nvme: add spdk_nvme_ctrlr_get_max_sges

Signed-off-by: Jim Harris <[email protected]> Change-Id: I41ecc9243c8d5b3969e9cc13dde9a538b13d71a3 Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/21956 Community-CI: Mellanox Build Bot Tested-by: SPDK CI Jenkins <[email protected]> Reviewed-by: Shuhei Matsumoto <[email protected]> Reviewed-by: Konrad Sztyber <[email protected]>
Mellanox · Feb 26, 2024 · 6f3e277 · 6f3e277
1 parent c522a81
commit 6f3e277
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -11,6 +11,10 @@ SPDK applications can now start with `--wait-for-rpc` and JSON configuration pro
 Function `spdk_subsystem_init_from_json_config` is deprecated and will be removed in 24.09 release.
 Please use `spdk_subsystem_load_config` instead.
 
+### nvme
+
+Added `spdk_nvme_ctrlr_get_max_sges`.
+
 ### bdev_uring
 
 Added `bdev_uring_rescan` RPC to allow rescaning the size of uring bdev.

diff --git a/include/spdk/nvme.h b/include/spdk/nvme.h
@@ -1330,6 +1330,17 @@ struct spdk_pci_device *spdk_nvme_ctrlr_get_pci_device(struct spdk_nvme_ctrlr *c
  */
 uint32_t spdk_nvme_ctrlr_get_max_xfer_size(const struct spdk_nvme_ctrlr *ctrlr);
 
+/**
+ * Get the maximum number of SGEs per request for the given NVMe controller.
+ *
+ * Controllers that do not support SGL will return UINT16_MAX.
+ *
+ * \param ctrlr Opaque handle to NVMe controller.
+ *
+ * \return Maximum number of SGEs per request
+ */
+uint16_t spdk_nvme_ctrlr_get_max_sges(const struct spdk_nvme_ctrlr *ctrlr);
+
 /**
  * Check whether the nsid is an active nv for the given NVMe controller.
  *

diff --git a/lib/nvme/nvme_ctrlr.c b/lib/nvme/nvme_ctrlr.c
@@ -4571,6 +4571,16 @@ spdk_nvme_ctrlr_get_max_xfer_size(const struct spdk_nvme_ctrlr *ctrlr)
 	return ctrlr->max_xfer_size;
 }
 
+uint16_t
+spdk_nvme_ctrlr_get_max_sges(const struct spdk_nvme_ctrlr *ctrlr)
+{
+	if (ctrlr->flags & SPDK_NVME_CTRLR_SGL_SUPPORTED) {
+		return ctrlr->max_sges;
+	} else {
+		return UINT16_MAX;
+	}
+}
+
 void
 spdk_nvme_ctrlr_register_aer_callback(struct spdk_nvme_ctrlr *ctrlr,
 				      spdk_nvme_aer_cb aer_cb_fn,

diff --git a/lib/nvme/spdk_nvme.map b/lib/nvme/spdk_nvme.map
@@ -56,6 +56,7 @@
 	spdk_nvme_ctrlr_get_num_ns;
 	spdk_nvme_ctrlr_get_pci_device;
 	spdk_nvme_ctrlr_get_max_xfer_size;
+	spdk_nvme_ctrlr_get_max_sges;
 	spdk_nvme_ctrlr_is_active_ns;
 	spdk_nvme_ctrlr_get_first_active_ns;
 	spdk_nvme_ctrlr_get_next_active_ns;