// 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
 */

#include <crypto/internal/scompress.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/sw842.h>

static void *crypto842_alloc_ctx(void)
{
        void *ctx;

        ctx = kmalloc(SW842_MEM_COMPRESS, GFP_KERNEL);
        if (!ctx)
                return ERR_PTR(-ENOMEM);

        return ctx;
}

static void crypto842_free_ctx(void *ctx)
{
        kfree(ctx);
}

static int crypto842_scompress(struct crypto_scomp *tfm,
                               const u8 *src, unsigned int slen,
                               u8 *dst, unsigned int *dlen, void *ctx)
{
        return sw842_compress(src, slen, dst, dlen, ctx);
}

static int crypto842_sdecompress(struct crypto_scomp *tfm,
                                 const u8 *src, unsigned int slen,
                                 u8 *dst, unsigned int *dlen, void *ctx)
{
        return sw842_decompress(src, slen, dst, dlen);
}

static struct scomp_alg scomp = {
        .streams                = {
                .alloc_ctx      = crypto842_alloc_ctx,
                .free_ctx       = crypto842_free_ctx,
        },
        .compress               = crypto842_scompress,
        .decompress             = crypto842_sdecompress,
        .base                   = {
                .cra_name       = "842",
                .cra_driver_name = "842-scomp",
                .cra_priority    = 100,
                .cra_module      = THIS_MODULE,
        }
};

static int __init crypto842_mod_init(void)
{
        return crypto_register_scomp(&scomp);
}
module_init(crypto842_mod_init);

static void __exit crypto842_mod_exit(void)
{
        crypto_unregister_scomp(&scomp);
}
module_exit(crypto842_mod_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("842 Software Compression Algorithm");
MODULE_ALIAS_CRYPTO("842");
MODULE_ALIAS_CRYPTO("842-generic");
MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");