svn commit: r253160 - stable/9/sys/dev/ciss

[Sean Bruno]

Author: sbruno
Date: Wed Jul 10 17:16:10 2013
New Revision: 253160
URL: http://svnweb.freebsd.org/changeset/base/253160

Log:
  Jump on the 9.2r MFC bonanza and update ciss(4)
  
  r250031
   - zero a data structure for notifications
  
  r250022 r249977 r249947 r249908
   - handle cases of controllers advertising an sg_list of less than
     CISS_MAX_SG_ELEMENTS.  Fixes ciss(4) ZMR cases.

Modified:
  stable/9/sys/dev/ciss/ciss.c
Directory Properties:
  stable/9/sys/   (props changed)
  stable/9/sys/dev/   (props changed)

Modified: stable/9/sys/dev/ciss/ciss.c
==============================================================================
--- stable/9/sys/dev/ciss/ciss.c	Wed Jul 10 16:28:24 2013	(r253159)
+++ stable/9/sys/dev/ciss/ciss.c	Wed Jul 10 17:16:10 2013	(r253160)
@@ -2487,6 +2487,7 @@ ciss_preen_command(struct ciss_request *
     cc->header.sg_total = 0;
     cc->header.host_tag = cr->cr_tag << 2;
     cc->header.host_tag_zeroes = 0;
+    bzero(&(cc->sg[0]), CISS_COMMAND_ALLOC_SIZE - sizeof(struct ciss_command));
     cmdphys = cr->cr_ccphys;
     cc->error_info.error_info_address = cmdphys + sizeof(struct ciss_command);
     cc->error_info.error_info_length = CISS_COMMAND_ALLOC_SIZE - sizeof(struct ciss_command);
@@ -2985,6 +2986,7 @@ ciss_cam_action(struct cam_sim *sim, uni
     case XPT_PATH_INQ:
     {
 	struct ccb_pathinq	*cpi = &ccb->cpi;
+	int			sg_length;
 
 	debug(1, "XPT_PATH_INQ %d:%d:%d", cam_sim_bus(sim), ccb->ccb_h.target_id, ccb->ccb_h.target_lun);
 
@@ -3005,7 +3007,22 @@ ciss_cam_action(struct cam_sim *sim, uni
 	cpi->transport_version = 2;
 	cpi->protocol = PROTO_SCSI;
 	cpi->protocol_version = SCSI_REV_2;
-	cpi->maxio = (CISS_MAX_SG_ELEMENTS - 1) * PAGE_SIZE;
+	if (sc->ciss_cfg->max_sg_length == 0) {
+		sg_length = 17;
+	} else {
+	/* XXX Fix for ZMR cards that advertise max_sg_length == 32
+	 * Confusing bit here. max_sg_length is usually a power of 2. We always
+	 * need to subtract 1 to account for partial pages. Then we need to 
+	 * align on a valid PAGE_SIZE so we round down to the nearest power of 2. 
+	 * Add 1 so we can then subtract it out in the assignment to maxio.
+	 * The reason for all these shenanigans is to create a maxio value that
+	 * creates IO operations to volumes that yield consistent operations
+	 * with good performance.
+	 */
+		sg_length = sc->ciss_cfg->max_sg_length - 1;
+		sg_length = (1 << (fls(sg_length) - 1)) + 1;
+	}
+	cpi->maxio = (min(CISS_MAX_SG_ELEMENTS, sg_length) - 1) * PAGE_SIZE;
 	ccb->ccb_h.status = CAM_REQ_CMP;
 	break;
     }