From: Thomas Hellström thomas.hellstrom@linux.intel.com
[ Upstream commit c2ea703dcafccf18d7d77d8b68fb08c2d9842b7a ]
Protect updates of struct i915_vma flags and async binding / unbinding with the vm::mutex. This means that i915_vma_bind() needs to assert vm::mutex held. In order to make that possible drop the caching of kmap_atomic() maps around i915_vma_bind().
An alternative would be to use kmap_local() but since we block cpu unplugging during sleeps inside kmap_local() sections this may have unwanted side-effects. Particularly since we might wait for gpu while holding the vm mutex.
This change may theoretically increase execbuf cpu-usage on snb, but at least on non-highmem systems that increase should be very small.
Signed-off-by: Thomas Hellström thomas.hellstrom@linux.intel.com Reviewed-by: Matthew Auld matthew.auld@intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20211221200050.436316-5-thomas... Signed-off-by: Sasha Levin sashal@kernel.org --- .../gpu/drm/i915/gem/i915_gem_execbuffer.c | 50 ++++++++++++++++++- drivers/gpu/drm/i915/i915_vma.c | 1 + 2 files changed, 50 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c index 1aa249908b64..0d480867fc0c 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c @@ -1060,6 +1060,47 @@ static inline struct i915_ggtt *cache_to_ggtt(struct reloc_cache *cache) return &i915->ggtt; }
+static void reloc_cache_unmap(struct reloc_cache *cache) +{ + void *vaddr; + + if (!cache->vaddr) + return; + + vaddr = unmask_page(cache->vaddr); + if (cache->vaddr & KMAP) + kunmap_atomic(vaddr); + else + io_mapping_unmap_atomic((void __iomem *)vaddr); +} + +static void reloc_cache_remap(struct reloc_cache *cache, + struct drm_i915_gem_object *obj) +{ + void *vaddr; + + if (!cache->vaddr) + return; + + if (cache->vaddr & KMAP) { + struct page *page = i915_gem_object_get_page(obj, cache->page); + + vaddr = kmap_atomic(page); + cache->vaddr = unmask_flags(cache->vaddr) | + (unsigned long)vaddr; + } else { + struct i915_ggtt *ggtt = cache_to_ggtt(cache); + unsigned long offset; + + offset = cache->node.start; + if (!drm_mm_node_allocated(&cache->node)) + offset += cache->page << PAGE_SHIFT; + + cache->vaddr = (unsigned long) + io_mapping_map_atomic_wc(&ggtt->iomap, offset); + } +} + static void reloc_cache_reset(struct reloc_cache *cache, struct i915_execbuffer *eb) { void *vaddr; @@ -1324,10 +1365,17 @@ eb_relocate_entry(struct i915_execbuffer *eb, * batchbuffers. */ if (reloc->write_domain == I915_GEM_DOMAIN_INSTRUCTION && - GRAPHICS_VER(eb->i915) == 6) { + GRAPHICS_VER(eb->i915) == 6 && + !i915_vma_is_bound(target->vma, I915_VMA_GLOBAL_BIND)) { + struct i915_vma *vma = target->vma; + + reloc_cache_unmap(&eb->reloc_cache); + mutex_lock(&vma->vm->mutex); err = i915_vma_bind(target->vma, target->vma->obj->cache_level, PIN_GLOBAL, NULL); + mutex_unlock(&vma->vm->mutex); + reloc_cache_remap(&eb->reloc_cache, ev->vma->obj); if (err) return err; } diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c index dfd20060812b..3df304edabc7 100644 --- a/drivers/gpu/drm/i915/i915_vma.c +++ b/drivers/gpu/drm/i915/i915_vma.c @@ -376,6 +376,7 @@ int i915_vma_bind(struct i915_vma *vma, u32 bind_flags; u32 vma_flags;
+ lockdep_assert_held(&vma->vm->mutex); GEM_BUG_ON(!drm_mm_node_allocated(&vma->node)); GEM_BUG_ON(vma->size > vma->node.size);