crypto: acomp - add asynchronous compression api

Add acomp, an asynchronous compression api that uses scatterlist
buffers.

Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/acompress.c

@@ -0,0 +1,118 @@
+/*
+ * Asynchronous Compression operations
+ *
+ * Copyright (c) 2016, Intel Corporation
+ * Authors: Weigang Li <weigang.li@intel.com>
+ *          Giovanni Cabiddu <giovanni.cabiddu@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/crypto.h>
+#include <crypto/algapi.h>
+#include <linux/cryptouser.h>
+#include <net/netlink.h>
+#include <crypto/internal/acompress.h>
+#include "internal.h"
+
+#ifdef CONFIG_NET
+static int crypto_acomp_report(struct sk_buff *skb, struct crypto_alg *alg)
+{
+	struct crypto_report_acomp racomp;
+
+	strncpy(racomp.type, "acomp", sizeof(racomp.type));
+
+	if (nla_put(skb, CRYPTOCFGA_REPORT_ACOMP,
+		    sizeof(struct crypto_report_acomp), &racomp))
+		goto nla_put_failure;
+	return 0;
+
+nla_put_failure:
+	return -EMSGSIZE;
+}
+#else
+static int crypto_acomp_report(struct sk_buff *skb, struct crypto_alg *alg)
+{
+	return -ENOSYS;
+}
+#endif
+
+static void crypto_acomp_show(struct seq_file *m, struct crypto_alg *alg)
+	__attribute__ ((unused));
+
+static void crypto_acomp_show(struct seq_file *m, struct crypto_alg *alg)
+{
+	seq_puts(m, "type         : acomp\n");
+}
+
+static void crypto_acomp_exit_tfm(struct crypto_tfm *tfm)
+{
+	struct crypto_acomp *acomp = __crypto_acomp_tfm(tfm);
+	struct acomp_alg *alg = crypto_acomp_alg(acomp);
+
+	alg->exit(acomp);
+}
+
+static int crypto_acomp_init_tfm(struct crypto_tfm *tfm)
+{
+	struct crypto_acomp *acomp = __crypto_acomp_tfm(tfm);
+	struct acomp_alg *alg = crypto_acomp_alg(acomp);
+
+	if (alg->exit)
+		acomp->base.exit = crypto_acomp_exit_tfm;
+
+	if (alg->init)
+		return alg->init(acomp);
+
+	return 0;
+}
+
+static const struct crypto_type crypto_acomp_type = {
+	.extsize = crypto_alg_extsize,
+	.init_tfm = crypto_acomp_init_tfm,
+#ifdef CONFIG_PROC_FS
+	.show = crypto_acomp_show,
+#endif
+	.report = crypto_acomp_report,
+	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
+	.maskset = CRYPTO_ALG_TYPE_MASK,
+	.type = CRYPTO_ALG_TYPE_ACOMPRESS,
+	.tfmsize = offsetof(struct crypto_acomp, base),
+};
+
+struct crypto_acomp *crypto_alloc_acomp(const char *alg_name, u32 type,
+					u32 mask)
+{
+	return crypto_alloc_tfm(alg_name, &crypto_acomp_type, type, mask);
+}
+EXPORT_SYMBOL_GPL(crypto_alloc_acomp);
+
+int crypto_register_acomp(struct acomp_alg *alg)
+{
+	struct crypto_alg *base = &alg->base;
+
+	base->cra_type = &crypto_acomp_type;
+	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
+	base->cra_flags |= CRYPTO_ALG_TYPE_ACOMPRESS;
+
+	return crypto_register_alg(base);
+}
+EXPORT_SYMBOL_GPL(crypto_register_acomp);
+
+int crypto_unregister_acomp(struct acomp_alg *alg)
+{
+	return crypto_unregister_alg(&alg->base);
+}
+EXPORT_SYMBOL_GPL(crypto_unregister_acomp);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Asynchronous compression type");