nvme: introduce transport abstraction

This will allow factoring out PCIe-specific code into a swappable
transport so that NVMe over Fabrics host support can be added.

Change-Id: I4df74dd268d655e3b36e8d6114ebe7d79a24844d
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>

lib/nvme/Makefile

@@ -35,7 +35,7 @@ SPDK_ROOT_DIR := $(abspath $(CURDIR)/../..)
 include $(SPDK_ROOT_DIR)/mk/spdk.common.mk
 
 CFLAGS += $(ENV_CFLAGS)
-C_SRCS = nvme_ctrlr_cmd.c nvme_ctrlr.c nvme_ns_cmd.c nvme_ns.c nvme_qpair.c nvme.c nvme_intel.c
+C_SRCS = nvme_ctrlr_cmd.c nvme_ctrlr.c nvme_ns_cmd.c nvme_ns.c nvme_pcie.c nvme_qpair.c nvme.c nvme_intel.c
 LIBNAME = nvme
 
 include $(SPDK_ROOT_DIR)/mk/spdk.lib.mk

lib/nvme/nvme.c

@@ -58,6 +58,8 @@ nvme_attach(void *devhandle)
 		return NULL;
 	}
 
+	ctrlr->transport = &spdk_nvme_transport_pcie;
+
 	status = nvme_ctrlr_construct(ctrlr, devhandle);
 	if (status != 0) {
 		spdk_free(ctrlr);

lib/nvme/nvme_internal.h

@@ -241,6 +241,10 @@ struct nvme_request {
 	void				*user_buffer;
 };
 
+struct spdk_nvme_transport {
+	int reserved;
+};
+
 struct nvme_completion_poll_status {
 	struct spdk_nvme_cpl	cpl;
 	bool			done;
@@ -284,6 +288,8 @@ struct spdk_nvme_qpair {
 	volatile uint32_t		*sq_tdbl;
 	volatile uint32_t		*cq_hdbl;
 
+	const struct spdk_nvme_transport *transport;
+
 	/**
 	 * Submission queue
 	 */
@@ -383,6 +389,8 @@ struct spdk_nvme_ctrlr {
 	/** NVMe MMIO register space */
 	volatile struct spdk_nvme_registers	*regs;
 
+	const struct spdk_nvme_transport	*transport;
+
 	/** I/O queue pairs */
 	struct spdk_nvme_qpair		*ioq;
 
@@ -480,6 +488,8 @@ struct pci_id {
 
 extern struct nvme_driver *g_spdk_nvme_driver;
 
+extern const struct spdk_nvme_transport spdk_nvme_transport_pcie;
+
 #define nvme_min(a,b) (((a)<(b))?(a):(b))
 
 #define INTEL_DC_P3X00_DEVID	0x09538086

lib/nvme/nvme_pcie.c

@@ -0,0 +1,41 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright (c) Intel Corporation.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+ * NVMe over PCIe transport
+ */
+
+#include "nvme_internal.h"
+
+const struct spdk_nvme_transport spdk_nvme_transport_pcie = {
+};

lib/nvme/nvme_qpair.c

@@ -546,6 +546,7 @@ nvme_qpair_construct(struct spdk_nvme_qpair *qpair, uint16_t id,
 	qpair->sq_in_cmb = false;
 
 	qpair->ctrlr = ctrlr;
+	qpair->transport = ctrlr->transport;
 
 	/* cmd and cpl rings must be aligned on 4KB boundaries. */
 	if (ctrlr->opts.use_cmb_sqs) {

test/lib/nvme/unit/nvme_c/nvme_ut.c

@@ -39,6 +39,9 @@
 
 #include "lib/nvme/unit/test_env.c"
 
+const struct spdk_nvme_transport spdk_nvme_transport_pcie = {
+};
+
 int
 spdk_pci_enumerate(enum spdk_pci_device_type type,
 		   spdk_pci_enum_cb enum_cb,

test/lib/nvme/unit/nvme_ns_cmd_c/nvme_ns_cmd_ut.c

@@ -39,6 +39,9 @@
 
 struct nvme_request *g_request = NULL;
 
+const struct spdk_nvme_transport spdk_nvme_transport_pcie = {
+};
+
 
 int
 spdk_pci_enumerate(enum spdk_pci_device_type type,