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
21struct 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
27static 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
34static 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
40static 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
46static 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(%zx)", 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
74fail:
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
85static 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(%zx)", i, iova, bytes);
103
104		BUG_ON(!PAGE_ALIGNED(bytes));
105
106		da += bytes;
107	}
108
109	return 0;
110}
111
112static 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
119static 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
127struct 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