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}