[S390] Add crypto support for 3592 tape devices

3592 tape devices are able to write data encrpyted on tape mediums.
This z/Linux device driver support includes the following functions:
 * ioctl to switch on/off encryption
 * ioctl to query encryption status of drive
 * ioctls to set and query key encrypting keys (kekls)
 * long busy interrupt handling

Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/char/tape_3590.c b/drivers/s390/char/tape_3590.c
index 9df912f..50f5eda 100644
--- a/drivers/s390/char/tape_3590.c
+++ b/drivers/s390/char/tape_3590.c
@@ -2,7 +2,7 @@
  *  drivers/s390/char/tape_3590.c
  *    tape device discipline for 3590 tapes.
  *
- *    Copyright (C) IBM Corp. 2001,2006
+ *    Copyright IBM Corp. 2001,2006
  *    Author(s): Stefan Bader <shbader@de.ibm.com>
  *		 Michael Holzheu <holzheu@de.ibm.com>
  *		 Martin Schwidefsky <schwidefsky@de.ibm.com>
@@ -11,6 +11,7 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/bio.h>
+#include <asm/ebcdic.h>
 
 #define TAPE_DBF_AREA	tape_3590_dbf
 
@@ -30,7 +31,7 @@
  * - Read Device (buffered) log: BRA
  * - Read Library log:		 BRA
  * - Swap Devices:		 BRA
- * - Long Busy:			 BRA
+ * - Long Busy:			 implemented
  * - Special Intercept:		 BRA
  * - Read Alternate:		 implemented
  *******************************************************************/
@@ -94,6 +95,332 @@
 	[0xae] = "Subsystem environmental alert",
 };
 
+static int crypt_supported(struct tape_device *device)
+{
+	return TAPE390_CRYPT_SUPPORTED(TAPE_3590_CRYPT_INFO(device));
+}
+
+static int crypt_enabled(struct tape_device *device)
+{
+	return TAPE390_CRYPT_ON(TAPE_3590_CRYPT_INFO(device));
+}
+
+static void ext_to_int_kekl(struct tape390_kekl *in,
+			    struct tape3592_kekl *out)
+{
+	int i;
+
+	memset(out, 0, sizeof(*out));
+	if (in->type == TAPE390_KEKL_TYPE_HASH)
+		out->flags |= 0x40;
+	if (in->type_on_tape == TAPE390_KEKL_TYPE_HASH)
+		out->flags |= 0x80;
+	strncpy(out->label, in->label, 64);
+	for (i = strlen(in->label); i < sizeof(out->label); i++)
+		out->label[i] = ' ';
+	ASCEBC(out->label, sizeof(out->label));
+}
+
+static void int_to_ext_kekl(struct tape3592_kekl *in,
+			    struct tape390_kekl *out)
+{
+	memset(out, 0, sizeof(*out));
+	if(in->flags & 0x40)
+		out->type = TAPE390_KEKL_TYPE_HASH;
+	else
+		out->type = TAPE390_KEKL_TYPE_LABEL;
+	if(in->flags & 0x80)
+		out->type_on_tape = TAPE390_KEKL_TYPE_HASH;
+	else
+		out->type_on_tape = TAPE390_KEKL_TYPE_LABEL;
+	memcpy(out->label, in->label, sizeof(in->label));
+	EBCASC(out->label, sizeof(in->label));
+	strstrip(out->label);
+}
+
+static void int_to_ext_kekl_pair(struct tape3592_kekl_pair *in,
+				 struct tape390_kekl_pair *out)
+{
+	if (in->count == 0) {
+		out->kekl[0].type = TAPE390_KEKL_TYPE_NONE;
+		out->kekl[0].type_on_tape = TAPE390_KEKL_TYPE_NONE;
+		out->kekl[1].type = TAPE390_KEKL_TYPE_NONE;
+		out->kekl[1].type_on_tape = TAPE390_KEKL_TYPE_NONE;
+	} else if (in->count == 1) {
+		int_to_ext_kekl(&in->kekl[0], &out->kekl[0]);
+		out->kekl[1].type = TAPE390_KEKL_TYPE_NONE;
+		out->kekl[1].type_on_tape = TAPE390_KEKL_TYPE_NONE;
+	} else if (in->count == 2) {
+		int_to_ext_kekl(&in->kekl[0], &out->kekl[0]);
+		int_to_ext_kekl(&in->kekl[1], &out->kekl[1]);
+	} else {
+		printk("Invalid KEKL number: %d\n", in->count);
+		BUG();
+	}
+}
+
+static int check_ext_kekl(struct tape390_kekl *kekl)
+{
+	if (kekl->type == TAPE390_KEKL_TYPE_NONE)
+		goto invalid;
+	if (kekl->type > TAPE390_KEKL_TYPE_HASH)
+		goto invalid;
+	if (kekl->type_on_tape == TAPE390_KEKL_TYPE_NONE)
+		goto invalid;
+	if (kekl->type_on_tape > TAPE390_KEKL_TYPE_HASH)
+		goto invalid;
+	if ((kekl->type == TAPE390_KEKL_TYPE_HASH) &&
+	    (kekl->type_on_tape == TAPE390_KEKL_TYPE_LABEL))
+		goto invalid;
+
+	return 0;
+invalid:
+	return -EINVAL;
+}
+
+static int check_ext_kekl_pair(struct tape390_kekl_pair *kekls)
+{
+	if (check_ext_kekl(&kekls->kekl[0]))
+		goto invalid;
+	if (check_ext_kekl(&kekls->kekl[1]))
+		goto invalid;
+
+	return 0;
+invalid:
+	return -EINVAL;
+}
+
+/*
+ * Query KEKLs
+ */
+static int tape_3592_kekl_query(struct tape_device *device,
+				struct tape390_kekl_pair *ext_kekls)
+{
+	struct tape_request *request;
+	struct tape3592_kekl_query_order *order;
+	struct tape3592_kekl_query_data *int_kekls;
+	int rc;
+
+	DBF_EVENT(6, "tape3592_kekl_query\n");
+	int_kekls = kmalloc(sizeof(*int_kekls), GFP_KERNEL|GFP_DMA);
+	if (!int_kekls)
+		return -ENOMEM;
+	request = tape_alloc_request(2, sizeof(*order));
+	if (IS_ERR(request)) {
+		rc = PTR_ERR(request);
+		goto fail_malloc;
+	}
+	order = request->cpdata;
+	memset(order,0,sizeof(*order));
+	order->code = 0xe2;
+	order->max_count = 2;
+	request->op = TO_KEKL_QUERY;
+	tape_ccw_cc(request->cpaddr, PERF_SUBSYS_FUNC, sizeof(*order), order);
+	tape_ccw_end(request->cpaddr + 1, READ_SS_DATA, sizeof(*int_kekls),
+		     int_kekls);
+	rc = tape_do_io(device, request);
+	if (rc)
+		goto fail_request;
+	int_to_ext_kekl_pair(&int_kekls->kekls, ext_kekls);
+
+	rc = 0;
+fail_request:
+	tape_free_request(request);
+fail_malloc:
+	kfree(int_kekls);
+	return rc;
+}
+
+/*
+ * IOCTL: Query KEKLs
+ */
+static int tape_3592_ioctl_kekl_query(struct tape_device *device,
+				      unsigned long arg)
+{
+	int rc;
+	struct tape390_kekl_pair *ext_kekls;
+
+	DBF_EVENT(6, "tape_3592_ioctl_kekl_query\n");
+	if (!crypt_supported(device))
+		return -ENOSYS;
+	if (!crypt_enabled(device))
+		return -EUNATCH;
+	ext_kekls = kmalloc(sizeof(*ext_kekls), GFP_KERNEL);
+	if (!ext_kekls)
+		return -ENOMEM;
+	rc = tape_3592_kekl_query(device, ext_kekls);
+	if (rc != 0)
+		goto fail;
+	if (copy_to_user((char __user *) arg, ext_kekls, sizeof(*ext_kekls))) {
+		rc = -EFAULT;
+		goto fail;
+	}
+	rc = 0;
+fail:
+	kfree(ext_kekls);
+	return rc;
+}
+
+static int tape_3590_mttell(struct tape_device *device, int mt_count);
+
+/*
+ * Set KEKLs
+ */
+static int tape_3592_kekl_set(struct tape_device *device,
+			      struct tape390_kekl_pair *ext_kekls)
+{
+	struct tape_request *request;
+	struct tape3592_kekl_set_order *order;
+
+	DBF_EVENT(6, "tape3592_kekl_set\n");
+	if (check_ext_kekl_pair(ext_kekls)) {
+		DBF_EVENT(6, "invalid kekls\n");
+		return -EINVAL;
+	}
+	if (tape_3590_mttell(device, 0) != 0)
+		return -EBADSLT;
+	request = tape_alloc_request(1, sizeof(*order));
+	if (IS_ERR(request))
+		return PTR_ERR(request);
+	order = request->cpdata;
+	memset(order, 0, sizeof(*order));
+	order->code = 0xe3;
+	order->kekls.count = 2;
+	ext_to_int_kekl(&ext_kekls->kekl[0], &order->kekls.kekl[0]);
+	ext_to_int_kekl(&ext_kekls->kekl[1], &order->kekls.kekl[1]);
+	request->op = TO_KEKL_SET;
+	tape_ccw_end(request->cpaddr, PERF_SUBSYS_FUNC, sizeof(*order), order);
+
+	return tape_do_io_free(device, request);
+}
+
+/*
+ * IOCTL: Set KEKLs
+ */
+static int tape_3592_ioctl_kekl_set(struct tape_device *device,
+				    unsigned long arg)
+{
+	int rc;
+	struct tape390_kekl_pair *ext_kekls;
+
+	DBF_EVENT(6, "tape_3592_ioctl_kekl_set\n");
+	if (!crypt_supported(device))
+		return -ENOSYS;
+	if (!crypt_enabled(device))
+		return -EUNATCH;
+	ext_kekls = kmalloc(sizeof(*ext_kekls), GFP_KERNEL);
+	if (!ext_kekls)
+		return -ENOMEM;
+	if (copy_from_user(ext_kekls, (char __user *)arg, sizeof(*ext_kekls))) {
+		rc = -EFAULT;
+		goto out;
+	}
+	rc = tape_3592_kekl_set(device, ext_kekls);
+out:
+	kfree(ext_kekls);
+	return rc;
+}
+
+/*
+ * Enable encryption
+ */
+static int tape_3592_enable_crypt(struct tape_device *device)
+{
+	struct tape_request *request;
+	char *data;
+
+	DBF_EVENT(6, "tape_3592_enable_crypt\n");
+	if (!crypt_supported(device))
+		return -ENOSYS;
+	request = tape_alloc_request(2, 72);
+	if (IS_ERR(request))
+		return PTR_ERR(request);
+	data = request->cpdata;
+	memset(data,0,72);
+
+	data[0]       = 0x05;
+	data[36 + 0]  = 0x03;
+	data[36 + 1]  = 0x03;
+	data[36 + 4]  = 0x40;
+	data[36 + 6]  = 0x01;
+	data[36 + 14] = 0x2f;
+	data[36 + 18] = 0xc3;
+	data[36 + 35] = 0x72;
+	request->op = TO_CRYPT_ON;
+	tape_ccw_cc(request->cpaddr, MODE_SET_CB, 36, data);
+	tape_ccw_end(request->cpaddr + 1, MODE_SET_CB, 36, data + 36);
+	return tape_do_io_free(device, request);
+}
+
+/*
+ * Disable encryption
+ */
+static int tape_3592_disable_crypt(struct tape_device *device)
+{
+	struct tape_request *request;
+	char *data;
+
+	DBF_EVENT(6, "tape_3592_disable_crypt\n");
+	if (!crypt_supported(device))
+		return -ENOSYS;
+	request = tape_alloc_request(2, 72);
+	if (IS_ERR(request))
+		return PTR_ERR(request);
+	data = request->cpdata;
+	memset(data,0,72);
+
+	data[0]       = 0x05;
+	data[36 + 0]  = 0x03;
+	data[36 + 1]  = 0x03;
+	data[36 + 35] = 0x32;
+
+	request->op = TO_CRYPT_OFF;
+	tape_ccw_cc(request->cpaddr, MODE_SET_CB, 36, data);
+	tape_ccw_end(request->cpaddr + 1, MODE_SET_CB, 36, data + 36);
+
+	return tape_do_io_free(device, request);
+}
+
+/*
+ * IOCTL: Set encryption status
+ */
+static int tape_3592_ioctl_crypt_set(struct tape_device *device,
+				     unsigned long arg)
+{
+	struct tape390_crypt_info info;
+
+	DBF_EVENT(6, "tape_3592_ioctl_crypt_set\n");
+	if (!crypt_supported(device))
+		return -ENOSYS;
+	if (copy_from_user(&info, (char __user *)arg, sizeof(info)))
+		return -EFAULT;
+	if (info.status & ~TAPE390_CRYPT_ON_MASK)
+		return -EINVAL;
+	if (info.status & TAPE390_CRYPT_ON_MASK)
+		return tape_3592_enable_crypt(device);
+	else
+		return tape_3592_disable_crypt(device);
+}
+
+static int tape_3590_sense_medium(struct tape_device *device);
+
+/*
+ * IOCTL: Query enryption status
+ */
+static int tape_3592_ioctl_crypt_query(struct tape_device *device,
+				       unsigned long arg)
+{
+	DBF_EVENT(6, "tape_3592_ioctl_crypt_query\n");
+	if (!crypt_supported(device))
+		return -ENOSYS;
+	tape_3590_sense_medium(device);
+	if (copy_to_user((char __user *) arg, &TAPE_3590_CRYPT_INFO(device),
+		sizeof(TAPE_3590_CRYPT_INFO(device))))
+		return -EFAULT;
+	else
+		return 0;
+}
+
 /*
  * 3590 IOCTL Overload
  */
@@ -109,6 +436,14 @@
 
 		return tape_std_display(device, &disp);
 	}
+	case TAPE390_KEKL_SET:
+		return tape_3592_ioctl_kekl_set(device, arg);
+	case TAPE390_KEKL_QUERY:
+		return tape_3592_ioctl_kekl_query(device, arg);
+	case TAPE390_CRYPT_SET:
+		return tape_3592_ioctl_crypt_set(device, arg);
+	case TAPE390_CRYPT_QUERY:
+		return tape_3592_ioctl_crypt_query(device, arg);
 	default:
 		return -EINVAL;	/* no additional ioctls */
 	}
@@ -248,6 +583,12 @@
 	case TO_READ_ATTMSG:
 		tape_3590_read_attmsg(p->device);
 		break;
+	case TO_CRYPT_ON:
+		tape_3592_enable_crypt(p->device);
+		break;
+	case TO_CRYPT_OFF:
+		tape_3592_disable_crypt(p->device);
+		break;
 	default:
 		DBF_EVENT(3, "T3590: work handler undefined for "
 			  "operation 0x%02x\n", p->op);
@@ -365,6 +706,33 @@
 }
 #endif
 
+static void tape_3590_med_state_set(struct tape_device *device,
+				    struct tape_3590_med_sense *sense)
+{
+	struct tape390_crypt_info *c_info;
+
+	c_info = &TAPE_3590_CRYPT_INFO(device);
+
+	if (sense->masst == MSENSE_UNASSOCIATED) {
+		tape_med_state_set(device, MS_UNLOADED);
+		TAPE_3590_CRYPT_INFO(device).medium_status = 0;
+		return;
+	}
+	if (sense->masst != MSENSE_ASSOCIATED_MOUNT) {
+		PRINT_ERR("Unknown medium state: %x\n", sense->masst);
+		return;
+	}
+	tape_med_state_set(device, MS_LOADED);
+	c_info->medium_status |= TAPE390_MEDIUM_LOADED_MASK;
+	if (sense->flags & MSENSE_CRYPT_MASK) {
+		PRINT_INFO("Medium is encrypted (%04x)\n", sense->flags);
+		c_info->medium_status |= TAPE390_MEDIUM_ENCRYPTED_MASK;
+	} else	{
+		DBF_EVENT(6, "Medium is not encrypted %04x\n", sense->flags);
+		c_info->medium_status &= ~TAPE390_MEDIUM_ENCRYPTED_MASK;
+	}
+}
+
 /*
  * The done handler is called at device/channel end and wakes up the sleeping
  * process
@@ -372,9 +740,10 @@
 static int
 tape_3590_done(struct tape_device *device, struct tape_request *request)
 {
-	struct tape_3590_med_sense *sense;
+	struct tape_3590_disc_data *disc_data;
 
 	DBF_EVENT(6, "%s done\n", tape_op_verbose[request->op]);
+	disc_data = device->discdata;
 
 	switch (request->op) {
 	case TO_BSB:
@@ -394,13 +763,20 @@
 		break;
 	case TO_RUN:
 		tape_med_state_set(device, MS_UNLOADED);
+		tape_3590_schedule_work(device, TO_CRYPT_OFF);
 		break;
 	case TO_MSEN:
-		sense = (struct tape_3590_med_sense *) request->cpdata;
-		if (sense->masst == MSENSE_UNASSOCIATED)
-			tape_med_state_set(device, MS_UNLOADED);
-		if (sense->masst == MSENSE_ASSOCIATED_MOUNT)
-			tape_med_state_set(device, MS_LOADED);
+		tape_3590_med_state_set(device, request->cpdata);
+		break;
+	case TO_CRYPT_ON:
+		TAPE_3590_CRYPT_INFO(device).status
+			|= TAPE390_CRYPT_ON_MASK;
+		*(device->modeset_byte) |= 0x03;
+		break;
+	case TO_CRYPT_OFF:
+		TAPE_3590_CRYPT_INFO(device).status
+			&= ~TAPE390_CRYPT_ON_MASK;
+		*(device->modeset_byte) &= ~0x03;
 		break;
 	case TO_RBI:	/* RBI seems to succeed even without medium loaded. */
 	case TO_NOP:	/* Same to NOP. */
@@ -409,8 +785,9 @@
 	case TO_DIS:
 	case TO_ASSIGN:
 	case TO_UNASSIGN:
-		break;
 	case TO_SIZE:
+	case TO_KEKL_SET:
+	case TO_KEKL_QUERY:
 		break;
 	}
 	return TAPE_IO_SUCCESS;
@@ -540,10 +917,8 @@
 tape_3590_erp_long_busy(struct tape_device *device,
 			struct tape_request *request, struct irb *irb)
 {
-	/* FIXME: how about WAITING for a minute ? */
-	PRINT_WARN("(%s): Device is busy! Please wait a minute!\n",
-		   device->cdev->dev.bus_id);
-	return tape_3590_erp_basic(device, request, irb, -EBUSY);
+	DBF_EVENT(6, "Device is busy\n");
+	return TAPE_IO_LONG_BUSY;
 }
 
 /*
@@ -951,6 +1326,34 @@
 		   device->cdev->dev.bus_id, sense->mc);
 }
 
+static int tape_3590_crypt_error(struct tape_device *device,
+				 struct tape_request *request, struct irb *irb)
+{
+	u8 cu_rc, ekm_rc1;
+	u16 ekm_rc2;
+	u32 drv_rc;
+	char *bus_id, *sense;
+
+	sense = ((struct tape_3590_sense *) irb->ecw)->fmt.data;
+	bus_id = device->cdev->dev.bus_id;
+	cu_rc = sense[0];
+	drv_rc = *((u32*) &sense[5]) & 0xffffff;
+	ekm_rc1 = sense[9];
+	ekm_rc2 = *((u16*) &sense[10]);
+	if ((cu_rc == 0) && (ekm_rc2 == 0xee31))
+		/* key not defined on EKM */
+		return tape_3590_erp_basic(device, request, irb, -EKEYREJECTED);
+	if ((cu_rc == 1) || (cu_rc == 2))
+		/* No connection to EKM */
+		return tape_3590_erp_basic(device, request, irb, -ENOTCONN);
+
+	PRINT_ERR("(%s): Unable to get encryption key from EKM\n", bus_id);
+	PRINT_ERR("(%s): CU=%02X DRIVE=%06X EKM=%02X:%04X\n", bus_id, cu_rc,
+		drv_rc, ekm_rc1, ekm_rc2);
+
+	return tape_3590_erp_basic(device, request, irb, -ENOKEY);
+}
+
 /*
  *  3590 error Recovery routine:
  *  If possible, it tries to recover from the error. If this is not possible,
@@ -979,6 +1382,8 @@
 
 	sense = (struct tape_3590_sense *) irb->ecw;
 
+	DBF_EVENT(6, "Unit Check: RQC = %x\n", sense->rc_rqc);
+
 	/*
 	 * First check all RC-QRCs where we want to do something special
 	 *   - "break":     basic error recovery is done
@@ -999,6 +1404,8 @@
 	case 0x2231:
 		tape_3590_print_era_msg(device, irb);
 		return tape_3590_erp_special_interrupt(device, request, irb);
+	case 0x2240:
+		return tape_3590_crypt_error(device, request, irb);
 
 	case 0x3010:
 		DBF_EVENT(2, "(%08x): Backward at Beginning of Partition\n",
@@ -1020,6 +1427,7 @@
 		DBF_EVENT(2, "(%08x): Rewind Unload complete\n",
 			  device->cdev_id);
 		tape_med_state_set(device, MS_UNLOADED);
+		tape_3590_schedule_work(device, TO_CRYPT_OFF);
 		return tape_3590_erp_basic(device, request, irb, 0);
 
 	case 0x4010:
@@ -1030,9 +1438,15 @@
 		PRINT_WARN("(%s): Tape operation when medium not loaded\n",
 			   device->cdev->dev.bus_id);
 		tape_med_state_set(device, MS_UNLOADED);
+		tape_3590_schedule_work(device, TO_CRYPT_OFF);
 		return tape_3590_erp_basic(device, request, irb, -ENOMEDIUM);
 	case 0x4012:		/* Device Long Busy */
+		/* XXX: Also use long busy handling here? */
+		DBF_EVENT(6, "(%08x): LONG BUSY\n", device->cdev_id);
 		tape_3590_print_era_msg(device, irb);
+		return tape_3590_erp_basic(device, request, irb, -EBUSY);
+	case 0x4014:
+		DBF_EVENT(6, "(%08x): Crypto LONG BUSY\n", device->cdev_id);
 		return tape_3590_erp_long_busy(device, request, irb);
 
 	case 0x5010:
@@ -1064,6 +1478,7 @@
 	case 0x5120:
 	case 0x1120:
 		tape_med_state_set(device, MS_UNLOADED);
+		tape_3590_schedule_work(device, TO_CRYPT_OFF);
 		return tape_3590_erp_basic(device, request, irb, -ENOMEDIUM);
 
 	case 0x6020:
@@ -1142,21 +1557,47 @@
 {
 	int rc;
 	struct tape_3590_disc_data *data;
+	char *rdc_data;
 
 	DBF_EVENT(6, "3590 device setup\n");
-	data = kmalloc(sizeof(struct tape_3590_disc_data),
-		       GFP_KERNEL | GFP_DMA);
+	data = kzalloc(sizeof(struct tape_3590_disc_data), GFP_KERNEL | GFP_DMA);
 	if (data == NULL)
 		return -ENOMEM;
 	data->read_back_op = READ_PREVIOUS;
 	device->discdata = data;
 
-	if ((rc = tape_std_assign(device)) == 0) {
-		/* Try to find out if medium is loaded */
-		if ((rc = tape_3590_sense_medium(device)) != 0)
-			DBF_LH(3, "3590 medium sense returned %d\n", rc);
+	rdc_data = kmalloc(64, GFP_KERNEL | GFP_DMA);
+	if (!rdc_data) {
+		rc = -ENOMEM;
+		goto fail_kmalloc;
 	}
+	rc = read_dev_chars(device->cdev, (void**)&rdc_data, 64);
+	if (rc) {
+		DBF_LH(3, "Read device characteristics failed!\n");
+		goto fail_kmalloc;
+	}
+	rc = tape_std_assign(device);
+	if (rc)
+		goto fail_rdc_data;
+	if (rdc_data[31] == 0x13) {
+		PRINT_INFO("Device has crypto support\n");
+		data->crypt_info.capability |= TAPE390_CRYPT_SUPPORTED_MASK;
+		tape_3592_disable_crypt(device);
+	} else {
+		DBF_EVENT(6, "Device has NO crypto support\n");
+	}
+	/* Try to find out if medium is loaded */
+	rc = tape_3590_sense_medium(device);
+	if (rc) {
+		DBF_LH(3, "3590 medium sense returned %d\n", rc);
+		goto fail_rdc_data;
+	}
+	return 0;
 
+fail_rdc_data:
+	kfree(rdc_data);
+fail_kmalloc:
+	kfree(data);
 	return rc;
 }