- Add a new ioctl to get the maximum number of ATA channels.

- Use it in atacontrol(8) when listing ATA devices instead of
  stopping at the first ENXIO received.

This makes atacontrol list work on my sparc64 where the two ATA
channels I have are numbered 2 and 3.

Reviewed by:	sos

sbin/atacontrol/atacontrol.c

@@ -249,7 +249,7 @@ int
 main(int argc, char **argv)
 {
 	struct ata_cmd iocmd;
-	int fd;
+	int fd, maxunit, unit;
 
 	if ((fd = open("/dev/ata", O_RDWR)) < 0)
 		err(1, "control device not found");
@@ -278,9 +278,12 @@ main(int argc, char **argv)
 	}
 
 	if (!strcmp(argv[1], "list") && argc == 2) {
-		int unit = 0;
-
-		while (info_print(fd, unit++, 1) != ENXIO);
+		iocmd.cmd = ATAGMAXCHANNEL;
+		if (ioctl(fd, IOCATA, &iocmd) < 0)
+			err(1, "ioctl(ATAGMAXCHANNEL)");
+		maxunit = iocmd.u.maxchan;
+		for (unit = 0; unit < maxunit; unit++)
+			info_print(fd, unit, 1);
 	}
 	else if (!strcmp(argv[1], "info") && argc == 3) {
 		info_print(fd, iocmd.channel, 0);

sys/dev/ata/ata-all.c

@@ -304,6 +304,11 @@ ataioctl(dev_t dev, u_long cmd, caddr_t addr, int32_t flag, struct thread *td)
     if (cmd != IOCATA)
 	return ENOTTY;
     
+    if (iocmd->cmd == ATAGMAXCHANNEL) {
+	iocmd->u.maxchan = devclass_get_maxunit(ata_devclass);
+	return 0;
+    }
+
     if (iocmd->channel < -1 || iocmd->device < -1 || iocmd->device > SLAVE)
 	return ENXIO;
 

sys/sys/ata.h

@@ -369,6 +369,7 @@ struct ata_cmd {
 #define ATARAIDDELETE		10
 #define ATARAIDSTATUS		11
 #define ATAENCSTAT		12
+#define ATAGMAXCHANNEL		13
 
     union {
 	struct {
@@ -421,6 +422,7 @@ struct ata_cmd {
 	    int			error;
 	    char		sense_data[18];
 	} atapi;
+	int			maxchan;
     } u;
 };