1 /*
2  * Copyright (C) 2016 Etnaviv Project
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/platform_device.h>
18 #include <linux/sizes.h>
19 #include <linux/slab.h>
20 #include <linux/dma-mapping.h>
21 #include <linux/bitops.h>
22 
23 #include "etnaviv_cmdbuf.h"
24 #include "etnaviv_gpu.h"
25 #include "etnaviv_mmu.h"
26 #include "etnaviv_iommu.h"
27 #include "state.xml.h"
28 #include "state_hi.xml.h"
29 
30 #define MMUv2_PTE_PRESENT		BIT(0)
31 #define MMUv2_PTE_EXCEPTION		BIT(1)
32 #define MMUv2_PTE_WRITEABLE		BIT(2)
33 
34 #define MMUv2_MTLB_MASK			0xffc00000
35 #define MMUv2_MTLB_SHIFT		22
36 #define MMUv2_STLB_MASK			0x003ff000
37 #define MMUv2_STLB_SHIFT		12
38 
39 #define MMUv2_MAX_STLB_ENTRIES		1024
40 
41 struct etnaviv_iommuv2_domain {
42 	struct etnaviv_iommu_domain base;
43 	/* M(aster) TLB aka first level pagetable */
44 	u32 *mtlb_cpu;
45 	dma_addr_t mtlb_dma;
46 	/* S(lave) TLB aka second level pagetable */
47 	u32 *stlb_cpu[1024];
48 	dma_addr_t stlb_dma[1024];
49 };
50 
51 static struct etnaviv_iommuv2_domain *
52 to_etnaviv_domain(struct etnaviv_iommu_domain *domain)
53 {
54 	return container_of(domain, struct etnaviv_iommuv2_domain, base);
55 }
56 
57 static int etnaviv_iommuv2_map(struct etnaviv_iommu_domain *domain,
58 			       unsigned long iova, phys_addr_t paddr,
59 			       size_t size, int prot)
60 {
61 	struct etnaviv_iommuv2_domain *etnaviv_domain =
62 			to_etnaviv_domain(domain);
63 	int mtlb_entry, stlb_entry;
64 	u32 entry = (u32)paddr | MMUv2_PTE_PRESENT;
65 
66 	if (size != SZ_4K)
67 		return -EINVAL;
68 
69 	if (prot & ETNAVIV_PROT_WRITE)
70 		entry |= MMUv2_PTE_WRITEABLE;
71 
72 	mtlb_entry = (iova & MMUv2_MTLB_MASK) >> MMUv2_MTLB_SHIFT;
73 	stlb_entry = (iova & MMUv2_STLB_MASK) >> MMUv2_STLB_SHIFT;
74 
75 	etnaviv_domain->stlb_cpu[mtlb_entry][stlb_entry] = entry;
76 
77 	return 0;
78 }
79 
80 static size_t etnaviv_iommuv2_unmap(struct etnaviv_iommu_domain *domain,
81 				    unsigned long iova, size_t size)
82 {
83 	struct etnaviv_iommuv2_domain *etnaviv_domain =
84 			to_etnaviv_domain(domain);
85 	int mtlb_entry, stlb_entry;
86 
87 	if (size != SZ_4K)
88 		return -EINVAL;
89 
90 	mtlb_entry = (iova & MMUv2_MTLB_MASK) >> MMUv2_MTLB_SHIFT;
91 	stlb_entry = (iova & MMUv2_STLB_MASK) >> MMUv2_STLB_SHIFT;
92 
93 	etnaviv_domain->stlb_cpu[mtlb_entry][stlb_entry] = MMUv2_PTE_EXCEPTION;
94 
95 	return SZ_4K;
96 }
97 
98 static int etnaviv_iommuv2_init(struct etnaviv_iommuv2_domain *etnaviv_domain)
99 {
100 	u32 *p;
101 	int ret, i, j;
102 
103 	/* allocate scratch page */
104 	etnaviv_domain->base.bad_page_cpu = dma_alloc_coherent(
105 						etnaviv_domain->base.dev,
106 						SZ_4K,
107 						&etnaviv_domain->base.bad_page_dma,
108 						GFP_KERNEL);
109 	if (!etnaviv_domain->base.bad_page_cpu) {
110 		ret = -ENOMEM;
111 		goto fail_mem;
112 	}
113 	p = etnaviv_domain->base.bad_page_cpu;
114 	for (i = 0; i < SZ_4K / 4; i++)
115 		*p++ = 0xdead55aa;
116 
117 	etnaviv_domain->mtlb_cpu = dma_alloc_coherent(etnaviv_domain->base.dev,
118 						  SZ_4K,
119 						  &etnaviv_domain->mtlb_dma,
120 						  GFP_KERNEL);
121 	if (!etnaviv_domain->mtlb_cpu) {
122 		ret = -ENOMEM;
123 		goto fail_mem;
124 	}
125 
126 	/* pre-populate STLB pages (may want to switch to on-demand later) */
127 	for (i = 0; i < MMUv2_MAX_STLB_ENTRIES; i++) {
128 		etnaviv_domain->stlb_cpu[i] =
129 				dma_alloc_coherent(etnaviv_domain->base.dev,
130 						   SZ_4K,
131 						   &etnaviv_domain->stlb_dma[i],
132 						   GFP_KERNEL);
133 		if (!etnaviv_domain->stlb_cpu[i]) {
134 			ret = -ENOMEM;
135 			goto fail_mem;
136 		}
137 		p = etnaviv_domain->stlb_cpu[i];
138 		for (j = 0; j < SZ_4K / 4; j++)
139 			*p++ = MMUv2_PTE_EXCEPTION;
140 
141 		etnaviv_domain->mtlb_cpu[i] = etnaviv_domain->stlb_dma[i] |
142 					      MMUv2_PTE_PRESENT;
143 	}
144 
145 	return 0;
146 
147 fail_mem:
148 	if (etnaviv_domain->base.bad_page_cpu)
149 		dma_free_coherent(etnaviv_domain->base.dev, SZ_4K,
150 				  etnaviv_domain->base.bad_page_cpu,
151 				  etnaviv_domain->base.bad_page_dma);
152 
153 	if (etnaviv_domain->mtlb_cpu)
154 		dma_free_coherent(etnaviv_domain->base.dev, SZ_4K,
155 				  etnaviv_domain->mtlb_cpu,
156 				  etnaviv_domain->mtlb_dma);
157 
158 	for (i = 0; i < MMUv2_MAX_STLB_ENTRIES; i++) {
159 		if (etnaviv_domain->stlb_cpu[i])
160 			dma_free_coherent(etnaviv_domain->base.dev, SZ_4K,
161 					  etnaviv_domain->stlb_cpu[i],
162 					  etnaviv_domain->stlb_dma[i]);
163 	}
164 
165 	return ret;
166 }
167 
168 static void etnaviv_iommuv2_domain_free(struct etnaviv_iommu_domain *domain)
169 {
170 	struct etnaviv_iommuv2_domain *etnaviv_domain =
171 			to_etnaviv_domain(domain);
172 	int i;
173 
174 	dma_free_coherent(etnaviv_domain->base.dev, SZ_4K,
175 			  etnaviv_domain->base.bad_page_cpu,
176 			  etnaviv_domain->base.bad_page_dma);
177 
178 	dma_free_coherent(etnaviv_domain->base.dev, SZ_4K,
179 			  etnaviv_domain->mtlb_cpu,
180 			  etnaviv_domain->mtlb_dma);
181 
182 	for (i = 0; i < MMUv2_MAX_STLB_ENTRIES; i++) {
183 		if (etnaviv_domain->stlb_cpu[i])
184 			dma_free_coherent(etnaviv_domain->base.dev, SZ_4K,
185 					  etnaviv_domain->stlb_cpu[i],
186 					  etnaviv_domain->stlb_dma[i]);
187 	}
188 
189 	vfree(etnaviv_domain);
190 }
191 
192 static size_t etnaviv_iommuv2_dump_size(struct etnaviv_iommu_domain *domain)
193 {
194 	struct etnaviv_iommuv2_domain *etnaviv_domain =
195 			to_etnaviv_domain(domain);
196 	size_t dump_size = SZ_4K;
197 	int i;
198 
199 	for (i = 0; i < MMUv2_MAX_STLB_ENTRIES; i++)
200 		if (etnaviv_domain->mtlb_cpu[i] & MMUv2_PTE_PRESENT)
201 			dump_size += SZ_4K;
202 
203 	return dump_size;
204 }
205 
206 static void etnaviv_iommuv2_dump(struct etnaviv_iommu_domain *domain, void *buf)
207 {
208 	struct etnaviv_iommuv2_domain *etnaviv_domain =
209 			to_etnaviv_domain(domain);
210 	int i;
211 
212 	memcpy(buf, etnaviv_domain->mtlb_cpu, SZ_4K);
213 	buf += SZ_4K;
214 	for (i = 0; i < MMUv2_MAX_STLB_ENTRIES; i++, buf += SZ_4K)
215 		if (etnaviv_domain->mtlb_cpu[i] & MMUv2_PTE_PRESENT)
216 			memcpy(buf, etnaviv_domain->stlb_cpu[i], SZ_4K);
217 }
218 
219 void etnaviv_iommuv2_restore(struct etnaviv_gpu *gpu)
220 {
221 	struct etnaviv_iommuv2_domain *etnaviv_domain =
222 			to_etnaviv_domain(gpu->mmu->domain);
223 	u16 prefetch;
224 
225 	/* If the MMU is already enabled the state is still there. */
226 	if (gpu_read(gpu, VIVS_MMUv2_CONTROL) & VIVS_MMUv2_CONTROL_ENABLE)
227 		return;
228 
229 	prefetch = etnaviv_buffer_config_mmuv2(gpu,
230 				(u32)etnaviv_domain->mtlb_dma,
231 				(u32)etnaviv_domain->base.bad_page_dma);
232 	etnaviv_gpu_start_fe(gpu, (u32)etnaviv_cmdbuf_get_pa(&gpu->buffer),
233 			     prefetch);
234 	etnaviv_gpu_wait_idle(gpu, 100);
235 
236 	gpu_write(gpu, VIVS_MMUv2_CONTROL, VIVS_MMUv2_CONTROL_ENABLE);
237 }
238 
239 const struct etnaviv_iommu_domain_ops etnaviv_iommuv2_ops = {
240 	.free = etnaviv_iommuv2_domain_free,
241 	.map = etnaviv_iommuv2_map,
242 	.unmap = etnaviv_iommuv2_unmap,
243 	.dump_size = etnaviv_iommuv2_dump_size,
244 	.dump = etnaviv_iommuv2_dump,
245 };
246 
247 struct etnaviv_iommu_domain *
248 etnaviv_iommuv2_domain_alloc(struct etnaviv_gpu *gpu)
249 {
250 	struct etnaviv_iommuv2_domain *etnaviv_domain;
251 	struct etnaviv_iommu_domain *domain;
252 	int ret;
253 
254 	etnaviv_domain = vzalloc(sizeof(*etnaviv_domain));
255 	if (!etnaviv_domain)
256 		return NULL;
257 
258 	domain = &etnaviv_domain->base;
259 
260 	domain->dev = gpu->dev;
261 	domain->base = 0;
262 	domain->size = (u64)SZ_1G * 4;
263 	domain->ops = &etnaviv_iommuv2_ops;
264 
265 	ret = etnaviv_iommuv2_init(etnaviv_domain);
266 	if (ret)
267 		goto out_free;
268 
269 	return &etnaviv_domain->base;
270 
271 out_free:
272 	vfree(etnaviv_domain);
273 	return NULL;
274 }
275