in the normal manner + * to catch cases where we are gazumped. + */ + err = i915_gem_object_wait(obj, + I915_WAIT_INTERRUPTIBLE | + I915_WAIT_PRIORITY | + (write_domain ? I915_WAIT_ALL : 0), + MAX_SCHEDULE_TIMEOUT); + if (err) + goto out; + + /* + * Proxy objects do not control access to the backing storage, ergo + * they cannot be used as a means to manipulate the cache domain + * tracking for that backing storage. The proxy object is always + * considered to be outside of any cache domain. + */ + if (i915_gem_object_is_proxy(obj)) { + err = -ENXIO; + goto out; + } + + /* + * Flush and acquire obj->pages so that we are coherent through + * direct access in memory with previous cached writes through + * shmemfs and that our cache domain tracking remains valid. + * For example, if the obj->filp was moved to swap without us + * being notified and releasing the pages, we would mistakenly + * continue to assume that the obj remained out of the CPU cached + * domain. + */ + err = i915_gem_object_pin_pages(obj); + if (err) + goto out; + + err = i915_gem_object_lock_interruptible(obj); + if (err) + goto out_unpin; + + if (read_domains & I915_GEM_DOMAIN_WC) + err = i915_gem_object_set_to_wc_domain(obj, write_domain); + else if (read_domains & I915_GEM_DOMAIN_GTT) + err = i915_gem_object_set_to_gtt_domain(obj, write_domain); + else + err = i915_gem_object_set_to_cpu_domain(obj, write_domain); + + /* And bump the LRU for this access */ + i915_gem_object_bump_inactive_ggtt(obj); + + i915_gem_object_unlock(obj); + + if (write_domain != 0) + intel_fb_obj_invalidate(obj, + fb_write_origin(obj, write_domain)); + +out_unpin: + i915_gem_object_unpin_pages(obj); +out: + i915_gem_object_put(obj); + return err; +} + +/* + * Pins the specified object's pages and synchronizes the object with + * GPU accesses. Sets needs_clflush to non-zero if the caller should + * flush the object from the CPU cache. + */ +int i915_gem_object_prepare_read(struct drm_i915_gem_object *obj, + unsigned int *needs_clflush) +{ + int ret; + + *needs_clflush = 0; + if (!i915_gem_object_has_struct_page(obj)) + return -ENODEV; + + ret = i915_gem_object_lock_interruptible(obj); + if (ret) + return ret; + + ret = i915_gem_object_wait(obj, + I915_WAIT_INTERRUPTIBLE, + MAX_SCHEDULE_TIMEOUT); + if (ret) + goto err_unlock; + + ret = i915_gem_object_pin_pages(obj); + if (ret) + goto err_unlock; + + if (obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_READ || + !static_cpu_has(X86_FEATURE_CLFLUSH)) { + ret = i915_gem_object_set_to_cpu_domain(obj, false); + if (ret) + goto err_unpin; + else + goto out; + } + + i915_gem_object_flush_write_domain(obj, ~I915_GEM_DOMAIN_CPU); + + /* If we're not in the cpu read domain, set ourself into the gtt + * read domain and manually flush cachelines (if required). This + * optimizes for the case when the gpu will dirty the data + * anyway again before the next pread happens. + */ + if (!obj->cache_dirty && + !(obj->read_domains & I915_GEM_DOMAIN_CPU)) + *needs_clflush = CLFLUSH_BEFORE; + +out: + /* return with the pages pinned */ + return 0; + +err_unpin: + i915_gem_object_unpin_pages(obj); +err_unlock: + i915_gem_object_unlock(obj); + return ret; +} + +int i915_gem_object_prepare_write(struct drm_i915_gem_object *obj, + unsigned int *needs_clflush) +{ + int ret; + + *needs_clflush = 0; + if (!i915_gem_object_has_struct_page(obj)) + return -ENODEV; + + ret = i915_gem_object_lock_interruptible(obj); + if (ret) + return ret; + + ret = i915_gem_object_wait(obj, + I915_WAIT_INTERRUPTIBLE | + I915_WAIT_ALL, + MAX_SCHEDULE_TIMEOUT); + if (ret) + goto err_unlock; + + ret = i915_gem_object_pin_pages(obj); + if (ret) + goto err_unlock; + + if (obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_WRITE || + !static_cpu_has(X86_FEATURE_CLFLUSH)) { + ret = i915_gem_object_set_to_cpu_domain(obj, true); + if (ret) + goto err_unpin; + else + goto out; + } + + i915_gem_object_flush_write_domain(obj, ~I915_GEM_DOMAIN_CPU); + + /* If we're not in the cpu write domain, set ourself into the + * gtt write domain and manually flush cachelines (as required). + * This optimizes for the case when the gpu will use the data + * right away and we therefore have to clflush anyway. + */ + if (!obj->cache_dirty) { + *needs_clflush |= CLFLUSH_AFTER; + + /* + * Same trick applies to invalidate partially written + * cachelines read before writing. + */ + if (!(obj->read_domains & I915_GEM_DOMAIN_CPU)) + *needs_clflush |= CLFLUSH_BEFORE; + } + +out: + intel_fb_obj_invalidate(obj, ORIGIN_CPU); + obj->mm.dirty = true; + /* return with the pages pinned */ + return 0; + +err_unpin: + i915_gem_object_unpin_pages(obj); +err_unlock: + i915_gem_object_unlock(obj); + return ret; +} |