From 6a9e923da298dda69cbdaf73eed6fb0e85ec2ad2 Mon Sep 17 00:00:00 2001
From: paul luse <paul.e.luse@intel.com>
Date: Wed, 1 Jul 2020 15:00:10 -0400
Subject: [PATCH] lib/ioat: add mew API to get the max # of descriptors
 supported

Needed by follow-on patches to aupport accel_fw batching in IOAT
module.

Signed-off-by: paul luse <paul.e.luse@intel.com>
Change-Id: Ie39718f42756c10af131ff7893874d19ea390ecc
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/3154
Community-CI: Mellanox Build Bot
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
---
 CHANGELOG.md           | 4 ++++
 include/spdk/ioat.h    | 9 +++++++++
 lib/ioat/Makefile      | 2 +-
 lib/ioat/ioat.c        | 6 ++++++
 lib/ioat/spdk_ioat.map | 1 +
 5 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e9d5a0795..5b53fdef4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## v20.07: (Upcoming Release)
 
+### ioat
+
+A new API `spdk_ioat_get_max_descriptors` was added.
+
 ### nvmf
 
 The NVMe-oF target no longer supports connecting scheduling configuration and instead
diff --git a/include/spdk/ioat.h b/include/spdk/ioat.h
index 9d32eaf0e..c4e66be3b 100644
--- a/include/spdk/ioat.h
+++ b/include/spdk/ioat.h
@@ -107,6 +107,15 @@ int spdk_ioat_probe(void *cb_ctx, spdk_ioat_probe_cb probe_cb, spdk_ioat_attach_
   */
 void spdk_ioat_detach(struct spdk_ioat_chan *ioat);
 
+/**
+ * Get the maximum number of descriptors supported by the library.
+ *
+ * \param chan I/OAT channel
+ *
+ * \return maximum number of descriptors.
+ */
+uint32_t spdk_ioat_get_max_descriptors(struct spdk_ioat_chan *chan);
+
 /**
  * Build a DMA engine memory copy request.
  *
diff --git a/lib/ioat/Makefile b/lib/ioat/Makefile
index a0da25b86..933ad5ef7 100644
--- a/lib/ioat/Makefile
+++ b/lib/ioat/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
 
 C_SRCS = ioat.c
 LIBNAME = ioat
diff --git a/lib/ioat/ioat.c b/lib/ioat/ioat.c
index bde3290cb..516fa545c 100644
--- a/lib/ioat/ioat.c
+++ b/lib/ioat/ioat.c
@@ -374,6 +374,12 @@ ioat_channel_destruct(struct spdk_ioat_chan *ioat)
 	}
 }
 
+uint32_t
+spdk_ioat_get_max_descriptors(struct spdk_ioat_chan *ioat)
+{
+	return 1 << ioat->ring_size_order;
+}
+
 static int
 ioat_channel_start(struct spdk_ioat_chan *ioat)
 {
diff --git a/lib/ioat/spdk_ioat.map b/lib/ioat/spdk_ioat.map
index a74768c9e..f467da817 100644
--- a/lib/ioat/spdk_ioat.map
+++ b/lib/ioat/spdk_ioat.map
@@ -11,6 +11,7 @@
 	spdk_ioat_flush;
 	spdk_ioat_process_events;
 	spdk_ioat_get_dma_capabilities;
+	spdk_ioat_get_max_descriptors;
 
 	local: *;
 };