Extend the meaning of the CTLFLAG_TUN flag to automatically check if

there is an environment variable which shall initialize the SYSCTL
during early boot. This works for all SYSCTL types both statically and
dynamically created ones, except for the SYSCTL NODE type and SYSCTLs
which belong to VNETs. A new flag, CTLFLAG_NOFETCH, has been added to
be used in the case a tunable sysctl has a custom initialisation
function allowing the sysctl to still be marked as a tunable. The
kernel SYSCTL API is mostly the same, with a few exceptions for some
special operations like iterating childrens of a static/extern SYSCTL
node. This operation should probably be made into a factored out
common macro, hence some device drivers use this. The reason for
changing the SYSCTL API was the need for a SYSCTL parent OID pointer
and not only the SYSCTL parent OID list pointer in order to quickly
generate the sysctl path. The motivation behind this patch is to avoid
parameter loading cludges inside the OFED driver subsystem. Instead of
adding special code to the OFED driver subsystem to post-load tunables
into dynamically created sysctls, we generalize this in the kernel.

Other changes:
- Corrected a possibly incorrect sysctl name from "hw.cbb.intr_mask"
to "hw.pcic.intr_mask".
- Removed redundant TUNABLE statements throughout the kernel.
- Some minor code rewrites in connection to removing not needed
TUNABLE statements.
- Added a missing SYSCTL_DECL().
- Wrapped two very long lines.
- Avoid malloc()/free() inside sysctl string handling, in case it is
called to initialize a sysctl from a tunable, hence malloc()/free() is
not ready when sysctls from the sysctl dataset are registered.
- Bumped FreeBSD version to indicate SYSCTL API change.

MFC after:	2 weeks
Sponsored by:	Mellanox Technologies

5 files changed, 12 insertions, 20 deletions

diff --git a/sys/cam/scsi/scsi_cd.c b/sys/cam/scsi/scsi_cd.c
index 81c29a6fb54c..47a5a438d294 100644
--- a/sys/cam/scsi/scsi_cd.c
+++ b/sys/cam/scsi/scsi_cd.c
@@ -277,15 +277,12 @@ static int cd_retry_count = CD_DEFAULT_RETRY;
 static int cd_timeout = CD_DEFAULT_TIMEOUT;
 
 static SYSCTL_NODE(_kern_cam, OID_AUTO, cd, CTLFLAG_RD, 0, "CAM CDROM driver");
-SYSCTL_INT(_kern_cam_cd, OID_AUTO, poll_period, CTLFLAG_RW,
+SYSCTL_INT(_kern_cam_cd, OID_AUTO, poll_period, CTLFLAG_RWTUN,
            &cd_poll_period, 0, "Media polling period in seconds");
-TUNABLE_INT("kern.cam.cd.poll_period", &cd_poll_period);
-SYSCTL_INT(_kern_cam_cd, OID_AUTO, retry_count, CTLFLAG_RW,
+SYSCTL_INT(_kern_cam_cd, OID_AUTO, retry_count, CTLFLAG_RWTUN,
            &cd_retry_count, 0, "Normal I/O retry count");
-TUNABLE_INT("kern.cam.cd.retry_count", &cd_retry_count);
-SYSCTL_INT(_kern_cam_cd, OID_AUTO, timeout, CTLFLAG_RW,
+SYSCTL_INT(_kern_cam_cd, OID_AUTO, timeout, CTLFLAG_RWTUN,
 	   &cd_timeout, 0, "Timeout, in us, for read operations");
-TUNABLE_INT("kern.cam.cd.timeout", &cd_timeout);
 
 static MALLOC_DEFINE(M_SCSICD, "scsi_cd", "scsi_cd buffers");
 
diff --git a/sys/cam/scsi/scsi_da.c b/sys/cam/scsi/scsi_da.c
index 1a0757702035..0b1f8d595e36 100644
--- a/sys/cam/scsi/scsi_da.c
+++ b/sys/cam/scsi/scsi_da.c
@@ -1188,18 +1188,14 @@ static int da_send_ordered = DA_DEFAULT_SEND_ORDERED;
 
 static SYSCTL_NODE(_kern_cam, OID_AUTO, da, CTLFLAG_RD, 0,
             "CAM Direct Access Disk driver");
-SYSCTL_INT(_kern_cam_da, OID_AUTO, poll_period, CTLFLAG_RW,
+SYSCTL_INT(_kern_cam_da, OID_AUTO, poll_period, CTLFLAG_RWTUN,
            &da_poll_period, 0, "Media polling period in seconds");
-TUNABLE_INT("kern.cam.da.poll_period", &da_poll_period);
-SYSCTL_INT(_kern_cam_da, OID_AUTO, retry_count, CTLFLAG_RW,
+SYSCTL_INT(_kern_cam_da, OID_AUTO, retry_count, CTLFLAG_RWTUN,
            &da_retry_count, 0, "Normal I/O retry count");
-TUNABLE_INT("kern.cam.da.retry_count", &da_retry_count);
-SYSCTL_INT(_kern_cam_da, OID_AUTO, default_timeout, CTLFLAG_RW,
+SYSCTL_INT(_kern_cam_da, OID_AUTO, default_timeout, CTLFLAG_RWTUN,
            &da_default_timeout, 0, "Normal I/O timeout (in seconds)");
-TUNABLE_INT("kern.cam.da.default_timeout", &da_default_timeout);
-SYSCTL_INT(_kern_cam_da, OID_AUTO, send_ordered, CTLFLAG_RW,
+SYSCTL_INT(_kern_cam_da, OID_AUTO, send_ordered, CTLFLAG_RWTUN,
            &da_send_ordered, 0, "Send Ordered Tags");
-TUNABLE_INT("kern.cam.da.send_ordered", &da_send_ordered);
 
 /*
  * DA_ORDEREDTAG_INTERVAL determines how often, relative
diff --git a/sys/cam/scsi/scsi_enc_safte.c b/sys/cam/scsi/scsi_enc_safte.c
index 8282d013bb58..89f70a5ada23 100644
--- a/sys/cam/scsi/scsi_enc_safte.c
+++ b/sys/cam/scsi/scsi_enc_safte.c
@@ -226,9 +226,8 @@ static char *safte_2little = "Too Little Data Returned (%d) at line %d\n";
 
 int emulate_array_devices = 1;
 SYSCTL_DECL(_kern_cam_enc);
-SYSCTL_INT(_kern_cam_enc, OID_AUTO, emulate_array_devices, CTLFLAG_RW,
+SYSCTL_INT(_kern_cam_enc, OID_AUTO, emulate_array_devices, CTLFLAG_RWTUN,
            &emulate_array_devices, 0, "Emulate Array Devices for SAF-TE");
-TUNABLE_INT("kern.cam.enc.emulate_array_devices", &emulate_array_devices);
 
 static int
 safte_fill_read_buf_io(enc_softc_t *enc, struct enc_fsm_state *state,
diff --git a/sys/cam/scsi/scsi_sa.c b/sys/cam/scsi/scsi_sa.c
index c1cd0f0bfdf6..16b7b149036f 100644
--- a/sys/cam/scsi/scsi_sa.c
+++ b/sys/cam/scsi/scsi_sa.c
@@ -445,9 +445,10 @@ static int sa_allow_io_split = SA_DEFAULT_IO_SPLIT;
  * is bad behavior, because it hides the true tape block size from the
  * application.
  */
-TUNABLE_INT("kern.cam.sa.allow_io_split", &sa_allow_io_split);
 static SYSCTL_NODE(_kern_cam, OID_AUTO, sa, CTLFLAG_RD, 0,
 		  "CAM Sequential Access Tape Driver");
+SYSCTL_INT(_kern_cam_sa, OID_AUTO, allow_io_split, CTLFLAG_RDTUN,
+    &sa_allow_io_split, 0, "Default I/O split value");
 
 static struct periph_driver sadriver =
 {
@@ -1494,7 +1495,7 @@ sasysctlinit(void *context, int pending)
 		goto bailout;
 
 	SYSCTL_ADD_INT(&softc->sysctl_ctx, SYSCTL_CHILDREN(softc->sysctl_tree),
-	    OID_AUTO, "allow_io_split", CTLTYPE_INT | CTLFLAG_RDTUN, 
+	    OID_AUTO, "allow_io_split", CTLTYPE_INT | CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 
 	    &softc->allow_io_split, 0, "Allow Splitting I/O");
 	SYSCTL_ADD_INT(&softc->sysctl_ctx, SYSCTL_CHILDREN(softc->sysctl_tree),
 	    OID_AUTO, "maxio", CTLTYPE_INT | CTLFLAG_RD, 
diff --git a/sys/cam/scsi/scsi_xpt.c b/sys/cam/scsi/scsi_xpt.c
index 942f7121cf5a..42b8774fd88a 100644
--- a/sys/cam/scsi/scsi_xpt.c
+++ b/sys/cam/scsi/scsi_xpt.c
@@ -78,9 +78,8 @@ struct scsi_quirk_entry {
 #define SCSI_QUIRK(dev)	((struct scsi_quirk_entry *)((dev)->quirk))
 
 static int cam_srch_hi = 0;
-TUNABLE_INT("kern.cam.cam_srch_hi", &cam_srch_hi);
 static int sysctl_cam_search_luns(SYSCTL_HANDLER_ARGS);
-SYSCTL_PROC(_kern_cam, OID_AUTO, cam_srch_hi, CTLTYPE_INT|CTLFLAG_RW, 0, 0,
+SYSCTL_PROC(_kern_cam, OID_AUTO, cam_srch_hi, CTLTYPE_INT | CTLFLAG_RWTUN, 0, 0,
     sysctl_cam_search_luns, "I",
     "allow search above LUN 7 for SCSI3 and greater devices");