[PATCH v2 3/6] ibmvfc: add helper for testing capability flags

Tyrel Datwyler
2020-11-17T19:17:13Z

Testing the NPIV Login response capabilities is a long winded process of
dereferencing the vhost->login_buf->resp.capabilities field byte
swapping that value to host endian and performing the bitwise test.
Currently we only ever check this in ibmvfc_cancel_all(), but follow-up
patches will need to regularly check for targetWWPN and channelization
support.

Add a helper to simplify checking various VIOS capabilities.

Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
---
drivers/scsi/ibmvscsi/ibmvfc.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
index d33b24668367..a68602cd1255 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc.c
@@ -138,6 +138,13 @@ static void ibmvfc_tgt_move_login(struct ibmvfc_target *);

static const char *unknown_error = "unknown error";

+static int ibmvfc_check_caps(struct ibmvfc_host *vhost, unsigned long cap_flags)
+{
+ u64 host_caps = be64_to_cpu(vhost->login_buf->resp.capabilities);
+
+ return (host_caps & cap_flags) ? 1 : 0;
+}
+
#ifdef CONFIG_SCSI_IBMVFC_TRACE
/**
* ibmvfc_trc_start - Log a start trace entry
@@ -2240,7 +2247,7 @@ static int ibmvfc_cancel_all(struct scsi_device *sdev, int type)
tmf->common.length = cpu_to_be16(sizeof(*tmf));
tmf->scsi_id = cpu_to_be64(rport->port_id);
int_to_scsilun(sdev->lun, &tmf->lun);
- if (!(be64_to_cpu(vhost->login_buf->resp.capabilities) & IBMVFC_CAN_SUPPRESS_ABTS))
+ if (!ibmvfc_check_caps(vhost, IBMVFC_CAN_SUPPRESS_ABTS))
type &= ~IBMVFC_TMF_SUPPRESS_ABTS;
if (vhost->state == IBMVFC_ACTIVE)
tmf->flags = cpu_to_be32((type | IBMVFC_TMF_LUA_VALID));
--
2.27.0