drivers/gpu/ion/ion_system_mapper.c

   1 /*
   2  * drivers/gpu/ion/ion_system_mapper.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
  17 #include <linux/err.h>
  18 #include <linux/ion.h>
  19 #include <linux/memory.h>
  20 #include <linux/mm.h>
  21 #include <linux/slab.h>
  22 #include <linux/vmalloc.h>
  23 #include "ion_priv.h"
  24 /*
  25  * This mapper is valid for any heap that allocates memory that already has
  26  * a kernel mapping, this includes vmalloc'd memory, kmalloc'd memory,
  27  * pages obtained via io_remap, etc.
  28  */
  29 static void *ion_kernel_mapper_map(struct ion_mapper *mapper,
  30                                    struct ion_buffer *buffer,
  31                                    struct ion_mapping **mapping)
  32 {
  33         if (!((1 << buffer->heap->type) & mapper->heap_mask)) {
  34                 pr_err("%s: attempting to map an unsupported heap\n", __func__);
  35                 return ERR_PTR(-EINVAL);
  36         }
  37         /* XXX REVISIT ME!!! */
  38         *((unsigned long *)mapping) = (unsigned long)buffer->priv;
  39         return buffer->priv;
  40 }
  41
  42 static void ion_kernel_mapper_unmap(struct ion_mapper *mapper,
  43                                     struct ion_buffer *buffer,
  44                                     struct ion_mapping *mapping)
  45 {
  46         if (!((1 << buffer->heap->type) & mapper->heap_mask))
  47                 pr_err("%s: attempting to unmap an unsupported heap\n",
  48                        __func__);
  49 }
  50
  51 static void *ion_kernel_mapper_map_kernel(struct ion_mapper *mapper,
  52                                         struct ion_buffer *buffer,
  53                                         struct ion_mapping *mapping)
  54 {
  55         if (!((1 << buffer->heap->type) & mapper->heap_mask)) {
  56                 pr_err("%s: attempting to unmap an unsupported heap\n",
  57                        __func__);
  58                 return ERR_PTR(-EINVAL);
  59         }
  60         return buffer->priv;
  61 }
  62
  63 static int ion_kernel_mapper_map_user(struct ion_mapper *mapper,
  64                                       struct ion_buffer *buffer,
  65                                       struct vm_area_struct *vma,
  66                                       struct ion_mapping *mapping)
  67 {
  68         int ret;
  69
  70         switch (buffer->heap->type) {
  71         case ION_HEAP_KMALLOC:
  72         {
  73                 unsigned long pfn = __phys_to_pfn(virt_to_phys(buffer->priv));
  74                 ret = remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
  75                                       vma->vm_end - vma->vm_start,
  76                                       vma->vm_page_prot);
  77                 break;
  78         }
  79         case ION_HEAP_VMALLOC:
  80                 ret = remap_vmalloc_range(vma, buffer->priv, vma->vm_pgoff);
  81                 break;
  82         default:
  83                 pr_err("%s: attempting to map unsupported heap to userspace\n",
  84                        __func__);
  85                 return -EINVAL;
  86         }
  87
  88         return ret;
  89 }
  90
  91 static struct ion_mapper_ops ops = {
  92         .map = ion_kernel_mapper_map,
  93         .map_kernel = ion_kernel_mapper_map_kernel,
  94         .map_user = ion_kernel_mapper_map_user,
  95         .unmap = ion_kernel_mapper_unmap,
  96 };
  97
  98 struct ion_mapper *ion_system_mapper_create(void)
  99 {
 100         struct ion_mapper *mapper;
 101         mapper = kzalloc(sizeof(struct ion_mapper), GFP_KERNEL);
 102         if (!mapper)
 103                 return ERR_PTR(-ENOMEM);
 104         mapper->type = ION_SYSTEM_MAPPER;
 105         mapper->ops = &ops;
 106         mapper->heap_mask = (1 << ION_HEAP_VMALLOC) | (1 << ION_HEAP_KMALLOC);
 107         return mapper;
 108 }
 109
 110 void ion_system_mapper_destroy(struct ion_mapper *mapper)
 111 {
 112         kfree(mapper);
 113 }
 114