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>
diff --git a/crypto/scompress.c b/crypto/scompress.c
new file mode 100644
index 0000000..35e396d
--- /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");