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 #include <linux/highmem.h>
  25
  26 #include "ion.h"
  27
  28 struct ion_cma_heap {
  29         struct ion_heap heap;
  30         struct cma *cma;
  31 };
  32
  33 #define to_cma_heap(x) container_of(x, struct ion_cma_heap, heap)
  34
  35 /* ION CMA heap operations functions */
  36 static int ion_cma_allocate(struct ion_heap *heap, struct ion_buffer *buffer,
  37                             unsigned long len,
  38                             unsigned long flags)
  39 {
  40         struct ion_cma_heap *cma_heap = to_cma_heap(heap);
  41         struct sg_table *table;
  42         struct page *pages;
  43         unsigned long size = PAGE_ALIGN(len);
  44         unsigned long nr_pages = size >> PAGE_SHIFT;
  45         unsigned long align = get_order(size);
  46         int ret;
  47
  48         if (align > CONFIG_CMA_ALIGNMENT)
  49                 align = CONFIG_CMA_ALIGNMENT;
  50
  51         pages = cma_alloc(cma_heap->cma, nr_pages, align, GFP_KERNEL);
  52         if (!pages)
  53                 return -ENOMEM;
  54
  55         if (PageHighMem(pages)) {
  56                 unsigned long nr_clear_pages = nr_pages;
  57                 struct page *page = pages;
  58
  59                 while (nr_clear_pages > 0) {
  60                         void *vaddr = kmap_atomic(page);
  61
  62                         memset(vaddr, 0, PAGE_SIZE);
  63                         kunmap_atomic(vaddr);
  64                         page++;
  65                         nr_clear_pages--;
  66                 }
  67         } else {
  68                 memset(page_address(pages), 0, size);
  69         }
  70
  71         table = kmalloc(sizeof(*table), GFP_KERNEL);
  72         if (!table)
  73                 goto err;
  74
  75         ret = sg_alloc_table(table, 1, GFP_KERNEL);
  76         if (ret)
  77                 goto free_mem;
  78
  79         sg_set_page(table->sgl, pages, size, 0);
  80
  81         buffer->priv_virt = pages;
  82         buffer->sg_table = table;
  83         return 0;
  84
  85 free_mem:
  86         kfree(table);
  87 err:
  88         cma_release(cma_heap->cma, pages, nr_pages);
  89         return -ENOMEM;
  90 }
  91
  92 static void ion_cma_free(struct ion_buffer *buffer)
  93 {
  94         struct ion_cma_heap *cma_heap = to_cma_heap(buffer->heap);
  95         struct page *pages = buffer->priv_virt;
  96         unsigned long nr_pages = PAGE_ALIGN(buffer->size) >> PAGE_SHIFT;
  97
  98         /* release memory */
  99         cma_release(cma_heap->cma, pages, nr_pages);
 100         /* release sg table */
 101         sg_free_table(buffer->sg_table);
 102         kfree(buffer->sg_table);
 103 }
 104
 105 static struct ion_heap_ops ion_cma_ops = {
 106         .allocate = ion_cma_allocate,
 107         .free = ion_cma_free,
 108         .map_user = ion_heap_map_user,
 109         .map_kernel = ion_heap_map_kernel,
 110         .unmap_kernel = ion_heap_unmap_kernel,
 111 };
 112
 113 static struct ion_heap *__ion_cma_heap_create(struct cma *cma)
 114 {
 115         struct ion_cma_heap *cma_heap;
 116
 117         cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL);
 118
 119         if (!cma_heap)
 120                 return ERR_PTR(-ENOMEM);
 121
 122         cma_heap->heap.ops = &ion_cma_ops;
 123         /*
 124          * get device from private heaps data, later it will be
 125          * used to make the link with reserved CMA memory
 126          */
 127         cma_heap->cma = cma;
 128         cma_heap->heap.type = ION_HEAP_TYPE_DMA;
 129         return &cma_heap->heap;
 130 }
 131
 132 static int __ion_add_cma_heaps(struct cma *cma, void *data)
 133 {
 134         struct ion_heap *heap;
 135
 136         heap = __ion_cma_heap_create(cma);
 137         if (IS_ERR(heap))
 138                 return PTR_ERR(heap);
 139
 140         heap->name = cma_get_name(cma);
 141
 142         ion_device_add_heap(heap);
 143         return 0;
 144 }
 145
 146 static int ion_add_cma_heaps(void)
 147 {
 148         cma_for_each_area(__ion_add_cma_heaps, NULL);
 149         return 0;
 150 }
 151 device_initcall(ion_add_cma_heaps);