Reintroduce bufqs. A few changes since it was backed out after some good

comments from dlg@.

No need for a separate bufq.h, keep all of in buf.h; As requested by kittens
and deraadt.

Only sd(4) and wd(4) for now. The rest of the drivers will be converted soon,
also other goodies like heuristics for sd(4) for selecting the bufq type and
the death of disksort() are forthcoming.

Tested on: i386, amd64, sparc64, macppc, loongson and alpha by myself and
phessler.

OK art@, beck@, kettenis@, oga@

2 files changed, 13 insertions, 12 deletions

diff --git a/sys/conf/files b/sys/conf/files
index 3cc13213774..4c9c5d674fb 100644
--- a/sys/conf/files
+++ b/sys/conf/files
@@ -1,4 +1,4 @@
-#	$OpenBSD: files,v 1.490 2010/05/11 09:37:13 claudio Exp $
+#	$OpenBSD: files,v 1.491 2010/05/26 16:16:23 thib Exp $
 #	$NetBSD: files,v 1.87 1996/05/19 17:17:50 jonathan Exp $
 
 #	@(#)files.newconf	7.5 (Berkeley) 5/10/93
@@ -692,6 +692,7 @@ file kern/exec_subr.c
 file kern/init_main.c
 file kern/init_sysent.c
 file kern/kern_acct.c			accounting
+file kern/kern_bufq.c
 file kern/kern_clock.c
 file kern/kern_descrip.c
 file kern/kern_event.c
diff --git a/sys/dev/ata/wd.c b/sys/dev/ata/wd.c
index 545236089f1..6b172b1a0e3 100644
--- a/sys/dev/ata/wd.c
+++ b/sys/dev/ata/wd.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: wd.c,v 1.82 2010/05/24 11:18:50 kettenis Exp $ */
+/*	$OpenBSD: wd.c,v 1.83 2010/05/26 16:16:23 thib Exp $ */
 /*	$NetBSD: wd.c,v 1.193 1999/02/28 17:15:27 explorer Exp $ */
 
 /*
@@ -70,6 +70,7 @@
 #include <sys/file.h>
 #include <sys/stat.h>
 #include <sys/ioctl.h>
+#include <sys/mutex.h>
 #include <sys/buf.h>
 #include <sys/uio.h>
 #include <sys/malloc.h>
@@ -120,7 +121,8 @@ struct wd_softc {
 	/* General disk infos */
 	struct device sc_dev;
 	struct disk sc_dk;
-	struct buf sc_q;
+	struct bufq	*sc_bufq;
+
 	/* IDE disk soft states */
 	struct ata_bio sc_wdc_bio; /* current transfer */
 	struct buf *sc_bp; /* buf being transferred */
@@ -367,6 +369,7 @@ wdattach(struct device *parent, struct device *self, void *aux)
 	 */
 	wd->sc_dk.dk_driver = &wddkdriver;
 	wd->sc_dk.dk_name = wd->sc_dev.dv_xname;
+	wd->sc_bufq = bufq_init(BUFQ_DEFAULT);
 	disk_attach(&wd->sc_dk);
 	wd->sc_wdc_bio.lp = wd->sc_dk.dk_label;
 	wd->sc_sdhook = shutdownhook_establish(wd_shutdown, wd);
@@ -403,13 +406,12 @@ int
 wddetach(struct device *self, int flags)
 {
 	struct wd_softc *sc = (struct wd_softc *)self;
-	struct buf *dp, *bp;
+	struct buf *bp;
 	int s, bmaj, cmaj, mn;
 
 	/* Remove unprocessed buffers from queue */
 	s = splbio();
-	for (dp = &sc->sc_q; (bp = dp->b_actf) != NULL; ) {
-		dp->b_actf = bp->b_actf;
+	while ((bp = BUFQ_DEQUEUE(sc->sc_bufq)) != NULL) {
 		bp->b_error = ENXIO;
 		bp->b_flags |= B_ERROR;
 		biodone(bp);
@@ -431,6 +433,7 @@ wddetach(struct device *self, int flags)
 		shutdownhook_disestablish(sc->sc_sdhook);
 
 	/* Detach disk. */
+	bufq_destroy(sc->sc_bufq);
 	disk_detach(&sc->sc_dk);
 
 	return (0);
@@ -481,8 +484,8 @@ wdstrategy(struct buf *bp)
 	    (wd->sc_flags & (WDF_WLABEL|WDF_LABELLING)) != 0) <= 0)
 		goto done;
 	/* Queue transfer on drive, activate drive and controller if idle. */
+	BUFQ_QUEUE(wd->sc_bufq, bp);
 	s = splbio();
-	disksort(&wd->sc_q, bp);
 	wdstart(wd);
 	splx(s);
 	device_unref(&wd->sc_dev);
@@ -506,18 +509,15 @@ void
 wdstart(void *arg)
 {
 	struct wd_softc *wd = arg;
-	struct buf *dp, *bp = NULL;
+	struct buf *bp = NULL;
 
 	WDCDEBUG_PRINT(("wdstart %s\n", wd->sc_dev.dv_xname),
 	    DEBUG_XFERS);
 	while (wd->openings > 0) {
 
 		/* Is there a buf for us ? */
-		dp = &wd->sc_q;
-		if ((bp = dp->b_actf) == NULL)  /* yes, an assign */
+		if ((bp = BUFQ_DEQUEUE(wd->sc_bufq)) == NULL)
 			return;
-		dp->b_actf = bp->b_actf;
-
 		/*
 		 * Make the command. First lock the device
 		 */