1/*
  2 * Copyright © 2014-2016 Intel Corporation
  3 *
  4 * Permission is hereby granted, free of charge, to any person obtaining a
  5 * copy of this software and associated documentation files (the "Software"),
  6 * to deal in the Software without restriction, including without limitation
  7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  8 * and/or sell copies of the Software, and to permit persons to whom the
  9 * Software is furnished to do so, subject to the following conditions:
 10 *
 11 * The above copyright notice and this permission notice (including the next
 12 * paragraph) shall be included in all copies or substantial portions of the
 13 * Software.
 14 *
 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 21 * IN THE SOFTWARE.
 22 *
 23 */
 24
 25#include <drm/drmP.h>
 26#include <drm/i915_drm.h>
 27#include "i915_drv.h"
 28
 29#define QUIET (__GFP_NORETRY | __GFP_NOWARN)
 30#define MAYFAIL (__GFP_RETRY_MAYFAIL | __GFP_NOWARN)
 31
 32/* convert swiotlb segment size into sensible units (pages)! */
 33#define IO_TLB_SEGPAGES (IO_TLB_SEGSIZE << IO_TLB_SHIFT >> PAGE_SHIFT)
 34
 35static void internal_free_pages(struct sg_table *st)
 36{
 37	struct scatterlist *sg;
 38
 39	for (sg = st->sgl; sg; sg = __sg_next(sg)) {
 40		if (sg_page(sg))
 41			__free_pages(sg_page(sg), get_order(sg->length));
 42	}
 43
 44	sg_free_table(st);
 45	kfree(st);
 46}
 47
 48static int i915_gem_object_get_pages_internal(struct drm_i915_gem_object *obj)
 49{
 50	struct drm_i915_private *i915 = to_i915(obj->base.dev);
 51	struct sg_table *st;
 52	struct scatterlist *sg;
 53	unsigned int sg_page_sizes;
 54	unsigned int npages;
 55	int max_order;
 56	gfp_t gfp;
 57
 58	max_order = MAX_ORDER;
 59#ifdef CONFIG_SWIOTLB
 60	if (swiotlb_nr_tbl()) {
 61		unsigned int max_segment;
 62
 63		max_segment = swiotlb_max_segment();
 64		if (max_segment) {
 65			max_segment = max_t(unsigned int, max_segment,
 66					    PAGE_SIZE) >> PAGE_SHIFT;
 67			max_order = min(max_order, ilog2(max_segment));
 68		}
 69	}
 70#endif
 71
 72	gfp = GFP_KERNEL | __GFP_HIGHMEM | __GFP_RECLAIMABLE;
 73	if (IS_I965GM(i915) || IS_I965G(i915)) {
 74		/* 965gm cannot relocate objects above 4GiB. */
 75		gfp &= ~__GFP_HIGHMEM;
 76		gfp |= __GFP_DMA32;
 77	}
 78
 79create_st:
 80	st = kmalloc(sizeof(*st), GFP_KERNEL);
 81	if (!st)
 82		return -ENOMEM;
 83
 84	npages = obj->base.size / PAGE_SIZE;
 85	if (sg_alloc_table(st, npages, GFP_KERNEL)) {
 86		kfree(st);
 87		return -ENOMEM;
 88	}
 89
 90	sg = st->sgl;
 91	st->nents = 0;
 92	sg_page_sizes = 0;
 93
 94	do {
 95		int order = min(fls(npages) - 1, max_order);
 96		struct page *page;
 97
 98		do {
 99			page = alloc_pages(gfp | (order ? QUIET : MAYFAIL),
100					   order);
101			if (page)
102				break;
103			if (!order--)
104				goto err;
105
106			/* Limit subsequent allocations as well */
107			max_order = order;
108		} while (1);
109
110		sg_set_page(sg, page, PAGE_SIZE << order, 0);
111		sg_page_sizes |= PAGE_SIZE << order;
112		st->nents++;
113
114		npages -= 1 << order;
115		if (!npages) {
116			sg_mark_end(sg);
117			break;
118		}
119
120		sg = __sg_next(sg);
121	} while (1);
122
123	if (i915_gem_gtt_prepare_pages(obj, st)) {
124		/* Failed to dma-map try again with single page sg segments */
125		if (get_order(st->sgl->length)) {
126			internal_free_pages(st);
127			max_order = 0;
128			goto create_st;
129		}
130		goto err;
131	}
132
133	/* Mark the pages as dontneed whilst they are still pinned. As soon
134	 * as they are unpinned they are allowed to be reaped by the shrinker,
135	 * and the caller is expected to repopulate - the contents of this
136	 * object are only valid whilst active and pinned.
137	 */
138	obj->mm.madv = I915_MADV_DONTNEED;
139
140	__i915_gem_object_set_pages(obj, st, sg_page_sizes);
141
142	return 0;
143
144err:
145	sg_set_page(sg, NULL, 0, 0);
146	sg_mark_end(sg);
147	internal_free_pages(st);
148
149	return -ENOMEM;
150}
151
152static void i915_gem_object_put_pages_internal(struct drm_i915_gem_object *obj,
153					       struct sg_table *pages)
154{
155	i915_gem_gtt_finish_pages(obj, pages);
156	internal_free_pages(pages);
157
158	obj->mm.dirty = false;
159	obj->mm.madv = I915_MADV_WILLNEED;
160}
161
162static const struct drm_i915_gem_object_ops i915_gem_object_internal_ops = {
163	.flags = I915_GEM_OBJECT_HAS_STRUCT_PAGE |
164		 I915_GEM_OBJECT_IS_SHRINKABLE,
165	.get_pages = i915_gem_object_get_pages_internal,
166	.put_pages = i915_gem_object_put_pages_internal,
167};
168
169/**
170 * i915_gem_object_create_internal: create an object with volatile pages
171 * @i915: the i915 device
172 * @size: the size in bytes of backing storage to allocate for the object
173 *
174 * Creates a new object that wraps some internal memory for private use.
175 * This object is not backed by swappable storage, and as such its contents
176 * are volatile and only valid whilst pinned. If the object is reaped by the
177 * shrinker, its pages and data will be discarded. Equally, it is not a full
178 * GEM object and so not valid for access from userspace. This makes it useful
179 * for hardware interfaces like ringbuffers (which are pinned from the time
180 * the request is written to the time the hardware stops accessing it), but
181 * not for contexts (which need to be preserved when not active for later
182 * reuse). Note that it is not cleared upon allocation.
183 */
184struct drm_i915_gem_object *
185i915_gem_object_create_internal(struct drm_i915_private *i915,
186				phys_addr_t size)
187{
188	struct drm_i915_gem_object *obj;
189	unsigned int cache_level;
190
191	GEM_BUG_ON(!size);
192	GEM_BUG_ON(!IS_ALIGNED(size, PAGE_SIZE));
193
194	if (overflows_type(size, obj->base.size))
195		return ERR_PTR(-E2BIG);
196
197	obj = i915_gem_object_alloc(i915);
198	if (!obj)
199		return ERR_PTR(-ENOMEM);
200
201	drm_gem_private_object_init(&i915->drm, &obj->base, size);
202	i915_gem_object_init(obj, &i915_gem_object_internal_ops);
203
204	obj->read_domains = I915_GEM_DOMAIN_CPU;
205	obj->write_domain = I915_GEM_DOMAIN_CPU;
206
207	cache_level = HAS_LLC(i915) ? I915_CACHE_LLC : I915_CACHE_NONE;
208	i915_gem_object_set_cache_coherency(obj, cache_level);
209
210	return obj;
211}