1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2018 Intel Corporation
4 * Copyright 2018 Google LLC.
5 *
6 * Author: Tomasz Figa <tfiga@chromium.org>
7 * Author: Yong Zhi <yong.zhi@intel.com>
8 */
9
10 #include <linux/vmalloc.h>
11
12 #include "ipu3.h"
13 #include "ipu3-css-pool.h"
14 #include "ipu3-mmu.h"
15 #include "ipu3-dmamap.h"
16
17 /*
18 * Free a buffer allocated by imgu_dmamap_alloc_buffer()
19 */
imgu_dmamap_free_buffer(struct page ** pages,size_t size)20 static void imgu_dmamap_free_buffer(struct page **pages,
21 size_t size)
22 {
23 int count = size >> PAGE_SHIFT;
24
25 while (count--)
26 __free_page(pages[count]);
27 kvfree(pages);
28 }
29
30 /*
31 * Based on the implementation of __iommu_dma_alloc_pages()
32 * defined in drivers/iommu/dma-iommu.c
33 */
imgu_dmamap_alloc_buffer(size_t size,gfp_t gfp)34 static struct page **imgu_dmamap_alloc_buffer(size_t size, gfp_t gfp)
35 {
36 struct page **pages;
37 unsigned int i = 0, count = size >> PAGE_SHIFT;
38 unsigned int order_mask = 1;
39 const gfp_t high_order_gfp = __GFP_NOWARN | __GFP_NORETRY;
40
41 /* Allocate mem for array of page ptrs */
42 pages = kvmalloc_array(count, sizeof(*pages), GFP_KERNEL);
43
44 if (!pages)
45 return NULL;
46
47 gfp |= __GFP_HIGHMEM | __GFP_ZERO;
48
49 while (count) {
50 struct page *page = NULL;
51 unsigned int order_size;
52
53 for (order_mask &= (2U << __fls(count)) - 1;
54 order_mask; order_mask &= ~order_size) {
55 unsigned int order = __fls(order_mask);
56
57 order_size = 1U << order;
58 page = alloc_pages((order_mask - order_size) ?
59 gfp | high_order_gfp : gfp, order);
60 if (!page)
61 continue;
62 if (!order)
63 break;
64 if (!PageCompound(page)) {
65 split_page(page, order);
66 break;
67 }
68
69 __free_pages(page, order);
70 }
71 if (!page) {
72 imgu_dmamap_free_buffer(pages, i << PAGE_SHIFT);
73 return NULL;
74 }
75 count -= order_size;
76 while (order_size--)
77 pages[i++] = page++;
78 }
79
80 return pages;
81 }
82
83 /**
84 * imgu_dmamap_alloc - allocate and map a buffer into KVA
85 * @imgu: struct device pointer
86 * @map: struct to store mapping variables
87 * @len: size required
88 *
89 * Returns:
90 * KVA on success
91 * %NULL on failure
92 */
imgu_dmamap_alloc(struct imgu_device * imgu,struct imgu_css_map * map,size_t len)93 void *imgu_dmamap_alloc(struct imgu_device *imgu, struct imgu_css_map *map,
94 size_t len)
95 {
96 unsigned long shift = iova_shift(&imgu->iova_domain);
97 struct device *dev = &imgu->pci_dev->dev;
98 size_t size = PAGE_ALIGN(len);
99 struct page **pages;
100 dma_addr_t iovaddr;
101 struct iova *iova;
102 int i, rval;
103
104 dev_dbg(dev, "%s: allocating %zu\n", __func__, size);
105
106 iova = alloc_iova(&imgu->iova_domain, size >> shift,
107 imgu->mmu->aperture_end >> shift, 0);
108 if (!iova)
109 return NULL;
110
111 pages = imgu_dmamap_alloc_buffer(size, GFP_KERNEL);
112 if (!pages)
113 goto out_free_iova;
114
115 /* Call IOMMU driver to setup pgt */
116 iovaddr = iova_dma_addr(&imgu->iova_domain, iova);
117 for (i = 0; i < size / PAGE_SIZE; ++i) {
118 rval = imgu_mmu_map(imgu->mmu, iovaddr,
119 page_to_phys(pages[i]), PAGE_SIZE);
120 if (rval)
121 goto out_unmap;
122
123 iovaddr += PAGE_SIZE;
124 }
125
126 /* Now grab a virtual region */
127 map->vma = __get_vm_area(size, VM_USERMAP, VMALLOC_START, VMALLOC_END);
128 if (!map->vma)
129 goto out_unmap;
130
131 map->vma->pages = pages;
132 /* And map it in KVA */
133 if (map_vm_area(map->vma, PAGE_KERNEL, pages))
134 goto out_vunmap;
135
136 map->size = size;
137 map->daddr = iova_dma_addr(&imgu->iova_domain, iova);
138 map->vaddr = map->vma->addr;
139
140 dev_dbg(dev, "%s: allocated %zu @ IOVA %pad @ VA %p\n", __func__,
141 size, &map->daddr, map->vma->addr);
142
143 return map->vma->addr;
144
145 out_vunmap:
146 vunmap(map->vma->addr);
147
148 out_unmap:
149 imgu_dmamap_free_buffer(pages, size);
150 imgu_mmu_unmap(imgu->mmu, iova_dma_addr(&imgu->iova_domain, iova),
151 i * PAGE_SIZE);
152 map->vma = NULL;
153
154 out_free_iova:
155 __free_iova(&imgu->iova_domain, iova);
156
157 return NULL;
158 }
159
imgu_dmamap_unmap(struct imgu_device * imgu,struct imgu_css_map * map)160 void imgu_dmamap_unmap(struct imgu_device *imgu, struct imgu_css_map *map)
161 {
162 struct iova *iova;
163
164 iova = find_iova(&imgu->iova_domain,
165 iova_pfn(&imgu->iova_domain, map->daddr));
166 if (WARN_ON(!iova))
167 return;
168
169 imgu_mmu_unmap(imgu->mmu, iova_dma_addr(&imgu->iova_domain, iova),
170 iova_size(iova) << iova_shift(&imgu->iova_domain));
171
172 __free_iova(&imgu->iova_domain, iova);
173 }
174
175 /*
176 * Counterpart of imgu_dmamap_alloc
177 */
imgu_dmamap_free(struct imgu_device * imgu,struct imgu_css_map * map)178 void imgu_dmamap_free(struct imgu_device *imgu, struct imgu_css_map *map)
179 {
180 struct vm_struct *area = map->vma;
181
182 dev_dbg(&imgu->pci_dev->dev, "%s: freeing %zu @ IOVA %pad @ VA %p\n",
183 __func__, map->size, &map->daddr, map->vaddr);
184
185 if (!map->vaddr)
186 return;
187
188 imgu_dmamap_unmap(imgu, map);
189
190 if (WARN_ON(!area) || WARN_ON(!area->pages))
191 return;
192
193 imgu_dmamap_free_buffer(area->pages, map->size);
194 vunmap(map->vaddr);
195 map->vaddr = NULL;
196 }
197
imgu_dmamap_map_sg(struct imgu_device * imgu,struct scatterlist * sglist,int nents,struct imgu_css_map * map)198 int imgu_dmamap_map_sg(struct imgu_device *imgu, struct scatterlist *sglist,
199 int nents, struct imgu_css_map *map)
200 {
201 unsigned long shift = iova_shift(&imgu->iova_domain);
202 struct scatterlist *sg;
203 struct iova *iova;
204 size_t size = 0;
205 int i;
206
207 for_each_sg(sglist, sg, nents, i) {
208 if (sg->offset)
209 return -EINVAL;
210
211 if (i != nents - 1 && !PAGE_ALIGNED(sg->length))
212 return -EINVAL;
213
214 size += sg->length;
215 }
216
217 size = iova_align(&imgu->iova_domain, size);
218 dev_dbg(&imgu->pci_dev->dev, "dmamap: mapping sg %d entries, %zu pages\n",
219 nents, size >> shift);
220
221 iova = alloc_iova(&imgu->iova_domain, size >> shift,
222 imgu->mmu->aperture_end >> shift, 0);
223 if (!iova)
224 return -ENOMEM;
225
226 dev_dbg(&imgu->pci_dev->dev, "dmamap: iova low pfn %lu, high pfn %lu\n",
227 iova->pfn_lo, iova->pfn_hi);
228
229 if (imgu_mmu_map_sg(imgu->mmu, iova_dma_addr(&imgu->iova_domain, iova),
230 sglist, nents) < size)
231 goto out_fail;
232
233 memset(map, 0, sizeof(*map));
234 map->daddr = iova_dma_addr(&imgu->iova_domain, iova);
235 map->size = size;
236
237 return 0;
238
239 out_fail:
240 __free_iova(&imgu->iova_domain, iova);
241
242 return -EFAULT;
243 }
244
imgu_dmamap_init(struct imgu_device * imgu)245 int imgu_dmamap_init(struct imgu_device *imgu)
246 {
247 unsigned long order, base_pfn;
248 int ret = iova_cache_get();
249
250 if (ret)
251 return ret;
252
253 order = __ffs(IPU3_PAGE_SIZE);
254 base_pfn = max_t(unsigned long, 1, imgu->mmu->aperture_start >> order);
255 init_iova_domain(&imgu->iova_domain, 1UL << order, base_pfn);
256
257 return 0;
258 }
259
imgu_dmamap_exit(struct imgu_device * imgu)260 void imgu_dmamap_exit(struct imgu_device *imgu)
261 {
262 put_iova_domain(&imgu->iova_domain);
263 iova_cache_put();
264 }
265