mtip32xx: updates based on feedback

* queue ncq commands when a non-ncq is in progress or error handling is active
* merge variables 'internal_cmd_in_progress' and 'eh_active' into new variable 'flags'
* get rid of read/write semaphore 'internal_sem'
* new service thread to issue queued commands
* use macros from ata.h for command codes
* return ENOTTY for BLKFLSBUF ioctl
* style changes

Signed-off-by: Asai Thambi S P <asamymuthupa@micron.com>
Signed-off-by: Sam Bradshaw <sbradshaw@micron.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 28 insertions, 14 deletions

diff --git a/drivers/block/mtip32xx/mtip32xx.h b/drivers/block/mtip32xx/mtip32xx.h
index 17be4f444e7d..933192abe178 100644
--- a/drivers/block/mtip32xx/mtip32xx.h
+++ b/drivers/block/mtip32xx/mtip32xx.h
@@ -47,11 +47,11 @@
 
 /* ftl rebuild */
 #define MTIP_FTL_REBUILD_OFFSET         142
-#define MTIP_FTL_REBUILD_MAGIC          0xed51
+#define MTIP_FTL_REBUILD_MAGIC          0xED51
 #define MTIP_FTL_REBUILD_TIMEOUT_MS     2400000
 
 /* Macro to extract the tag bit number from a tag value. */
-#define MTIP_TAG_BIT(tag)       (tag & 0x1f)
+#define MTIP_TAG_BIT(tag)       (tag & 0x1F)
 
 /*
  * Macro to extract the tag index from a tag value. The index
@@ -81,7 +81,7 @@
 
 /* Driver name and version strings */
 #define MTIP_DRV_NAME           "mtip32xx"
-#define MTIP_DRV_VERSION        "1.2.6os2"
+#define MTIP_DRV_VERSION        "1.2.6os3"
 
 /* Maximum number of minor device numbers per device. */
 #define MTIP_MAX_MINORS         16
@@ -114,6 +114,15 @@
  #define dbg_printk(format, arg...)
 #endif
 
+#define __force_bit2int (unsigned int __force)
+
+/* below are bit numbers in 'flags' defined in mtip_port */
+#define MTIP_FLAG_IC_ACTIVE_BIT                 0
+#define MTIP_FLAG_EH_ACTIVE_BIT                 1
+#define MTIP_FLAG_SVC_THD_ACTIVE_BIT            2
+#define MTIP_FLAG_ISSUE_CMDS_BIT                4
+#define MTIP_FLAG_SVC_THD_SHOULD_STOP_BIT       8
+
 /* Register Frame Information Structure (FIS), host to device. */
 struct host_to_dev_fis {
         /*
@@ -262,7 +271,7 @@ struct mtip_cmd {
 
         unsigned long comp_time; /* command completion time, in jiffies */
 
-        atomic_t active; /* declares if this command sent to the drive.  */
+        atomic_t active; /* declares if this command sent to the drive. */
 };
 
 /* Structure used to describe a port. */
@@ -278,7 +287,7 @@ struct mtip_port {
         void __iomem *mmio;
         /* Array of pointers to the memory mapped s_active registers. */
         void __iomem *s_active[MTIP_MAX_SLOT_GROUPS];
-        /* Array of pointers to the memory mapped completed registers.  */
+        /* Array of pointers to the memory mapped completed registers. */
         void __iomem *completed[MTIP_MAX_SLOT_GROUPS];
         /* Array of pointers to the memory mapped Command Issue registers. */
         void __iomem *cmd_issue[MTIP_MAX_SLOT_GROUPS];
@@ -340,13 +349,23 @@ struct mtip_port {
          */
         unsigned long allocated[SLOTBITS_IN_LONGS];
         /*
+         * used to queue commands when an internal command is in progress
+         * or error handling is active
+         */
+        unsigned long cmds_to_issue[SLOTBITS_IN_LONGS];
+        /*
          * Array of command slots. Structure includes pointers to the
          * command header and command table, and completion function and data
          * pointers.
          */
         struct mtip_cmd commands[MTIP_MAX_COMMAND_SLOTS];
-        /* Non-zero if an internal command is in progress. */
-        int internal_cmd_in_progress;
+        /* Used by mtip_service_thread to wait for an event */
+        wait_queue_head_t svc_wait;
+        /*
+         * indicates the state of the port. Also, helps the service thread
+         * to determine its action on wake up.
+         */
+        unsigned long flags;
         /*
          * Timer used to complete commands that have been active for too long.
          */
@@ -372,18 +391,11 @@ struct driver_data {
 
         int instance; /* Instance number. First device probed is 0, ... */
 
-        int protocol; /* FIXME: Protocol ops array index. */
-
         struct gendisk *disk; /* Pointer to our gendisk structure. */
 
         struct pci_dev *pdev; /* Pointer to the PCI device structure. */
 
         struct request_queue *queue; /* Our request queue. */
-        /*
-         * Semaphore used to lock out read/write commands during the
-         * execution of an internal command.
-         */
-        struct rw_semaphore internal_sem;
 
         struct mtip_port *port; /* Pointer to the port data structure. */
 
@@ -403,6 +415,8 @@ struct driver_data {
         atomic_t resumeflag; /* Atomic variable to track suspend/resume */
 
         atomic_t eh_active; /* Flag for error handling tracking */
+
+        struct task_struct *mtip_svc_handler; /* task_struct of svc thd */
 };
 
 #endif