drivers/staging/media/ipu3/ipu3-dmamap.c

   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  */
  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  */
  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  */
  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
 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  */
 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
 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
 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
 260 void imgu_dmamap_exit(struct imgu_device *imgu)
 261 {
 262         put_iova_domain(&imgu->iova_domain);
 263         iova_cache_put();
 264 }