accel: add new API to discover an engine's capabilities

This patch also implements the new API for the 3 existing engines.
There was also some minor clean in one file, moving a function to
eliminate multiple forward declarations (there would have been
another one with this new API).

The next patch will use this API in the accel perf tool.

Signed-off-by: paul luse <paul.e.luse@intel.com>
Change-Id: I4ebc9cb3d1c588919235b5080cbeec29189efa21
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/2025
Community-CI: Mellanox Build Bot
Community-CI: Broadcom CI
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@mellanox.com>
Reviewed-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+### accel
+
+A new API was added `spdk_accel_get_capabilities` that allows applications to
+query the capabilities of the currently enabled accel engine back-end.
+
 ## v20.04: (Upcoming Release)
 
 ### configuration

include/spdk/accel_engine.h

@@ -44,6 +44,16 @@
 extern "C" {
 #endif
 
+enum accel_capability {
+	ACCEL_COPY		= 1 << 0,
+	ACCEL_FILL		= 1 << 1,
+	ACCEL_DUALCAST		= 1 << 2,
+	ACCEL_COMPARE		= 1 << 3,
+	ACCEL_BATCH		= 1 << 4,
+	ACCEL_CRC		= 1 << 5,
+	ACCEL_DIF		= 1 << 6,
+};
+
 /**
  * Acceleration operation callback.
  *
@@ -99,6 +109,16 @@ void spdk_accel_engine_module_finish(void);
  */
 struct spdk_io_channel *spdk_accel_engine_get_io_channel(void);
 
+/**
+ * Retrieve accel engine capabilities.
+ *
+ * \param ch I/O channel to submit request to the accel engine. This channel can
+ * be obtained by the function spdk_accel_engine_get_io_channel().
+ *
+ * \return bitmap of capabilities defined by enum accel_capability.
+ */
+uint64_t spdk_accel_get_capabilities(struct spdk_io_channel *ch);
+
 /**
  * Submit a copy request.
  *

include/spdk_internal/accel_engine.h

@@ -55,10 +55,11 @@ struct spdk_accel_task {
 };
 
 struct spdk_accel_engine {
-	int	(*copy)(void *cb_arg, struct spdk_io_channel *ch, void *dst, void *src,
-			uint64_t nbytes, spdk_accel_completion_cb cb);
-	int	(*fill)(void *cb_arg, struct spdk_io_channel *ch, void *dst, uint8_t fill,
-			uint64_t nbytes, spdk_accel_completion_cb cb);
+	uint64_t (*get_capabilities)(void);
+	int (*copy)(void *cb_arg, struct spdk_io_channel *ch, void *dst, void *src,
+		    uint64_t nbytes, spdk_accel_completion_cb cb);
+	int (*fill)(void *cb_arg, struct spdk_io_channel *ch, void *dst, uint8_t fill,
+		    uint64_t nbytes, spdk_accel_completion_cb cb);
 	struct spdk_io_channel *(*get_io_channel)(void);
 };
 

lib/accel/Makefile

@@ -35,7 +35,7 @@ SPDK_ROOT_DIR := $(abspath $(CURDIR)/../..)
 include $(SPDK_ROOT_DIR)/mk/spdk.common.mk
 
 SO_VER := 2
-SO_MINOR := 0
+SO_MINOR := 1
 SO_SUFFIX := $(SO_VER).$(SO_MINOR)
 
 LIBNAME = accel

lib/accel/accel_engine.c

@@ -109,6 +109,14 @@ _accel_engine_done(void *ref, int status)
 	req->cb(req, status);
 }
 
+uint64_t
+spdk_accel_get_capabilities(struct spdk_io_channel *ch)
+{
+	struct accel_io_channel *accel_ch = spdk_io_channel_get_ctx(ch);
+
+	return accel_ch->engine->get_capabilities();
+}
+
 /* Accel framework public API for copy function */
 int
 spdk_accel_submit_copy(struct spdk_accel_task *accel_req, struct spdk_io_channel *ch,
@@ -297,6 +305,12 @@ spdk_accel_engine_config_text(FILE *fp)
 
 /* The SW Accelerator module is "built in" here (rest of file) */
 
+static uint64_t
+sw_accel_get_capabilities(void)
+{
+	return ACCEL_COPY | ACCEL_FILL;
+}
+
 static int
 sw_accel_submit_copy(void *cb_arg, struct spdk_io_channel *ch, void *dst, void *src,
 		     uint64_t nbytes,
@@ -330,9 +344,10 @@ sw_accel_submit_fill(void *cb_arg, struct spdk_io_channel *ch, void *dst, uint8_
 static struct spdk_io_channel *sw_accel_get_io_channel(void);
 
 static struct spdk_accel_engine sw_accel_engine = {
-	.copy		= sw_accel_submit_copy,
-	.fill		= sw_accel_submit_fill,
-	.get_io_channel	= sw_accel_get_io_channel,
+	.get_capabilities	= sw_accel_get_capabilities,
+	.copy			= sw_accel_submit_copy,
+	.fill			= sw_accel_submit_fill,
+	.get_io_channel		= sw_accel_get_io_channel,
 };
 
 static int

lib/accel/spdk_accel.map

@@ -7,6 +7,7 @@
 	spdk_accel_engine_config_text;
 	spdk_accel_engine_module_finish;
 	spdk_accel_engine_get_io_channel;
+	spdk_accel_get_capabilities;
 	spdk_accel_submit_copy;
 	spdk_accel_submit_fill;
 	spdk_accel_task_size;

module/accel/idxd/accel_engine_idxd.c

@@ -102,20 +102,9 @@ struct idxd_task {
 	spdk_accel_completion_cb	cb;
 };
 
-static int accel_engine_idxd_init(void);
-static void accel_engine_idxd_exit(void *ctx);
-static struct spdk_io_channel *idxd_get_io_channel(void);
-static int idxd_submit_copy(void *cb_arg, struct spdk_io_channel *ch, void *dst, void *src,
-			    uint64_t nbytes,
-			    spdk_accel_completion_cb cb);
-static int idxd_submit_fill(void *cb_arg, struct spdk_io_channel *ch, void *dst, uint8_t fill,
-			    uint64_t nbytes, spdk_accel_completion_cb cb);
+pthread_mutex_t g_num_channels_lock = PTHREAD_MUTEX_INITIALIZER;
 
-static struct spdk_accel_engine idxd_accel_engine = {
-	.copy		= idxd_submit_copy,
-	.fill		= idxd_submit_fill,
-	.get_io_channel	= idxd_get_io_channel,
-};
+static struct spdk_io_channel *idxd_get_io_channel(void);
 
 static struct idxd_device *
 idxd_select_device(void)
@@ -271,7 +260,19 @@ idxd_submit_fill(void *cb_arg, struct spdk_io_channel *ch, void *dst, uint8_t fi
 	return rc;
 }
 
-pthread_mutex_t g_num_channels_lock = PTHREAD_MUTEX_INITIALIZER;
+static uint64_t
+idxd_get_capabilities(void)
+{
+	return ACCEL_COPY | ACCEL_FILL | ACCEL_DUALCAST | ACCEL_COMPARE |
+	       ACCEL_BATCH | ACCEL_CRC	| ACCEL_DIF;
+}
+
+static struct spdk_accel_engine idxd_accel_engine = {
+	.get_capabilities	= idxd_get_capabilities,
+	.copy			= idxd_submit_copy,
+	.fill			= idxd_submit_fill,
+	.get_io_channel		= idxd_get_io_channel,
+};
 
 /*
  * Configure the max number of descriptors that a channel is

module/accel/ioat/accel_engine_ioat.c

@@ -191,10 +191,21 @@ ioat_poll(void *arg)
 
 static struct spdk_io_channel *ioat_get_io_channel(void);
 
+/*
+ * The IOAT engine has more capabilities than this but these are
+ * the only ones we expose via the accel engine.
+ */
+static uint64_t
+ioat_get_capabilities(void)
+{
+	return ACCEL_COPY | ACCEL_FILL;
+}
+
 static struct spdk_accel_engine ioat_accel_engine = {
-	.copy		= ioat_submit_copy,
-	.fill		= ioat_submit_fill,
-	.get_io_channel	= ioat_get_io_channel,
+	.get_capabilities	= ioat_get_capabilities,
+	.copy			= ioat_submit_copy,
+	.fill			= ioat_submit_fill,
+	.get_io_channel		= ioat_get_io_channel,
 };
 
 static int