drm/i915/ttm: Use TTM for system memory

For discrete, use TTM for both cached and WC system memory. That means
we currently rely on the TTM memory accounting / shrinker. For cached
system memory we should consider remaining shmem-backed, which can be
implemented from our ttm_tt_populate callback. We can then also reuse our
own very elaborate shrinker for that memory.

If an object is evicted to a gem allowable region, we will now consider
the object migrated, and we flip the gem region and move the object to a
different region list. Since we are now changing gem regions, we can't
any longer rely on the CONTIGUOUS flag being set based on the region
min page size, so remove that flag update. If we want to reintroduce it,
we need to put it in the mutable flags.

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210624084240.270219-4-thomas.hellstrom@linux.intel.com

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_region.c b/drivers/gpu/drm/i915/gem/i915_gem_region.c
index d1f1840540dd9670536f4cb2d41317b272b45e70..4925563018b4551d248310ee2befb360317004b6 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_region.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_region.c
@@ -13,11 +13,7 @@ void i915_gem_object_init_memory_region(struct drm_i915_gem_object *obj,
 {
        obj->mm.region = intel_memory_region_get(mem);
 
-       if (obj->base.size <= mem->min_page_size)
-               obj->flags |= I915_BO_ALLOC_CONTIGUOUS;
-
        mutex_lock(&mem->objects.lock);
-
        list_add(&obj->mm.region_link, &mem->objects.list);
        mutex_unlock(&mem->objects.lock);
 }

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
index 7aa1c95c7b7ddcd2a8fa04ffb273357c52c65839..e9ac913b923aee36e4d46c04a29f1fe46a4ee159 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
@@ -302,6 +302,7 @@ void i915_gem_object_put_pages_shmem(struct drm_i915_gem_object *obj, struct sg_
        struct pagevec pvec;
        struct page *page;
 
+       GEM_WARN_ON(IS_DGFX(to_i915(obj->base.dev)));
        __i915_gem_object_release_shmem(obj, pages, true);
 
        i915_gem_gtt_finish_pages(obj, pages);
@@ -560,6 +561,7 @@ i915_gem_object_create_shmem_from_data(struct drm_i915_private *dev_priv,
        resource_size_t offset;
        int err;
 
+       GEM_WARN_ON(IS_DGFX(dev_priv));
        obj = i915_gem_object_create_shmem(dev_priv, round_up(size, PAGE_SIZE));
        if (IS_ERR(obj))
                return obj;

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
index 47cd3ee2e2623963a779f1ca983e50fca4dffddf..c39d982c4fa66a290856eba28a50d8d43aba5229 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
@@ -286,6 +286,26 @@ static void i915_ttm_adjust_gem_after_move(struct drm_i915_gem_object *obj)
 {
        struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
        unsigned int cache_level;
+       unsigned int i;
+
+       /*
+        * If object was moved to an allowable region, update the object
+        * region to consider it migrated. Note that if it's currently not
+        * in an allowable region, it's evicted and we don't update the
+        * object region.
+        */
+       if (intel_region_to_ttm_type(obj->mm.region) != bo->resource->mem_type) {
+               for (i = 0; i < obj->mm.n_placements; ++i) {
+                       struct intel_memory_region *mr = obj->mm.placements[i];
+
+                       if (intel_region_to_ttm_type(mr) == bo->resource->mem_type &&
+                           mr != obj->mm.region) {
+                               i915_gem_object_release_memory_region(obj);
+                               i915_gem_object_init_memory_region(obj, mr);
+                               break;
+                       }
+               }
+       }
 
        obj->mem_flags &= ~(I915_BO_FLAG_STRUCT_PAGE | I915_BO_FLAG_IOMEM);
 
@@ -615,13 +635,6 @@ static int i915_ttm_get_pages(struct drm_i915_gem_object *obj)
        /* Move to the requested placement. */
        i915_ttm_placement_from_obj(obj, &requested, busy, &placement);
 
-       /*
-        * For now we support LMEM only with TTM.
-        * TODO: Remove with system support
-        */
-       GEM_BUG_ON(requested.mem_type < I915_PL_LMEM0 ||
-                  busy[0].mem_type < I915_PL_LMEM0);
-
        /* First try only the requested placement. No eviction. */
        real_num_busy = fetch_and_zero(&placement.num_busy_placement);
        ret = ttm_bo_validate(bo, &placement, &ctx);
@@ -635,9 +648,6 @@ static int i915_ttm_get_pages(struct drm_i915_gem_object *obj)
                    ret == -EAGAIN)
                        return ret;
 
-               /* TODO: Remove this when we support system as TTM. */
-               real_num_busy = 1;
-
                /*
                 * If the initial attempt fails, allow all accepted placements,
                 * evicting if necessary.
@@ -873,3 +883,25 @@ int __i915_gem_ttm_object_init(struct intel_memory_region *mem,
 
        return 0;
 }
+
+static const struct intel_memory_region_ops ttm_system_region_ops = {
+       .init_object = __i915_gem_ttm_object_init,
+};
+
+struct intel_memory_region *
+i915_gem_ttm_system_setup(struct drm_i915_private *i915,
+                         u16 type, u16 instance)
+{
+       struct intel_memory_region *mr;
+
+       mr = intel_memory_region_create(i915, 0,
+                                       totalram_pages() << PAGE_SHIFT,
+                                       PAGE_SIZE, 0,
+                                       type, instance,
+                                       &ttm_system_region_ops);
+       if (IS_ERR(mr))
+               return mr;
+
+       intel_memory_region_set_name(mr, "system-ttm");
+       return mr;
+}

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 01e11fe38642d791ac47c2d74516949ee0c9bd8e..bfbfbae575737b44cfa96aaf15d3d2dfdd2b03ee 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1751,9 +1751,6 @@ void i915_gem_cleanup_userptr(struct drm_i915_private *dev_priv);
 void i915_gem_init_early(struct drm_i915_private *dev_priv);
 void i915_gem_cleanup_early(struct drm_i915_private *dev_priv);
 
-struct intel_memory_region *i915_gem_shmem_setup(struct drm_i915_private *i915,
-                                                u16 type, u16 instance);
-
 static inline void i915_gem_drain_freed_objects(struct drm_i915_private *i915)
 {
        /*

diff --git a/drivers/gpu/drm/i915/intel_memory_region.c b/drivers/gpu/drm/i915/intel_memory_region.c
index df59f884d37c2a46049c035d408be312d8c4796d..779eb2fa90b6a7e0bc37f4a25173484990c38c8a 100644 (file)
--- a/drivers/gpu/drm/i915/intel_memory_region.c
+++ b/drivers/gpu/drm/i915/intel_memory_region.c
@@ -173,7 +173,12 @@ int intel_memory_regions_hw_probe(struct drm_i915_private *i915)
                instance = intel_region_map[i].instance;
                switch (type) {
                case INTEL_MEMORY_SYSTEM:
-                       mem = i915_gem_shmem_setup(i915, type, instance);
+                       if (IS_DGFX(i915))
+                               mem = i915_gem_ttm_system_setup(i915, type,
+                                                               instance);
+                       else
+                               mem = i915_gem_shmem_setup(i915, type,
+                                                          instance);
                        break;
                case INTEL_MEMORY_STOLEN_LOCAL:
                        mem = i915_gem_stolen_lmem_setup(i915, type, instance);

diff --git a/drivers/gpu/drm/i915/intel_memory_region.h b/drivers/gpu/drm/i915/intel_memory_region.h
index 2be8433d373ac6c800ad5749fa4ec80f062f1af9..b1b9e461d53be119d28aad160704e50bb6019ce2 100644 (file)
--- a/drivers/gpu/drm/i915/intel_memory_region.h
+++ b/drivers/gpu/drm/i915/intel_memory_region.h
@@ -125,4 +125,12 @@ intel_memory_region_set_name(struct intel_memory_region *mem,
 int intel_memory_region_reserve(struct intel_memory_region *mem,
                                resource_size_t offset,
                                resource_size_t size);
+
+struct intel_memory_region *
+i915_gem_ttm_system_setup(struct drm_i915_private *i915,
+                         u16 type, u16 instance);
+struct intel_memory_region *
+i915_gem_shmem_setup(struct drm_i915_private *i915,
+                    u16 type, u16 instance);
+
 #endif