[PATCH v10 18/25] 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 get_batch_size() interface to:

  struct acomp_alg
  struct crypto_acomp

A crypto_acomp compression algorithm that supports batching of compressions
and decompressions must provide an implementation for this API to return
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.

A new helper function acomp_has_async_batching() can be invoked to query
if a crypto_acomp implements get_batch_size().

The new crypto_acomp_batch_size() API uses this helper function to return
the batch-size for compressors that implement get_batch_size(). If no
implementation is provided by the crypto_acomp, a default of "1" is
returned for the batch-size.

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.

Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com>
---
 crypto/acompress.c                  |  1 +
 include/crypto/acompress.h          | 27 +++++++++++++++++++++++++++
 include/crypto/internal/acompress.h |  3 +++
 3 files changed, 31 insertions(+)

diff --git a/crypto/acompress.c b/crypto/acompress.c
index be28cbfd22e32..f440724719655 100644
--- a/crypto/acompress.c
+++ b/crypto/acompress.c
@@ -105,6 +105,7 @@ static int crypto_acomp_init_tfm(struct crypto_tfm *tfm)
 
 	acomp->compress = alg->compress;
 	acomp->decompress = alg->decompress;
+	acomp->get_batch_size = alg->get_batch_size;
 	acomp->reqsize = alg->base.cra_reqsize;
 
 	acomp->base.exit = crypto_acomp_exit_tfm;
diff --git a/include/crypto/acompress.h b/include/crypto/acompress.h
index 0312322d2ca03..898104745cd24 100644
--- a/include/crypto/acompress.h
+++ b/include/crypto/acompress.h
@@ -108,6 +108,8 @@ struct acomp_req {
  *
  * @compress:		Function performs a compress operation
  * @decompress:		Function performs a de-compress operation
+ * @get_batch_size:	Maximum batch-size for batching compress/decompress
+ *			operations.
  * @reqsize:		Context size for (de)compression requests
  * @fb:			Synchronous fallback tfm
  * @base:		Common crypto API algorithm data structure
@@ -115,6 +117,7 @@ struct acomp_req {
 struct crypto_acomp {
 	int (*compress)(struct acomp_req *req);
 	int (*decompress)(struct acomp_req *req);
+	unsigned int (*get_batch_size)(void);
 	unsigned int reqsize;
 	struct crypto_tfm base;
 };
@@ -205,6 +208,13 @@ static inline bool acomp_is_async(struct crypto_acomp *tfm)
 	       CRYPTO_ALG_ASYNC;
 }
 
+static inline bool acomp_has_async_batching(struct crypto_acomp *tfm)
+{
+	return (acomp_is_async(tfm) &&
+		(crypto_comp_alg_common(tfm)->base.cra_flags & CRYPTO_ALG_TYPE_ACOMPRESS) &&
+		tfm->get_batch_size);
+}
+
 static inline struct crypto_acomp *crypto_acomp_reqtfm(struct acomp_req *req)
 {
 	return __crypto_acomp_tfm(req->base.tfm);
@@ -545,6 +555,23 @@ 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:	crypto_acomp's batch size.
+ */
+static inline unsigned int crypto_acomp_batch_size(struct crypto_acomp *tfm)
+{
+	if (acomp_has_async_batching(tfm))
+		return tfm->get_batch_size();
+
+	return 1;
+}
+
 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 ffffd88bbbad3..2325ee18e7a10 100644
--- a/include/crypto/internal/acompress.h
+++ b/include/crypto/internal/acompress.h
@@ -28,6 +28,8 @@
  *
  * @compress:	Function performs a compress operation
  * @decompress:	Function performs a de-compress operation
+ * @get_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
@@ -46,6 +48,7 @@
 struct acomp_alg {
 	int (*compress)(struct acomp_req *req);
 	int (*decompress)(struct acomp_req *req);
+	unsigned int (*get_batch_size)(void);
 	int (*init)(struct crypto_acomp *tfm);
 	void (*exit)(struct crypto_acomp *tfm);
 
-- 
2.27.0