crypto: acomp - add driver-side scomp interface

Add a synchronous back-end (scomp) to acomp. This allows to easily
expose the already present compression algorithms in LKCF via acomp.

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

1 files changed, 356 insertions, 0 deletions

diff --git a/crypto/scompress.c b/crypto/scompress.c
new file mode 100644
index 000000000000..35e396d154b7
--- /dev/null
+++ b/crypto/scompress.c
@@ -0,0 +1,356 @@
+/*
+ * Synchronous Compression operations
+ *
+ * Copyright 2015 LG Electronics Inc.
+ * Copyright (c) 2016, Intel Corporation
+ * Author: 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 <linux/vmalloc.h>
+#include <crypto/algapi.h>
+#include <linux/cryptouser.h>
+#include <net/netlink.h>
+#include <linux/scatterlist.h>
+#include <crypto/scatterwalk.h>
+#include <crypto/internal/acompress.h>
+#include <crypto/internal/scompress.h>
+#include "internal.h"
+
+static const struct crypto_type crypto_scomp_type;
+static void * __percpu *scomp_src_scratches;
+static void * __percpu *scomp_dst_scratches;
+static int scomp_scratch_users;
+static DEFINE_MUTEX(scomp_lock);
+
+#ifdef CONFIG_NET
+static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
+{
+	struct crypto_report_comp rscomp;
+
+	strncpy(rscomp.type, "scomp", sizeof(rscomp.type));
+
+	if (nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS,
+		    sizeof(struct crypto_report_comp), &rscomp))
+		goto nla_put_failure;
+	return 0;
+
+nla_put_failure:
+	return -EMSGSIZE;
+}
+#else
+static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
+{
+	return -ENOSYS;
+}
+#endif
+
+static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
+	__attribute__ ((unused));
+
+static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
+{
+	seq_puts(m, "type         : scomp\n");
+}
+
+static int crypto_scomp_init_tfm(struct crypto_tfm *tfm)
+{
+	return 0;
+}
+
+static void crypto_scomp_free_scratches(void * __percpu *scratches)
+{
+	int i;
+
+	if (!scratches)
+		return;
+
+	for_each_possible_cpu(i)
+		vfree(*per_cpu_ptr(scratches, i));
+
+	free_percpu(scratches);
+}
+
+static void * __percpu *crypto_scomp_alloc_scratches(void)
+{
+	void * __percpu *scratches;
+	int i;
+
+	scratches = alloc_percpu(void *);
+	if (!scratches)
+		return NULL;
+
+	for_each_possible_cpu(i) {
+		void *scratch;
+
+		scratch = vmalloc_node(SCOMP_SCRATCH_SIZE, cpu_to_node(i));
+		if (!scratch)
+			goto error;
+		*per_cpu_ptr(scratches, i) = scratch;
+	}
+
+	return scratches;
+
+error:
+	crypto_scomp_free_scratches(scratches);
+	return NULL;
+}
+
+static void crypto_scomp_free_all_scratches(void)
+{
+	if (!--scomp_scratch_users) {
+		crypto_scomp_free_scratches(scomp_src_scratches);
+		crypto_scomp_free_scratches(scomp_dst_scratches);
+		scomp_src_scratches = NULL;
+		scomp_dst_scratches = NULL;
+	}
+}
+
+static int crypto_scomp_alloc_all_scratches(void)
+{
+	if (!scomp_scratch_users++) {
+		scomp_src_scratches = crypto_scomp_alloc_scratches();
+		if (!scomp_src_scratches)
+			return -ENOMEM;
+		scomp_dst_scratches = crypto_scomp_alloc_scratches();
+		if (!scomp_dst_scratches)
+			return -ENOMEM;
+	}
+	return 0;
+}
+
+static void crypto_scomp_sg_free(struct scatterlist *sgl)
+{
+	int i, n;
+	struct page *page;
+
+	if (!sgl)
+		return;
+
+	n = sg_nents(sgl);
+	for_each_sg(sgl, sgl, n, i) {
+		page = sg_page(sgl);
+		if (page)
+			__free_page(page);
+	}
+
+	kfree(sgl);
+}
+
+static struct scatterlist *crypto_scomp_sg_alloc(size_t size, gfp_t gfp)
+{
+	struct scatterlist *sgl;
+	struct page *page;
+	int i, n;
+
+	n = ((size - 1) >> PAGE_SHIFT) + 1;
+
+	sgl = kmalloc_array(n, sizeof(struct scatterlist), gfp);
+	if (!sgl)
+		return NULL;
+
+	sg_init_table(sgl, n);
+
+	for (i = 0; i < n; i++) {
+		page = alloc_page(gfp);
+		if (!page)
+			goto err;
+		sg_set_page(sgl + i, page, PAGE_SIZE, 0);
+	}
+
+	return sgl;
+
+err:
+	sg_mark_end(sgl + i);
+	crypto_scomp_sg_free(sgl);
+	return NULL;
+}
+
+static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
+{
+	struct crypto_acomp *tfm = crypto_acomp_reqtfm(req);
+	void **tfm_ctx = acomp_tfm_ctx(tfm);
+	struct crypto_scomp *scomp = *tfm_ctx;
+	void **ctx = acomp_request_ctx(req);
+	const int cpu = get_cpu();
+	u8 *scratch_src = *per_cpu_ptr(scomp_src_scratches, cpu);
+	u8 *scratch_dst = *per_cpu_ptr(scomp_dst_scratches, cpu);
+	int ret;
+
+	if (!req->src || !req->slen || req->slen > SCOMP_SCRATCH_SIZE) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (req->dst && !req->dlen) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (!req->dlen || req->dlen > SCOMP_SCRATCH_SIZE)
+		req->dlen = SCOMP_SCRATCH_SIZE;
+
+	scatterwalk_map_and_copy(scratch_src, req->src, 0, req->slen, 0);
+	if (dir)
+		ret = crypto_scomp_compress(scomp, scratch_src, req->slen,
+					    scratch_dst, &req->dlen, *ctx);
+	else
+		ret = crypto_scomp_decompress(scomp, scratch_src, req->slen,
+					      scratch_dst, &req->dlen, *ctx);
+	if (!ret) {
+		if (!req->dst) {
+			req->dst = crypto_scomp_sg_alloc(req->dlen,
+				   req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
+				   GFP_KERNEL : GFP_ATOMIC);
+			if (!req->dst)
+				goto out;
+		}
+		scatterwalk_map_and_copy(scratch_dst, req->dst, 0, req->dlen,
+					 1);
+	}
+out:
+	put_cpu();
+	return ret;
+}
+
+static int scomp_acomp_compress(struct acomp_req *req)
+{
+	return scomp_acomp_comp_decomp(req, 1);
+}
+
+static int scomp_acomp_decompress(struct acomp_req *req)
+{
+	return scomp_acomp_comp_decomp(req, 0);
+}
+
+static void crypto_exit_scomp_ops_async(struct crypto_tfm *tfm)
+{
+	struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
+
+	crypto_free_scomp(*ctx);
+}
+
+int crypto_init_scomp_ops_async(struct crypto_tfm *tfm)
+{
+	struct crypto_alg *calg = tfm->__crt_alg;
+	struct crypto_acomp *crt = __crypto_acomp_tfm(tfm);
+	struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
+	struct crypto_scomp *scomp;
+
+	if (!crypto_mod_get(calg))
+		return -EAGAIN;
+
+	scomp = crypto_create_tfm(calg, &crypto_scomp_type);
+	if (IS_ERR(scomp)) {
+		crypto_mod_put(calg);
+		return PTR_ERR(scomp);
+	}
+
+	*ctx = scomp;
+	tfm->exit = crypto_exit_scomp_ops_async;
+
+	crt->compress = scomp_acomp_compress;
+	crt->decompress = scomp_acomp_decompress;
+	crt->dst_free = crypto_scomp_sg_free;
+	crt->reqsize = sizeof(void *);
+
+	return 0;
+}
+
+struct acomp_req *crypto_acomp_scomp_alloc_ctx(struct acomp_req *req)
+{
+	struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
+	struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
+	struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
+	struct crypto_scomp *scomp = *tfm_ctx;
+	void *ctx;
+
+	ctx = crypto_scomp_alloc_ctx(scomp);
+	if (IS_ERR(ctx)) {
+		kfree(req);
+		return NULL;
+	}
+
+	*req->__ctx = ctx;
+
+	return req;
+}
+
+void crypto_acomp_scomp_free_ctx(struct acomp_req *req)
+{
+	struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
+	struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
+	struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
+	struct crypto_scomp *scomp = *tfm_ctx;
+	void *ctx = *req->__ctx;
+
+	if (ctx)
+		crypto_scomp_free_ctx(scomp, ctx);
+}
+
+static const struct crypto_type crypto_scomp_type = {
+	.extsize = crypto_alg_extsize,
+	.init_tfm = crypto_scomp_init_tfm,
+#ifdef CONFIG_PROC_FS
+	.show = crypto_scomp_show,
+#endif
+	.report = crypto_scomp_report,
+	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
+	.maskset = CRYPTO_ALG_TYPE_MASK,
+	.type = CRYPTO_ALG_TYPE_SCOMPRESS,
+	.tfmsize = offsetof(struct crypto_scomp, base),
+};
+
+int crypto_register_scomp(struct scomp_alg *alg)
+{
+	struct crypto_alg *base = &alg->base;
+	int ret = -ENOMEM;
+
+	mutex_lock(&scomp_lock);
+	if (crypto_scomp_alloc_all_scratches())
+		goto error;
+
+	base->cra_type = &crypto_scomp_type;
+	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
+	base->cra_flags |= CRYPTO_ALG_TYPE_SCOMPRESS;
+
+	ret = crypto_register_alg(base);
+	if (ret)
+		goto error;
+
+	mutex_unlock(&scomp_lock);
+	return ret;
+
+error:
+	crypto_scomp_free_all_scratches();
+	mutex_unlock(&scomp_lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(crypto_register_scomp);
+
+int crypto_unregister_scomp(struct scomp_alg *alg)
+{
+	int ret;
+
+	mutex_lock(&scomp_lock);
+	ret = crypto_unregister_alg(&alg->base);
+	crypto_scomp_free_all_scratches();
+	mutex_unlock(&scomp_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(crypto_unregister_scomp);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Synchronous compression type");