drivers/staging/android/ion/ion_carveout_heap.c

   1 /*
   2  * drivers/staging/android/ion/ion_carveout_heap.c
   3  *
   4  * Copyright (C) 2011 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/spinlock.h>
  17 #include <linux/dma-mapping.h>
  18 #include <linux/err.h>
  19 #include <linux/genalloc.h>
  20 #include <linux/io.h>
  21 #include <linux/mm.h>
  22 #include <linux/scatterlist.h>
  23 #include <linux/slab.h>
  24 #include <linux/vmalloc.h>
  25 #include "ion.h"
  26
  27 #define ION_CARVEOUT_ALLOCATE_FAIL      -1
  28
  29 struct ion_carveout_heap {
  30         struct ion_heap heap;
  31         struct gen_pool *pool;
  32         phys_addr_t base;
  33 };
  34
  35 static phys_addr_t ion_carveout_allocate(struct ion_heap *heap,
  36                                          unsigned long size)
  37 {
  38         struct ion_carveout_heap *carveout_heap =
  39                 container_of(heap, struct ion_carveout_heap, heap);
  40         unsigned long offset = gen_pool_alloc(carveout_heap->pool, size);
  41
  42         if (!offset)
  43                 return ION_CARVEOUT_ALLOCATE_FAIL;
  44
  45         return offset;
  46 }
  47
  48 static void ion_carveout_free(struct ion_heap *heap, phys_addr_t addr,
  49                               unsigned long size)
  50 {
  51         struct ion_carveout_heap *carveout_heap =
  52                 container_of(heap, struct ion_carveout_heap, heap);
  53
  54         if (addr == ION_CARVEOUT_ALLOCATE_FAIL)
  55                 return;
  56         gen_pool_free(carveout_heap->pool, addr, size);
  57 }
  58
  59 static int ion_carveout_heap_allocate(struct ion_heap *heap,
  60                                       struct ion_buffer *buffer,
  61                                       unsigned long size,
  62                                       unsigned long flags)
  63 {
  64         struct sg_table *table;
  65         phys_addr_t paddr;
  66         int ret;
  67
  68         table = kmalloc(sizeof(*table), GFP_KERNEL);
  69         if (!table)
  70                 return -ENOMEM;
  71         ret = sg_alloc_table(table, 1, GFP_KERNEL);
  72         if (ret)
  73                 goto err_free;
  74
  75         paddr = ion_carveout_allocate(heap, size);
  76         if (paddr == ION_CARVEOUT_ALLOCATE_FAIL) {
  77                 ret = -ENOMEM;
  78                 goto err_free_table;
  79         }
  80
  81         sg_set_page(table->sgl, pfn_to_page(PFN_DOWN(paddr)), size, 0);
  82         buffer->sg_table = table;
  83
  84         return 0;
  85
  86 err_free_table:
  87         sg_free_table(table);
  88 err_free:
  89         kfree(table);
  90         return ret;
  91 }
  92
  93 static void ion_carveout_heap_free(struct ion_buffer *buffer)
  94 {
  95         struct ion_heap *heap = buffer->heap;
  96         struct sg_table *table = buffer->sg_table;
  97         struct page *page = sg_page(table->sgl);
  98         phys_addr_t paddr = PFN_PHYS(page_to_pfn(page));
  99
 100         ion_heap_buffer_zero(buffer);
 101
 102         ion_carveout_free(heap, paddr, buffer->size);
 103         sg_free_table(table);
 104         kfree(table);
 105 }
 106
 107 static struct ion_heap_ops carveout_heap_ops = {
 108         .allocate = ion_carveout_heap_allocate,
 109         .free = ion_carveout_heap_free,
 110         .map_user = ion_heap_map_user,
 111         .map_kernel = ion_heap_map_kernel,
 112         .unmap_kernel = ion_heap_unmap_kernel,
 113 };
 114
 115 struct ion_heap *ion_carveout_heap_create(struct ion_platform_heap *heap_data)
 116 {
 117         struct ion_carveout_heap *carveout_heap;
 118         int ret;
 119
 120         struct page *page;
 121         size_t size;
 122
 123         page = pfn_to_page(PFN_DOWN(heap_data->base));
 124         size = heap_data->size;
 125
 126         ret = ion_heap_pages_zero(page, size, pgprot_writecombine(PAGE_KERNEL));
 127         if (ret)
 128                 return ERR_PTR(ret);
 129
 130         carveout_heap = kzalloc(sizeof(*carveout_heap), GFP_KERNEL);
 131         if (!carveout_heap)
 132                 return ERR_PTR(-ENOMEM);
 133
 134         carveout_heap->pool = gen_pool_create(PAGE_SHIFT, -1);
 135         if (!carveout_heap->pool) {
 136                 kfree(carveout_heap);
 137                 return ERR_PTR(-ENOMEM);
 138         }
 139         carveout_heap->base = heap_data->base;
 140         gen_pool_add(carveout_heap->pool, carveout_heap->base, heap_data->size,
 141                      -1);
 142         carveout_heap->heap.ops = &carveout_heap_ops;
 143         carveout_heap->heap.type = ION_HEAP_TYPE_CARVEOUT;
 144         carveout_heap->heap.flags = ION_HEAP_FLAG_DEFER_FREE;
 145
 146         return &carveout_heap->heap;
 147 }