1 files changed, 88 insertions, 36 deletions

diff --git a/drivers/s390/char/tape_3590.c b/drivers/s390/char/tape_3590.c
index fc993acf99b6..a7d570728882 100644
--- a/drivers/s390/char/tape_3590.c
+++ b/drivers/s390/char/tape_3590.c
@@ -24,6 +24,8 @@
 #include "tape_std.h"
 #include "tape_3590.h"
 
+static struct workqueue_struct *tape_3590_wq;
+
 /*
  * Pointer to debug area.
  */
@@ -31,7 +33,7 @@ debug_info_t *TAPE_DBF_AREA = NULL;
 EXPORT_SYMBOL(TAPE_DBF_AREA);
 
 /*******************************************************************
- * Error Recovery fuctions:
+ * Error Recovery functions:
  * - Read Opposite:              implemented
  * - Read Device (buffered) log: BRA
  * - Read Library log:           BRA
@@ -327,17 +329,17 @@ out:
 /*
  * Enable encryption
  */
-static int tape_3592_enable_crypt(struct tape_device *device)
+static struct tape_request *__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;
+                return ERR_PTR(-ENOSYS);
         request = tape_alloc_request(2, 72);
         if (IS_ERR(request))
-                return PTR_ERR(request);
+                return request;
         data = request->cpdata;
         memset(data,0,72);
 
@@ -352,23 +354,42 @@ static int tape_3592_enable_crypt(struct tape_device *device)
         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 request;
+}
+
+static int tape_3592_enable_crypt(struct tape_device *device)
+{
+        struct tape_request *request;
+
+        request = __tape_3592_enable_crypt(device);
+        if (IS_ERR(request))
+                return PTR_ERR(request);
         return tape_do_io_free(device, request);
 }
 
+static void tape_3592_enable_crypt_async(struct tape_device *device)
+{
+        struct tape_request *request;
+
+        request = __tape_3592_enable_crypt(device);
+        if (!IS_ERR(request))
+                tape_do_io_async_free(device, request);
+}
+
 /*
  * Disable encryption
  */
-static int tape_3592_disable_crypt(struct tape_device *device)
+static struct tape_request *__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;
+                return ERR_PTR(-ENOSYS);
         request = tape_alloc_request(2, 72);
         if (IS_ERR(request))
-                return PTR_ERR(request);
+                return request;
         data = request->cpdata;
         memset(data,0,72);
 
@@ -381,9 +402,28 @@ static int tape_3592_disable_crypt(struct tape_device *device)
         tape_ccw_cc(request->cpaddr, MODE_SET_CB, 36, data);
         tape_ccw_end(request->cpaddr + 1, MODE_SET_CB, 36, data + 36);
 
+        return request;
+}
+
+static int tape_3592_disable_crypt(struct tape_device *device)
+{
+        struct tape_request *request;
+
+        request = __tape_3592_disable_crypt(device);
+        if (IS_ERR(request))
+                return PTR_ERR(request);
         return tape_do_io_free(device, request);
 }
 
+static void tape_3592_disable_crypt_async(struct tape_device *device)
+{
+        struct tape_request *request;
+
+        request = __tape_3592_disable_crypt(device);
+        if (!IS_ERR(request))
+                tape_do_io_async_free(device, request);
+}
+
 /*
  * IOCTL: Set encryption status
  */
@@ -455,8 +495,7 @@ tape_3590_ioctl(struct tape_device *device, unsigned int cmd, unsigned long arg)
 /*
  * SENSE Medium: Get Sense data about medium state
  */
-static int
-tape_3590_sense_medium(struct tape_device *device)
+static int tape_3590_sense_medium(struct tape_device *device)
 {
         struct tape_request *request;
 
@@ -468,6 +507,18 @@ tape_3590_sense_medium(struct tape_device *device)
         return tape_do_io_free(device, request);
 }
 
+static void tape_3590_sense_medium_async(struct tape_device *device)
+{
+        struct tape_request *request;
+
+        request = tape_alloc_request(1, 128);
+        if (IS_ERR(request))
+                return;
+        request->op = TO_MSEN;
+        tape_ccw_end(request->cpaddr, MEDIUM_SENSE, 128, request->cpdata);
+        tape_do_io_async_free(device, request);
+}
+
 /*
  * MTTELL: Tell block. Return the number of block relative to current file.
  */
@@ -544,15 +595,14 @@ tape_3590_read_opposite(struct tape_device *device,
  * 2. The attention msg is written to the "read subsystem data" buffer.
  * In this case we probably should print it to the console.
  */
-static int
-tape_3590_read_attmsg(struct tape_device *device)
+static void tape_3590_read_attmsg_async(struct tape_device *device)
 {
         struct tape_request *request;
         char *buf;
 
         request = tape_alloc_request(3, 4096);
         if (IS_ERR(request))
-                return PTR_ERR(request);
+                return;
         request->op = TO_READ_ATTMSG;
         buf = request->cpdata;
         buf[0] = PREP_RD_SS_DATA;
@@ -560,12 +610,15 @@ tape_3590_read_attmsg(struct tape_device *device)
         tape_ccw_cc(request->cpaddr, PERFORM_SS_FUNC, 12, buf);
         tape_ccw_cc(request->cpaddr + 1, READ_SS_DATA, 4096 - 12, buf + 12);
         tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);
-        return tape_do_io_free(device, request);
+        tape_do_io_async_free(device, request);
 }
 
 /*
  * These functions are used to schedule follow-up actions from within an
  * interrupt context (like unsolicited interrupts).
+ * Note: the work handler is called by the system work queue. The tape
+ * commands started by the handler need to be asynchrounous, otherwise
+ * a deadlock can occur e.g. in case of a deferred cc=1 (see __tape_do_irq).
  */
 struct work_handler_data {
         struct tape_device *device;
@@ -581,16 +634,16 @@ tape_3590_work_handler(struct work_struct *work)
 
         switch (p->op) {
         case TO_MSEN:
-                tape_3590_sense_medium(p->device);
+                tape_3590_sense_medium_async(p->device);
                 break;
         case TO_READ_ATTMSG:
-                tape_3590_read_attmsg(p->device);
+                tape_3590_read_attmsg_async(p->device);
                 break;
         case TO_CRYPT_ON:
-                tape_3592_enable_crypt(p->device);
+                tape_3592_enable_crypt_async(p->device);
                 break;
         case TO_CRYPT_OFF:
-                tape_3592_disable_crypt(p->device);
+                tape_3592_disable_crypt_async(p->device);
                 break;
         default:
                 DBF_EVENT(3, "T3590: work handler undefined for "
@@ -613,7 +666,7 @@ tape_3590_schedule_work(struct tape_device *device, enum tape_op op)
         p->device = tape_get_device(device);
         p->op = op;
 
-        schedule_work(&p->work);
+        queue_work(tape_3590_wq, &p->work);
         return 0;
 }
 
@@ -743,10 +796,8 @@ static void tape_3590_med_state_set(struct tape_device *device,
 static int
 tape_3590_done(struct tape_device *device, struct tape_request *request)
 {
-        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:
@@ -798,7 +849,7 @@ tape_3590_done(struct tape_device *device, struct tape_request *request)
 }
 
 /*
- * This fuction is called, when error recovery was successfull
+ * This function is called, when error recovery was successful
  */
 static inline int
 tape_3590_erp_succeded(struct tape_device *device, struct tape_request *request)
@@ -809,7 +860,7 @@ tape_3590_erp_succeded(struct tape_device *device, struct tape_request *request)
 }
 
 /*
- * This fuction is called, when error recovery was not successfull
+ * This function is called, when error recovery was not successful
  */
 static inline int
 tape_3590_erp_failed(struct tape_device *device, struct tape_request *request,
@@ -1341,17 +1392,12 @@ tape_3590_print_era_msg(struct tape_device *device, struct irb *irb)
 static int tape_3590_crypt_error(struct tape_device *device,
                                  struct tape_request *request, struct irb *irb)
 {
-        u8 cu_rc, ekm_rc1;
+        u8 cu_rc;
         u16 ekm_rc2;
-        u32 drv_rc;
-        const char *bus_id;
         char *sense;
 
         sense = ((struct tape_3590_sense *) irb->ecw)->fmt.data;
-        bus_id = dev_name(&device->cdev->dev);
         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 */
@@ -1376,7 +1422,6 @@ tape_3590_unit_check(struct tape_device *device, struct tape_request *request,
                      struct irb *irb)
 {
         struct tape_3590_sense *sense;
-        int rc;
 
 #ifdef CONFIG_S390_TAPE_BLOCK
         if (request->op == TO_BLOCK) {
@@ -1401,7 +1446,6 @@ tape_3590_unit_check(struct tape_device *device, struct tape_request *request,
          *   - "break":     basic error recovery is done
          *   - "goto out:": just print error message if available
          */
-        rc = -EIO;
         switch (sense->rc_rqc) {
 
         case 0x1110:
@@ -1629,7 +1673,7 @@ fail_kmalloc:
 static void
 tape_3590_cleanup_device(struct tape_device *device)
 {
-        flush_scheduled_work();
+        flush_workqueue(tape_3590_wq);
         tape_std_unassign(device);
 
         kfree(device->discdata);
@@ -1708,8 +1752,10 @@ tape_3590_online(struct ccw_device *cdev)
 }
 
 static struct ccw_driver tape_3590_driver = {
-        .name = "tape_3590",
-        .owner = THIS_MODULE,
+        .driver = {
+                .name = "tape_3590",
+                .owner = THIS_MODULE,
+        },
         .ids = tape_3590_ids,
         .probe = tape_generic_probe,
         .remove = tape_generic_remove,
@@ -1733,11 +1779,17 @@ tape_3590_init(void)
 #endif
 
         DBF_EVENT(3, "3590 init\n");
+
+        tape_3590_wq = alloc_workqueue("tape_3590", 0, 0);
+        if (!tape_3590_wq)
+                return -ENOMEM;
+
         /* Register driver for 3590 tapes. */
         rc = ccw_driver_register(&tape_3590_driver);
-        if (rc)
+        if (rc) {
+                destroy_workqueue(tape_3590_wq);
                 DBF_EVENT(3, "3590 init failed\n");
-        else
+        } else
                 DBF_EVENT(3, "3590 registered\n");
         return rc;
 }
@@ -1746,7 +1798,7 @@ static void
 tape_3590_exit(void)
 {
         ccw_driver_unregister(&tape_3590_driver);
-
+        destroy_workqueue(tape_3590_wq);
         debug_unregister(TAPE_DBF_AREA);
 }