util: Add get feature length 2 API to support direction parameter

Since feature identifier 0Dh: host memory buffer length is affected by the
direction as mentioned by the issue #1681.

Signed-off-by: Tokunori Ikegami <ikegami.t@gmail.com>
[dwagner: reordered definitions and declerations]
Signed-off-by: Daniel Wagner <dwagner@suse.de>

diff --git a/src/libnvme.map b/src/libnvme.map
index ac27d129edbaff4349929ad9aa7ef42439656b64..fdbb5e57179730aaade6133b58a126698a39453d 100644 (file)
--- a/src/libnvme.map
+++ b/src/libnvme.map
@@ -5,6 +5,7 @@ LIBNVME_1_2 {
                nvme_ctrl_get_dhchap_host_key;
                nvme_ctrl_set_dhchap_host_key;
                nvmf_get_discovery_wargs;
+               nvme_get_feature_length2;
 };
 
 LIBNVME_1_1 {

diff --git a/src/nvme/util.c b/src/nvme/util.c
index 4363d5e468e4781c2c6a8dda650b692f5a25cd7c..653bb3623b211ba2ee805797edf59f45dc3893b6 100644 (file)
--- a/src/nvme/util.c
+++ b/src/nvme/util.c
@@ -494,6 +494,22 @@ int nvme_get_feature_length(int fid, __u32 cdw11, __u32 *len)
        return 0;
 }
 
+int nvme_get_feature_length2(int fid, __u32 cdw11, enum nvme_data_tfr dir,
+                            __u32 *len)
+{
+       switch (fid) {
+       case NVME_FEAT_FID_HOST_MEM_BUF:
+               if (dir == NVME_DATA_TFR_HOST_TO_CTRL) {
+                       *len = 0;
+                       break;
+               }
+               fallthrough;
+       default:
+               return nvme_get_feature_length(fid, cdw11, len);
+       }
+       return 0;
+}
+
 int nvme_get_directive_receive_length(enum nvme_directive_dtype dtype,
                enum nvme_directive_receive_doper doper, __u32 *len)
 {

diff --git a/src/nvme/util.h b/src/nvme/util.h
index 6f1d3e9f15c4501bf849a8e631a3a45f6e6543eb..6848c67f0c60187360cee0cb6442aa79faa2d2ae 100644 (file)
--- a/src/nvme/util.h
+++ b/src/nvme/util.h
@@ -17,6 +17,12 @@
  * libnvme utility functions
  */
 
+#if __has_attribute(__fallthrough__)
+# define fallthrough __attribute__((__fallthrough__))
+#else
+# define fallthrough do {} while (0) /* fallthrough */
+#endif
+
 /**
  * enum nvme_connect_err - nvme connect error codes
  * @ENVME_CONNECT_RESOLVE:     failed to resolve host
@@ -155,6 +161,37 @@ void nvme_init_copy_range_f1(struct nvme_copy_range_f1 *copy, __u16 *nlbs,
  */
 int nvme_get_feature_length(int fid, __u32 cdw11, __u32 *len);
 
+/**
+ * enum nvme_data_tfr - Data transfer direction of the command
+ * @NVME_DATA_TFR_NO_DATA_TFR:         No data transfer
+ * @NVME_DATA_TFR_HOST_TO_CTRL:                Host to controller
+ * @NVME_DATA_TFR_CTRL_TO_HOST:                Controller to host
+ * @NVME_DATA_TFR_BIDIRECTIONAL:       Bidirectional
+ */
+enum nvme_data_tfr {
+       NVME_DATA_TFR_NO_DATA_TFR,
+       NVME_DATA_TFR_HOST_TO_CTRL,
+       NVME_DATA_TFR_CTRL_TO_HOST,
+       NVME_DATA_TFR_BIDIRECTIONAL
+};
+
+/**
+ * nvme_get_feature_length2() - Retreive the command payload length for a
+ *                            specific feature identifier
+ * @fid:   Feature identifier, see &enum nvme_features_id.
+ * @cdw11: The cdw11 value may affect the transfer (only known fid is
+ *        %NVME_FEAT_FID_HOST_ID)
+ * @dir:   Data transfer direction: false - host to controller, true -
+ *        controller to host may affect the transfer (only known fid is
+ *        %NVME_FEAT_FID_HOST_MEM_BUF).
+ * @len:   On success, set to this features payload length in bytes.
+ *
+ * Return: 0 on success, -1 with errno set to EINVAL if the function did not
+ * recognize &fid.
+ */
+int nvme_get_feature_length2(int fid, __u32 cdw11, enum nvme_data_tfr dir,
+                            __u32 *len);
+
 /**
  * nvme_get_directive_receive_length() - Get directive receive length
  * @dtype: Directive type, see &enum nvme_directive_dtype