sound/sound_firmware.c

   1 #include <linux/vmalloc.h>
   2 #include <linux/module.h>
   3 #include <linux/fs.h>
   4 #include <linux/mm.h>
   5 #include <linux/slab.h>
   6 #include <asm/uaccess.h>
   7
   8 static int do_mod_firmware_load(const char *fn, char **fp)
   9 {
  10         struct file* filp;
  11         long l;
  12         char *dp;
  13         loff_t pos;
  14
  15         filp = filp_open(fn, 0, 0);
  16         if (IS_ERR(filp))
  17         {
  18                 printk(KERN_INFO "Unable to load '%s'.\n", fn);
  19                 return 0;
  20         }
  21         l = filp->f_dentry->d_inode->i_size;
  22         if (l <= 0 || l > 131072)
  23         {
  24                 printk(KERN_INFO "Invalid firmware '%s'\n", fn);
  25                 filp_close(filp, current->files);
  26                 return 0;
  27         }
  28         dp = vmalloc(l);
  29         if (dp == NULL)
  30         {
  31                 printk(KERN_INFO "Out of memory loading '%s'.\n", fn);
  32                 filp_close(filp, current->files);
  33                 return 0;
  34         }
  35         pos = 0;
  36         if (vfs_read(filp, dp, l, &pos) != l)
  37         {
  38                 printk(KERN_INFO "Failed to read '%s'.\n", fn);
  39                 vfree(dp);
  40                 filp_close(filp, current->files);
  41                 return 0;
  42         }
  43         filp_close(filp, current->files);
  44         *fp = dp;
  45         return (int) l;
  46 }
  47
  48 /**
  49  *      mod_firmware_load - load sound driver firmware
  50  *      @fn: filename
  51  *      @fp: return for the buffer.
  52  *
  53  *      Load the firmware for a sound module (up to 128K) into a buffer.
  54  *      The buffer is returned in *fp. It is allocated with vmalloc so is
  55  *      virtually linear and not DMAable. The caller should free it with
  56  *      vfree when finished.
  57  *
  58  *      The length of the buffer is returned on a successful load, the
  59  *      value zero on a failure.
  60  *
  61  *      Caution: This API is not recommended. Firmware should be loaded via
  62  *      an ioctl call and a setup application. This function may disappear
  63  *      in future.
  64  */
  65
  66 int mod_firmware_load(const char *fn, char **fp)
  67 {
  68         int r;
  69         mm_segment_t fs = get_fs();
  70
  71         set_fs(get_ds());
  72         r = do_mod_firmware_load(fn, fp);
  73         set_fs(fs);
  74         return r;
  75 }
  76