Source
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Cryptographic API for the 842 software compression algorithm.
*
* Copyright (C) IBM Corporation, 2011-2015
*
* Original Authors: Robert Jennings <rcj@linux.vnet.ibm.com>
* Seth Jennings <sjenning@linux.vnet.ibm.com>
*
* Rewrite: Dan Streetman <ddstreet@ieee.org>
*
* This is the software implementation of compression and decompression using
* the 842 format. This uses the software 842 library at lib/842/ which is
* only a reference implementation, and is very, very slow as compared to other
* software compressors. You probably do not want to use this software
* compression. If you have access to the PowerPC 842 compression hardware, you
* want to use the 842 hardware compression interface, which is at:
* drivers/crypto/nx/nx-842-crypto.c
*/
struct crypto842_ctx {
void *wmem; /* working memory for compress */
};
static void *crypto842_alloc_ctx(struct crypto_scomp *tfm)
{
void *ctx;
ctx = kmalloc(SW842_MEM_COMPRESS, GFP_KERNEL);
if (!ctx)
return ERR_PTR(-ENOMEM);
return ctx;
}
static int crypto842_init(struct crypto_tfm *tfm)
{
struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm);
ctx->wmem = crypto842_alloc_ctx(NULL);
if (IS_ERR(ctx->wmem))
return -ENOMEM;
return 0;
}
static void crypto842_free_ctx(struct crypto_scomp *tfm, void *ctx)
{
kfree(ctx);
}
static void crypto842_exit(struct crypto_tfm *tfm)
{
struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm);
crypto842_free_ctx(NULL, ctx->wmem);
}