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_gem.h"
9#include "msm_mmu.h"
10
11static void
12msm_gem_address_space_destroy(struct kref *kref)
13{
14	struct msm_gem_address_space *aspace = container_of(kref,
15			struct msm_gem_address_space, kref);
16
17	drm_mm_takedown(&aspace->mm);
18	if (aspace->mmu)
19		aspace->mmu->funcs->destroy(aspace->mmu);
20	put_pid(aspace->pid);
21	kfree(aspace);
22}
23
24
25void msm_gem_address_space_put(struct msm_gem_address_space *aspace)
26{
27	if (aspace)
28		kref_put(&aspace->kref, msm_gem_address_space_destroy);
29}
30
31struct msm_gem_address_space *
32msm_gem_address_space_get(struct msm_gem_address_space *aspace)
33{
34	if (!IS_ERR_OR_NULL(aspace))
35		kref_get(&aspace->kref);
36
37	return aspace;
38}
39
40/* Actually unmap memory for the vma */
41void msm_gem_purge_vma(struct msm_gem_address_space *aspace,
42		struct msm_gem_vma *vma)
43{
44	unsigned size = vma->node.size << PAGE_SHIFT;
45
46	/* Print a message if we try to purge a vma in use */
47	if (WARN_ON(vma->inuse > 0))
48		return;
49
50	/* Don't do anything if the memory isn't mapped */
51	if (!vma->mapped)
52		return;
53
54	if (aspace->mmu)
55		aspace->mmu->funcs->unmap(aspace->mmu, vma->iova, size);
56
57	vma->mapped = false;
58}
59
60/* Remove reference counts for the mapping */
61void msm_gem_unmap_vma(struct msm_gem_address_space *aspace,
62		struct msm_gem_vma *vma)
63{
64	if (!WARN_ON(!vma->iova))
65		vma->inuse--;
66}
67
68int
69msm_gem_map_vma(struct msm_gem_address_space *aspace,
70		struct msm_gem_vma *vma, int prot,
71		struct sg_table *sgt, int npages)
72{
73	unsigned size = npages << PAGE_SHIFT;
74	int ret = 0;
75
76	if (WARN_ON(!vma->iova))
77		return -EINVAL;
78
79	/* Increase the usage counter */
80	vma->inuse++;
81
82	if (vma->mapped)
83		return 0;
84
85	vma->mapped = true;
86
87	if (aspace && aspace->mmu)
88		ret = aspace->mmu->funcs->map(aspace->mmu, vma->iova, sgt,
89				size, prot);
90
91	if (ret) {
92		vma->mapped = false;
93		vma->inuse--;
94	}
95
96	return ret;
97}
98
99/* Close an iova.  Warn if it is still in use */
100void msm_gem_close_vma(struct msm_gem_address_space *aspace,
101		struct msm_gem_vma *vma)
102{
103	if (WARN_ON(vma->inuse > 0 || vma->mapped))
104		return;
105
106	spin_lock(&aspace->lock);
107	if (vma->iova)
108		drm_mm_remove_node(&vma->node);
109	spin_unlock(&aspace->lock);
110
111	vma->iova = 0;
112
113	msm_gem_address_space_put(aspace);
114}
115
116/* Initialize a new vma and allocate an iova for it */
117int msm_gem_init_vma(struct msm_gem_address_space *aspace,
118		struct msm_gem_vma *vma, int npages,
119		u64 range_start, u64 range_end)
120{
121	int ret;
122
123	if (WARN_ON(vma->iova))
124		return -EBUSY;
125
126	spin_lock(&aspace->lock);
127	ret = drm_mm_insert_node_in_range(&aspace->mm, &vma->node, npages, 0,
128		0, range_start, range_end, 0);
129	spin_unlock(&aspace->lock);
130
131	if (ret)
132		return ret;
133
134	vma->iova = vma->node.start << PAGE_SHIFT;
135	vma->mapped = false;
136
137	kref_get(&aspace->kref);
138
139	return 0;
140}
141
142struct msm_gem_address_space *
143msm_gem_address_space_create(struct msm_mmu *mmu, const char *name,
144		u64 va_start, u64 size)
145{
146	struct msm_gem_address_space *aspace;
147
148	if (IS_ERR(mmu))
149		return ERR_CAST(mmu);
150
151	aspace = kzalloc(sizeof(*aspace), GFP_KERNEL);
152	if (!aspace)
153		return ERR_PTR(-ENOMEM);
154
155	spin_lock_init(&aspace->lock);
156	aspace->name = name;
157	aspace->mmu = mmu;
158
159	drm_mm_init(&aspace->mm, va_start >> PAGE_SHIFT, size >> PAGE_SHIFT);
160
161	kref_init(&aspace->kref);
162
163	return aspace;
164}
165