[PATCH v3] mm/zswap: move to use crypto_acomp API for hardware acceleration

[Barry Song]

right now, all new ZIP drivers are using crypto_acomp APIs rather than
legacy crypto_comp APIs. But zswap.c is still using the old APIs. That
means zswap won't be able to use any new zip drivers in kernel.

This patch moves to use cryto_acomp APIs to fix the problem. On the
other hand, tradiontal compressors like lz4,lzo etc have been wrapped
into acomp via scomp backend. So platforms without async compressors
can fallback to use acomp via scomp backend.

Cc: Luis Claudio R. Goncalves <lgoncalv@xxxxxxxxxx>
Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Mahipal Challa <mahipalreddy2006@xxxxxxxxx>
Cc: Seth Jennings <sjenning@xxxxxxxxxx>
Cc: Dan Streetman <ddstreet@xxxxxxxx>
Cc: Vitaly Wool <vitaly.wool@xxxxxxxxxxxx>
Cc: Zhou Wang <wangzhou1@xxxxxxxxxxxxx>
Cc: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Signed-off-by: Barry Song <song.bao.hua@xxxxxxxxxxxxx>
---
 -v3: fix resource leak in error handle path;
 remove redundant assignment according to Colin King, thanks!

 mm/zswap.c | 160 +++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 117 insertions(+), 43 deletions(-)

diff --git a/mm/zswap.c b/mm/zswap.c
index fbb782924ccc..d170ef06c693 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -24,8 +24,10 @@
 #include <linux/rbtree.h>
 #include <linux/swap.h>
 #include <linux/crypto.h>
+#include <linux/scatterlist.h>
 #include <linux/mempool.h>
 #include <linux/zpool.h>
+#include <crypto/acompress.h>
 
 #include <linux/mm_types.h>
 #include <linux/page-flags.h>
@@ -127,9 +129,17 @@ module_param_named(same_filled_pages_enabled, zswap_same_filled_pages_enabled,
 * data structures
 **********************************/
 
+struct crypto_acomp_ctx {
+	struct crypto_acomp *acomp;
+	struct acomp_req *req;
+	struct crypto_wait wait;
+	u8 *dstmem;
+	struct mutex mutex;
+};
+
 struct zswap_pool {
 	struct zpool *zpool;
-	struct crypto_comp * __percpu *tfm;
+	struct crypto_acomp_ctx * __percpu *acomp_ctx;
 	struct kref kref;
 	struct list_head list;
 	struct work_struct release_work;
@@ -415,30 +425,68 @@ static int zswap_dstmem_dead(unsigned int cpu)
 static int zswap_cpu_comp_prepare(unsigned int cpu, struct hlist_node *node)
 {
 	struct zswap_pool *pool = hlist_entry(node, struct zswap_pool, node);
-	struct crypto_comp *tfm;
+	struct crypto_acomp *acomp;
+	struct acomp_req *req;
+	struct crypto_acomp_ctx *acomp_ctx;
+	int ret;
 
-	if (WARN_ON(*per_cpu_ptr(pool->tfm, cpu)))
+	if (WARN_ON(*per_cpu_ptr(pool->acomp_ctx, cpu)))
 		return 0;
 
-	tfm = crypto_alloc_comp(pool->tfm_name, 0, 0);
-	if (IS_ERR_OR_NULL(tfm)) {
-		pr_err("could not alloc crypto comp %s : %ld\n",
-		       pool->tfm_name, PTR_ERR(tfm));
+	acomp_ctx = kzalloc(sizeof(*acomp_ctx), GFP_KERNEL);
+	if (!acomp_ctx)
 		return -ENOMEM;
+
+	acomp = crypto_alloc_acomp(pool->tfm_name, 0, 0);
+	if (IS_ERR(acomp)) {
+		pr_err("could not alloc crypto acomp %s : %ld\n",
+				pool->tfm_name, PTR_ERR(acomp));
+		ret = PTR_ERR(acomp);
+		goto free_ctx;
+	}
+	acomp_ctx->acomp = acomp;
+
+	req = acomp_request_alloc(acomp_ctx->acomp);
+	if (!req) {
+		pr_err("could not alloc crypto acomp_request %s\n",
+		       pool->tfm_name);
+		ret = -ENOMEM;
+		goto free_acomp;
 	}
-	*per_cpu_ptr(pool->tfm, cpu) = tfm;
+	acomp_ctx->req = req;
+
+	mutex_init(&acomp_ctx->mutex);
+	crypto_init_wait(&acomp_ctx->wait);
+	acomp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
+				   crypto_req_done, &acomp_ctx->wait);
+
+	acomp_ctx->dstmem = per_cpu(zswap_dstmem, cpu);
+	*per_cpu_ptr(pool->acomp_ctx, cpu) = acomp_ctx;
+
 	return 0;
+
+free_acomp:
+	crypto_free_acomp(acomp_ctx->acomp);
+free_ctx:
+	kfree(acomp_ctx);
+	return ret;
 }
 
 static int zswap_cpu_comp_dead(unsigned int cpu, struct hlist_node *node)
 {
 	struct zswap_pool *pool = hlist_entry(node, struct zswap_pool, node);
-	struct crypto_comp *tfm;
+	struct crypto_acomp_ctx *acomp_ctx;
+
+	acomp_ctx = *per_cpu_ptr(pool->acomp_ctx, cpu);
+	if (!IS_ERR_OR_NULL(acomp_ctx)) {
+		if (!IS_ERR_OR_NULL(acomp_ctx->req))
+			acomp_request_free(acomp_ctx->req);
+		if (!IS_ERR_OR_NULL(acomp_ctx->acomp))
+			crypto_free_acomp(acomp_ctx->acomp);
+		kfree(acomp_ctx);
+	}
+	*per_cpu_ptr(pool->acomp_ctx, cpu) = NULL;
 
-	tfm = *per_cpu_ptr(pool->tfm, cpu);
-	if (!IS_ERR_OR_NULL(tfm))
-		crypto_free_comp(tfm);
-	*per_cpu_ptr(pool->tfm, cpu) = NULL;
 	return 0;
 }
 
@@ -561,8 +609,9 @@ static struct zswap_pool *zswap_pool_create(char *type, char *compressor)
 	pr_debug("using %s zpool\n", zpool_get_type(pool->zpool));
 
 	strlcpy(pool->tfm_name, compressor, sizeof(pool->tfm_name));
-	pool->tfm = alloc_percpu(struct crypto_comp *);
-	if (!pool->tfm) {
+
+	pool->acomp_ctx = alloc_percpu(struct crypto_acomp_ctx *);
+	if (!pool->acomp_ctx) {
 		pr_err("percpu alloc failed\n");
 		goto error;
 	}
@@ -585,7 +634,7 @@ static struct zswap_pool *zswap_pool_create(char *type, char *compressor)
 	return pool;
 
 error:
-	free_percpu(pool->tfm);
+	free_percpu(pool->acomp_ctx);
 	if (pool->zpool)
 		zpool_destroy_pool(pool->zpool);
 	kfree(pool);
@@ -596,14 +645,14 @@ static __init struct zswap_pool *__zswap_pool_create_fallback(void)
 {
 	bool has_comp, has_zpool;
 
-	has_comp = crypto_has_comp(zswap_compressor, 0, 0);
+	has_comp = crypto_has_acomp(zswap_compressor, 0, 0);
 	if (!has_comp && strcmp(zswap_compressor,
 				CONFIG_ZSWAP_COMPRESSOR_DEFAULT)) {
 		pr_err("compressor %s not available, using default %s\n",
 		       zswap_compressor, CONFIG_ZSWAP_COMPRESSOR_DEFAULT);
 		param_free_charp(&zswap_compressor);
 		zswap_compressor = CONFIG_ZSWAP_COMPRESSOR_DEFAULT;
-		has_comp = crypto_has_comp(zswap_compressor, 0, 0);
+		has_comp = crypto_has_acomp(zswap_compressor, 0, 0);
 	}
 	if (!has_comp) {
 		pr_err("default compressor %s not available\n",
@@ -639,7 +688,7 @@ static void zswap_pool_destroy(struct zswap_pool *pool)
 	zswap_pool_debug("destroying", pool);
 
 	cpuhp_state_remove_instance(CPUHP_MM_ZSWP_POOL_PREPARE, &pool->node);
-	free_percpu(pool->tfm);
+	free_percpu(pool->acomp_ctx);
 	zpool_destroy_pool(pool->zpool);
 	kfree(pool);
 }
@@ -723,7 +772,7 @@ static int __zswap_param_set(const char *val, const struct kernel_param *kp,
 		}
 		type = s;
 	} else if (!compressor) {
-		if (!crypto_has_comp(s, 0, 0)) {
+		if (!crypto_has_acomp(s, 0, 0)) {
 			pr_err("compressor %s not available\n", s);
 			return -ENOENT;
 		}
@@ -774,7 +823,7 @@ static int __zswap_param_set(const char *val, const struct kernel_param *kp,
 		 * failed, maybe both compressor and zpool params were bad.
 		 * Allow changing this param, so pool creation will succeed
 		 * when the other param is changed. We already verified this
-		 * param is ok in the zpool_has_pool() or crypto_has_comp()
+		 * param is ok in the zpool_has_pool() or crypto_has_acomp()
 		 * checks above.
 		 */
 		ret = param_set_charp(s, kp);
@@ -876,7 +925,9 @@ static int zswap_writeback_entry(struct zpool *pool, unsigned long handle)
 	pgoff_t offset;
 	struct zswap_entry *entry;
 	struct page *page;
-	struct crypto_comp *tfm;
+	struct scatterlist input, output;
+	struct crypto_acomp_ctx *acomp_ctx;
+
 	u8 *src, *dst;
 	unsigned int dlen;
 	int ret;
@@ -916,14 +967,21 @@ static int zswap_writeback_entry(struct zpool *pool, unsigned long handle)
 
 	case ZSWAP_SWAPCACHE_NEW: /* page is locked */
 		/* decompress */
+		acomp_ctx = *this_cpu_ptr(entry->pool->acomp_ctx);
+
 		dlen = PAGE_SIZE;
 		src = (u8 *)zhdr + sizeof(struct zswap_header);
-		dst = kmap_atomic(page);
-		tfm = *get_cpu_ptr(entry->pool->tfm);
-		ret = crypto_comp_decompress(tfm, src, entry->length,
-					     dst, &dlen);
-		put_cpu_ptr(entry->pool->tfm);
-		kunmap_atomic(dst);
+		dst = kmap(page);
+
+		mutex_lock(&acomp_ctx->mutex);
+		sg_init_one(&input, src, entry->length);
+		sg_init_one(&output, dst, dlen);
+		acomp_request_set_params(acomp_ctx->req, &input, &output, entry->length, dlen);
+		ret = crypto_wait_req(crypto_acomp_decompress(acomp_ctx->req), &acomp_ctx->wait);
+		dlen = acomp_ctx->req->dlen;
+		mutex_unlock(&acomp_ctx->mutex);
+
+		kunmap(page);
 		BUG_ON(ret);
 		BUG_ON(dlen != PAGE_SIZE);
 
@@ -1004,7 +1062,8 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset,
 {
 	struct zswap_tree *tree = zswap_trees[type];
 	struct zswap_entry *entry, *dupentry;
-	struct crypto_comp *tfm;
+	struct scatterlist input, output;
+	struct crypto_acomp_ctx *acomp_ctx;
 	int ret;
 	unsigned int hlen, dlen = PAGE_SIZE;
 	unsigned long handle, value;
@@ -1074,12 +1133,20 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset,
 	}
 
 	/* compress */
-	dst = get_cpu_var(zswap_dstmem);
-	tfm = *get_cpu_ptr(entry->pool->tfm);
-	src = kmap_atomic(page);
-	ret = crypto_comp_compress(tfm, src, PAGE_SIZE, dst, &dlen);
-	kunmap_atomic(src);
-	put_cpu_ptr(entry->pool->tfm);
+	acomp_ctx = *this_cpu_ptr(entry->pool->acomp_ctx);
+
+	mutex_lock(&acomp_ctx->mutex);
+
+	src = kmap(page);
+	dst = acomp_ctx->dstmem;
+	sg_init_one(&input, src, PAGE_SIZE);
+	/* zswap_dstmem is of size (PAGE_SIZE * 2). Reflect same in sg_list */
+	sg_init_one(&output, dst, PAGE_SIZE * 2);
+	acomp_request_set_params(acomp_ctx->req, &input, &output, PAGE_SIZE, dlen);
+	ret = crypto_wait_req(crypto_acomp_compress(acomp_ctx->req), &acomp_ctx->wait);
+	dlen = acomp_ctx->req->dlen;
+	kunmap(page);
+
 	if (ret) {
 		ret = -EINVAL;
 		goto put_dstmem;
@@ -1103,7 +1170,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset,
 	memcpy(buf, &zhdr, hlen);
 	memcpy(buf + hlen, dst, dlen);
 	zpool_unmap_handle(entry->pool->zpool, handle);
-	put_cpu_var(zswap_dstmem);
+	mutex_unlock(&acomp_ctx->mutex);
 
 	/* populate entry */
 	entry->offset = offset;
@@ -1131,7 +1198,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset,
 	return 0;
 
 put_dstmem:
-	put_cpu_var(zswap_dstmem);
+	mutex_unlock(&acomp_ctx->mutex);
 	zswap_pool_put(entry->pool);
 freepage:
 	zswap_entry_cache_free(entry);
@@ -1148,7 +1215,8 @@ static int zswap_frontswap_load(unsigned type, pgoff_t offset,
 {
 	struct zswap_tree *tree = zswap_trees[type];
 	struct zswap_entry *entry;
-	struct crypto_comp *tfm;
+	struct scatterlist input, output;
+	struct crypto_acomp_ctx *acomp_ctx;
 	u8 *src, *dst;
 	unsigned int dlen;
 	int ret;
@@ -1175,11 +1243,17 @@ static int zswap_frontswap_load(unsigned type, pgoff_t offset,
 	src = zpool_map_handle(entry->pool->zpool, entry->handle, ZPOOL_MM_RO);
 	if (zpool_evictable(entry->pool->zpool))
 		src += sizeof(struct zswap_header);
-	dst = kmap_atomic(page);
-	tfm = *get_cpu_ptr(entry->pool->tfm);
-	ret = crypto_comp_decompress(tfm, src, entry->length, dst, &dlen);
-	put_cpu_ptr(entry->pool->tfm);
-	kunmap_atomic(dst);
+	dst = kmap(page);
+
+	acomp_ctx = *this_cpu_ptr(entry->pool->acomp_ctx);
+	mutex_lock(&acomp_ctx->mutex);
+	sg_init_one(&input, src, entry->length);
+	sg_init_one(&output, dst, dlen);
+	acomp_request_set_params(acomp_ctx->req, &input, &output, entry->length, dlen);
+	ret = crypto_wait_req(crypto_acomp_decompress(acomp_ctx->req), &acomp_ctx->wait);
+	mutex_unlock(&acomp_ctx->mutex);
+
+	kunmap(page);
 	zpool_unmap_handle(entry->pool->zpool, entry->handle);
 	BUG_ON(ret);
 
-- 
2.27.0