nvme: spdk_nvme_ctrlr_get_registers

This function returns a pointer to the PCIe I/O registers for a controller
or NULL if unsupported for this transport.

Used for PCIe only, other transports return NULL.

Use with caution.

Signed-off-by: James Bergsten <jamesx.bergsten@intel.com>
Change-Id: I849f9de9ad259a65b1eef9c1237345eb7195b9bf
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/452927
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>

include/spdk/nvme.h

@@ -1504,6 +1504,18 @@ int spdk_nvme_ctrlr_update_firmware(struct spdk_nvme_ctrlr *ctrlr, void *payload
 				    int slot, enum spdk_nvme_fw_commit_action commit_action,
 				    struct spdk_nvme_status *completion_status);
 
+/**
+ * Return virtual address of PCIe NVM I/O registers
+ *
+ * This function returns a pointer to the PCIe I/O registers for a controller
+ * or NULL if unsupported for this transport.
+ *
+ * \param ctrlr Controller whose registers are to be accessed.
+ *
+ * \return Pointer to virtual address of register bank, or NULL.
+ */
+volatile struct spdk_nvme_registers *spdk_nvme_ctrlr_get_registers(struct spdk_nvme_ctrlr *ctrlr);
+
 /**
  * Allocate an I/O buffer from the controller memory buffer (Experimental).
  *

lib/nvme/nvme_internal.h

@@ -989,6 +989,7 @@ struct spdk_nvme_ctrlr *spdk_nvme_get_ctrlr_by_trid_unsafe(
 	struct spdk_nvme_qpair *nvme_ ## name ## _ctrlr_create_io_qpair(struct spdk_nvme_ctrlr *ctrlr, uint16_t qid, const struct spdk_nvme_io_qpair_opts *opts); \
 	void *nvme_ ## name ## _ctrlr_alloc_cmb_io_buffer(struct spdk_nvme_ctrlr *ctrlr, size_t size); \
 	int nvme_ ## name ## _ctrlr_free_cmb_io_buffer(struct spdk_nvme_ctrlr *ctrlr, void *buf, size_t size); \
+	volatile struct spdk_nvme_registers *nvme_ ## name ## _ctrlr_get_registers(struct spdk_nvme_ctrlr *ctrlr); \
 	int nvme_ ## name ## _ctrlr_delete_io_qpair(struct spdk_nvme_ctrlr *ctrlr, struct spdk_nvme_qpair *qpair); \
 	int nvme_ ## name ## _ctrlr_reconnect_qpair(struct spdk_nvme_ctrlr *ctrlr, struct spdk_nvme_qpair *qpair); \
 	void nvme_ ## name ## _qpair_abort_reqs(struct spdk_nvme_qpair *qpair, uint32_t dnr); \

lib/nvme/nvme_pcie.c

@@ -594,6 +594,14 @@ nvme_pcie_ctrlr_alloc_cmb(struct spdk_nvme_ctrlr *ctrlr, uint64_t length, uint64
 	return 0;
 }
 
+volatile struct spdk_nvme_registers *
+nvme_pcie_ctrlr_get_registers(struct spdk_nvme_ctrlr *ctrlr)
+{
+	struct nvme_pcie_ctrlr *pctrlr = nvme_pcie_ctrlr(ctrlr);
+
+	return pctrlr->regs;
+}
+
 void *
 nvme_pcie_ctrlr_alloc_cmb_io_buffer(struct spdk_nvme_ctrlr *ctrlr, size_t size)
 {

lib/nvme/nvme_rdma.c

@@ -1761,6 +1761,12 @@ nvme_rdma_ctrlr_get_max_sges(struct spdk_nvme_ctrlr *ctrlr)
 	return spdk_min(ctrlr->cdata.nvmf_specific.msdbd, NVME_RDMA_MAX_SGL_DESCRIPTORS);
 }
 
+volatile struct spdk_nvme_registers *
+nvme_rdma_ctrlr_get_registers(struct spdk_nvme_ctrlr *ctrlr)
+{
+	return NULL;
+}
+
 void *
 nvme_rdma_ctrlr_alloc_cmb_io_buffer(struct spdk_nvme_ctrlr *ctrlr, size_t size)
 {

lib/nvme/nvme_tcp.c

@@ -1852,6 +1852,12 @@ nvme_tcp_ctrlr_get_max_sges(struct spdk_nvme_ctrlr *ctrlr)
 	return 1;
 }
 
+volatile struct spdk_nvme_registers *
+nvme_tcp_ctrlr_get_registers(struct spdk_nvme_ctrlr *ctrlr)
+{
+	return NULL;
+}
+
 void *
 nvme_tcp_ctrlr_alloc_cmb_io_buffer(struct spdk_nvme_ctrlr *ctrlr, size_t size)
 {

lib/nvme/nvme_transport.c

@@ -185,6 +185,12 @@ nvme_transport_ctrlr_reconnect_qpair(struct spdk_nvme_ctrlr *ctrlr, struct spdk_
 	NVME_TRANSPORT_CALL(ctrlr->trid.trtype, ctrlr_reconnect_qpair, (ctrlr, qpair));
 }
 
+volatile struct spdk_nvme_registers *
+nvme_transport_ctrlr_get_registers(struct spdk_nvme_ctrlr *ctrlr)
+{
+	NVME_TRANSPORT_CALL(ctrlr->trid.trtype, ctrlr_get_registers, (ctrlr));
+}
+
 void
 nvme_transport_qpair_abort_reqs(struct spdk_nvme_qpair *qpair, uint32_t dnr)
 {