xref: /openbmc/linux/drivers/gpu/drm/msm/msm_iommu.c (revision 4c79e98b)
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 *domain, struct device *dev,
28 		unsigned long iova, int flags, void *arg)
29 {
30 	struct msm_iommu *iommu = arg;
31 	if (iommu->base.handler)
32 		return iommu->base.handler(iommu->base.arg, iova, flags);
33 	pr_warn_ratelimited("*** fault: iova=%08lx, flags=%d\n", iova, flags);
34 	return 0;
35 }
36 
37 static int msm_iommu_attach(struct msm_mmu *mmu, const char * const *names,
38 			    int cnt)
39 {
40 	struct msm_iommu *iommu = to_msm_iommu(mmu);
41 	return iommu_attach_device(iommu->domain, mmu->dev);
42 }
43 
44 static void msm_iommu_detach(struct msm_mmu *mmu, const char * const *names,
45 			     int cnt)
46 {
47 	struct msm_iommu *iommu = to_msm_iommu(mmu);
48 	iommu_detach_device(iommu->domain, mmu->dev);
49 }
50 
51 static int msm_iommu_map(struct msm_mmu *mmu, uint64_t iova,
52 		struct sg_table *sgt, unsigned len, int prot)
53 {
54 	struct msm_iommu *iommu = to_msm_iommu(mmu);
55 	struct iommu_domain *domain = iommu->domain;
56 	struct scatterlist *sg;
57 	unsigned long da = iova;
58 	unsigned int i, j;
59 	int ret;
60 
61 	if (!domain || !sgt)
62 		return -EINVAL;
63 
64 	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
65 		dma_addr_t pa = sg_phys(sg) - sg->offset;
66 		size_t bytes = sg->length + sg->offset;
67 
68 		VERB("map[%d]: %08lx %08lx(%zx)", i, da, (unsigned long)pa, bytes);
69 
70 		ret = iommu_map(domain, da, pa, bytes, prot);
71 		if (ret)
72 			goto fail;
73 
74 		da += bytes;
75 	}
76 
77 	return 0;
78 
79 fail:
80 	da = iova;
81 
82 	for_each_sg(sgt->sgl, sg, i, j) {
83 		size_t bytes = sg->length + sg->offset;
84 		iommu_unmap(domain, da, bytes);
85 		da += bytes;
86 	}
87 	return ret;
88 }
89 
90 static int msm_iommu_unmap(struct msm_mmu *mmu, uint64_t iova,
91 		struct sg_table *sgt, unsigned len)
92 {
93 	struct msm_iommu *iommu = to_msm_iommu(mmu);
94 	struct iommu_domain *domain = iommu->domain;
95 	struct scatterlist *sg;
96 	unsigned long da = iova;
97 	int i;
98 
99 	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
100 		size_t bytes = sg->length + sg->offset;
101 		size_t unmapped;
102 
103 		unmapped = iommu_unmap(domain, da, bytes);
104 		if (unmapped < bytes)
105 			return unmapped;
106 
107 		VERB("unmap[%d]: %08lx(%zx)", i, da, bytes);
108 
109 		BUG_ON(!PAGE_ALIGNED(bytes));
110 
111 		da += bytes;
112 	}
113 
114 	return 0;
115 }
116 
117 static void msm_iommu_destroy(struct msm_mmu *mmu)
118 {
119 	struct msm_iommu *iommu = to_msm_iommu(mmu);
120 	iommu_domain_free(iommu->domain);
121 	kfree(iommu);
122 }
123 
124 static const struct msm_mmu_funcs funcs = {
125 		.attach = msm_iommu_attach,
126 		.detach = msm_iommu_detach,
127 		.map = msm_iommu_map,
128 		.unmap = msm_iommu_unmap,
129 		.destroy = msm_iommu_destroy,
130 };
131 
132 struct msm_mmu *msm_iommu_new(struct device *dev, struct iommu_domain *domain)
133 {
134 	struct msm_iommu *iommu;
135 
136 	iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
137 	if (!iommu)
138 		return ERR_PTR(-ENOMEM);
139 
140 	iommu->domain = domain;
141 	msm_mmu_init(&iommu->base, dev, &funcs);
142 	iommu_set_fault_handler(domain, msm_fault_handler, iommu);
143 
144 	return &iommu->base;
145 }
146