Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted

Pull I3C updates from Alexandre Belloni:
 "A new driver this cycle, for the AMD AXI I3C controller.

  There are also new features such as IBI wakeup support, SETAASA device
  discovery and ACPI support for the the DAA methods, meaning we can now
  communicate with the SPD devices on DDR5 modules.

  New driver:
   - AMD AXI I3C master controller

  Subsystem:
   - I3C Common Command Code (CCC) handling improvements, especially
     around GET CCCs
   - SETAASA device discovery support
   - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
     well as I2C devices on I3C bus
   - IBI-based wakeup support

  Drivers:
   - dw: SETAASA support
   - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
     controller support, PIO queue management support for HCI v1.2
   - renesas: improve suspend to RAM support, add runtime PM support"

* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
  i3c: dw: reduce do_daa time if there's no client
  i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
  i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
  i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
  i3c: dw: rename "pclk" to "apb" to match dt-binding
  i3c: dw: make struct dw_i3c_cmd smaller
  i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
  i3c: renesas: Don't register devices when ENTDAA times out
  i3c: master: dw-i3c-master: fix OD timing for first broadcast
  i3c: mipi-i3c-hci: Advertise IBI wakeup capability
  i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
  i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
  i3c: master: Reject IBI requests from non-IBI-capable devices
  i3c: master: Add helper to query bus wakeup requirements
  i3c: master: Report wakeup events for IBIs
  i3c: master: Support IBI-based wakeup capability
  i3c: master: Fix potential UAF in i3c_device_match()
  i3c: master: Fix potential UAF in i3c_device_uevent()
  i3c: Make dev->desc locking assumptions explicit
  i3c: master: Fix use-after-free of master->this
  ...

1 files changed, 1037 insertions, 0 deletions

diff --git a/drivers/scsi/ch.c b/drivers/scsi/ch.c
new file mode 100644
index 000000000..4010fdbf8
--- /dev/null
+++ b/drivers/scsi/ch.c
@@ -0,0 +1,1037 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * SCSI Media Changer device driver for Linux 2.6
+ *
+ *     (c) 1996-2003 Gerd Knorr <kraxel@bytesex.org>
+ *
+ */
+
+#define VERSION "0.25"
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/major.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/blkdev.h>
+#include <linux/completion.h>
+#include <linux/compat.h>
+#include <linux/chio.h>			/* here are all the ioctls */
+#include <linux/mutex.h>
+#include <linux/idr.h>
+#include <linux/slab.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_driver.h>
+#include <scsi/scsi_ioctl.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_eh.h>
+#include <scsi/scsi_dbg.h>
+
+#define CH_DT_MAX       16
+#define CH_TYPES        8
+#define CH_MAX_DEVS     128
+
+MODULE_DESCRIPTION("device driver for scsi media changer devices");
+MODULE_AUTHOR("Gerd Knorr <kraxel@bytesex.org>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_CHARDEV_MAJOR(SCSI_CHANGER_MAJOR);
+MODULE_ALIAS_SCSI_DEVICE(TYPE_MEDIUM_CHANGER);
+
+static int init = 1;
+module_param(init, int, 0444);
+MODULE_PARM_DESC(init, \
+    "initialize element status on driver load (default: on)");
+
+static int timeout_move = 300;
+module_param(timeout_move, int, 0644);
+MODULE_PARM_DESC(timeout_move,"timeout for move commands "
+		 "(default: 300 seconds)");
+
+static int timeout_init = 3600;
+module_param(timeout_init, int, 0644);
+MODULE_PARM_DESC(timeout_init,"timeout for INITIALIZE ELEMENT STATUS "
+		 "(default: 3600 seconds)");
+
+static int verbose = 1;
+module_param(verbose, int, 0644);
+MODULE_PARM_DESC(verbose,"be verbose (default: on)");
+
+static int debug;
+module_param(debug, int, 0644);
+MODULE_PARM_DESC(debug,"enable/disable debug messages, also prints more "
+		 "detailed sense codes on scsi errors (default: off)");
+
+static int dt_id[CH_DT_MAX] = { [ 0 ... (CH_DT_MAX-1) ] = -1 };
+static int dt_lun[CH_DT_MAX];
+module_param_array(dt_id,  int, NULL, 0444);
+module_param_array(dt_lun, int, NULL, 0444);
+
+/* tell the driver about vendor-specific slots */
+static int vendor_firsts[CH_TYPES-4];
+static int vendor_counts[CH_TYPES-4];
+module_param_array(vendor_firsts, int, NULL, 0444);
+module_param_array(vendor_counts, int, NULL, 0444);
+
+static const char * vendor_labels[CH_TYPES-4] = {
+	"v0", "v1", "v2", "v3"
+};
+// module_param_string_array(vendor_labels, NULL, 0444);
+
+#define ch_printk(prefix, ch, fmt, a...) \
+	sdev_prefix_printk(prefix, (ch)->device, (ch)->name, fmt, ##a)
+
+#define DPRINTK(fmt, arg...)						\
+do {									\
+	if (debug)							\
+		ch_printk(KERN_DEBUG, ch, fmt, ##arg);			\
+} while (0)
+#define VPRINTK(level, fmt, arg...)					\
+do {									\
+	if (verbose)							\
+		ch_printk(level, ch, fmt, ##arg);			\
+} while (0)
+
+/* ------------------------------------------------------------------- */
+
+#define MAX_RETRIES   1
+
+static const struct class ch_sysfs_class = {
+	.name = "scsi_changer",
+};
+
+typedef struct {
+	struct kref         ref;
+	struct list_head    list;
+	int                 minor;
+	char                name[8];
+	struct scsi_device  *device;
+	struct scsi_device  **dt;        /* ptrs to data transfer elements */
+	u_int               firsts[CH_TYPES];
+	u_int               counts[CH_TYPES];
+	u_int		    voltags;
+	struct mutex	    lock;
+} scsi_changer;
+
+static DEFINE_IDR(ch_index_idr);
+static DEFINE_SPINLOCK(ch_index_lock);
+
+static const struct {
+	unsigned char  sense;
+	unsigned char  asc;
+	unsigned char  ascq;
+	int	       errno;
+} ch_err[] = {
+/* Just filled in what looks right. Hav'nt checked any standard paper for
+   these errno assignments, so they may be wrong... */
+	{
+		.sense  = ILLEGAL_REQUEST,
+		.asc    = 0x21,
+		.ascq   = 0x01,
+		.errno  = EBADSLT, /* Invalid element address */
+	},{
+		.sense  = ILLEGAL_REQUEST,
+		.asc    = 0x28,
+		.ascq   = 0x01,
+		.errno  = EBADE,   /* Import or export element accessed */
+	},{
+		.sense  = ILLEGAL_REQUEST,
+		.asc    = 0x3B,
+		.ascq   = 0x0D,
+		.errno  = EXFULL,  /* Medium destination element full */
+	},{
+		.sense  = ILLEGAL_REQUEST,
+		.asc    = 0x3B,
+		.ascq   = 0x0E,
+		.errno  = EBADE,   /* Medium source element empty */
+	},{
+		.sense  = ILLEGAL_REQUEST,
+		.asc    = 0x20,
+		.ascq   = 0x00,
+		.errno  = EBADRQC, /* Invalid command operation code */
+	},{
+	        /* end of list */
+	}
+};
+
+/* ------------------------------------------------------------------- */
+
+static int ch_find_errno(struct scsi_sense_hdr *sshdr)
+{
+	int i,errno = 0;
+
+	/* Check to see if additional sense information is available */
+	if (scsi_sense_valid(sshdr) &&
+	    sshdr->asc != 0) {
+		for (i = 0; ch_err[i].errno != 0; i++) {
+			if (ch_err[i].sense == sshdr->sense_key &&
+			    ch_err[i].asc   == sshdr->asc &&
+			    ch_err[i].ascq  == sshdr->ascq) {
+				errno = -ch_err[i].errno;
+				break;
+			}
+		}
+	}
+	if (errno == 0)
+		errno = -EIO;
+	return errno;
+}
+
+static int
+ch_do_scsi(scsi_changer *ch, unsigned char *cmd, int cmd_len,
+	   void *buffer, unsigned int buflength, enum req_op op)
+{
+	int errno = 0, timeout, result;
+	struct scsi_sense_hdr sshdr;
+	struct scsi_failure failure_defs[] = {
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = SCMD_FAILURE_ASC_ANY,
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.allowed = 3,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = failure_defs,
+	};
+	const struct scsi_exec_args exec_args = {
+		.sshdr = &sshdr,
+		.failures = &failures,
+	};
+
+	timeout = (cmd[0] == INITIALIZE_ELEMENT_STATUS)
+		? timeout_init : timeout_move;
+
+	result = scsi_execute_cmd(ch->device, cmd, op, buffer, buflength,
+				  timeout * HZ, MAX_RETRIES, &exec_args);
+	if (result < 0)
+		return result;
+	if (scsi_sense_valid(&sshdr)) {
+		if (debug)
+			scsi_print_sense_hdr(ch->device, ch->name, &sshdr);
+		errno = ch_find_errno(&sshdr);
+	}
+	return errno;
+}
+
+/* ------------------------------------------------------------------------ */
+
+static int
+ch_elem_to_typecode(scsi_changer *ch, u_int elem)
+{
+	int i;
+
+	for (i = 0; i < CH_TYPES; i++) {
+		if (elem >= ch->firsts[i]  &&
+		    elem <  ch->firsts[i] +
+	            ch->counts[i])
+			return i+1;
+	}
+	return 0;
+}
+
+static int
+ch_read_element_status(scsi_changer *ch, u_int elem, char *data)
+{
+	u_char  cmd[12];
+	u_char  *buffer;
+	int     result;
+
+	buffer = kmalloc(512, GFP_KERNEL);
+	if(!buffer)
+		return -ENOMEM;
+
+ retry:
+	memset(cmd,0,sizeof(cmd));
+	cmd[0] = READ_ELEMENT_STATUS;
+	cmd[1] = ((ch->device->lun & 0x7) << 5) |
+		(ch->voltags ? 0x10 : 0) |
+		ch_elem_to_typecode(ch,elem);
+	cmd[2] = (elem >> 8) & 0xff;
+	cmd[3] = elem        & 0xff;
+	cmd[5] = 1;
+	cmd[9] = 255;
+	if (0 == (result = ch_do_scsi(ch, cmd, 12,
+				      buffer, 256, REQ_OP_DRV_IN))) {
+		if (((buffer[16] << 8) | buffer[17]) != elem) {
+			DPRINTK("asked for element 0x%02x, got 0x%02x\n",
+				elem,(buffer[16] << 8) | buffer[17]);
+			kfree(buffer);
+			return -EIO;
+		}
+		memcpy(data,buffer+16,16);
+	} else {
+		if (ch->voltags) {
+			ch->voltags = 0;
+			VPRINTK(KERN_INFO, "device has no volume tag support\n");
+			goto retry;
+		}
+		DPRINTK("READ ELEMENT STATUS for element 0x%x failed\n",elem);
+	}
+	kfree(buffer);
+	return result;
+}
+
+static int
+ch_init_elem(scsi_changer *ch)
+{
+	int err;
+	u_char cmd[6];
+
+	VPRINTK(KERN_INFO, "INITIALIZE ELEMENT STATUS, may take some time ...\n");
+	memset(cmd,0,sizeof(cmd));
+	cmd[0] = INITIALIZE_ELEMENT_STATUS;
+	cmd[1] = (ch->device->lun & 0x7) << 5;
+	err = ch_do_scsi(ch, cmd, 6, NULL, 0, REQ_OP_DRV_IN);
+	VPRINTK(KERN_INFO, "... finished\n");
+	return err;
+}
+
+static int
+ch_readconfig(scsi_changer *ch)
+{
+	u_char  cmd[10], data[16];
+	u_char  *buffer;
+	int     result,id,lun,i;
+	u_int   elem;
+
+	buffer = kzalloc(512, GFP_KERNEL);
+	if (!buffer)
+		return -ENOMEM;
+
+	memset(cmd,0,sizeof(cmd));
+	cmd[0] = MODE_SENSE;
+	cmd[1] = (ch->device->lun & 0x7) << 5;
+	cmd[2] = 0x1d;
+	cmd[4] = 255;
+	result = ch_do_scsi(ch, cmd, 10, buffer, 255, REQ_OP_DRV_IN);
+	if (0 != result) {
+		cmd[1] |= (1<<3);
+		result  = ch_do_scsi(ch, cmd, 10, buffer, 255, REQ_OP_DRV_IN);
+	}
+	if (0 == result) {
+		ch->firsts[CHET_MT] =
+			(buffer[buffer[3]+ 6] << 8) | buffer[buffer[3]+ 7];
+		ch->counts[CHET_MT] =
+			(buffer[buffer[3]+ 8] << 8) | buffer[buffer[3]+ 9];
+		ch->firsts[CHET_ST] =
+			(buffer[buffer[3]+10] << 8) | buffer[buffer[3]+11];
+		ch->counts[CHET_ST] =
+			(buffer[buffer[3]+12] << 8) | buffer[buffer[3]+13];
+		ch->firsts[CHET_IE] =
+			(buffer[buffer[3]+14] << 8) | buffer[buffer[3]+15];
+		ch->counts[CHET_IE] =
+			(buffer[buffer[3]+16] << 8) | buffer[buffer[3]+17];
+		ch->firsts[CHET_DT] =
+			(buffer[buffer[3]+18] << 8) | buffer[buffer[3]+19];
+		ch->counts[CHET_DT] =
+			(buffer[buffer[3]+20] << 8) | buffer[buffer[3]+21];
+		VPRINTK(KERN_INFO, "type #1 (mt): 0x%x+%d [medium transport]\n",
+			ch->firsts[CHET_MT],
+			ch->counts[CHET_MT]);
+		VPRINTK(KERN_INFO, "type #2 (st): 0x%x+%d [storage]\n",
+			ch->firsts[CHET_ST],
+			ch->counts[CHET_ST]);
+		VPRINTK(KERN_INFO, "type #3 (ie): 0x%x+%d [import/export]\n",
+			ch->firsts[CHET_IE],
+			ch->counts[CHET_IE]);
+		VPRINTK(KERN_INFO, "type #4 (dt): 0x%x+%d [data transfer]\n",
+			ch->firsts[CHET_DT],
+			ch->counts[CHET_DT]);
+	} else {
+		VPRINTK(KERN_INFO, "reading element address assignment page failed!\n");
+	}
+
+	/* vendor specific element types */
+	for (i = 0; i < 4; i++) {
+		if (0 == vendor_counts[i])
+			continue;
+		if (NULL == vendor_labels[i])
+			continue;
+		ch->firsts[CHET_V1+i] = vendor_firsts[i];
+		ch->counts[CHET_V1+i] = vendor_counts[i];
+		VPRINTK(KERN_INFO, "type #%d (v%d): 0x%x+%d [%s, vendor specific]\n",
+			i+5,i+1,vendor_firsts[i],vendor_counts[i],
+			vendor_labels[i]);
+	}
+
+	/* look up the devices of the data transfer elements */
+	ch->dt = kzalloc_objs(*ch->dt, ch->counts[CHET_DT]);
+
+	if (!ch->dt) {
+		kfree(buffer);
+		return -ENOMEM;
+	}
+
+	for (elem = 0; elem < ch->counts[CHET_DT]; elem++) {
+		id  = -1;
+		lun = 0;
+		if (elem < CH_DT_MAX  &&  -1 != dt_id[elem]) {
+			id  = dt_id[elem];
+			lun = dt_lun[elem];
+			VPRINTK(KERN_INFO, "dt 0x%x: [insmod option] ",
+				elem+ch->firsts[CHET_DT]);
+		} else if (0 != ch_read_element_status
+			   (ch,elem+ch->firsts[CHET_DT],data)) {
+			VPRINTK(KERN_INFO, "dt 0x%x: READ ELEMENT STATUS failed\n",
+				elem+ch->firsts[CHET_DT]);
+		} else {
+			VPRINTK(KERN_INFO, "dt 0x%x: ",elem+ch->firsts[CHET_DT]);
+			if (data[6] & 0x80) {
+				VPRINTK(KERN_CONT, "not this SCSI bus\n");
+				ch->dt[elem] = NULL;
+			} else if (0 == (data[6] & 0x30)) {
+				VPRINTK(KERN_CONT, "ID/LUN unknown\n");
+				ch->dt[elem] = NULL;
+			} else {
+				id  = ch->device->id;
+				lun = 0;
+				if (data[6] & 0x20) id  = data[7];
+				if (data[6] & 0x10) lun = data[6] & 7;
+			}
+		}
+		if (-1 != id) {
+			VPRINTK(KERN_CONT, "ID %i, LUN %i, ",id,lun);
+			ch->dt[elem] =
+				scsi_device_lookup(ch->device->host,
+						   ch->device->channel,
+						   id,lun);
+			if (!ch->dt[elem]) {
+				/* should not happen */
+				VPRINTK(KERN_CONT, "Huh? device not found!\n");
+			} else {
+				VPRINTK(KERN_CONT, "name: %8.8s %16.16s %4.4s\n",
+					ch->dt[elem]->vendor,
+					ch->dt[elem]->model,
+					ch->dt[elem]->rev);
+			}
+		}
+	}
+	ch->voltags = 1;
+	kfree(buffer);
+
+	return 0;
+}
+
+/* ------------------------------------------------------------------------ */
+
+static int
+ch_position(scsi_changer *ch, u_int trans, u_int elem, int rotate)
+{
+	u_char  cmd[10];
+
+	DPRINTK("position: 0x%x\n",elem);
+	if (0 == trans)
+		trans = ch->firsts[CHET_MT];
+	memset(cmd,0,sizeof(cmd));
+	cmd[0]  = POSITION_TO_ELEMENT;
+	cmd[1]  = (ch->device->lun & 0x7) << 5;
+	cmd[2]  = (trans >> 8) & 0xff;
+	cmd[3]  =  trans       & 0xff;
+	cmd[4]  = (elem  >> 8) & 0xff;
+	cmd[5]  =  elem        & 0xff;
+	cmd[8]  = rotate ? 1 : 0;
+	return ch_do_scsi(ch, cmd, 10, NULL, 0, REQ_OP_DRV_IN);
+}
+
+static int
+ch_move(scsi_changer *ch, u_int trans, u_int src, u_int dest, int rotate)
+{
+	u_char  cmd[12];
+
+	DPRINTK("move: 0x%x => 0x%x\n",src,dest);
+	if (0 == trans)
+		trans = ch->firsts[CHET_MT];
+	memset(cmd,0,sizeof(cmd));
+	cmd[0]  = MOVE_MEDIUM;
+	cmd[1]  = (ch->device->lun & 0x7) << 5;
+	cmd[2]  = (trans >> 8) & 0xff;
+	cmd[3]  =  trans       & 0xff;
+	cmd[4]  = (src   >> 8) & 0xff;
+	cmd[5]  =  src         & 0xff;
+	cmd[6]  = (dest  >> 8) & 0xff;
+	cmd[7]  =  dest        & 0xff;
+	cmd[10] = rotate ? 1 : 0;
+	return ch_do_scsi(ch, cmd, 12, NULL, 0, REQ_OP_DRV_IN);
+}
+
+static int
+ch_exchange(scsi_changer *ch, u_int trans, u_int src,
+	    u_int dest1, u_int dest2, int rotate1, int rotate2)
+{
+	u_char  cmd[12];
+
+	DPRINTK("exchange: 0x%x => 0x%x => 0x%x\n",
+		src,dest1,dest2);
+	if (0 == trans)
+		trans = ch->firsts[CHET_MT];
+	memset(cmd,0,sizeof(cmd));
+	cmd[0]  = EXCHANGE_MEDIUM;
+	cmd[1]  = (ch->device->lun & 0x7) << 5;
+	cmd[2]  = (trans >> 8) & 0xff;
+	cmd[3]  =  trans       & 0xff;
+	cmd[4]  = (src   >> 8) & 0xff;
+	cmd[5]  =  src         & 0xff;
+	cmd[6]  = (dest1 >> 8) & 0xff;
+	cmd[7]  =  dest1       & 0xff;
+	cmd[8]  = (dest2 >> 8) & 0xff;
+	cmd[9]  =  dest2       & 0xff;
+	cmd[10] = (rotate1 ? 1 : 0) | (rotate2 ? 2 : 0);
+
+	return ch_do_scsi(ch, cmd, 12, NULL, 0, REQ_OP_DRV_IN);
+}
+
+static void
+ch_check_voltag(char *tag)
+{
+	int i;
+
+	for (i = 0; i < 32; i++) {
+		/* restrict to ascii */
+		if (tag[i] >= 0x7f || tag[i] < 0x20)
+			tag[i] = ' ';
+		/* don't allow search wildcards */
+		if (tag[i] == '?' ||
+		    tag[i] == '*')
+			tag[i] = ' ';
+	}
+}
+
+static int
+ch_set_voltag(scsi_changer *ch, u_int elem,
+	      int alternate, int clear, u_char *tag)
+{
+	u_char  cmd[12];
+	u_char  *buffer;
+	int result;
+
+	buffer = kzalloc(512, GFP_KERNEL);
+	if (!buffer)
+		return -ENOMEM;
+
+	DPRINTK("%s %s voltag: 0x%x => \"%s\"\n",
+		clear     ? "clear"     : "set",
+		alternate ? "alternate" : "primary",
+		elem, tag);
+	memset(cmd,0,sizeof(cmd));
+	cmd[0]  = SEND_VOLUME_TAG;
+	cmd[1] = ((ch->device->lun & 0x7) << 5) |
+		ch_elem_to_typecode(ch,elem);
+	cmd[2] = (elem >> 8) & 0xff;
+	cmd[3] = elem        & 0xff;
+	cmd[5] = clear
+		? (alternate ? 0x0d : 0x0c)
+		: (alternate ? 0x0b : 0x0a);
+
+	cmd[9] = 255;
+
+	memcpy(buffer,tag,32);
+	ch_check_voltag(buffer);
+
+	result = ch_do_scsi(ch, cmd, 12, buffer, 256, REQ_OP_DRV_OUT);
+	kfree(buffer);
+	return result;
+}
+
+static int ch_gstatus(scsi_changer *ch, int type, unsigned char __user *dest)
+{
+	int retval = 0;
+	u_char data[16];
+	unsigned int i;
+
+	mutex_lock(&ch->lock);
+	for (i = 0; i < ch->counts[type]; i++) {
+		if (0 != ch_read_element_status
+		    (ch, ch->firsts[type]+i,data)) {
+			retval = -EIO;
+			break;
+		}
+		put_user(data[2], dest+i);
+		if (data[2] & CESTATUS_EXCEPT)
+			VPRINTK(KERN_INFO, "element 0x%x: asc=0x%x, ascq=0x%x\n",
+				ch->firsts[type]+i,
+				(int)data[4],(int)data[5]);
+		retval = ch_read_element_status
+			(ch, ch->firsts[type]+i,data);
+		if (0 != retval)
+			break;
+	}
+	mutex_unlock(&ch->lock);
+	return retval;
+}
+
+/* ------------------------------------------------------------------------ */
+
+static void ch_destroy(struct kref *ref)
+{
+	scsi_changer *ch = container_of(ref, scsi_changer, ref);
+
+	ch->device = NULL;
+	kfree(ch->dt);
+	kfree(ch);
+}
+
+static int
+ch_release(struct inode *inode, struct file *file)
+{
+	scsi_changer *ch = file->private_data;
+
+	scsi_device_put(ch->device);
+	file->private_data = NULL;
+	kref_put(&ch->ref, ch_destroy);
+	return 0;
+}
+
+static int
+ch_open(struct inode *inode, struct file *file)
+{
+	scsi_changer *ch;
+	int minor = iminor(inode);
+
+	spin_lock(&ch_index_lock);
+	ch = idr_find(&ch_index_idr, minor);
+
+	if (ch == NULL || !kref_get_unless_zero(&ch->ref)) {
+		spin_unlock(&ch_index_lock);
+		return -ENXIO;
+	}
+	spin_unlock(&ch_index_lock);
+	if (scsi_device_get(ch->device)) {
+		kref_put(&ch->ref, ch_destroy);
+		return -ENXIO;
+	}
+	/* Synchronize with ch_probe() */
+	mutex_lock(&ch->lock);
+	file->private_data = ch;
+	mutex_unlock(&ch->lock);
+	return 0;
+}
+
+static int
+ch_checkrange(scsi_changer *ch, unsigned int type, unsigned int unit)
+{
+	if (type >= CH_TYPES  ||  unit >= ch->counts[type])
+		return -1;
+	return 0;
+}
+
+struct changer_element_status32 {
+	int		ces_type;
+	compat_uptr_t	ces_data;
+};
+#define CHIOGSTATUS32  _IOW('c', 8, struct changer_element_status32)
+
+static long ch_ioctl(struct file *file,
+		    unsigned int cmd, unsigned long arg)
+{
+	scsi_changer *ch = file->private_data;
+	int retval;
+	void __user *argp = (void __user *)arg;
+
+	retval = scsi_ioctl_block_when_processing_errors(ch->device, cmd,
+			file->f_flags & O_NDELAY);
+	if (retval)
+		return retval;
+
+	switch (cmd) {
+	case CHIOGPARAMS:
+	{
+		struct changer_params params;
+
+		params.cp_curpicker = 0;
+		params.cp_npickers  = ch->counts[CHET_MT];
+		params.cp_nslots    = ch->counts[CHET_ST];
+		params.cp_nportals  = ch->counts[CHET_IE];
+		params.cp_ndrives   = ch->counts[CHET_DT];
+
+		if (copy_to_user(argp, &params, sizeof(params)))
+			return -EFAULT;
+		return 0;
+	}
+	case CHIOGVPARAMS:
+	{
+		struct changer_vendor_params vparams;
+
+		memset(&vparams,0,sizeof(vparams));
+		if (ch->counts[CHET_V1]) {
+			vparams.cvp_n1  = ch->counts[CHET_V1];
+			strscpy(vparams.cvp_label1, vendor_labels[0],
+				sizeof(vparams.cvp_label1));
+		}
+		if (ch->counts[CHET_V2]) {
+			vparams.cvp_n2  = ch->counts[CHET_V2];
+			strscpy(vparams.cvp_label2, vendor_labels[1],
+				sizeof(vparams.cvp_label2));
+		}
+		if (ch->counts[CHET_V3]) {
+			vparams.cvp_n3  = ch->counts[CHET_V3];
+			strscpy(vparams.cvp_label3, vendor_labels[2],
+				sizeof(vparams.cvp_label3));
+		}
+		if (ch->counts[CHET_V4]) {
+			vparams.cvp_n4  = ch->counts[CHET_V4];
+			strscpy(vparams.cvp_label4, vendor_labels[3],
+				sizeof(vparams.cvp_label4));
+		}
+		if (copy_to_user(argp, &vparams, sizeof(vparams)))
+			return -EFAULT;
+		return 0;
+	}
+
+	case CHIOPOSITION:
+	{
+		struct changer_position pos;
+
+		if (copy_from_user(&pos, argp, sizeof (pos)))
+			return -EFAULT;
+
+		if (0 != ch_checkrange(ch, pos.cp_type, pos.cp_unit)) {
+			DPRINTK("CHIOPOSITION: invalid parameter\n");
+			return -EBADSLT;
+		}
+		mutex_lock(&ch->lock);
+		retval = ch_position(ch,0,
+				     ch->firsts[pos.cp_type] + pos.cp_unit,
+				     pos.cp_flags & CP_INVERT);
+		mutex_unlock(&ch->lock);
+		return retval;
+	}
+
+	case CHIOMOVE:
+	{
+		struct changer_move mv;
+
+		if (copy_from_user(&mv, argp, sizeof (mv)))
+			return -EFAULT;
+
+		if (0 != ch_checkrange(ch, mv.cm_fromtype, mv.cm_fromunit) ||
+		    0 != ch_checkrange(ch, mv.cm_totype,   mv.cm_tounit  )) {
+			DPRINTK("CHIOMOVE: invalid parameter\n");
+			return -EBADSLT;
+		}
+
+		mutex_lock(&ch->lock);
+		retval = ch_move(ch,0,
+				 ch->firsts[mv.cm_fromtype] + mv.cm_fromunit,
+				 ch->firsts[mv.cm_totype]   + mv.cm_tounit,
+				 mv.cm_flags & CM_INVERT);
+		mutex_unlock(&ch->lock);
+		return retval;
+	}
+
+	case CHIOEXCHANGE:
+	{
+		struct changer_exchange mv;
+
+		if (copy_from_user(&mv, argp, sizeof (mv)))
+			return -EFAULT;
+
+		if (0 != ch_checkrange(ch, mv.ce_srctype,  mv.ce_srcunit ) ||
+		    0 != ch_checkrange(ch, mv.ce_fdsttype, mv.ce_fdstunit) ||
+		    0 != ch_checkrange(ch, mv.ce_sdsttype, mv.ce_sdstunit)) {
+			DPRINTK("CHIOEXCHANGE: invalid parameter\n");
+			return -EBADSLT;
+		}
+
+		mutex_lock(&ch->lock);
+		retval = ch_exchange
+			(ch,0,
+			 ch->firsts[mv.ce_srctype]  + mv.ce_srcunit,
+			 ch->firsts[mv.ce_fdsttype] + mv.ce_fdstunit,
+			 ch->firsts[mv.ce_sdsttype] + mv.ce_sdstunit,
+			 mv.ce_flags & CE_INVERT1, mv.ce_flags & CE_INVERT2);
+		mutex_unlock(&ch->lock);
+		return retval;
+	}
+
+	case CHIOGSTATUS:
+	{
+		struct changer_element_status ces;
+
+		if (copy_from_user(&ces, argp, sizeof (ces)))
+			return -EFAULT;
+		if (ces.ces_type < 0 || ces.ces_type >= CH_TYPES)
+			return -EINVAL;
+
+		return ch_gstatus(ch, ces.ces_type, ces.ces_data);
+	}
+#ifdef CONFIG_COMPAT
+	case CHIOGSTATUS32:
+	{
+		struct changer_element_status32 ces32;
+
+		if (copy_from_user(&ces32, argp, sizeof(ces32)))
+			return -EFAULT;
+		if (ces32.ces_type < 0 || ces32.ces_type >= CH_TYPES)
+			return -EINVAL;
+
+		return ch_gstatus(ch, ces32.ces_type,
+				  compat_ptr(ces32.ces_data));
+	}
+#endif
+	case CHIOGELEM:
+	{
+		struct changer_get_element cge;
+		u_char ch_cmd[12];
+		u_char *buffer;
+		unsigned int elem;
+		int     result,i;
+
+		if (copy_from_user(&cge, argp, sizeof (cge)))
+			return -EFAULT;
+
+		if (0 != ch_checkrange(ch, cge.cge_type, cge.cge_unit))
+			return -EINVAL;
+		elem = ch->firsts[cge.cge_type] + cge.cge_unit;
+
+		buffer = kmalloc(512, GFP_KERNEL);
+		if (!buffer)
+			return -ENOMEM;
+		mutex_lock(&ch->lock);
+
+	voltag_retry:
+		memset(ch_cmd, 0, sizeof(ch_cmd));
+		ch_cmd[0] = READ_ELEMENT_STATUS;
+		ch_cmd[1] = ((ch->device->lun & 0x7) << 5) |
+			(ch->voltags ? 0x10 : 0) |
+			ch_elem_to_typecode(ch,elem);
+		ch_cmd[2] = (elem >> 8) & 0xff;
+		ch_cmd[3] = elem        & 0xff;
+		ch_cmd[5] = 1;
+		ch_cmd[9] = 255;
+
+		result = ch_do_scsi(ch, ch_cmd, 12, buffer, 256, REQ_OP_DRV_IN);
+		if (!result) {
+			cge.cge_status = buffer[18];
+			cge.cge_flags = 0;
+			if (buffer[18] & CESTATUS_EXCEPT) {
+				cge.cge_errno = EIO;
+			}
+			if (buffer[25] & 0x80) {
+				cge.cge_flags |= CGE_SRC;
+				if (buffer[25] & 0x40)
+					cge.cge_flags |= CGE_INVERT;
+				elem = (buffer[26]<<8) | buffer[27];
+				for (i = 0; i < 4; i++) {
+					if (elem >= ch->firsts[i] &&
+					    elem <  ch->firsts[i] + ch->counts[i]) {
+						cge.cge_srctype = i;
+						cge.cge_srcunit = elem-ch->firsts[i];
+					}
+				}
+			}
+			if ((buffer[22] & 0x30) == 0x30) {
+				cge.cge_flags |= CGE_IDLUN;
+				cge.cge_id  = buffer[23];
+				cge.cge_lun = buffer[22] & 7;
+			}
+			if (buffer[9] & 0x80) {
+				cge.cge_flags |= CGE_PVOLTAG;
+				memcpy(cge.cge_pvoltag,buffer+28,36);
+			}
+			if (buffer[9] & 0x40) {
+				cge.cge_flags |= CGE_AVOLTAG;
+				memcpy(cge.cge_avoltag,buffer+64,36);
+			}
+		} else if (ch->voltags) {
+			ch->voltags = 0;
+			VPRINTK(KERN_INFO, "device has no volume tag support\n");
+			goto voltag_retry;
+		}
+		kfree(buffer);
+		mutex_unlock(&ch->lock);
+
+		if (copy_to_user(argp, &cge, sizeof (cge)))
+			return -EFAULT;
+		return result;
+	}
+
+	case CHIOINITELEM:
+	{
+		mutex_lock(&ch->lock);
+		retval = ch_init_elem(ch);
+		mutex_unlock(&ch->lock);
+		return retval;
+	}
+
+	case CHIOSVOLTAG:
+	{
+		struct changer_set_voltag csv;
+		int elem;
+
+		if (copy_from_user(&csv, argp, sizeof(csv)))
+			return -EFAULT;
+
+		if (0 != ch_checkrange(ch, csv.csv_type, csv.csv_unit)) {
+			DPRINTK("CHIOSVOLTAG: invalid parameter\n");
+			return -EBADSLT;
+		}
+		elem = ch->firsts[csv.csv_type] + csv.csv_unit;
+		mutex_lock(&ch->lock);
+		retval = ch_set_voltag(ch, elem,
+				       csv.csv_flags & CSV_AVOLTAG,
+				       csv.csv_flags & CSV_CLEARTAG,
+				       csv.csv_voltag);
+		mutex_unlock(&ch->lock);
+		return retval;
+	}
+
+	default:
+		return scsi_ioctl(ch->device, file->f_mode & FMODE_WRITE, cmd,
+				  argp);
+
+	}
+}
+
+/* ------------------------------------------------------------------------ */
+
+static int ch_probe(struct scsi_device *sd)
+{
+	struct device *dev = &sd->sdev_gendev;
+	struct device *class_dev;
+	int ret;
+	scsi_changer *ch;
+
+	if (sd->type != TYPE_MEDIUM_CHANGER)
+		return -ENODEV;
+
+	ch = kzalloc_obj(*ch);
+	if (NULL == ch)
+		return -ENOMEM;
+
+	idr_preload(GFP_KERNEL);
+	spin_lock(&ch_index_lock);
+	ret = idr_alloc(&ch_index_idr, ch, 0, CH_MAX_DEVS + 1, GFP_NOWAIT);
+	spin_unlock(&ch_index_lock);
+	idr_preload_end();
+
+	if (ret < 0) {
+		if (ret == -ENOSPC)
+			ret = -ENODEV;
+		goto free_ch;
+	}
+
+	ch->minor = ret;
+	sprintf(ch->name,"ch%d",ch->minor);
+	ret = scsi_device_get(sd);
+	if (ret) {
+		sdev_printk(KERN_WARNING, sd, "ch%d: failed to get device\n",
+			    ch->minor);
+		goto remove_idr;
+	}
+
+	mutex_init(&ch->lock);
+	kref_init(&ch->ref);
+	ch->device = sd;
+	class_dev = device_create(&ch_sysfs_class, dev,
+				  MKDEV(SCSI_CHANGER_MAJOR, ch->minor), ch,
+				  "s%s", ch->name);
+	if (IS_ERR(class_dev)) {
+		sdev_printk(KERN_WARNING, sd, "ch%d: device_create failed\n",
+			    ch->minor);
+		ret = PTR_ERR(class_dev);
+		goto put_device;
+	}
+
+	mutex_lock(&ch->lock);
+	ret = ch_readconfig(ch);
+	if (ret) {
+		mutex_unlock(&ch->lock);
+		goto destroy_dev;
+	}
+	if (init)
+		ch_init_elem(ch);
+
+	mutex_unlock(&ch->lock);
+	dev_set_drvdata(dev, ch);
+	sdev_printk(KERN_INFO, sd, "Attached scsi changer %s\n", ch->name);
+
+	return 0;
+destroy_dev:
+	device_destroy(&ch_sysfs_class, MKDEV(SCSI_CHANGER_MAJOR, ch->minor));
+put_device:
+	scsi_device_put(sd);
+remove_idr:
+	idr_remove(&ch_index_idr, ch->minor);
+free_ch:
+	kfree(ch);
+	return ret;
+}
+
+static void ch_remove(struct scsi_device *sd)
+{
+	struct device *dev = &sd->sdev_gendev;
+	scsi_changer *ch = dev_get_drvdata(dev);
+
+	spin_lock(&ch_index_lock);
+	idr_remove(&ch_index_idr, ch->minor);
+	dev_set_drvdata(dev, NULL);
+	spin_unlock(&ch_index_lock);
+
+	device_destroy(&ch_sysfs_class, MKDEV(SCSI_CHANGER_MAJOR, ch->minor));
+	scsi_device_put(ch->device);
+	kref_put(&ch->ref, ch_destroy);
+}
+
+static struct scsi_driver ch_template = {
+	.probe = ch_probe,
+	.remove = ch_remove,
+	.gendrv = {
+		.name	= "ch",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static const struct file_operations changer_fops = {
+	.owner		= THIS_MODULE,
+	.open		= ch_open,
+	.release	= ch_release,
+	.unlocked_ioctl	= ch_ioctl,
+	.compat_ioctl	= compat_ptr_ioctl,
+	.llseek		= noop_llseek,
+};
+
+static int __init init_ch_module(void)
+{
+	int rc;
+
+	printk(KERN_INFO "SCSI Media Changer driver v" VERSION " \n");
+	rc = class_register(&ch_sysfs_class);
+	if (rc)
+		return rc;
+	rc = register_chrdev(SCSI_CHANGER_MAJOR,"ch",&changer_fops);
+	if (rc < 0) {
+		printk("Unable to get major %d for SCSI-Changer\n",
+		       SCSI_CHANGER_MAJOR);
+		goto fail1;
+	}
+	rc = scsi_register_driver(&ch_template);
+	if (rc < 0)
+		goto fail2;
+	return 0;
+
+ fail2:
+	unregister_chrdev(SCSI_CHANGER_MAJOR, "ch");
+ fail1:
+	class_unregister(&ch_sysfs_class);
+	return rc;
+}
+
+static void __exit exit_ch_module(void)
+{
+	scsi_unregister_driver(&ch_template);
+	unregister_chrdev(SCSI_CHANGER_MAJOR, "ch");
+	class_unregister(&ch_sysfs_class);
+	idr_destroy(&ch_index_idr);
+}
+
+module_init(init_ch_module);
+module_exit(exit_ch_module);