xref: /openbmc/linux/drivers/gpu/drm/msm/msm_iommu.c (revision 94cdda6b)
1 /*
2  * Copyright (C) 2013 Red Hat
3  * Author: Rob Clark <robdclark@gmail.com>
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms of the GNU General Public License version 2 as published by
7  * the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  * You should have received a copy of the GNU General Public License along with
15  * this program.  If not, see <http://www.gnu.org/licenses/>.
16  */
17 
18 #include "msm_drv.h"
19 #include "msm_mmu.h"
20 
21 struct msm_iommu {
22 	struct msm_mmu base;
23 	struct iommu_domain *domain;
24 };
25 #define to_msm_iommu(x) container_of(x, struct msm_iommu, base)
26 
27 static int msm_fault_handler(struct iommu_domain *iommu, struct device *dev,
28 		unsigned long iova, int flags, void *arg)
29 {
30 	pr_warn_ratelimited("*** fault: iova=%08lx, flags=%d\n", iova, flags);
31 	return 0;
32 }
33 
34 static int msm_iommu_attach(struct msm_mmu *mmu, const char **names, int cnt)
35 {
36 	struct msm_iommu *iommu = to_msm_iommu(mmu);
37 	return iommu_attach_device(iommu->domain, mmu->dev);
38 }
39 
40 static void msm_iommu_detach(struct msm_mmu *mmu, const char **names, int cnt)
41 {
42 	struct msm_iommu *iommu = to_msm_iommu(mmu);
43 	iommu_detach_device(iommu->domain, mmu->dev);
44 }
45 
46 static int msm_iommu_map(struct msm_mmu *mmu, uint32_t iova,
47 		struct sg_table *sgt, unsigned len, int prot)
48 {
49 	struct msm_iommu *iommu = to_msm_iommu(mmu);
50 	struct iommu_domain *domain = iommu->domain;
51 	struct scatterlist *sg;
52 	unsigned int da = iova;
53 	unsigned int i, j;
54 	int ret;
55 
56 	if (!domain || !sgt)
57 		return -EINVAL;
58 
59 	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
60 		u32 pa = sg_phys(sg) - sg->offset;
61 		size_t bytes = sg->length + sg->offset;
62 
63 		VERB("map[%d]: %08x %08x(%x)", i, iova, pa, bytes);
64 
65 		ret = iommu_map(domain, da, pa, bytes, prot);
66 		if (ret)
67 			goto fail;
68 
69 		da += bytes;
70 	}
71 
72 	return 0;
73 
74 fail:
75 	da = iova;
76 
77 	for_each_sg(sgt->sgl, sg, i, j) {
78 		size_t bytes = sg->length + sg->offset;
79 		iommu_unmap(domain, da, bytes);
80 		da += bytes;
81 	}
82 	return ret;
83 }
84 
85 static int msm_iommu_unmap(struct msm_mmu *mmu, uint32_t iova,
86 		struct sg_table *sgt, unsigned len)
87 {
88 	struct msm_iommu *iommu = to_msm_iommu(mmu);
89 	struct iommu_domain *domain = iommu->domain;
90 	struct scatterlist *sg;
91 	unsigned int da = iova;
92 	int i;
93 
94 	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
95 		size_t bytes = sg->length + sg->offset;
96 		size_t unmapped;
97 
98 		unmapped = iommu_unmap(domain, da, bytes);
99 		if (unmapped < bytes)
100 			return unmapped;
101 
102 		VERB("unmap[%d]: %08x(%x)", i, iova, bytes);
103 
104 		BUG_ON(!PAGE_ALIGNED(bytes));
105 
106 		da += bytes;
107 	}
108 
109 	return 0;
110 }
111 
112 static void msm_iommu_destroy(struct msm_mmu *mmu)
113 {
114 	struct msm_iommu *iommu = to_msm_iommu(mmu);
115 	iommu_domain_free(iommu->domain);
116 	kfree(iommu);
117 }
118 
119 static const struct msm_mmu_funcs funcs = {
120 		.attach = msm_iommu_attach,
121 		.detach = msm_iommu_detach,
122 		.map = msm_iommu_map,
123 		.unmap = msm_iommu_unmap,
124 		.destroy = msm_iommu_destroy,
125 };
126 
127 struct msm_mmu *msm_iommu_new(struct device *dev, struct iommu_domain *domain)
128 {
129 	struct msm_iommu *iommu;
130 
131 	iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
132 	if (!iommu)
133 		return ERR_PTR(-ENOMEM);
134 
135 	iommu->domain = domain;
136 	msm_mmu_init(&iommu->base, dev, &funcs);
137 	iommu_set_fault_handler(domain, msm_fault_handler, dev);
138 
139 	return &iommu->base;
140 }
141