drivers/staging/android/ion/ion_chunk_heap.c

   1 /*
   2  * drivers/staging/android/ion/ion_chunk_heap.c
   3  *
   4  * Copyright (C) 2012 Google, Inc.
   5  *
   6  * This software is licensed under the terms of the GNU General Public
   7  * License version 2, as published by the Free Software Foundation, and
   8  * may be copied, distributed, and modified under those terms.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  */
  16 #include <linux/dma-mapping.h>
  17 #include <linux/err.h>
  18 #include <linux/genalloc.h>
  19 #include <linux/io.h>
  20 #include <linux/mm.h>
  21 #include <linux/scatterlist.h>
  22 #include <linux/slab.h>
  23 #include <linux/vmalloc.h>
  24 #include "ion.h"
  25
  26 struct ion_chunk_heap {
  27         struct ion_heap heap;
  28         struct gen_pool *pool;
  29         phys_addr_t base;
  30         unsigned long chunk_size;
  31         unsigned long size;
  32         unsigned long allocated;
  33 };
  34
  35 static int ion_chunk_heap_allocate(struct ion_heap *heap,
  36                                    struct ion_buffer *buffer,
  37                                    unsigned long size,
  38                                    unsigned long flags)
  39 {
  40         struct ion_chunk_heap *chunk_heap =
  41                 container_of(heap, struct ion_chunk_heap, heap);
  42         struct sg_table *table;
  43         struct scatterlist *sg;
  44         int ret, i;
  45         unsigned long num_chunks;
  46         unsigned long allocated_size;
  47
  48         allocated_size = ALIGN(size, chunk_heap->chunk_size);
  49         num_chunks = allocated_size / chunk_heap->chunk_size;
  50
  51         if (allocated_size > chunk_heap->size - chunk_heap->allocated)
  52                 return -ENOMEM;
  53
  54         table = kmalloc(sizeof(*table), GFP_KERNEL);
  55         if (!table)
  56                 return -ENOMEM;
  57         ret = sg_alloc_table(table, num_chunks, GFP_KERNEL);
  58         if (ret) {
  59                 kfree(table);
  60                 return ret;
  61         }
  62
  63         sg = table->sgl;
  64         for (i = 0; i < num_chunks; i++) {
  65                 unsigned long paddr = gen_pool_alloc(chunk_heap->pool,
  66                                                      chunk_heap->chunk_size);
  67                 if (!paddr)
  68                         goto err;
  69                 sg_set_page(sg, pfn_to_page(PFN_DOWN(paddr)),
  70                             chunk_heap->chunk_size, 0);
  71                 sg = sg_next(sg);
  72         }
  73
  74         buffer->sg_table = table;
  75         chunk_heap->allocated += allocated_size;
  76         return 0;
  77 err:
  78         sg = table->sgl;
  79         for (i -= 1; i >= 0; i--) {
  80                 gen_pool_free(chunk_heap->pool, page_to_phys(sg_page(sg)),
  81                               sg->length);
  82                 sg = sg_next(sg);
  83         }
  84         sg_free_table(table);
  85         kfree(table);
  86         return -ENOMEM;
  87 }
  88
  89 static void ion_chunk_heap_free(struct ion_buffer *buffer)
  90 {
  91         struct ion_heap *heap = buffer->heap;
  92         struct ion_chunk_heap *chunk_heap =
  93                 container_of(heap, struct ion_chunk_heap, heap);
  94         struct sg_table *table = buffer->sg_table;
  95         struct scatterlist *sg;
  96         int i;
  97         unsigned long allocated_size;
  98
  99         allocated_size = ALIGN(buffer->size, chunk_heap->chunk_size);
 100
 101         ion_heap_buffer_zero(buffer);
 102
 103         for_each_sg(table->sgl, sg, table->nents, i) {
 104                 gen_pool_free(chunk_heap->pool, page_to_phys(sg_page(sg)),
 105                               sg->length);
 106         }
 107         chunk_heap->allocated -= allocated_size;
 108         sg_free_table(table);
 109         kfree(table);
 110 }
 111
 112 static struct ion_heap_ops chunk_heap_ops = {
 113         .allocate = ion_chunk_heap_allocate,
 114         .free = ion_chunk_heap_free,
 115         .map_user = ion_heap_map_user,
 116         .map_kernel = ion_heap_map_kernel,
 117         .unmap_kernel = ion_heap_unmap_kernel,
 118 };
 119
 120 struct ion_heap *ion_chunk_heap_create(struct ion_platform_heap *heap_data)
 121 {
 122         struct ion_chunk_heap *chunk_heap;
 123         int ret;
 124         struct page *page;
 125         size_t size;
 126
 127         page = pfn_to_page(PFN_DOWN(heap_data->base));
 128         size = heap_data->size;
 129
 130         ret = ion_heap_pages_zero(page, size, pgprot_writecombine(PAGE_KERNEL));
 131         if (ret)
 132                 return ERR_PTR(ret);
 133
 134         chunk_heap = kzalloc(sizeof(*chunk_heap), GFP_KERNEL);
 135         if (!chunk_heap)
 136                 return ERR_PTR(-ENOMEM);
 137
 138         chunk_heap->chunk_size = (unsigned long)heap_data->priv;
 139         chunk_heap->pool = gen_pool_create(get_order(chunk_heap->chunk_size) +
 140                                            PAGE_SHIFT, -1);
 141         if (!chunk_heap->pool) {
 142                 ret = -ENOMEM;
 143                 goto error_gen_pool_create;
 144         }
 145         chunk_heap->base = heap_data->base;
 146         chunk_heap->size = heap_data->size;
 147         chunk_heap->allocated = 0;
 148
 149         gen_pool_add(chunk_heap->pool, chunk_heap->base, heap_data->size, -1);
 150         chunk_heap->heap.ops = &chunk_heap_ops;
 151         chunk_heap->heap.type = ION_HEAP_TYPE_CHUNK;
 152         chunk_heap->heap.flags = ION_HEAP_FLAG_DEFER_FREE;
 153         pr_debug("%s: base %pa size %zu\n", __func__,
 154                  &chunk_heap->base, heap_data->size);
 155
 156         return &chunk_heap->heap;
 157
 158 error_gen_pool_create:
 159         kfree(chunk_heap);
 160         return ERR_PTR(ret);
 161 }
 162