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_gem_tiling.h"
18 #include "i915_scatterlist.h"
19 
20 static int i915_gem_object_get_pages_phys(struct drm_i915_gem_object *obj)
21 {
22 	struct address_space *mapping = obj->base.filp->f_mapping;
23 	struct drm_i915_private *i915 = to_i915(obj->base.dev);
24 	struct scatterlist *sg;
25 	struct sg_table *st;
26 	dma_addr_t dma;
27 	void *vaddr;
28 	void *dst;
29 	int i;
30 
31 	/* Contiguous chunk, with a single scatterlist element */
32 	if (overflows_type(obj->base.size, sg->length))
33 		return -E2BIG;
34 
35 	if (GEM_WARN_ON(i915_gem_object_needs_bit17_swizzle(obj)))
36 		return -EINVAL;
37 
38 	/*
39 	 * Always aligning to the object size, allows a single allocation
40 	 * to handle all possible callers, and given typical object sizes,
41 	 * the alignment of the buddy allocation will naturally match.
42 	 */
43 	vaddr = dma_alloc_coherent(obj->base.dev->dev,
44 				   roundup_pow_of_two(obj->base.size),
45 				   &dma, GFP_KERNEL);
46 	if (!vaddr)
47 		return -ENOMEM;
48 
49 	st = kmalloc(sizeof(*st), GFP_KERNEL);
50 	if (!st)
51 		goto err_pci;
52 
53 	if (sg_alloc_table(st, 1, GFP_KERNEL))
54 		goto err_st;
55 
56 	sg = st->sgl;
57 	sg->offset = 0;
58 	sg->length = obj->base.size;
59 
60 	sg_assign_page(sg, (struct page *)vaddr);
61 	sg_dma_address(sg) = dma;
62 	sg_dma_len(sg) = obj->base.size;
63 
64 	dst = vaddr;
65 	for (i = 0; i < obj->base.size / PAGE_SIZE; i++) {
66 		struct page *page;
67 		void *src;
68 
69 		page = shmem_read_mapping_page(mapping, i);
70 		if (IS_ERR(page))
71 			goto err_st;
72 
73 		src = kmap_atomic(page);
74 		memcpy(dst, src, PAGE_SIZE);
75 		drm_clflush_virt_range(dst, PAGE_SIZE);
76 		kunmap_atomic(src);
77 
78 		put_page(page);
79 		dst += PAGE_SIZE;
80 	}
81 
82 	intel_gt_chipset_flush(to_gt(i915));
83 
84 	/* We're no longer struct page backed */
85 	obj->mem_flags &= ~I915_BO_FLAG_STRUCT_PAGE;
86 	__i915_gem_object_set_pages(obj, st);
87 
88 	return 0;
89 
90 err_st:
91 	kfree(st);
92 err_pci:
93 	dma_free_coherent(obj->base.dev->dev,
94 			  roundup_pow_of_two(obj->base.size),
95 			  vaddr, dma);
96 	return -ENOMEM;
97 }
98 
99 void
100 i915_gem_object_put_pages_phys(struct drm_i915_gem_object *obj,
101 			       struct sg_table *pages)
102 {
103 	dma_addr_t dma = sg_dma_address(pages->sgl);
104 	void *vaddr = sg_page(pages->sgl);
105 
106 	__i915_gem_object_release_shmem(obj, pages, false);
107 
108 	if (obj->mm.dirty) {
109 		struct address_space *mapping = obj->base.filp->f_mapping;
110 		void *src = vaddr;
111 		int i;
112 
113 		for (i = 0; i < obj->base.size / PAGE_SIZE; i++) {
114 			struct page *page;
115 			char *dst;
116 
117 			page = shmem_read_mapping_page(mapping, i);
118 			if (IS_ERR(page))
119 				continue;
120 
121 			dst = kmap_atomic(page);
122 			drm_clflush_virt_range(src, PAGE_SIZE);
123 			memcpy(dst, src, PAGE_SIZE);
124 			kunmap_atomic(dst);
125 
126 			set_page_dirty(page);
127 			if (obj->mm.madv == I915_MADV_WILLNEED)
128 				mark_page_accessed(page);
129 			put_page(page);
130 
131 			src += PAGE_SIZE;
132 		}
133 		obj->mm.dirty = false;
134 	}
135 
136 	sg_free_table(pages);
137 	kfree(pages);
138 
139 	dma_free_coherent(obj->base.dev->dev,
140 			  roundup_pow_of_two(obj->base.size),
141 			  vaddr, dma);
142 }
143 
144 int i915_gem_object_pwrite_phys(struct drm_i915_gem_object *obj,
145 				const struct drm_i915_gem_pwrite *args)
146 {
147 	void *vaddr = sg_page(obj->mm.pages->sgl) + args->offset;
148 	char __user *user_data = u64_to_user_ptr(args->data_ptr);
149 	struct drm_i915_private *i915 = to_i915(obj->base.dev);
150 	int err;
151 
152 	err = i915_gem_object_wait(obj,
153 				   I915_WAIT_INTERRUPTIBLE |
154 				   I915_WAIT_ALL,
155 				   MAX_SCHEDULE_TIMEOUT);
156 	if (err)
157 		return err;
158 
159 	/*
160 	 * We manually control the domain here and pretend that it
161 	 * remains coherent i.e. in the GTT domain, like shmem_pwrite.
162 	 */
163 	i915_gem_object_invalidate_frontbuffer(obj, ORIGIN_CPU);
164 
165 	if (copy_from_user(vaddr, user_data, args->size))
166 		return -EFAULT;
167 
168 	drm_clflush_virt_range(vaddr, args->size);
169 	intel_gt_chipset_flush(to_gt(i915));
170 
171 	i915_gem_object_flush_frontbuffer(obj, ORIGIN_CPU);
172 	return 0;
173 }
174 
175 int i915_gem_object_pread_phys(struct drm_i915_gem_object *obj,
176 			       const struct drm_i915_gem_pread *args)
177 {
178 	void *vaddr = sg_page(obj->mm.pages->sgl) + args->offset;
179 	char __user *user_data = u64_to_user_ptr(args->data_ptr);
180 	int err;
181 
182 	err = i915_gem_object_wait(obj,
183 				   I915_WAIT_INTERRUPTIBLE,
184 				   MAX_SCHEDULE_TIMEOUT);
185 	if (err)
186 		return err;
187 
188 	drm_clflush_virt_range(vaddr, args->size);
189 	if (copy_to_user(user_data, vaddr, args->size))
190 		return -EFAULT;
191 
192 	return 0;
193 }
194 
195 static int i915_gem_object_shmem_to_phys(struct drm_i915_gem_object *obj)
196 {
197 	struct sg_table *pages;
198 	int err;
199 
200 	pages = __i915_gem_object_unset_pages(obj);
201 
202 	err = i915_gem_object_get_pages_phys(obj);
203 	if (err)
204 		goto err_xfer;
205 
206 	/* Perma-pin (until release) the physical set of pages */
207 	__i915_gem_object_pin_pages(obj);
208 
209 	if (!IS_ERR_OR_NULL(pages))
210 		i915_gem_object_put_pages_shmem(obj, pages);
211 
212 	i915_gem_object_release_memory_region(obj);
213 	return 0;
214 
215 err_xfer:
216 	if (!IS_ERR_OR_NULL(pages))
217 		__i915_gem_object_set_pages(obj, pages);
218 	return err;
219 }
220 
221 int i915_gem_object_attach_phys(struct drm_i915_gem_object *obj, int align)
222 {
223 	int err;
224 
225 	assert_object_held(obj);
226 
227 	if (align > obj->base.size)
228 		return -EINVAL;
229 
230 	if (!i915_gem_object_is_shmem(obj))
231 		return -EINVAL;
232 
233 	if (!i915_gem_object_has_struct_page(obj))
234 		return 0;
235 
236 	err = i915_gem_object_unbind(obj, I915_GEM_OBJECT_UNBIND_ACTIVE);
237 	if (err)
238 		return err;
239 
240 	if (obj->mm.madv != I915_MADV_WILLNEED)
241 		return -EFAULT;
242 
243 	if (i915_gem_object_has_tiling_quirk(obj))
244 		return -EFAULT;
245 
246 	if (obj->mm.mapping || i915_gem_object_has_pinned_pages(obj))
247 		return -EBUSY;
248 
249 	if (unlikely(obj->mm.madv != I915_MADV_WILLNEED)) {
250 		drm_dbg(obj->base.dev,
251 			"Attempting to obtain a purgeable object\n");
252 		return -EFAULT;
253 	}
254 
255 	return i915_gem_object_shmem_to_phys(obj);
256 }
257 
258 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
259 #include "selftests/i915_gem_phys.c"
260 #endif
261