[PATCH v14 22/26] crypto: acomp - Add crypto_acomp_batch_size() to get an algorithm's batch-size.

[Kanchana P Sridhar <kanchana.p.sridhar@intel.com>]

This commit adds a @batch_size data member to struct acomp_alg.

An acomp_alg compression algorithm that supports batching of
compressions and decompressions must provide a @batch_size greater than
one, representing the maximum batch-size that the compressor supports,
so that kernel users of crypto_acomp, such as zswap, can allocate
resources for submitting multiple compress/decompress jobs that can be
batched, and invoke batching of [de]compressions.

The new crypto_acomp_batch_size() API queries the crypto_acomp's
acomp_alg for the batch-size. If the acomp_alg has registered a
@batch_size greater than 1, this is returned. If not, a default of "1"
is returned.

zswap can invoke crypto_acomp_batch_size() to query the maximum number
of requests that can be batch [de]compressed. Based on this, zswap
can use the minimum of any zswap-specific upper limits for batch-size
and the compressor's max @batch_size, to allocate batching resources.

The IAA acomp_algs Fixed ("deflate-iaa") and Dynamic
("deflate-iaa-dynamic") register @batch_size as
IAA_CRYPTO_MAX_BATCH_SIZE.

This enables zswap to compress/decompress pages in parallel in the IAA
hardware accelerator to improve swapout/swapin performance and memory
savings.

Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com>
---
 crypto/acompress.c                         | 14 ++++++++++++++
 drivers/crypto/intel/iaa/iaa_crypto_main.c |  2 ++
 include/crypto/acompress.h                 | 12 ++++++++++++
 include/crypto/internal/acompress.h        |  3 +++
 4 files changed, 31 insertions(+)

diff --git a/crypto/acompress.c b/crypto/acompress.c
index c48a1a20e21f..02c25c79c0d4 100644
--- a/crypto/acompress.c
+++ b/crypto/acompress.c
@@ -387,6 +387,20 @@ int crypto_acomp_decompress(struct acomp_req *req)
 }
 EXPORT_SYMBOL_GPL(crypto_acomp_decompress);
 
+unsigned int crypto_acomp_batch_size(struct crypto_acomp *tfm)
+{
+	if (acomp_is_async(tfm) &&
+		(crypto_comp_alg_common(tfm)->base.cra_flags & CRYPTO_ALG_TYPE_ACOMPRESS)) {
+		struct acomp_alg *alg = crypto_acomp_alg(tfm);
+
+		if (alg && alg->batch_size > 1)
+			return alg->batch_size;
+	}
+
+	return 1;
+}
+EXPORT_SYMBOL_GPL(crypto_acomp_batch_size);
+
 void comp_prepare_alg(struct comp_alg_common *alg)
 {
 	struct crypto_alg *base = &alg->base;
diff --git a/drivers/crypto/intel/iaa/iaa_crypto_main.c b/drivers/crypto/intel/iaa/iaa_crypto_main.c
index fe9f59ede577..e735aa01dce8 100644
--- a/drivers/crypto/intel/iaa/iaa_crypto_main.c
+++ b/drivers/crypto/intel/iaa/iaa_crypto_main.c
@@ -2729,6 +2729,7 @@ static struct acomp_alg iaa_acomp_fixed_deflate = {
 	.compress		= iaa_crypto_acomp_acompress_main,
 	.decompress		= iaa_crypto_acomp_adecompress_main,
 	.batch_completed	= iaa_crypto_acomp_batch_completed,
+	.batch_size		= IAA_CRYPTO_MAX_BATCH_SIZE,
 	.base			= {
 		.cra_name		= "deflate",
 		.cra_driver_name	= "deflate-iaa",
@@ -2755,6 +2756,7 @@ static struct acomp_alg iaa_acomp_dynamic_deflate = {
 	.compress		= iaa_crypto_acomp_acompress_main,
 	.decompress		= iaa_crypto_acomp_adecompress_main,
 	.batch_completed	= iaa_crypto_acomp_batch_completed,
+	.batch_size		= IAA_CRYPTO_MAX_BATCH_SIZE,
 	.base			= {
 		.cra_name		= "deflate",
 		.cra_driver_name	= "deflate-iaa-dynamic",
diff --git a/include/crypto/acompress.h b/include/crypto/acompress.h
index 752110a7719c..1448b20de492 100644
--- a/include/crypto/acompress.h
+++ b/include/crypto/acompress.h
@@ -598,6 +598,18 @@ int crypto_acomp_compress(struct acomp_req *req);
  */
 int crypto_acomp_decompress(struct acomp_req *req);
 
+/**
+ * crypto_acomp_batch_size() -- Get the algorithm's batch size
+ *
+ * Function returns the algorithm's batch size for batching operations
+ *
+ * @tfm:	ACOMPRESS tfm handle allocated with crypto_alloc_acomp()
+ *
+ * Return:	@tfm's acomp_alg's @batch_size, if it has defined a
+ *		@batch_size greater than 1; else return 1.
+ */
+unsigned int crypto_acomp_batch_size(struct crypto_acomp *tfm);
+
 static inline struct acomp_req *acomp_request_on_stack_init(
 	char *buf, struct crypto_acomp *tfm)
 {
diff --git a/include/crypto/internal/acompress.h b/include/crypto/internal/acompress.h
index 7c4e14491d59..dc126a8cfea2 100644
--- a/include/crypto/internal/acompress.h
+++ b/include/crypto/internal/acompress.h
@@ -34,6 +34,8 @@
  *                      of all batch sub-requests having completed.
  *                      Returns an error code in @req->slen if any
  *                      of the sub-requests completed with an error.
+ * @batch_size:	Maximum batch-size for batching compress/decompress
+ *		operations.
  * @init:	Initialize the cryptographic transformation object.
  *		This function is used to initialize the cryptographic
  *		transformation object. This function is called only once at
@@ -53,6 +55,7 @@ struct acomp_alg {
 	int (*compress)(struct acomp_req *req);
 	int (*decompress)(struct acomp_req *req);
 	bool (*batch_completed)(struct acomp_req *req, bool comp);
+	unsigned int batch_size;
 	int (*init)(struct crypto_acomp *tfm);
 	void (*exit)(struct crypto_acomp *tfm);
 
-- 
2.27.0