1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * NVIDIA Tegra Video decoder driver
4 *
5 * Copyright (C) 2016-2019 GRATE-DRIVER project
6 */
7
8 #include <linux/iommu.h>
9 #include <linux/iova.h>
10 #include <linux/kernel.h>
11 #include <linux/platform_device.h>
12
13 #if IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)
14 #include <asm/dma-iommu.h>
15 #endif
16
17 #include "vde.h"
18
tegra_vde_iommu_map(struct tegra_vde * vde,struct sg_table * sgt,struct iova ** iovap,size_t size)19 int tegra_vde_iommu_map(struct tegra_vde *vde,
20 struct sg_table *sgt,
21 struct iova **iovap,
22 size_t size)
23 {
24 struct iova *iova;
25 unsigned long shift;
26 unsigned long end;
27 dma_addr_t addr;
28
29 end = vde->domain->geometry.aperture_end;
30 size = iova_align(&vde->iova, size);
31 shift = iova_shift(&vde->iova);
32
33 iova = alloc_iova(&vde->iova, size >> shift, end >> shift, true);
34 if (!iova)
35 return -ENOMEM;
36
37 addr = iova_dma_addr(&vde->iova, iova);
38
39 size = iommu_map_sgtable(vde->domain, addr, sgt,
40 IOMMU_READ | IOMMU_WRITE);
41 if (!size) {
42 __free_iova(&vde->iova, iova);
43 return -ENXIO;
44 }
45
46 *iovap = iova;
47
48 return 0;
49 }
50
tegra_vde_iommu_unmap(struct tegra_vde * vde,struct iova * iova)51 void tegra_vde_iommu_unmap(struct tegra_vde *vde, struct iova *iova)
52 {
53 unsigned long shift = iova_shift(&vde->iova);
54 unsigned long size = iova_size(iova) << shift;
55 dma_addr_t addr = iova_dma_addr(&vde->iova, iova);
56
57 iommu_unmap(vde->domain, addr, size);
58 __free_iova(&vde->iova, iova);
59 }
60
tegra_vde_iommu_init(struct tegra_vde * vde)61 int tegra_vde_iommu_init(struct tegra_vde *vde)
62 {
63 struct device *dev = vde->miscdev.parent;
64 struct iova *iova;
65 unsigned long order;
66 unsigned long shift;
67 int err;
68
69 vde->group = iommu_group_get(dev);
70 if (!vde->group)
71 return 0;
72
73 #if IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)
74 if (dev->archdata.mapping) {
75 struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
76
77 arm_iommu_detach_device(dev);
78 arm_iommu_release_mapping(mapping);
79 }
80 #endif
81 vde->domain = iommu_domain_alloc(&platform_bus_type);
82 if (!vde->domain) {
83 err = -ENOMEM;
84 goto put_group;
85 }
86
87 err = iova_cache_get();
88 if (err)
89 goto free_domain;
90
91 order = __ffs(vde->domain->pgsize_bitmap);
92 init_iova_domain(&vde->iova, 1UL << order, 0);
93
94 err = iommu_attach_group(vde->domain, vde->group);
95 if (err)
96 goto put_iova;
97
98 /*
99 * We're using some static addresses that are not accessible by VDE
100 * to trap invalid memory accesses.
101 */
102 shift = iova_shift(&vde->iova);
103 iova = reserve_iova(&vde->iova, 0x60000000 >> shift,
104 0x70000000 >> shift);
105 if (!iova) {
106 err = -ENOMEM;
107 goto detach_group;
108 }
109
110 vde->iova_resv_static_addresses = iova;
111
112 /*
113 * BSEV's end-address wraps around due to integer overflow during
114 * of hardware context preparation if IOVA is allocated at the end
115 * of address space and VDE can't handle that. Hence simply reserve
116 * the last page to avoid the problem.
117 */
118 iova = reserve_iova(&vde->iova, 0xffffffff >> shift,
119 (0xffffffff >> shift) + 1);
120 if (!iova) {
121 err = -ENOMEM;
122 goto unreserve_iova;
123 }
124
125 vde->iova_resv_last_page = iova;
126
127 return 0;
128
129 unreserve_iova:
130 __free_iova(&vde->iova, vde->iova_resv_static_addresses);
131 detach_group:
132 iommu_detach_group(vde->domain, vde->group);
133 put_iova:
134 put_iova_domain(&vde->iova);
135 iova_cache_put();
136 free_domain:
137 iommu_domain_free(vde->domain);
138 put_group:
139 iommu_group_put(vde->group);
140
141 return err;
142 }
143
tegra_vde_iommu_deinit(struct tegra_vde * vde)144 void tegra_vde_iommu_deinit(struct tegra_vde *vde)
145 {
146 if (vde->domain) {
147 __free_iova(&vde->iova, vde->iova_resv_last_page);
148 __free_iova(&vde->iova, vde->iova_resv_static_addresses);
149 iommu_detach_group(vde->domain, vde->group);
150 put_iova_domain(&vde->iova);
151 iova_cache_put();
152 iommu_domain_free(vde->domain);
153 iommu_group_put(vde->group);
154
155 vde->domain = NULL;
156 }
157 }
158