drivers/crypto/nx/nx-842.c

   1 /*
   2  * Driver frontend for IBM Power 842 compression accelerator
   3  *
   4  * Copyright (C) 2015 Dan Streetman, IBM Corp
   5  *
   6  * Designer of the Power data compression engine:
   7  *   Bulent Abali <abali@us.ibm.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  */
  19
  20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  21
  22 #include "nx-842.h"
  23
  24 #define MODULE_NAME "nx-compress"
  25 MODULE_LICENSE("GPL");
  26 MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");
  27 MODULE_DESCRIPTION("842 H/W Compression driver for IBM Power processors");
  28
  29 /* Only one driver is expected, based on the HW platform */
  30 static struct nx842_driver *nx842_driver;
  31 static DEFINE_SPINLOCK(nx842_driver_lock); /* protects driver pointers */
  32
  33 void nx842_register_driver(struct nx842_driver *driver)
  34 {
  35         spin_lock(&nx842_driver_lock);
  36
  37         if (nx842_driver) {
  38                 pr_err("can't register driver %s, already using driver %s\n",
  39                        driver->owner->name, nx842_driver->owner->name);
  40         } else {
  41                 pr_info("registering driver %s\n", driver->owner->name);
  42                 nx842_driver = driver;
  43         }
  44
  45         spin_unlock(&nx842_driver_lock);
  46 }
  47 EXPORT_SYMBOL_GPL(nx842_register_driver);
  48
  49 void nx842_unregister_driver(struct nx842_driver *driver)
  50 {
  51         spin_lock(&nx842_driver_lock);
  52
  53         if (nx842_driver == driver) {
  54                 pr_info("unregistering driver %s\n", driver->owner->name);
  55                 nx842_driver = NULL;
  56         } else if (nx842_driver) {
  57                 pr_err("can't unregister driver %s, using driver %s\n",
  58                        driver->owner->name, nx842_driver->owner->name);
  59         } else {
  60                 pr_err("can't unregister driver %s, no driver in use\n",
  61                        driver->owner->name);
  62         }
  63
  64         spin_unlock(&nx842_driver_lock);
  65 }
  66 EXPORT_SYMBOL_GPL(nx842_unregister_driver);
  67
  68 static struct nx842_driver *get_driver(void)
  69 {
  70         struct nx842_driver *driver = NULL;
  71
  72         spin_lock(&nx842_driver_lock);
  73
  74         driver = nx842_driver;
  75
  76         if (driver && !try_module_get(driver->owner))
  77                 driver = NULL;
  78
  79         spin_unlock(&nx842_driver_lock);
  80
  81         return driver;
  82 }
  83
  84 static void put_driver(struct nx842_driver *driver)
  85 {
  86         module_put(driver->owner);
  87 }
  88
  89 int nx842_compress(const unsigned char *in, unsigned int in_len,
  90                    unsigned char *out, unsigned int *out_len,
  91                    void *wrkmem)
  92 {
  93         struct nx842_driver *driver = get_driver();
  94         int ret;
  95
  96         if (!driver)
  97                 return -ENODEV;
  98
  99         ret = driver->compress(in, in_len, out, out_len, wrkmem);
 100
 101         put_driver(driver);
 102
 103         return ret;
 104 }
 105 EXPORT_SYMBOL_GPL(nx842_compress);
 106
 107 int nx842_decompress(const unsigned char *in, unsigned int in_len,
 108                      unsigned char *out, unsigned int *out_len,
 109                      void *wrkmem)
 110 {
 111         struct nx842_driver *driver = get_driver();
 112         int ret;
 113
 114         if (!driver)
 115                 return -ENODEV;
 116
 117         ret = driver->decompress(in, in_len, out, out_len, wrkmem);
 118
 119         put_driver(driver);
 120
 121         return ret;
 122 }
 123 EXPORT_SYMBOL_GPL(nx842_decompress);
 124
 125 static __init int nx842_init(void)
 126 {
 127         pr_info("loading\n");
 128
 129         if (of_find_compatible_node(NULL, NULL, NX842_PSERIES_COMPAT_NAME))
 130                 request_module_nowait(NX842_PSERIES_MODULE_NAME);
 131         else
 132                 pr_err("no nx842 driver found.\n");
 133
 134         pr_info("loaded\n");
 135
 136         return 0;
 137 }
 138 module_init(nx842_init);
 139
 140 static void __exit nx842_exit(void)
 141 {
 142         pr_info("NX842 unloaded\n");
 143 }
 144 module_exit(nx842_exit);