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 MODULE_LICENSE("GPL");
  25 MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");
  26 MODULE_DESCRIPTION("842 H/W Compression driver for IBM Power processors");
  27
  28 /**
  29  * nx842_constraints
  30  *
  31  * This provides the driver's constraints.  Different nx842 implementations
  32  * may have varying requirements.  The constraints are:
  33  *   @alignment:        All buffers should be aligned to this
  34  *   @multiple:         All buffer lengths should be a multiple of this
  35  *   @minimum:          Buffer lengths must not be less than this amount
  36  *   @maximum:          Buffer lengths must not be more than this amount
  37  *
  38  * The constraints apply to all buffers and lengths, both input and output,
  39  * for both compression and decompression, except for the minimum which
  40  * only applies to compression input and decompression output; the
  41  * compressed data can be less than the minimum constraint.  It can be
  42  * assumed that compressed data will always adhere to the multiple
  43  * constraint.
  44  *
  45  * The driver may succeed even if these constraints are violated;
  46  * however the driver can return failure or suffer reduced performance
  47  * if any constraint is not met.
  48  */
  49 int nx842_constraints(struct nx842_constraints *c)
  50 {
  51         memcpy(c, nx842_platform_driver()->constraints, sizeof(*c));
  52         return 0;
  53 }
  54 EXPORT_SYMBOL_GPL(nx842_constraints);
  55
  56 /**
  57  * nx842_workmem_size
  58  *
  59  * Get the amount of working memory the driver requires.
  60  */
  61 size_t nx842_workmem_size(void)
  62 {
  63         return nx842_platform_driver()->workmem_size;
  64 }
  65 EXPORT_SYMBOL_GPL(nx842_workmem_size);
  66
  67 int nx842_compress(const unsigned char *in, unsigned int ilen,
  68                    unsigned char *out, unsigned int *olen, void *wmem)
  69 {
  70         return nx842_platform_driver()->compress(in, ilen, out, olen, wmem);
  71 }
  72 EXPORT_SYMBOL_GPL(nx842_compress);
  73
  74 int nx842_decompress(const unsigned char *in, unsigned int ilen,
  75                      unsigned char *out, unsigned int *olen, void *wmem)
  76 {
  77         return nx842_platform_driver()->decompress(in, ilen, out, olen, wmem);
  78 }
  79 EXPORT_SYMBOL_GPL(nx842_decompress);
  80
  81 static __init int nx842_init(void)
  82 {
  83         request_module("nx-compress-powernv");
  84         request_module("nx-compress-pseries");
  85
  86         /* we prevent loading if there's no platform driver, and we get the
  87          * module that set it so it won't unload, so we don't need to check
  88          * if it's set in any of the above functions
  89          */
  90         if (!nx842_platform_driver_get()) {
  91                 pr_err("no nx842 driver found.\n");
  92                 return -ENODEV;
  93         }
  94
  95         return 0;
  96 }
  97 module_init(nx842_init);
  98
  99 static void __exit nx842_exit(void)
 100 {
 101         nx842_platform_driver_put();
 102 }
 103 module_exit(nx842_exit);