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         int count = size >> PAGE_SHIFT;
 100         struct page **pages;
 101         dma_addr_t iovaddr;
 102         struct iova *iova;
 103         int i, rval;
 104
 105         dev_dbg(dev, "%s: allocating %zu\n", __func__, size);
 106
 107         iova = alloc_iova(&imgu->iova_domain, size >> shift,
 108                           imgu->mmu->aperture_end >> shift, 0);
 109         if (!iova)
 110                 return NULL;
 111
 112         pages = imgu_dmamap_alloc_buffer(size, GFP_KERNEL);
 113         if (!pages)
 114                 goto out_free_iova;
 115
 116         /* Call IOMMU driver to setup pgt */
 117         iovaddr = iova_dma_addr(&imgu->iova_domain, iova);
 118         for (i = 0; i < count; ++i) {
 119                 rval = imgu_mmu_map(imgu->mmu, iovaddr,
 120                                     page_to_phys(pages[i]), PAGE_SIZE);
 121                 if (rval)
 122                         goto out_unmap;
 123
 124                 iovaddr += PAGE_SIZE;
 125         }
 126
 127         map->vaddr = vmap(pages, count, VM_USERMAP, PAGE_KERNEL);
 128         if (!map->vaddr)
 129                 goto out_unmap;
 130
 131         map->pages = pages;
 132         map->size = size;
 133         map->daddr = iova_dma_addr(&imgu->iova_domain, iova);
 134
 135         dev_dbg(dev, "%s: allocated %zu @ IOVA %pad @ VA %p\n", __func__,
 136                 size, &map->daddr, map->vaddr);
 137
 138         return map->vaddr;
 139
 140 out_unmap:
 141         imgu_dmamap_free_buffer(pages, size);
 142         imgu_mmu_unmap(imgu->mmu, iova_dma_addr(&imgu->iova_domain, iova),
 143                        i * PAGE_SIZE);
 144
 145 out_free_iova:
 146         __free_iova(&imgu->iova_domain, iova);
 147
 148         return NULL;
 149 }
 150
 151 void imgu_dmamap_unmap(struct imgu_device *imgu, struct imgu_css_map *map)
 152 {
 153         struct iova *iova;
 154
 155         iova = find_iova(&imgu->iova_domain,
 156                          iova_pfn(&imgu->iova_domain, map->daddr));
 157         if (WARN_ON(!iova))
 158                 return;
 159
 160         imgu_mmu_unmap(imgu->mmu, iova_dma_addr(&imgu->iova_domain, iova),
 161                        iova_size(iova) << iova_shift(&imgu->iova_domain));
 162
 163         __free_iova(&imgu->iova_domain, iova);
 164 }
 165
 166 /*
 167  * Counterpart of imgu_dmamap_alloc
 168  */
 169 void imgu_dmamap_free(struct imgu_device *imgu, struct imgu_css_map *map)
 170 {
 171         dev_dbg(&imgu->pci_dev->dev, "%s: freeing %zu @ IOVA %pad @ VA %p\n",
 172                 __func__, map->size, &map->daddr, map->vaddr);
 173
 174         if (!map->vaddr)
 175                 return;
 176
 177         imgu_dmamap_unmap(imgu, map);
 178
 179         vunmap(map->vaddr);
 180         imgu_dmamap_free_buffer(map->pages, map->size);
 181         map->vaddr = NULL;
 182 }
 183
 184 int imgu_dmamap_map_sg(struct imgu_device *imgu, struct scatterlist *sglist,
 185                        int nents, struct imgu_css_map *map)
 186 {
 187         unsigned long shift = iova_shift(&imgu->iova_domain);
 188         struct scatterlist *sg;
 189         struct iova *iova;
 190         size_t size = 0;
 191         int i;
 192
 193         for_each_sg(sglist, sg, nents, i) {
 194                 if (sg->offset)
 195                         return -EINVAL;
 196
 197                 if (i != nents - 1 && !PAGE_ALIGNED(sg->length))
 198                         return -EINVAL;
 199
 200                 size += sg->length;
 201         }
 202
 203         size = iova_align(&imgu->iova_domain, size);
 204         dev_dbg(&imgu->pci_dev->dev, "dmamap: mapping sg %d entries, %zu pages\n",
 205                 nents, size >> shift);
 206
 207         iova = alloc_iova(&imgu->iova_domain, size >> shift,
 208                           imgu->mmu->aperture_end >> shift, 0);
 209         if (!iova)
 210                 return -ENOMEM;
 211
 212         dev_dbg(&imgu->pci_dev->dev, "dmamap: iova low pfn %lu, high pfn %lu\n",
 213                 iova->pfn_lo, iova->pfn_hi);
 214
 215         if (imgu_mmu_map_sg(imgu->mmu, iova_dma_addr(&imgu->iova_domain, iova),
 216                             sglist, nents) < size)
 217                 goto out_fail;
 218
 219         memset(map, 0, sizeof(*map));
 220         map->daddr = iova_dma_addr(&imgu->iova_domain, iova);
 221         map->size = size;
 222
 223         return 0;
 224
 225 out_fail:
 226         __free_iova(&imgu->iova_domain, iova);
 227
 228         return -EFAULT;
 229 }
 230
 231 int imgu_dmamap_init(struct imgu_device *imgu)
 232 {
 233         unsigned long order, base_pfn;
 234         int ret = iova_cache_get();
 235
 236         if (ret)
 237                 return ret;
 238
 239         order = __ffs(IPU3_PAGE_SIZE);
 240         base_pfn = max_t(unsigned long, 1, imgu->mmu->aperture_start >> order);
 241         init_iova_domain(&imgu->iova_domain, 1UL << order, base_pfn);
 242
 243         return 0;
 244 }
 245
 246 void imgu_dmamap_exit(struct imgu_device *imgu)
 247 {
 248         put_iova_domain(&imgu->iova_domain);
 249         iova_cache_put();
 250 }