xref: /openbmc/linux/drivers/gpu/drm/msm/msm_iommu.c (revision 82003e04)
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 * const *names,
35 			    int cnt)
36 {
37 	struct msm_iommu *iommu = to_msm_iommu(mmu);
38 	return iommu_attach_device(iommu->domain, mmu->dev);
39 }
40 
41 static void msm_iommu_detach(struct msm_mmu *mmu, const char * const *names,
42 			     int cnt)
43 {
44 	struct msm_iommu *iommu = to_msm_iommu(mmu);
45 	iommu_detach_device(iommu->domain, mmu->dev);
46 }
47 
48 static int msm_iommu_map(struct msm_mmu *mmu, uint32_t iova,
49 		struct sg_table *sgt, unsigned len, int prot)
50 {
51 	struct msm_iommu *iommu = to_msm_iommu(mmu);
52 	struct iommu_domain *domain = iommu->domain;
53 	struct scatterlist *sg;
54 	unsigned int da = iova;
55 	unsigned int i, j;
56 	int ret;
57 
58 	if (!domain || !sgt)
59 		return -EINVAL;
60 
61 	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
62 		dma_addr_t pa = sg_phys(sg) - sg->offset;
63 		size_t bytes = sg->length + sg->offset;
64 
65 		VERB("map[%d]: %08x %08lx(%zx)", i, da, (unsigned long)pa, bytes);
66 
67 		ret = iommu_map(domain, da, pa, bytes, prot);
68 		if (ret)
69 			goto fail;
70 
71 		da += bytes;
72 	}
73 
74 	return 0;
75 
76 fail:
77 	da = iova;
78 
79 	for_each_sg(sgt->sgl, sg, i, j) {
80 		size_t bytes = sg->length + sg->offset;
81 		iommu_unmap(domain, da, bytes);
82 		da += bytes;
83 	}
84 	return ret;
85 }
86 
87 static int msm_iommu_unmap(struct msm_mmu *mmu, uint32_t iova,
88 		struct sg_table *sgt, unsigned len)
89 {
90 	struct msm_iommu *iommu = to_msm_iommu(mmu);
91 	struct iommu_domain *domain = iommu->domain;
92 	struct scatterlist *sg;
93 	unsigned int da = iova;
94 	int i;
95 
96 	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
97 		size_t bytes = sg->length + sg->offset;
98 		size_t unmapped;
99 
100 		unmapped = iommu_unmap(domain, da, bytes);
101 		if (unmapped < bytes)
102 			return unmapped;
103 
104 		VERB("unmap[%d]: %08x(%zx)", i, da, bytes);
105 
106 		BUG_ON(!PAGE_ALIGNED(bytes));
107 
108 		da += bytes;
109 	}
110 
111 	return 0;
112 }
113 
114 static void msm_iommu_destroy(struct msm_mmu *mmu)
115 {
116 	struct msm_iommu *iommu = to_msm_iommu(mmu);
117 	iommu_domain_free(iommu->domain);
118 	kfree(iommu);
119 }
120 
121 static const struct msm_mmu_funcs funcs = {
122 		.attach = msm_iommu_attach,
123 		.detach = msm_iommu_detach,
124 		.map = msm_iommu_map,
125 		.unmap = msm_iommu_unmap,
126 		.destroy = msm_iommu_destroy,
127 };
128 
129 struct msm_mmu *msm_iommu_new(struct device *dev, struct iommu_domain *domain)
130 {
131 	struct msm_iommu *iommu;
132 
133 	iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
134 	if (!iommu)
135 		return ERR_PTR(-ENOMEM);
136 
137 	iommu->domain = domain;
138 	msm_mmu_init(&iommu->base, dev, &funcs);
139 	iommu_set_fault_handler(domain, msm_fault_handler, dev);
140 
141 	return &iommu->base;
142 }
143