[PATCH v2 2/7] ibmvfc: Add NOOP command support

[Dave Marquardt via B4 Relay]

From: Dave Marquardt <davem...@linux.ibm.com>

This patch adds support for receiving and recognizing VFC_NOOP
messages from VIOS. This is done by
- defining the VFC_NOOP CRQ format
- recognizing the VFC_NOOP CRQ format in the CRQ handler. If the VIOS
  has not provided the "support VFC_NOOP" bit in its capabilities on
  NPIV login, note that the VFC_NOOP is unexpected
- setting the "can use VFC_NOOP" bit in the capabilities sent during
  NPIV login
---
 drivers/scsi/ibmvscsi/ibmvfc.c | 11 ++++++++++-
 drivers/scsi/ibmvscsi/ibmvfc.h |  3 +++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
index 9e5f0c0f0369..88386d7c9106 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc.c
@@ -1512,7 +1512,9 @@ static void ibmvfc_set_login_info(struct ibmvfc_host 
*vhost)
                login_info->flags |= cpu_to_be16(IBMVFC_CLIENT_MIGRATED);
 
        login_info->max_cmds = cpu_to_be32(max_cmds);
-       login_info->capabilities = cpu_to_be64(IBMVFC_CAN_MIGRATE | 
IBMVFC_CAN_SEND_VF_WWPN);
+       login_info->capabilities =
+               cpu_to_be64(IBMVFC_CAN_MIGRATE | IBMVFC_CAN_SEND_VF_WWPN |
+                           IBMVFC_CAN_USE_NOOP_CMD);
 
        if (vhost->mq_enabled || vhost->using_channels)
                login_info->capabilities |= 
cpu_to_be64(IBMVFC_CAN_USE_CHANNELS);
@@ -3555,6 +3557,13 @@ static void ibmvfc_handle_crq(struct ibmvfc_crq *crq, 
struct ibmvfc_host *vhost,
        if (crq->format == IBMVFC_ASYNC_EVENT)
                return;
 
+       if (crq->format == IBMVFC_VFC_NOOP) {
+               if (!ibmvfc_check_caps(vhost, IBMVFC_SUPPORT_NOOP_CMD))
+                       dev_err_ratelimited(vhost->dev,
+                                           "Received unexpected NOOP command 
from partner\n");
+               return;
+       }
+
        /* The only kind of payload CRQs we should get are responses to
         * things we send. Make sure this response is to something we
         * actually sent
diff --git a/drivers/scsi/ibmvscsi/ibmvfc.h b/drivers/scsi/ibmvscsi/ibmvfc.h
index 8eb1493cbac8..dd26248cac3e 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.h
+++ b/drivers/scsi/ibmvscsi/ibmvfc.h
@@ -180,6 +180,7 @@ struct ibmvfc_npiv_login {
 #define IBMVFC_CAN_HANDLE_FPIN         0x04
 #define IBMVFC_CAN_USE_MAD_VERSION     0x08
 #define IBMVFC_CAN_SEND_VF_WWPN                0x10
+#define IBMVFC_CAN_USE_NOOP_CMD                0x200
        __be64 node_name;
        struct srp_direct_buf async;
        u8 partition_name[IBMVFC_MAX_NAME];
@@ -226,6 +227,7 @@ struct ibmvfc_npiv_login_resp {
 #define IBMVFC_MAD_VERSION_CAP         0x20
 #define IBMVFC_HANDLE_VF_WWPN          0x40
 #define IBMVFC_CAN_SUPPORT_CHANNELS    0x80
+#define IBMVFC_SUPPORT_NOOP_CMD                0x1000
        __be32 max_cmds;
        __be32 scsi_id_sz;
        __be64 max_dma_len;
@@ -621,6 +623,7 @@ struct ibmvfc_trace_entry {
 enum ibmvfc_crq_formats {
        IBMVFC_CMD_FORMAT               = 0x01,
        IBMVFC_ASYNC_EVENT      = 0x02,
+       IBMVFC_VFC_NOOP         = 0x03,
        IBMVFC_MAD_FORMAT               = 0x04,
 };
 

-- 
2.54.0