drivers/staging/android/ion/ion_test.c

   1 /*
   2  *
   3  * Copyright (C) 2013 Google, Inc.
   4  *
   5  * This software is licensed under the terms of the GNU General Public
   6  * License version 2, as published by the Free Software Foundation, and
   7  * may be copied, distributed, and modified under those terms.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  */
  15
  16 #define pr_fmt(fmt) "ion-test: " fmt
  17
  18 #include <linux/dma-buf.h>
  19 #include <linux/dma-direction.h>
  20 #include <linux/fs.h>
  21 #include <linux/miscdevice.h>
  22 #include <linux/mm.h>
  23 #include <linux/module.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/sched.h>
  26 #include <linux/slab.h>
  27 #include <linux/uaccess.h>
  28 #include <linux/vmalloc.h>
  29
  30 #include "ion.h"
  31 #include "../uapi/ion_test.h"
  32
  33 #define u64_to_uptr(x) ((void __user *)(unsigned long)(x))
  34
  35 struct ion_test_device {
  36         struct miscdevice misc;
  37 };
  38
  39 struct ion_test_data {
  40         struct dma_buf *dma_buf;
  41         struct device *dev;
  42 };
  43
  44 static int ion_handle_test_dma(struct device *dev, struct dma_buf *dma_buf,
  45                 void __user *ptr, size_t offset, size_t size, bool write)
  46 {
  47         int ret = 0;
  48         struct dma_buf_attachment *attach;
  49         struct sg_table *table;
  50         pgprot_t pgprot = pgprot_writecombine(PAGE_KERNEL);
  51         enum dma_data_direction dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
  52         struct sg_page_iter sg_iter;
  53         unsigned long offset_page;
  54
  55         attach = dma_buf_attach(dma_buf, dev);
  56         if (IS_ERR(attach))
  57                 return PTR_ERR(attach);
  58
  59         table = dma_buf_map_attachment(attach, dir);
  60         if (IS_ERR(table))
  61                 return PTR_ERR(table);
  62
  63         offset_page = offset >> PAGE_SHIFT;
  64         offset %= PAGE_SIZE;
  65
  66         for_each_sg_page(table->sgl, &sg_iter, table->nents, offset_page) {
  67                 struct page *page = sg_page_iter_page(&sg_iter);
  68                 void *vaddr = vmap(&page, 1, VM_MAP, pgprot);
  69                 size_t to_copy = PAGE_SIZE - offset;
  70
  71                 to_copy = min(to_copy, size);
  72                 if (!vaddr) {
  73                         ret = -ENOMEM;
  74                         goto err;
  75                 }
  76
  77                 if (write)
  78                         ret = copy_from_user(vaddr + offset, ptr, to_copy);
  79                 else
  80                         ret = copy_to_user(ptr, vaddr + offset, to_copy);
  81
  82                 vunmap(vaddr);
  83                 if (ret) {
  84                         ret = -EFAULT;
  85                         goto err;
  86                 }
  87                 size -= to_copy;
  88                 if (!size)
  89                         break;
  90                 ptr += to_copy;
  91                 offset = 0;
  92         }
  93
  94 err:
  95         dma_buf_unmap_attachment(attach, table, dir);
  96         dma_buf_detach(dma_buf, attach);
  97         return ret;
  98 }
  99
 100 static int ion_handle_test_kernel(struct dma_buf *dma_buf, void __user *ptr,
 101                 size_t offset, size_t size, bool write)
 102 {
 103         int ret;
 104         unsigned long page_offset = offset >> PAGE_SHIFT;
 105         size_t copy_offset = offset % PAGE_SIZE;
 106         size_t copy_size = size;
 107         enum dma_data_direction dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
 108
 109         if (offset > dma_buf->size || size > dma_buf->size - offset)
 110                 return -EINVAL;
 111
 112         ret = dma_buf_begin_cpu_access(dma_buf, offset, size, dir);
 113         if (ret)
 114                 return ret;
 115
 116         while (copy_size > 0) {
 117                 size_t to_copy;
 118                 void *vaddr = dma_buf_kmap(dma_buf, page_offset);
 119
 120                 if (!vaddr)
 121                         goto err;
 122
 123                 to_copy = min_t(size_t, PAGE_SIZE - copy_offset, copy_size);
 124
 125                 if (write)
 126                         ret = copy_from_user(vaddr + copy_offset, ptr, to_copy);
 127                 else
 128                         ret = copy_to_user(ptr, vaddr + copy_offset, to_copy);
 129
 130                 dma_buf_kunmap(dma_buf, page_offset, vaddr);
 131                 if (ret) {
 132                         ret = -EFAULT;
 133                         goto err;
 134                 }
 135
 136                 copy_size -= to_copy;
 137                 ptr += to_copy;
 138                 page_offset++;
 139                 copy_offset = 0;
 140         }
 141 err:
 142         dma_buf_end_cpu_access(dma_buf, offset, size, dir);
 143         return ret;
 144 }
 145
 146 static long ion_test_ioctl(struct file *filp, unsigned int cmd,
 147                                                 unsigned long arg)
 148 {
 149         struct ion_test_data *test_data = filp->private_data;
 150         int ret = 0;
 151
 152         union {
 153                 struct ion_test_rw_data test_rw;
 154         } data;
 155
 156         if (_IOC_SIZE(cmd) > sizeof(data))
 157                 return -EINVAL;
 158
 159         if (_IOC_DIR(cmd) & _IOC_WRITE)
 160                 if (copy_from_user(&data, (void __user *)arg, _IOC_SIZE(cmd)))
 161                         return -EFAULT;
 162
 163         switch (cmd) {
 164         case ION_IOC_TEST_SET_FD:
 165         {
 166                 struct dma_buf *dma_buf = NULL;
 167                 int fd = arg;
 168
 169                 if (fd >= 0) {
 170                         dma_buf = dma_buf_get((int)arg);
 171                         if (IS_ERR(dma_buf))
 172                                 return PTR_ERR(dma_buf);
 173                 }
 174                 if (test_data->dma_buf)
 175                         dma_buf_put(test_data->dma_buf);
 176                 test_data->dma_buf = dma_buf;
 177                 break;
 178         }
 179         case ION_IOC_TEST_DMA_MAPPING:
 180         {
 181                 ret = ion_handle_test_dma(test_data->dev, test_data->dma_buf,
 182                                         u64_to_uptr(data.test_rw.ptr),
 183                                         data.test_rw.offset, data.test_rw.size,
 184                                         data.test_rw.write);
 185                 break;
 186         }
 187         case ION_IOC_TEST_KERNEL_MAPPING:
 188         {
 189                 ret = ion_handle_test_kernel(test_data->dma_buf,
 190                                         u64_to_uptr(data.test_rw.ptr),
 191                                         data.test_rw.offset, data.test_rw.size,
 192                                         data.test_rw.write);
 193                 break;
 194         }
 195         default:
 196                 return -ENOTTY;
 197         }
 198
 199         if (_IOC_DIR(cmd) & _IOC_READ) {
 200                 if (copy_to_user((void __user *)arg, &data, sizeof(data)))
 201                         return -EFAULT;
 202         }
 203         return ret;
 204 }
 205
 206 static int ion_test_open(struct inode *inode, struct file *file)
 207 {
 208         struct ion_test_data *data;
 209         struct miscdevice *miscdev = file->private_data;
 210
 211         data = kzalloc(sizeof(struct ion_test_data), GFP_KERNEL);
 212         if (!data)
 213                 return -ENOMEM;
 214
 215         data->dev = miscdev->parent;
 216
 217         file->private_data = data;
 218
 219         return 0;
 220 }
 221
 222 static int ion_test_release(struct inode *inode, struct file *file)
 223 {
 224         struct ion_test_data *data = file->private_data;
 225
 226         kfree(data);
 227
 228         return 0;
 229 }
 230
 231 static const struct file_operations ion_test_fops = {
 232         .owner = THIS_MODULE,
 233         .unlocked_ioctl = ion_test_ioctl,
 234         .compat_ioctl = ion_test_ioctl,
 235         .open = ion_test_open,
 236         .release = ion_test_release,
 237 };
 238
 239 static int __init ion_test_probe(struct platform_device *pdev)
 240 {
 241         int ret;
 242         struct ion_test_device *testdev;
 243
 244         testdev = devm_kzalloc(&pdev->dev, sizeof(struct ion_test_device),
 245                                 GFP_KERNEL);
 246         if (!testdev)
 247                 return -ENOMEM;
 248
 249         testdev->misc.minor = MISC_DYNAMIC_MINOR;
 250         testdev->misc.name = "ion-test";
 251         testdev->misc.fops = &ion_test_fops;
 252         testdev->misc.parent = &pdev->dev;
 253         ret = misc_register(&testdev->misc);
 254         if (ret) {
 255                 pr_err("failed to register misc device.\n");
 256                 return ret;
 257         }
 258
 259         platform_set_drvdata(pdev, testdev);
 260
 261         return 0;
 262 }
 263
 264 static int ion_test_remove(struct platform_device *pdev)
 265 {
 266         struct ion_test_device *testdev;
 267
 268         testdev = platform_get_drvdata(pdev);
 269         if (!testdev)
 270                 return -ENODATA;
 271
 272         misc_deregister(&testdev->misc);
 273         return 0;
 274 }
 275
 276 static struct platform_device *ion_test_pdev;
 277 static struct platform_driver ion_test_platform_driver = {
 278         .remove = ion_test_remove,
 279         .driver = {
 280                 .name = "ion-test",
 281         },
 282 };
 283
 284 static int __init ion_test_init(void)
 285 {
 286         ion_test_pdev = platform_device_register_simple("ion-test",
 287                                                         -1, NULL, 0);
 288         if (!ion_test_pdev)
 289                 return -ENODEV;
 290
 291         return platform_driver_probe(&ion_test_platform_driver, ion_test_probe);
 292 }
 293
 294 static void __exit ion_test_exit(void)
 295 {
 296         platform_driver_unregister(&ion_test_platform_driver);
 297         platform_device_unregister(ion_test_pdev);
 298 }
 299
 300 module_init(ion_test_init);
 301 module_exit(ion_test_exit);
 302 MODULE_LICENSE("GPL v2");