drivers/staging/android/ion/ion_cma_heap.c

   1 /*
   2  * drivers/staging/android/ion/ion_cma_heap.c
   3  *
   4  * Copyright (C) Linaro 2012
   5  * Author: <benjamin.gaignard@linaro.org> for ST-Ericsson.
   6  *
   7  * This software is licensed under the terms of the GNU General Public
   8  * License version 2, as published by the Free Software Foundation, and
   9  * may be copied, distributed, and modified under those terms.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  */
  17
  18 #include <linux/device.h>
  19 #include <linux/slab.h>
  20 #include <linux/errno.h>
  21 #include <linux/err.h>
  22 #include <linux/dma-mapping.h>
  23
  24 #include "ion.h"
  25 #include "ion_priv.h"
  26
  27 #define ION_CMA_ALLOCATE_FAILED -1
  28
  29 struct ion_cma_heap {
  30         struct ion_heap heap;
  31         struct device *dev;
  32 };
  33
  34 #define to_cma_heap(x) container_of(x, struct ion_cma_heap, heap)
  35
  36 struct ion_cma_buffer_info {
  37         void *cpu_addr;
  38         dma_addr_t handle;
  39         struct sg_table *table;
  40 };
  41
  42 /*
  43  * Create scatter-list for the already allocated DMA buffer.
  44  * This function could be replaced by dma_common_get_sgtable
  45  * as soon as it will avalaible.
  46  */
  47 int ion_cma_get_sgtable(struct device *dev, struct sg_table *sgt,
  48                         void *cpu_addr, dma_addr_t handle, size_t size)
  49 {
  50         struct page *page = virt_to_page(cpu_addr);
  51         int ret;
  52
  53         ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
  54         if (unlikely(ret))
  55                 return ret;
  56
  57         sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
  58         return 0;
  59 }
  60
  61 /*
  62  * Create scatter-list for each page of the already allocated DMA buffer.
  63  */
  64 int ion_cma_get_sgtable_per_page(struct device *dev, struct sg_table *sgt,
  65                         void *cpu_addr, dma_addr_t handle, size_t size)
  66 {
  67         struct page *page = virt_to_page(cpu_addr);
  68         int ret, i;
  69         struct scatterlist *sg;
  70
  71         ret = sg_alloc_table(sgt, PAGE_ALIGN(size) / PAGE_SIZE, GFP_KERNEL);
  72         if (unlikely(ret))
  73                 return ret;
  74
  75         sg = sgt->sgl;
  76         for (i = 0; i < (PAGE_ALIGN(size) / PAGE_SIZE); i++) {
  77                 page = virt_to_page(cpu_addr + (i * PAGE_SIZE));
  78                 sg_set_page(sg, page, PAGE_SIZE, 0);
  79                 sg = sg_next(sg);
  80         }
  81         return 0;
  82 }
  83
  84 /* ION CMA heap operations functions */
  85 static int ion_cma_allocate(struct ion_heap *heap, struct ion_buffer *buffer,
  86                             unsigned long len, unsigned long align,
  87                             unsigned long flags)
  88 {
  89         struct ion_cma_heap *cma_heap = to_cma_heap(heap);
  90         struct device *dev = cma_heap->dev;
  91         struct ion_cma_buffer_info *info;
  92
  93         dev_dbg(dev, "Request buffer allocation len %ld\n", len);
  94
  95         info = kzalloc(sizeof(struct ion_cma_buffer_info), GFP_KERNEL);
  96         if (!info) {
  97                 dev_err(dev, "Can't allocate buffer info\n");
  98                 return ION_CMA_ALLOCATE_FAILED;
  99         }
 100
 101         info->cpu_addr = dma_alloc_coherent(dev, len, &(info->handle), 0);
 102
 103         if (!info->cpu_addr) {
 104                 dev_err(dev, "Fail to allocate buffer\n");
 105                 goto err;
 106         }
 107
 108         info->table = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
 109         if (!info->table) {
 110                 dev_err(dev, "Fail to allocate sg table\n");
 111                 goto free_mem;
 112         }
 113
 114         if (ion_buffer_fault_user_mappings(buffer)) {
 115                 if (ion_cma_get_sgtable_per_page
 116                         (dev, info->table, info->cpu_addr, info->handle, len))
 117                         goto free_table;
 118         } else {
 119                 if (ion_cma_get_sgtable
 120                         (dev, info->table, info->cpu_addr, info->handle, len))
 121                         goto free_table;
 122         }
 123         /* keep this for memory release */
 124         buffer->priv_virt = info;
 125         dev_dbg(dev, "Allocate buffer %p\n", buffer);
 126         return 0;
 127
 128 free_table:
 129         kfree(info->table);
 130 free_mem:
 131         dma_free_coherent(dev, len, info->cpu_addr, info->handle);
 132 err:
 133         kfree(info);
 134         return ION_CMA_ALLOCATE_FAILED;
 135 }
 136
 137 static void ion_cma_free(struct ion_buffer *buffer)
 138 {
 139         struct ion_cma_heap *cma_heap = to_cma_heap(buffer->heap);
 140         struct device *dev = cma_heap->dev;
 141         struct ion_cma_buffer_info *info = buffer->priv_virt;
 142
 143         dev_dbg(dev, "Release buffer %p\n", buffer);
 144         /* release memory */
 145         dma_free_coherent(dev, buffer->size, info->cpu_addr, info->handle);
 146         /* release sg table */
 147         sg_free_table(info->table);
 148         kfree(info->table);
 149         kfree(info);
 150 }
 151
 152 /* return physical address in addr */
 153 static int ion_cma_phys(struct ion_heap *heap, struct ion_buffer *buffer,
 154                         ion_phys_addr_t *addr, size_t *len)
 155 {
 156         struct ion_cma_heap *cma_heap = to_cma_heap(buffer->heap);
 157         struct device *dev = cma_heap->dev;
 158         struct ion_cma_buffer_info *info = buffer->priv_virt;
 159
 160         dev_dbg(dev, "Return buffer %p physical address 0x%x\n", buffer,
 161                 info->handle);
 162
 163         *addr = info->handle;
 164         *len = buffer->size;
 165
 166         return 0;
 167 }
 168
 169 struct sg_table *ion_cma_heap_map_dma(struct ion_heap *heap,
 170                                          struct ion_buffer *buffer)
 171 {
 172         struct ion_cma_buffer_info *info = buffer->priv_virt;
 173
 174         return info->table;
 175 }
 176
 177 void ion_cma_heap_unmap_dma(struct ion_heap *heap,
 178                                struct ion_buffer *buffer)
 179 {
 180         return;
 181 }
 182
 183 static int ion_cma_mmap(struct ion_heap *mapper, struct ion_buffer *buffer,
 184                         struct vm_area_struct *vma)
 185 {
 186         struct ion_cma_heap *cma_heap = to_cma_heap(buffer->heap);
 187         struct device *dev = cma_heap->dev;
 188         struct ion_cma_buffer_info *info = buffer->priv_virt;
 189
 190         return dma_mmap_coherent(dev, vma, info->cpu_addr, info->handle,
 191                                  buffer->size);
 192 }
 193
 194 void *ion_cma_map_kernel(struct ion_heap *heap, struct ion_buffer *buffer)
 195 {
 196         struct ion_cma_buffer_info *info = buffer->priv_virt;
 197         /* kernel memory mapping has been done at allocation time */
 198         return info->cpu_addr;
 199 }
 200
 201 static struct ion_heap_ops ion_cma_ops = {
 202         .allocate = ion_cma_allocate,
 203         .free = ion_cma_free,
 204         .map_dma = ion_cma_heap_map_dma,
 205         .unmap_dma = ion_cma_heap_unmap_dma,
 206         .phys = ion_cma_phys,
 207         .map_user = ion_cma_mmap,
 208         .map_kernel = ion_cma_map_kernel,
 209 };
 210
 211 struct ion_heap *ion_cma_heap_create(struct ion_platform_heap *data)
 212 {
 213         struct ion_cma_heap *cma_heap;
 214
 215         cma_heap = kzalloc(sizeof(struct ion_cma_heap), GFP_KERNEL);
 216
 217         if (!cma_heap)
 218                 return ERR_PTR(-ENOMEM);
 219
 220         cma_heap->heap.ops = &ion_cma_ops;
 221         /* get device from private heaps data, later it will be
 222          * used to make the link with reserved CMA memory */
 223         cma_heap->dev = data->priv;
 224         cma_heap->heap.type = ION_HEAP_TYPE_DMA;
 225         return &cma_heap->heap;
 226 }
 227
 228 void ion_cma_heap_destroy(struct ion_heap *heap)
 229 {
 230         struct ion_cma_heap *cma_heap = to_cma_heap(heap);
 231
 232         kfree(cma_heap);
 233 }