New subject: [PATCH 2/2] drm/ttm: remove io_reserve_lru handling

30 Sep 2019

While working on TTM cleanups I've found that the io_reserve_lru used by
Nouveau is actually not working at all.
In general we should remove driver specific handling from the memory
management, so this patch moves the io_reserve_lru handling into Nouveau
instead.
The patch should be functional correct, but is only compile tested!
Signed-off-by: Christian König christian.koenig@amd.com
---
 drivers/gpu/drm/nouveau/nouveau_bo.c  | 106 ++++++++++++++++++++++++++--------
 drivers/gpu/drm/nouveau/nouveau_bo.h  |   3 +
 drivers/gpu/drm/nouveau/nouveau_drv.h |   2 +
 drivers/gpu/drm/nouveau/nouveau_ttm.c |  43 +++++++++++++-
 4 files changed, 130 insertions(+), 24 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index e918b437af17..9532ad1bd474 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -139,6 +139,7 @@ nouveau_bo_del_ttm(struct ttm_buffer_object *bo)
    if (unlikely(nvbo->bo.base.filp))
    	DRM_ERROR("bo %p still attached to GEM object\n", bo);
    WARN_ON(nvbo->pin_refcnt > 0);
+	nouveau_bo_del_io_reserve_lru(bo);
    nv10_bo_put_tile_region(dev, nvbo->tile, NULL);
    kfree(nvbo);
 }
@@ -297,6 +298,7 @@ nouveau_bo_init(struct nouveau_bo *nvbo, u64 size, int align, u32 flags,
    nouveau_bo_fixup_align(nvbo, flags, &align, &size);
    nvbo->bo.mem.num_pages = size >> PAGE_SHIFT;
    nouveau_bo_placement_set(nvbo, flags, 0);
+	INIT_LIST_HEAD(&nvbo->io_reserve_lru);
ret = ttm_bo_init(nvbo->bo.bdev, &nvbo->bo, size, type,
    		  &nvbo->placement, align >> PAGE_SHIFT, false,
@@ -566,6 +568,26 @@ nouveau_bo_sync_for_cpu(struct nouveau_bo *nvbo)
    				PAGE_SIZE, DMA_FROM_DEVICE);
 }
+void nouveau_bo_add_io_reserve_lru(struct ttm_buffer_object *bo)
+{
+	struct nouveau_drm *drm = nouveau_bdev(bo->bdev);
+	struct nouveau_bo *nvbo = nouveau_bo(bo);
+
+	mutex_lock(&drm->ttm.io_reserve_mutex);
+	list_move_tail(&nvbo->io_reserve_lru, &drm->ttm.io_reserve_lru);
+	mutex_unlock(&drm->ttm.io_reserve_mutex);
+}
+
+void nouveau_bo_del_io_reserve_lru(struct ttm_buffer_object *bo)
+{
+	struct nouveau_drm *drm = nouveau_bdev(bo->bdev);
+	struct nouveau_bo *nvbo = nouveau_bo(bo);
+
+	mutex_lock(&drm->ttm.io_reserve_mutex);
+	list_del_init(&nvbo->io_reserve_lru);
+	mutex_unlock(&drm->ttm.io_reserve_mutex);
+}
+
 int
 nouveau_bo_validate(struct nouveau_bo *nvbo, bool interruptible,
    	    bool no_wait_gpu)
@@ -674,8 +696,6 @@ nouveau_bo_init_mem_type(struct ttm_bo_device *bdev, uint32_t type,
    		}
man->func = &nouveau_vram_manager;
-			man->io_reserve_fastpath = false;
-			man->use_io_reserve_lru = true;
    	} else {
    		man->func = &ttm_bo_manager_func;
    	}
@@ -1304,6 +1324,8 @@ nouveau_bo_move_ntfy(struct ttm_buffer_object *bo, bool evict,
    if (bo->destroy != nouveau_bo_del_ttm)
    	return;
+	nouveau_bo_del_io_reserve_lru(bo);
+
    if (mem && new_reg->mem_type != TTM_PL_SYSTEM &&
        mem->mem.page == nvbo->page) {
    	list_for_each_entry(vma, &nvbo->vma_list, head) {
@@ -1426,6 +1448,30 @@ nouveau_bo_verify_access(struct ttm_buffer_object *bo, struct file *filp)
    				  filp->private_data);
 }
+static void
+nouveau_ttm_io_mem_free_locked(struct nouveau_drm *drm, struct ttm_mem_reg *reg)
+{
+	struct nouveau_mem *mem = nouveau_mem(reg);
+
+	if (!reg->bus.base)
+		return; /* already freed */
+
+	if (drm->client.mem->oclass >= NVIF_CLASS_MEM_NV50) {
+		switch (reg->mem_type) {
+		case TTM_PL_TT:
+			if (mem->kind)
+				nvif_object_unmap_handle(&mem->mem.object);
+			break;
+		case TTM_PL_VRAM:
+			nvif_object_unmap_handle(&mem->mem.object);
+			break;
+		default:
+			break;
+		}
+	}
+	reg->bus.base = 0;
+}
+
 static int
 nouveau_ttm_io_mem_reserve(struct ttm_bo_device *bdev, struct ttm_mem_reg *reg)
 {
@@ -1433,18 +1479,26 @@ nouveau_ttm_io_mem_reserve(struct ttm_bo_device *bdev, struct ttm_mem_reg *reg)
    struct nouveau_drm *drm = nouveau_bdev(bdev);
    struct nvkm_device *device = nvxx_device(&drm->client.device);
    struct nouveau_mem *mem = nouveau_mem(reg);
+	struct nouveau_bo *nvbo;
+	int ret;
+
+	if (reg->bus.base)
+		return 0; /* already mapped */
reg->bus.addr = NULL;
    reg->bus.offset = 0;
    reg->bus.size = reg->num_pages << PAGE_SHIFT;
-	reg->bus.base = 0;
    reg->bus.is_iomem = false;
    if (!(man->flags & TTM_MEMTYPE_FLAG_MAPPABLE))
    	return -EINVAL;
+
+	mutex_lock(&drm->ttm.io_reserve_mutex);
+retry:
    switch (reg->mem_type) {
    case TTM_PL_SYSTEM:
    	/* System memory */
-		return 0;
+		ret = 0;
+		goto out;
    case TTM_PL_TT:
 #if IS_ENABLED(CONFIG_AGP)
    	if (drm->agp.bridge) {
@@ -1468,7 +1522,6 @@ nouveau_ttm_io_mem_reserve(struct ttm_bo_device *bdev, struct ttm_mem_reg *reg)
    		} args;
    		u64 handle, length;
    		u32 argc = 0;
-			int ret;
switch (mem->mem.object.oclass) {
    		case NVIF_CLASS_MEM_NV50:
@@ -1492,38 +1545,45 @@ nouveau_ttm_io_mem_reserve(struct ttm_bo_device *bdev, struct ttm_mem_reg *reg)
    		ret = nvif_object_map_handle(&mem->mem.object,
    					     &args, argc,
    					     &handle, &length);
-			if (ret != 1)
-				return ret ? ret : -EINVAL;
+			if (ret != 1) {
+				ret = ret ? ret : -EINVAL;
+				goto out;
+			}
+			ret = 0;
reg->bus.base = 0;
    		reg->bus.offset = handle;
    	}
    	break;
    default:
-		return -EINVAL;
+		ret = -EINVAL;
    }
-	return 0;
+
+out:
+	if (ret == -EAGAIN) {
+		nvbo = list_first_entry_or_null(&drm->ttm.io_reserve_lru,
+						typeof(*nvbo),
+						io_reserve_lru);
+		if (nvbo) {
+			list_del_init(&nvbo->io_reserve_lru);
+			ttm_bo_unmap_virtual(&nvbo->bo);
+			nouveau_ttm_io_mem_free_locked(drm, &nvbo->bo.mem);
+			goto retry;
+		}
+
+	}
+	mutex_unlock(&drm->ttm.io_reserve_mutex);
+	return ret;
 }
static void
 nouveau_ttm_io_mem_free(struct ttm_bo_device *bdev, struct ttm_mem_reg *reg)
 {
    struct nouveau_drm *drm = nouveau_bdev(bdev);
-	struct nouveau_mem *mem = nouveau_mem(reg);
-	if (drm->client.mem->oclass >= NVIF_CLASS_MEM_NV50) {
-		switch (reg->mem_type) {
-		case TTM_PL_TT:
-			if (mem->kind)
-				nvif_object_unmap_handle(&mem->mem.object);
-			break;
-		case TTM_PL_VRAM:
-			nvif_object_unmap_handle(&mem->mem.object);
-			break;
-		default:
-			break;
-		}
-	}
+	mutex_lock(&drm->ttm.io_reserve_mutex);
+	nouveau_ttm_io_mem_free_locked(drm, reg);
+	mutex_unlock(&drm->ttm.io_reserve_mutex);
 }
static int
diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.h b/drivers/gpu/drm/nouveau/nouveau_bo.h
index 62930d834fba..b8a17bc19d7b 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.h
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.h
@@ -17,6 +17,7 @@ struct nouveau_bo {
    bool force_coherent;
    struct ttm_bo_kmap_obj kmap;
    struct list_head head;
+	struct list_head io_reserve_lru;
/* protected by ttm_bo_reserve() */
    struct drm_file *reserved_by;
@@ -92,6 +93,8 @@ int  nouveau_bo_validate(struct nouveau_bo *, bool interruptible,
    		 bool no_wait_gpu);
 void nouveau_bo_sync_for_device(struct nouveau_bo *nvbo);
 void nouveau_bo_sync_for_cpu(struct nouveau_bo *nvbo);
+void nouveau_bo_add_io_reserve_lru(struct ttm_buffer_object *bo);
+void nouveau_bo_del_io_reserve_lru(struct ttm_buffer_object *bo);
/* TODO: submit equivalent to TTM generic API upstream? */
 static inline void __iomem *
diff --git a/drivers/gpu/drm/nouveau/nouveau_drv.h b/drivers/gpu/drm/nouveau/nouveau_drv.h
index 70f34cacc552..060e2ab1fd95 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drv.h
+++ b/drivers/gpu/drm/nouveau/nouveau_drv.h
@@ -158,6 +158,8 @@ struct nouveau_drm {
    	int type_vram;
    	int type_host[2];
    	int type_ncoh[2];
+		struct mutex io_reserve_mutex;
+		struct list_head io_reserve_lru;
    } ttm;
/* GEM interface support */
diff --git a/drivers/gpu/drm/nouveau/nouveau_ttm.c b/drivers/gpu/drm/nouveau/nouveau_ttm.c
index f0daf958e03a..7f8495066e8b 100644
--- a/drivers/gpu/drm/nouveau/nouveau_ttm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_ttm.c
@@ -162,13 +162,51 @@ const struct ttm_mem_type_manager_func nv04_gart_manager = {
    .debug = nouveau_manager_debug
 };
+static vm_fault_t nouveau_ttm_fault(struct vm_fault *vmf)
+{
+	struct vm_area_struct *vma = vmf->vma;
+	struct ttm_buffer_object *bo = vma->vm_private_data;
+	pgprot_t prot;
+	vm_fault_t ret;
+
+	ret = ttm_bo_vm_reserve(bo, vmf);
+	if (ret)
+		return ret;
+
+	nouveau_bo_del_io_reserve_lru(bo);
+
+	prot = vm_get_page_prot(vma->vm_flags);
+	ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT);
+	if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT))
+		return ret;
+
+	nouveau_bo_add_io_reserve_lru(bo);
+
+	dma_resv_unlock(bo->base.resv);
+
+	return ret;
+}
+
+static struct vm_operations_struct nouveau_ttm_vm_ops = {
+	.fault = nouveau_ttm_fault,
+	.open = ttm_bo_vm_open,
+	.close = ttm_bo_vm_close,
+	.access = ttm_bo_vm_access
+};
+
 int
 nouveau_ttm_mmap(struct file *filp, struct vm_area_struct *vma)
 {
    struct drm_file *file_priv = filp->private_data;
    struct nouveau_drm *drm = nouveau_drm(file_priv->minor->dev);
+	int ret;
-	return ttm_bo_mmap(filp, vma, &drm->ttm.bdev);
+	ret = ttm_bo_mmap(filp, vma, &drm->ttm.bdev);
+	if (ret)
+		return ret;
+
+	vma->vm_ops = &nouveau_ttm_vm_ops;
+	return 0;
 }
static int
@@ -272,6 +310,9 @@ nouveau_ttm_init(struct nouveau_drm *drm)
    	return ret;
    }
+	mutex_init(&drm->ttm.io_reserve_mutex);
+	INIT_LIST_HEAD(&drm->ttm.io_reserve_lru);
+
    NV_INFO(drm, "VRAM: %d MiB\n", (u32)(drm->gem.vram_available >> 20));
    NV_INFO(drm, "GART: %d MiB\n", (u32)(drm->gem.gart_available >> 20));
    return 0;
-- 
2.14.1


    

[PATCH 1/2] drm/nouveau: move io_reserve_lru handling into the driver