ttm_device.c

  1/* SPDX-License-Identifier: GPL-2.0 OR MIT */
  2
  3/*
  4 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
  5 * Copyright 2020 Advanced Micro Devices, Inc.
  6 *
  7 * Permission is hereby granted, free of charge, to any person obtaining a
  8 * copy of this software and associated documentation files (the "Software"),
  9 * to deal in the Software without restriction, including without limitation
 10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 11 * and/or sell copies of the Software, and to permit persons to whom the
 12 * Software is furnished to do so, subject to the following conditions:
 13 *
 14 * The above copyright notice and this permission notice shall be included in
 15 * all copies or substantial portions of the Software.
 16 *
 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 20 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 21 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 22 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 23 * OTHER DEALINGS IN THE SOFTWARE.
 24 *
 25 * Authors: Christian König
 26 */
 27
 28#define pr_fmt(fmt) "[TTM DEVICE] " fmt
 29
 30#include <linux/debugfs.h>
 31#include <linux/export.h>
 32#include <linux/mm.h>
 33
 34#include <drm/ttm/ttm_allocation.h>
 35#include <drm/ttm/ttm_bo.h>
 36#include <drm/ttm/ttm_device.h>
 37#include <drm/ttm/ttm_tt.h>
 38#include <drm/ttm/ttm_placement.h>
 39
 40#include "ttm_module.h"
 41#include "ttm_bo_internal.h"
 42
 43/*
 44 * ttm_global_mutex - protecting the global state
 45 */
 46static DEFINE_MUTEX(ttm_global_mutex);
 47static unsigned ttm_glob_use_count;
 48struct ttm_global ttm_glob;
 49EXPORT_SYMBOL(ttm_glob);
 50
 51struct dentry *ttm_debugfs_root;
 52
 53static void ttm_global_release(void)
 54{
 55	struct ttm_global *glob = &ttm_glob;
 56
 57	mutex_lock(&ttm_global_mutex);
 58	if (--ttm_glob_use_count > 0)
 59		goto out;
 60
 61	ttm_pool_mgr_fini();
 62	debugfs_remove(ttm_debugfs_root);
 63
 64	__free_page(glob->dummy_read_page);
 65	memset(glob, 0, sizeof(*glob));
 66out:
 67	mutex_unlock(&ttm_global_mutex);
 68}
 69
 70static int ttm_global_init(void)
 71{
 72	struct ttm_global *glob = &ttm_glob;
 73	unsigned long num_pages, num_dma32;
 74	struct sysinfo si;
 75	int ret = 0;
 76
 77	mutex_lock(&ttm_global_mutex);
 78	if (++ttm_glob_use_count > 1)
 79		goto out;
 80
 81	si_meminfo(&si);
 82
 83	ttm_debugfs_root = debugfs_create_dir("ttm", NULL);
 84	if (IS_ERR(ttm_debugfs_root)) {
 85		ttm_debugfs_root = NULL;
 86	}
 87
 88	/* Limit the number of pages in the pool to about 50% of the total
 89	 * system memory.
 90	 */
 91	num_pages = ((u64)si.totalram * si.mem_unit) >> PAGE_SHIFT;
 92	num_pages /= 2;
 93
 94	/* But for DMA32 we limit ourself to only use 2GiB maximum. */
 95	num_dma32 = (u64)(si.totalram - si.totalhigh) * si.mem_unit
 96		>> PAGE_SHIFT;
 97	num_dma32 = min(num_dma32, 2UL << (30 - PAGE_SHIFT));
 98
 99	ttm_pool_mgr_init(num_pages);
100	ttm_tt_mgr_init(num_pages, num_dma32);
101
102	glob->dummy_read_page = alloc_page(__GFP_ZERO | GFP_DMA32 |
103					   __GFP_NOWARN);
104
105	/* Retry without GFP_DMA32 for platforms DMA32 is not available */
106	if (unlikely(glob->dummy_read_page == NULL)) {
107		glob->dummy_read_page = alloc_page(__GFP_ZERO);
108		if (unlikely(glob->dummy_read_page == NULL)) {
109			ret = -ENOMEM;
110			goto out;
111		}
112		pr_warn("Using GFP_DMA32 fallback for dummy_read_page\n");
113	}
114
115	INIT_LIST_HEAD(&glob->device_list);
116	atomic_set(&glob->bo_count, 0);
117
118	debugfs_create_atomic_t("buffer_objects", 0444, ttm_debugfs_root,
119				&glob->bo_count);
120out:
121	if (ret && ttm_debugfs_root)
122		debugfs_remove(ttm_debugfs_root);
123	if (ret)
124		--ttm_glob_use_count;
125	mutex_unlock(&ttm_global_mutex);
126	return ret;
127}
128
129/**
130 * ttm_device_prepare_hibernation - move GTT BOs to shmem for hibernation.
131 *
132 * @bdev: A pointer to a struct ttm_device to prepare hibernation for.
133 *
134 * Return: 0 on success, negative number on failure.
135 */
136int ttm_device_prepare_hibernation(struct ttm_device *bdev)
137{
138	struct ttm_operation_ctx ctx = {
139		.interruptible = false,
140		.no_wait_gpu = false,
141	};
142	int ret;
143
144	do {
145		ret = ttm_device_swapout(bdev, &ctx, GFP_KERNEL);
146	} while (ret > 0);
147	return ret;
148}
149EXPORT_SYMBOL(ttm_device_prepare_hibernation);
150
151/*
152 * A buffer object shrink method that tries to swap out the first
153 * buffer object on the global::swap_lru list.
154 */
155int ttm_global_swapout(struct ttm_operation_ctx *ctx, gfp_t gfp_flags)
156{
157	struct ttm_global *glob = &ttm_glob;
158	struct ttm_device *bdev;
159	int ret = 0;
160
161	mutex_lock(&ttm_global_mutex);
162	list_for_each_entry(bdev, &glob->device_list, device_list) {
163		ret = ttm_device_swapout(bdev, ctx, gfp_flags);
164		if (ret > 0) {
165			list_move_tail(&bdev->device_list, &glob->device_list);
166			break;
167		}
168	}
169	mutex_unlock(&ttm_global_mutex);
170	return ret;
171}
172
173int ttm_device_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx,
174		       gfp_t gfp_flags)
175{
176	struct ttm_resource_manager *man;
177	unsigned i;
178	s64 lret;
179
180	for (i = TTM_PL_SYSTEM; i < TTM_NUM_MEM_TYPES; ++i) {
181		man = ttm_manager_type(bdev, i);
182		if (!man || !man->use_tt)
183			continue;
184
185		lret = ttm_bo_swapout(bdev, ctx, man, gfp_flags, 1);
186		/* Can be both positive (num_pages) and negative (error) */
187		if (lret)
188			return lret;
189	}
190	return 0;
191}
192EXPORT_SYMBOL(ttm_device_swapout);
193
194/**
195 * ttm_device_init
196 *
197 * @bdev: A pointer to a struct ttm_device to initialize.
198 * @funcs: Function table for the device.
199 * @dev: The core kernel device pointer for DMA mappings and allocations.
200 * @mapping: The address space to use for this bo.
201 * @vma_manager: A pointer to a vma manager.
202 * @alloc_flags: TTM_ALLOCATION_* flags.
203 *
204 * Initializes a struct ttm_device:
205 * Returns:
206 * !0: Failure.
207 */
208int ttm_device_init(struct ttm_device *bdev, const struct ttm_device_funcs *funcs,
209		    struct device *dev, struct address_space *mapping,
210		    struct drm_vma_offset_manager *vma_manager,
211		    unsigned int alloc_flags)
212{
213	struct ttm_global *glob = &ttm_glob;
214	int ret, nid;
215
216	if (WARN_ON(vma_manager == NULL))
217		return -EINVAL;
218
219	ret = ttm_global_init();
220	if (ret)
221		return ret;
222
223	bdev->wq = alloc_workqueue("ttm",
224				   WQ_MEM_RECLAIM | WQ_HIGHPRI | WQ_UNBOUND, 16);
225	if (!bdev->wq) {
226		ttm_global_release();
227		return -ENOMEM;
228	}
229
230	bdev->alloc_flags = alloc_flags;
231	bdev->funcs = funcs;
232
233	ttm_sys_man_init(bdev);
234
235	if (dev)
236		nid = dev_to_node(dev);
237	else
238		nid = NUMA_NO_NODE;
239
240	ttm_pool_init(&bdev->pool, dev, nid, alloc_flags);
241
242	bdev->vma_manager = vma_manager;
243	spin_lock_init(&bdev->lru_lock);
244	INIT_LIST_HEAD(&bdev->unevictable);
245	bdev->dev_mapping = mapping;
246	mutex_lock(&ttm_global_mutex);
247	list_add_tail(&bdev->device_list, &glob->device_list);
248	mutex_unlock(&ttm_global_mutex);
249
250	return 0;
251}
252EXPORT_SYMBOL(ttm_device_init);
253
254void ttm_device_fini(struct ttm_device *bdev)
255{
256	struct ttm_resource_manager *man;
257	unsigned i;
258
259	mutex_lock(&ttm_global_mutex);
260	list_del(&bdev->device_list);
261	mutex_unlock(&ttm_global_mutex);
262
263	drain_workqueue(bdev->wq);
264	destroy_workqueue(bdev->wq);
265
266	man = ttm_manager_type(bdev, TTM_PL_SYSTEM);
267	ttm_resource_manager_set_used(man, false);
268	ttm_set_driver_manager(bdev, TTM_PL_SYSTEM, NULL);
269
270	spin_lock(&bdev->lru_lock);
271	for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i)
272		if (list_empty(&man->lru[0]))
273			pr_debug("Swap list %d was clean\n", i);
274	spin_unlock(&bdev->lru_lock);
275
276	ttm_pool_fini(&bdev->pool);
277	ttm_global_release();
278}
279EXPORT_SYMBOL(ttm_device_fini);
280
281static void ttm_device_clear_lru_dma_mappings(struct ttm_device *bdev,
282					      struct list_head *list)
283{
284	struct ttm_resource *res;
285
286	spin_lock(&bdev->lru_lock);
287	while ((res = ttm_lru_first_res_or_null(list))) {
288		struct ttm_buffer_object *bo = res->bo;
289
290		/* Take ref against racing releases once lru_lock is unlocked */
291		if (!ttm_bo_get_unless_zero(bo))
292			continue;
293
294		list_del_init(&bo->resource->lru.link);
295		spin_unlock(&bdev->lru_lock);
296
297		if (bo->ttm)
298			ttm_tt_unpopulate(bo->bdev, bo->ttm);
299
300		ttm_bo_put(bo);
301		spin_lock(&bdev->lru_lock);
302	}
303	spin_unlock(&bdev->lru_lock);
304}
305
306void ttm_device_clear_dma_mappings(struct ttm_device *bdev)
307{
308	struct ttm_resource_manager *man;
309	unsigned int i, j;
310
311	ttm_device_clear_lru_dma_mappings(bdev, &bdev->unevictable);
312
313	for (i = TTM_PL_SYSTEM; i < TTM_NUM_MEM_TYPES; ++i) {
314		man = ttm_manager_type(bdev, i);
315		if (!man || !man->use_tt)
316			continue;
317
318		for (j = 0; j < TTM_MAX_BO_PRIORITY; ++j)
319			ttm_device_clear_lru_dma_mappings(bdev, &man->lru[j]);
320	}
321}
322EXPORT_SYMBOL(ttm_device_clear_dma_mappings);