1 /*
2  * SPDX-License-Identifier: MIT
3  *
4  * Copyright © 2014-2016 Intel Corporation
5  */
6 
7 #include <linux/highmem.h>
8 #include <linux/shmem_fs.h>
9 #include <linux/swap.h>
10 
11 #include <drm/drm_cache.h>
12 
13 #include "gt/intel_gt.h"
14 #include "i915_drv.h"
15 #include "i915_gem_object.h"
16 #include "i915_gem_region.h"
17 #include "i915_scatterlist.h"
18 
19 static int i915_gem_object_get_pages_phys(struct drm_i915_gem_object *obj)
20 {
21 	struct address_space *mapping = obj->base.filp->f_mapping;
22 	struct drm_i915_private *i915 = to_i915(obj->base.dev);
23 	struct scatterlist *sg;
24 	struct sg_table *st;
25 	dma_addr_t dma;
26 	void *vaddr;
27 	void *dst;
28 	int i;
29 
30 	if (GEM_WARN_ON(i915_gem_object_needs_bit17_swizzle(obj)))
31 		return -EINVAL;
32 
33 	/*
34 	 * Always aligning to the object size, allows a single allocation
35 	 * to handle all possible callers, and given typical object sizes,
36 	 * the alignment of the buddy allocation will naturally match.
37 	 */
38 	vaddr = dma_alloc_coherent(obj->base.dev->dev,
39 				   roundup_pow_of_two(obj->base.size),
40 				   &dma, GFP_KERNEL);
41 	if (!vaddr)
42 		return -ENOMEM;
43 
44 	st = kmalloc(sizeof(*st), GFP_KERNEL);
45 	if (!st)
46 		goto err_pci;
47 
48 	if (sg_alloc_table(st, 1, GFP_KERNEL))
49 		goto err_st;
50 
51 	sg = st->sgl;
52 	sg->offset = 0;
53 	sg->length = obj->base.size;
54 
55 	sg_assign_page(sg, (struct page *)vaddr);
56 	sg_dma_address(sg) = dma;
57 	sg_dma_len(sg) = obj->base.size;
58 
59 	dst = vaddr;
60 	for (i = 0; i < obj->base.size / PAGE_SIZE; i++) {
61 		struct page *page;
62 		void *src;
63 
64 		page = shmem_read_mapping_page(mapping, i);
65 		if (IS_ERR(page))
66 			goto err_st;
67 
68 		src = kmap_atomic(page);
69 		memcpy(dst, src, PAGE_SIZE);
70 		drm_clflush_virt_range(dst, PAGE_SIZE);
71 		kunmap_atomic(src);
72 
73 		put_page(page);
74 		dst += PAGE_SIZE;
75 	}
76 
77 	intel_gt_chipset_flush(to_gt(i915));
78 
79 	/* We're no longer struct page backed */
80 	obj->mem_flags &= ~I915_BO_FLAG_STRUCT_PAGE;
81 	__i915_gem_object_set_pages(obj, st, sg->length);
82 
83 	return 0;
84 
85 err_st:
86 	kfree(st);
87 err_pci:
88 	dma_free_coherent(obj->base.dev->dev,
89 			  roundup_pow_of_two(obj->base.size),
90 			  vaddr, dma);
91 	return -ENOMEM;
92 }
93 
94 void
95 i915_gem_object_put_pages_phys(struct drm_i915_gem_object *obj,
96 			       struct sg_table *pages)
97 {
98 	dma_addr_t dma = sg_dma_address(pages->sgl);
99 	void *vaddr = sg_page(pages->sgl);
100 
101 	__i915_gem_object_release_shmem(obj, pages, false);
102 
103 	if (obj->mm.dirty) {
104 		struct address_space *mapping = obj->base.filp->f_mapping;
105 		void *src = vaddr;
106 		int i;
107 
108 		for (i = 0; i < obj->base.size / PAGE_SIZE; i++) {
109 			struct page *page;
110 			char *dst;
111 
112 			page = shmem_read_mapping_page(mapping, i);
113 			if (IS_ERR(page))
114 				continue;
115 
116 			dst = kmap_atomic(page);
117 			drm_clflush_virt_range(src, PAGE_SIZE);
118 			memcpy(dst, src, PAGE_SIZE);
119 			kunmap_atomic(dst);
120 
121 			set_page_dirty(page);
122 			if (obj->mm.madv == I915_MADV_WILLNEED)
123 				mark_page_accessed(page);
124 			put_page(page);
125 
126 			src += PAGE_SIZE;
127 		}
128 		obj->mm.dirty = false;
129 	}
130 
131 	sg_free_table(pages);
132 	kfree(pages);
133 
134 	dma_free_coherent(obj->base.dev->dev,
135 			  roundup_pow_of_two(obj->base.size),
136 			  vaddr, dma);
137 }
138 
139 int i915_gem_object_pwrite_phys(struct drm_i915_gem_object *obj,
140 				const struct drm_i915_gem_pwrite *args)
141 {
142 	void *vaddr = sg_page(obj->mm.pages->sgl) + args->offset;
143 	char __user *user_data = u64_to_user_ptr(args->data_ptr);
144 	struct drm_i915_private *i915 = to_i915(obj->base.dev);
145 	int err;
146 
147 	err = i915_gem_object_wait(obj,
148 				   I915_WAIT_INTERRUPTIBLE |
149 				   I915_WAIT_ALL,
150 				   MAX_SCHEDULE_TIMEOUT);
151 	if (err)
152 		return err;
153 
154 	/*
155 	 * We manually control the domain here and pretend that it
156 	 * remains coherent i.e. in the GTT domain, like shmem_pwrite.
157 	 */
158 	i915_gem_object_invalidate_frontbuffer(obj, ORIGIN_CPU);
159 
160 	if (copy_from_user(vaddr, user_data, args->size))
161 		return -EFAULT;
162 
163 	drm_clflush_virt_range(vaddr, args->size);
164 	intel_gt_chipset_flush(to_gt(i915));
165 
166 	i915_gem_object_flush_frontbuffer(obj, ORIGIN_CPU);
167 	return 0;
168 }
169 
170 int i915_gem_object_pread_phys(struct drm_i915_gem_object *obj,
171 			       const struct drm_i915_gem_pread *args)
172 {
173 	void *vaddr = sg_page(obj->mm.pages->sgl) + args->offset;
174 	char __user *user_data = u64_to_user_ptr(args->data_ptr);
175 	int err;
176 
177 	err = i915_gem_object_wait(obj,
178 				   I915_WAIT_INTERRUPTIBLE,
179 				   MAX_SCHEDULE_TIMEOUT);
180 	if (err)
181 		return err;
182 
183 	drm_clflush_virt_range(vaddr, args->size);
184 	if (copy_to_user(user_data, vaddr, args->size))
185 		return -EFAULT;
186 
187 	return 0;
188 }
189 
190 static int i915_gem_object_shmem_to_phys(struct drm_i915_gem_object *obj)
191 {
192 	struct sg_table *pages;
193 	int err;
194 
195 	pages = __i915_gem_object_unset_pages(obj);
196 
197 	err = i915_gem_object_get_pages_phys(obj);
198 	if (err)
199 		goto err_xfer;
200 
201 	/* Perma-pin (until release) the physical set of pages */
202 	__i915_gem_object_pin_pages(obj);
203 
204 	if (!IS_ERR_OR_NULL(pages))
205 		i915_gem_object_put_pages_shmem(obj, pages);
206 
207 	i915_gem_object_release_memory_region(obj);
208 	return 0;
209 
210 err_xfer:
211 	if (!IS_ERR_OR_NULL(pages)) {
212 		unsigned int sg_page_sizes = i915_sg_dma_sizes(pages->sgl);
213 
214 		__i915_gem_object_set_pages(obj, pages, sg_page_sizes);
215 	}
216 	return err;
217 }
218 
219 int i915_gem_object_attach_phys(struct drm_i915_gem_object *obj, int align)
220 {
221 	int err;
222 
223 	assert_object_held(obj);
224 
225 	if (align > obj->base.size)
226 		return -EINVAL;
227 
228 	if (!i915_gem_object_is_shmem(obj))
229 		return -EINVAL;
230 
231 	if (!i915_gem_object_has_struct_page(obj))
232 		return 0;
233 
234 	err = i915_gem_object_unbind(obj, I915_GEM_OBJECT_UNBIND_ACTIVE);
235 	if (err)
236 		return err;
237 
238 	if (obj->mm.madv != I915_MADV_WILLNEED)
239 		return -EFAULT;
240 
241 	if (i915_gem_object_has_tiling_quirk(obj))
242 		return -EFAULT;
243 
244 	if (obj->mm.mapping || i915_gem_object_has_pinned_pages(obj))
245 		return -EBUSY;
246 
247 	if (unlikely(obj->mm.madv != I915_MADV_WILLNEED)) {
248 		drm_dbg(obj->base.dev,
249 			"Attempting to obtain a purgeable object\n");
250 		return -EFAULT;
251 	}
252 
253 	return i915_gem_object_shmem_to_phys(obj);
254 }
255 
256 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
257 #include "selftests/i915_gem_phys.c"
258 #endif
259