xref: /openbmc/linux/drivers/gpu/drm/msm/msm_gem_vma.c (revision 2a598d0b)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2016 Red Hat
4  * Author: Rob Clark <robdclark@gmail.com>
5  */
6 
7 #include "msm_drv.h"
8 #include "msm_fence.h"
9 #include "msm_gem.h"
10 #include "msm_mmu.h"
11 
12 static void
13 msm_gem_address_space_destroy(struct kref *kref)
14 {
15 	struct msm_gem_address_space *aspace = container_of(kref,
16 			struct msm_gem_address_space, kref);
17 
18 	drm_mm_takedown(&aspace->mm);
19 	if (aspace->mmu)
20 		aspace->mmu->funcs->destroy(aspace->mmu);
21 	put_pid(aspace->pid);
22 	kfree(aspace);
23 }
24 
25 
26 void msm_gem_address_space_put(struct msm_gem_address_space *aspace)
27 {
28 	if (aspace)
29 		kref_put(&aspace->kref, msm_gem_address_space_destroy);
30 }
31 
32 struct msm_gem_address_space *
33 msm_gem_address_space_get(struct msm_gem_address_space *aspace)
34 {
35 	if (!IS_ERR_OR_NULL(aspace))
36 		kref_get(&aspace->kref);
37 
38 	return aspace;
39 }
40 
41 bool msm_gem_vma_inuse(struct msm_gem_vma *vma)
42 {
43 	bool ret = true;
44 
45 	spin_lock(&vma->lock);
46 
47 	if (vma->inuse > 0)
48 		goto out;
49 
50 	while (vma->fence_mask) {
51 		unsigned idx = ffs(vma->fence_mask) - 1;
52 
53 		if (!msm_fence_completed(vma->fctx[idx], vma->fence[idx]))
54 			goto out;
55 
56 		vma->fence_mask &= ~BIT(idx);
57 	}
58 
59 	ret = false;
60 
61 out:
62 	spin_unlock(&vma->lock);
63 
64 	return ret;
65 }
66 
67 /* Actually unmap memory for the vma */
68 void msm_gem_vma_purge(struct msm_gem_vma *vma)
69 {
70 	struct msm_gem_address_space *aspace = vma->aspace;
71 	unsigned size = vma->node.size;
72 
73 	/* Print a message if we try to purge a vma in use */
74 	GEM_WARN_ON(msm_gem_vma_inuse(vma));
75 
76 	/* Don't do anything if the memory isn't mapped */
77 	if (!vma->mapped)
78 		return;
79 
80 	aspace->mmu->funcs->unmap(aspace->mmu, vma->iova, size);
81 
82 	vma->mapped = false;
83 }
84 
85 static void vma_unpin_locked(struct msm_gem_vma *vma)
86 {
87 	if (GEM_WARN_ON(!vma->inuse))
88 		return;
89 	if (!GEM_WARN_ON(!vma->iova))
90 		vma->inuse--;
91 }
92 
93 /* Remove reference counts for the mapping */
94 void msm_gem_vma_unpin(struct msm_gem_vma *vma)
95 {
96 	spin_lock(&vma->lock);
97 	vma_unpin_locked(vma);
98 	spin_unlock(&vma->lock);
99 }
100 
101 /* Replace pin reference with fence: */
102 void msm_gem_vma_unpin_fenced(struct msm_gem_vma *vma, struct msm_fence_context *fctx)
103 {
104 	spin_lock(&vma->lock);
105 	vma->fctx[fctx->index] = fctx;
106 	vma->fence[fctx->index] = fctx->last_fence;
107 	vma->fence_mask |= BIT(fctx->index);
108 	vma_unpin_locked(vma);
109 	spin_unlock(&vma->lock);
110 }
111 
112 /* Map and pin vma: */
113 int
114 msm_gem_vma_map(struct msm_gem_vma *vma, int prot,
115 		struct sg_table *sgt, int size)
116 {
117 	struct msm_gem_address_space *aspace = vma->aspace;
118 	int ret;
119 
120 	if (GEM_WARN_ON(!vma->iova))
121 		return -EINVAL;
122 
123 	/* Increase the usage counter */
124 	spin_lock(&vma->lock);
125 	vma->inuse++;
126 	spin_unlock(&vma->lock);
127 
128 	if (vma->mapped)
129 		return 0;
130 
131 	vma->mapped = true;
132 
133 	if (!aspace)
134 		return 0;
135 
136 	/*
137 	 * NOTE: iommu/io-pgtable can allocate pages, so we cannot hold
138 	 * a lock across map/unmap which is also used in the job_run()
139 	 * path, as this can cause deadlock in job_run() vs shrinker/
140 	 * reclaim.
141 	 *
142 	 * Revisit this if we can come up with a scheme to pre-alloc pages
143 	 * for the pgtable in map/unmap ops.
144 	 */
145 	ret = aspace->mmu->funcs->map(aspace->mmu, vma->iova, sgt, size, prot);
146 
147 	if (ret) {
148 		vma->mapped = false;
149 		spin_lock(&vma->lock);
150 		vma->inuse--;
151 		spin_unlock(&vma->lock);
152 	}
153 
154 	return ret;
155 }
156 
157 /* Close an iova.  Warn if it is still in use */
158 void msm_gem_vma_close(struct msm_gem_vma *vma)
159 {
160 	struct msm_gem_address_space *aspace = vma->aspace;
161 
162 	GEM_WARN_ON(msm_gem_vma_inuse(vma) || vma->mapped);
163 
164 	spin_lock(&aspace->lock);
165 	if (vma->iova)
166 		drm_mm_remove_node(&vma->node);
167 	spin_unlock(&aspace->lock);
168 
169 	vma->iova = 0;
170 
171 	msm_gem_address_space_put(aspace);
172 }
173 
174 struct msm_gem_vma *msm_gem_vma_new(struct msm_gem_address_space *aspace)
175 {
176 	struct msm_gem_vma *vma;
177 
178 	vma = kzalloc(sizeof(*vma), GFP_KERNEL);
179 	if (!vma)
180 		return NULL;
181 
182 	spin_lock_init(&vma->lock);
183 	vma->aspace = aspace;
184 
185 	return vma;
186 }
187 
188 /* Initialize a new vma and allocate an iova for it */
189 int msm_gem_vma_init(struct msm_gem_vma *vma, int size,
190 		u64 range_start, u64 range_end)
191 {
192 	struct msm_gem_address_space *aspace = vma->aspace;
193 	int ret;
194 
195 	if (GEM_WARN_ON(!aspace))
196 		return -EINVAL;
197 
198 	if (GEM_WARN_ON(vma->iova))
199 		return -EBUSY;
200 
201 	spin_lock(&aspace->lock);
202 	ret = drm_mm_insert_node_in_range(&aspace->mm, &vma->node,
203 					  size, PAGE_SIZE, 0,
204 					  range_start, range_end, 0);
205 	spin_unlock(&aspace->lock);
206 
207 	if (ret)
208 		return ret;
209 
210 	vma->iova = vma->node.start;
211 	vma->mapped = false;
212 
213 	kref_get(&aspace->kref);
214 
215 	return 0;
216 }
217 
218 struct msm_gem_address_space *
219 msm_gem_address_space_create(struct msm_mmu *mmu, const char *name,
220 		u64 va_start, u64 size)
221 {
222 	struct msm_gem_address_space *aspace;
223 
224 	if (IS_ERR(mmu))
225 		return ERR_CAST(mmu);
226 
227 	aspace = kzalloc(sizeof(*aspace), GFP_KERNEL);
228 	if (!aspace)
229 		return ERR_PTR(-ENOMEM);
230 
231 	spin_lock_init(&aspace->lock);
232 	aspace->name = name;
233 	aspace->mmu = mmu;
234 	aspace->va_start = va_start;
235 	aspace->va_size  = size;
236 
237 	drm_mm_init(&aspace->mm, va_start, size);
238 
239 	kref_init(&aspace->kref);
240 
241 	return aspace;
242 }
243