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/cma.h>
  23 #include <linux/scatterlist.h>
  24
  25 #include "ion.h"
  26
  27 struct ion_cma_heap {
  28         struct ion_heap heap;
  29         struct cma *cma;
  30 };
  31
  32 #define to_cma_heap(x) container_of(x, struct ion_cma_heap, heap)
  33
  34 /* ION CMA heap operations functions */
  35 static int ion_cma_allocate(struct ion_heap *heap, struct ion_buffer *buffer,
  36                             unsigned long len,
  37                             unsigned long flags)
  38 {
  39         struct ion_cma_heap *cma_heap = to_cma_heap(heap);
  40         struct sg_table *table;
  41         struct page *pages;
  42         int ret;
  43
  44         pages = cma_alloc(cma_heap->cma, len, 0, GFP_KERNEL);
  45         if (!pages)
  46                 return -ENOMEM;
  47
  48         table = kmalloc(sizeof(*table), GFP_KERNEL);
  49         if (!table)
  50                 goto err;
  51
  52         ret = sg_alloc_table(table, 1, GFP_KERNEL);
  53         if (ret)
  54                 goto free_mem;
  55
  56         sg_set_page(table->sgl, pages, len, 0);
  57
  58         buffer->priv_virt = pages;
  59         buffer->sg_table = table;
  60         return 0;
  61
  62 free_mem:
  63         kfree(table);
  64 err:
  65         cma_release(cma_heap->cma, pages, buffer->size);
  66         return -ENOMEM;
  67 }
  68
  69 static void ion_cma_free(struct ion_buffer *buffer)
  70 {
  71         struct ion_cma_heap *cma_heap = to_cma_heap(buffer->heap);
  72         struct page *pages = buffer->priv_virt;
  73
  74         /* release memory */
  75         cma_release(cma_heap->cma, pages, buffer->size);
  76         /* release sg table */
  77         sg_free_table(buffer->sg_table);
  78         kfree(buffer->sg_table);
  79 }
  80
  81 static struct ion_heap_ops ion_cma_ops = {
  82         .allocate = ion_cma_allocate,
  83         .free = ion_cma_free,
  84         .map_user = ion_heap_map_user,
  85         .map_kernel = ion_heap_map_kernel,
  86         .unmap_kernel = ion_heap_unmap_kernel,
  87 };
  88
  89 static struct ion_heap *__ion_cma_heap_create(struct cma *cma)
  90 {
  91         struct ion_cma_heap *cma_heap;
  92
  93         cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL);
  94
  95         if (!cma_heap)
  96                 return ERR_PTR(-ENOMEM);
  97
  98         cma_heap->heap.ops = &ion_cma_ops;
  99         /*
 100          * get device from private heaps data, later it will be
 101          * used to make the link with reserved CMA memory
 102          */
 103         cma_heap->cma = cma;
 104         cma_heap->heap.type = ION_HEAP_TYPE_DMA;
 105         return &cma_heap->heap;
 106 }
 107
 108 static int __ion_add_cma_heaps(struct cma *cma, void *data)
 109 {
 110         struct ion_heap *heap;
 111
 112         heap = __ion_cma_heap_create(cma);
 113         if (IS_ERR(heap))
 114                 return PTR_ERR(heap);
 115
 116         heap->name = cma_get_name(cma);
 117
 118         ion_device_add_heap(heap);
 119         return 0;
 120 }
 121
 122 static int ion_add_cma_heaps(void)
 123 {
 124         cma_for_each_area(__ion_add_cma_heaps, NULL);
 125         return 0;
 126 }
 127 device_initcall(ion_add_cma_heaps);