1 /*
2  * Copyright (C) 2014 Christian Gmeiner <christian.gmeiner@gmail.com>
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of the GNU General Public License version 2 as published by
6  * the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * You should have received a copy of the GNU General Public License along with
14  * this program.  If not, see <http://www.gnu.org/licenses/>.
15  */
16 
17 #include <linux/iommu.h>
18 #include <linux/platform_device.h>
19 #include <linux/sizes.h>
20 #include <linux/slab.h>
21 #include <linux/dma-mapping.h>
22 #include <linux/bitops.h>
23 
24 #include "etnaviv_gpu.h"
25 #include "etnaviv_mmu.h"
26 #include "etnaviv_iommu.h"
27 #include "state_hi.xml.h"
28 
29 #define PT_SIZE		SZ_2M
30 #define PT_ENTRIES	(PT_SIZE / sizeof(u32))
31 
32 #define GPU_MEM_START	0x80000000
33 
34 struct etnaviv_iommu_domain_pgtable {
35 	u32 *pgtable;
36 	dma_addr_t paddr;
37 };
38 
39 struct etnaviv_iommu_domain {
40 	struct iommu_domain domain;
41 	struct device *dev;
42 	void *bad_page_cpu;
43 	dma_addr_t bad_page_dma;
44 	struct etnaviv_iommu_domain_pgtable pgtable;
45 	spinlock_t map_lock;
46 };
47 
48 static struct etnaviv_iommu_domain *to_etnaviv_domain(struct iommu_domain *domain)
49 {
50 	return container_of(domain, struct etnaviv_iommu_domain, domain);
51 }
52 
53 static int pgtable_alloc(struct etnaviv_iommu_domain_pgtable *pgtable,
54 			 size_t size)
55 {
56 	pgtable->pgtable = dma_alloc_coherent(NULL, size, &pgtable->paddr, GFP_KERNEL);
57 	if (!pgtable->pgtable)
58 		return -ENOMEM;
59 
60 	return 0;
61 }
62 
63 static void pgtable_free(struct etnaviv_iommu_domain_pgtable *pgtable,
64 			 size_t size)
65 {
66 	dma_free_coherent(NULL, size, pgtable->pgtable, pgtable->paddr);
67 }
68 
69 static u32 pgtable_read(struct etnaviv_iommu_domain_pgtable *pgtable,
70 			   unsigned long iova)
71 {
72 	/* calcuate index into page table */
73 	unsigned int index = (iova - GPU_MEM_START) / SZ_4K;
74 	phys_addr_t paddr;
75 
76 	paddr = pgtable->pgtable[index];
77 
78 	return paddr;
79 }
80 
81 static void pgtable_write(struct etnaviv_iommu_domain_pgtable *pgtable,
82 			  unsigned long iova, phys_addr_t paddr)
83 {
84 	/* calcuate index into page table */
85 	unsigned int index = (iova - GPU_MEM_START) / SZ_4K;
86 
87 	pgtable->pgtable[index] = paddr;
88 }
89 
90 static int __etnaviv_iommu_init(struct etnaviv_iommu_domain *etnaviv_domain)
91 {
92 	u32 *p;
93 	int ret, i;
94 
95 	etnaviv_domain->bad_page_cpu = dma_alloc_coherent(etnaviv_domain->dev,
96 						  SZ_4K,
97 						  &etnaviv_domain->bad_page_dma,
98 						  GFP_KERNEL);
99 	if (!etnaviv_domain->bad_page_cpu)
100 		return -ENOMEM;
101 
102 	p = etnaviv_domain->bad_page_cpu;
103 	for (i = 0; i < SZ_4K / 4; i++)
104 		*p++ = 0xdead55aa;
105 
106 	ret = pgtable_alloc(&etnaviv_domain->pgtable, PT_SIZE);
107 	if (ret < 0) {
108 		dma_free_coherent(etnaviv_domain->dev, SZ_4K,
109 				  etnaviv_domain->bad_page_cpu,
110 				  etnaviv_domain->bad_page_dma);
111 		return ret;
112 	}
113 
114 	for (i = 0; i < PT_ENTRIES; i++)
115 		etnaviv_domain->pgtable.pgtable[i] =
116 			etnaviv_domain->bad_page_dma;
117 
118 	spin_lock_init(&etnaviv_domain->map_lock);
119 
120 	return 0;
121 }
122 
123 static void etnaviv_domain_free(struct iommu_domain *domain)
124 {
125 	struct etnaviv_iommu_domain *etnaviv_domain = to_etnaviv_domain(domain);
126 
127 	pgtable_free(&etnaviv_domain->pgtable, PT_SIZE);
128 
129 	dma_free_coherent(etnaviv_domain->dev, SZ_4K,
130 			  etnaviv_domain->bad_page_cpu,
131 			  etnaviv_domain->bad_page_dma);
132 
133 	kfree(etnaviv_domain);
134 }
135 
136 static int etnaviv_iommuv1_map(struct iommu_domain *domain, unsigned long iova,
137 	   phys_addr_t paddr, size_t size, int prot)
138 {
139 	struct etnaviv_iommu_domain *etnaviv_domain = to_etnaviv_domain(domain);
140 
141 	if (size != SZ_4K)
142 		return -EINVAL;
143 
144 	spin_lock(&etnaviv_domain->map_lock);
145 	pgtable_write(&etnaviv_domain->pgtable, iova, paddr);
146 	spin_unlock(&etnaviv_domain->map_lock);
147 
148 	return 0;
149 }
150 
151 static size_t etnaviv_iommuv1_unmap(struct iommu_domain *domain,
152 	unsigned long iova, size_t size)
153 {
154 	struct etnaviv_iommu_domain *etnaviv_domain = to_etnaviv_domain(domain);
155 
156 	if (size != SZ_4K)
157 		return -EINVAL;
158 
159 	spin_lock(&etnaviv_domain->map_lock);
160 	pgtable_write(&etnaviv_domain->pgtable, iova,
161 		      etnaviv_domain->bad_page_dma);
162 	spin_unlock(&etnaviv_domain->map_lock);
163 
164 	return SZ_4K;
165 }
166 
167 static phys_addr_t etnaviv_iommu_iova_to_phys(struct iommu_domain *domain,
168 	dma_addr_t iova)
169 {
170 	struct etnaviv_iommu_domain *etnaviv_domain = to_etnaviv_domain(domain);
171 
172 	return pgtable_read(&etnaviv_domain->pgtable, iova);
173 }
174 
175 static size_t etnaviv_iommuv1_dump_size(struct iommu_domain *domain)
176 {
177 	return PT_SIZE;
178 }
179 
180 static void etnaviv_iommuv1_dump(struct iommu_domain *domain, void *buf)
181 {
182 	struct etnaviv_iommu_domain *etnaviv_domain = to_etnaviv_domain(domain);
183 
184 	memcpy(buf, etnaviv_domain->pgtable.pgtable, PT_SIZE);
185 }
186 
187 static struct etnaviv_iommu_ops etnaviv_iommu_ops = {
188 	.ops = {
189 		.domain_free = etnaviv_domain_free,
190 		.map = etnaviv_iommuv1_map,
191 		.unmap = etnaviv_iommuv1_unmap,
192 		.iova_to_phys = etnaviv_iommu_iova_to_phys,
193 		.pgsize_bitmap = SZ_4K,
194 	},
195 	.dump_size = etnaviv_iommuv1_dump_size,
196 	.dump = etnaviv_iommuv1_dump,
197 };
198 
199 void etnaviv_iommu_domain_restore(struct etnaviv_gpu *gpu,
200 	struct iommu_domain *domain)
201 {
202 	struct etnaviv_iommu_domain *etnaviv_domain = to_etnaviv_domain(domain);
203 	u32 pgtable;
204 
205 	/* set page table address in MC */
206 	pgtable = (u32)etnaviv_domain->pgtable.paddr;
207 
208 	gpu_write(gpu, VIVS_MC_MMU_FE_PAGE_TABLE, pgtable);
209 	gpu_write(gpu, VIVS_MC_MMU_TX_PAGE_TABLE, pgtable);
210 	gpu_write(gpu, VIVS_MC_MMU_PE_PAGE_TABLE, pgtable);
211 	gpu_write(gpu, VIVS_MC_MMU_PEZ_PAGE_TABLE, pgtable);
212 	gpu_write(gpu, VIVS_MC_MMU_RA_PAGE_TABLE, pgtable);
213 }
214 
215 struct iommu_domain *etnaviv_iommu_domain_alloc(struct etnaviv_gpu *gpu)
216 {
217 	struct etnaviv_iommu_domain *etnaviv_domain;
218 	int ret;
219 
220 	etnaviv_domain = kzalloc(sizeof(*etnaviv_domain), GFP_KERNEL);
221 	if (!etnaviv_domain)
222 		return NULL;
223 
224 	etnaviv_domain->dev = gpu->dev;
225 
226 	etnaviv_domain->domain.type = __IOMMU_DOMAIN_PAGING;
227 	etnaviv_domain->domain.ops = &etnaviv_iommu_ops.ops;
228 	etnaviv_domain->domain.geometry.aperture_start = GPU_MEM_START;
229 	etnaviv_domain->domain.geometry.aperture_end = GPU_MEM_START + PT_ENTRIES * SZ_4K - 1;
230 
231 	ret = __etnaviv_iommu_init(etnaviv_domain);
232 	if (ret)
233 		goto out_free;
234 
235 	return &etnaviv_domain->domain;
236 
237 out_free:
238 	kfree(etnaviv_domain);
239 	return NULL;
240 }
241