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         unsigned long size = PAGE_ALIGN(len);
  43         unsigned long nr_pages = size >> PAGE_SHIFT;
  44         unsigned long align = get_order(size);
  45         int ret;
  46
  47         if (align > CONFIG_CMA_ALIGNMENT)
  48                 align = CONFIG_CMA_ALIGNMENT;
  49
  50         pages = cma_alloc(cma_heap->cma, nr_pages, align, GFP_KERNEL);
  51         if (!pages)
  52                 return -ENOMEM;
  53
  54         table = kmalloc(sizeof(*table), GFP_KERNEL);
  55         if (!table)
  56                 goto err;
  57
  58         ret = sg_alloc_table(table, 1, GFP_KERNEL);
  59         if (ret)
  60                 goto free_mem;
  61
  62         sg_set_page(table->sgl, pages, size, 0);
  63
  64         buffer->priv_virt = pages;
  65         buffer->sg_table = table;
  66         return 0;
  67
  68 free_mem:
  69         kfree(table);
  70 err:
  71         cma_release(cma_heap->cma, pages, nr_pages);
  72         return -ENOMEM;
  73 }
  74
  75 static void ion_cma_free(struct ion_buffer *buffer)
  76 {
  77         struct ion_cma_heap *cma_heap = to_cma_heap(buffer->heap);
  78         struct page *pages = buffer->priv_virt;
  79         unsigned long nr_pages = PAGE_ALIGN(buffer->size) >> PAGE_SHIFT;
  80
  81         /* release memory */
  82         cma_release(cma_heap->cma, pages, nr_pages);
  83         /* release sg table */
  84         sg_free_table(buffer->sg_table);
  85         kfree(buffer->sg_table);
  86 }
  87
  88 static struct ion_heap_ops ion_cma_ops = {
  89         .allocate = ion_cma_allocate,
  90         .free = ion_cma_free,
  91         .map_user = ion_heap_map_user,
  92         .map_kernel = ion_heap_map_kernel,
  93         .unmap_kernel = ion_heap_unmap_kernel,
  94 };
  95
  96 static struct ion_heap *__ion_cma_heap_create(struct cma *cma)
  97 {
  98         struct ion_cma_heap *cma_heap;
  99
 100         cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL);
 101
 102         if (!cma_heap)
 103                 return ERR_PTR(-ENOMEM);
 104
 105         cma_heap->heap.ops = &ion_cma_ops;
 106         /*
 107          * get device from private heaps data, later it will be
 108          * used to make the link with reserved CMA memory
 109          */
 110         cma_heap->cma = cma;
 111         cma_heap->heap.type = ION_HEAP_TYPE_DMA;
 112         return &cma_heap->heap;
 113 }
 114
 115 static int __ion_add_cma_heaps(struct cma *cma, void *data)
 116 {
 117         struct ion_heap *heap;
 118
 119         heap = __ion_cma_heap_create(cma);
 120         if (IS_ERR(heap))
 121                 return PTR_ERR(heap);
 122
 123         heap->name = cma_get_name(cma);
 124
 125         ion_device_add_heap(heap);
 126         return 0;
 127 }
 128
 129 static int ion_add_cma_heaps(void)
 130 {
 131         cma_for_each_area(__ion_add_cma_heaps, NULL);
 132         return 0;
 133 }
 134 device_initcall(ion_add_cma_heaps);