/*
* Design
- * Issues :
*
- * The other Linux SCSI drivers were written when Linux was Intel PC-only,
- * and specifically for each board rather than each chip. This makes their
- * adaptation to platforms like the Mac (Some of which use NCR5380's)
- * more difficult than it has to be.
- *
- * Also, many of the SCSI drivers were written before the command queuing
- * routines were implemented, meaning their implementations of queued
- * commands were hacked on rather than designed in from the start.
- *
- * When I designed the Linux SCSI drivers I figured that
- * while having two different SCSI boards in a system might be useful
- * for debugging things, two of the same type wouldn't be used.
- * Well, I was wrong and a number of users have mailed me about running
- * multiple high-performance SCSI boards in a server.
- *
- * Finally, when I get questions from users, I have no idea what
- * revision of my driver they are running.
- *
- * This driver attempts to address these problems :
* This is a generic 5380 driver. To use it on a different platform,
* one simply writes appropriate system specific macros (ie, data
* transfer - some PC's will use the I/O bus, 68K's must use
* allowing multiple commands to propagate all the way to a SCSI-II device
* while a command is already executing.
*
- * To solve the multiple-boards-in-the-same-system problem,
- * there is a separate instance structure for each instance
- * of a 5380 in the system. So, multiple NCR5380 drivers will
- * be able to coexist with appropriate changes to the high level
- * SCSI code.
*
* Issues specific to the NCR5380 :
*
* Architecture :
*
* At the heart of the design is a coroutine, NCR5380_main,
- * which is started when not running by the interrupt handler,
- * timer, and queue command function. It attempts to establish
- * I_T_L or I_T_L_Q nexuses by removing the commands from the
- * issue queue and calling NCR5380_select() if a nexus
- * is not established.
+ * which is started from a workqueue for each NCR5380 host in the
+ * system. It attempts to establish I_T_L or I_T_L_Q nexuses by
+ * removing the commands from the issue queue and calling
+ * NCR5380_select() if a nexus is not established.
*
* Once a nexus is established, the NCR5380_information_transfer()
* phase goes through the various phases as instructed by the target.
* if the target goes into MSG IN and sends a DISCONNECT message,
* the command structure is placed into the per instance disconnected
- * queue, and NCR5380_main tries to find more work. If USLEEP
- * was defined, and the target is idle for too long, the system
- * will try to sleep.
+ * queue, and NCR5380_main tries to find more work. If the target is
+ * idle for too long, the system will try to sleep.
*
* If a command has disconnected, eventually an interrupt will trigger,
* calling NCR5380_intr() which will in turn call NCR5380_reselect
* AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
* for commands that return with a CHECK CONDITION status.
*
+ * DIFFERENTIAL - if defined, NCR53c81 chips will use external differential
+ * transceivers.
+ *
* LINKED - if defined, linked commands are supported.
*
* REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
*
* NCR5380_write(register, value) - write to the specific register
*
+ * NCR5380_implementation_fields - additional fields needed for this
+ * specific implementation of the NCR5380
+ *
* Either real DMA *or* pseudo DMA may be implemented
* REAL functions :
* NCR5380_REAL_DMA should be defined if real DMA is to be used.
* NCR5380_pwrite(instance, src, count)
* NCR5380_pread(instance, dst, count);
*
- * If nothing specific to this implementation needs doing (ie, with external
- * hardware), you must also define
- *
- * NCR5380_queue_command
- * NCR5380_reset
- * NCR5380_abort
- *
- * to be the global entry points into the specific driver, ie
- * #define NCR5380_queue_command t128_queue_command.
- *
- * If this is not done, the routines will be defined as static functions
- * with the NCR5380* names and the user must provide a globally
- * accessible wrapper function.
- *
* The generic driver is initialized by calling NCR5380_init(instance),
* after setting the appropriate host specific fields and ID. If the
* driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
#endif /* !defined(CONFIG_SUN3) */
}
-/*
- * Function : void initialize_SCp(struct scsi_cmnd *cmd)
- *
- * Purpose : initialize the saved data pointers for cmd to point to the
- * start of the buffer.
+/**
+ * initialize_SCp - init the scsi pointer field
+ * @cmd: command block to set up
*
- * Inputs : cmd - scsi_cmnd structure to have pointers reset.
+ * Set up the internal fields in the SCSI command.
*/
static inline void initialize_SCp(struct scsi_cmnd *cmd)
{0, NULL}
};
-/*
- * Function : void NCR5380_print(struct Scsi_Host *instance)
- *
- * Purpose : print the SCSI bus signals for debugging purposes
+/**
+ * NCR5380_print - print scsi bus signals
+ * @instance: adapter state to dump
*
- * Input : instance - which NCR5380
+ * Print the SCSI bus signals for debugging purposes
*/
static void NCR5380_print(struct Scsi_Host *instance)
{PHASE_UNKNOWN, "UNKNOWN"}
};
-/*
- * Function : void NCR5380_print_phase(struct Scsi_Host *instance)
+/**
+ * NCR5380_print_phase - show SCSI phase
+ * @instance: adapter to dump
*
- * Purpose : print the current SCSI phase for debugging purposes
+ * Print the current SCSI phase for debugging purposes
*
- * Input : instance - which NCR5380
+ * Locks: none
*/
static void NCR5380_print_phase(struct Scsi_Host *instance)
"");
}
-/*
- * Function : void NCR5380_print_status (struct Scsi_Host *instance)
- *
- * Purpose : print commands in the various queues, called from
- * NCR5380_abort and NCR5380_debug to aid debugging.
+/**
+ * NCR5380_print_status - dump controller info
+ * @instance: controller to dump
*
- * Inputs : instance, pointer to this instance.
+ * Print commands in the various queues, called from NCR5380_abort
+ * to aid debugging.
*/
static void lprint_Scsi_Cmnd(struct scsi_cmnd *cmd)
return 0;
}
-/*
- * Function : void NCR5380_init (struct Scsi_Host *instance)
- *
- * Purpose : initializes *instance and corresponding 5380 chip.
+/**
+ * NCR5380_init - initialise an NCR5380
+ * @instance: adapter to configure
+ * @flags: control flags
*
- * Inputs : instance - instantiation of the 5380 driver.
+ * Initializes *instance and corresponding 5380 chip,
+ * with flags OR'd into the initial flags value.
*
* Notes : I assume that the host, hostno, and id bits have been
- * set correctly. I don't care about the irq and other fields.
+ * set correctly. I don't care about the irq and other fields.
*
+ * Returns 0 for success
*/
static int __init NCR5380_init(struct Scsi_Host *instance, int flags)
return 0;
}
+/**
+ * NCR5380_exit - remove an NCR5380
+ * @instance: adapter to remove
+ *
+ * Assumes that no more work can be queued (e.g. by NCR5380_intr).
+ */
+
static void NCR5380_exit(struct Scsi_Host *instance)
{
- /* Empty, as we didn't schedule any delayed work */
+ cancel_work_sync(&NCR5380_tqueue);
}
-/*
- * Function : int NCR5380_queue_command (struct scsi_cmnd *cmd,
- * void (*done)(struct scsi_cmnd *))
- *
- * Purpose : enqueues a SCSI command
- *
- * Inputs : cmd - SCSI command, done - function called on completion, with
- * a pointer to the command descriptor.
- *
- * Returns : 0
- *
- * Side effects :
- * cmd is added to the per instance issue_queue, with minor
- * twiddling done to the host specific fields of cmd. If the
- * main coroutine is not running, it is restarted.
+/**
+ * NCR5380_queue_command - queue a command
+ * @instance: the relevant SCSI adapter
+ * @cmd: SCSI command
*
+ * cmd is added to the per instance issue_queue, with minor
+ * twiddling done to the host specific fields of cmd. If the
+ * main coroutine is not running, it is restarted.
*/
static int NCR5380_queue_command(struct Scsi_Host *instance,
local_irq_save(flags);
+ /*
+ * Insert the cmd into the issue queue. Note that REQUEST SENSE
+ * commands are added to the head of the queue since any command will
+ * clear the contingent allegiance condition that exists and the
+ * sense data is only guaranteed to be valid while the condition exists.
+ */
+
if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
LIST(cmd, hostdata->issue_queue);
SET_NEXT(cmd, hostdata->issue_queue);
NCR5380_release_dma_irq(instance);
}
-/*
- * Function : NCR5380_main (void)
+/**
+ * NCR5380_main - NCR state machines
*
- * Purpose : NCR5380_main is a coroutine that runs as long as more work can
- * be done on the NCR5380 host adapters in a system. Both
- * NCR5380_queue_command() and NCR5380_intr() will try to start it
- * in case it is not running.
+ * NCR5380_main is a coroutine that runs as long as more work can
+ * be done on the NCR5380 host adapters in a system. Both
+ * NCR5380_queue_command() and NCR5380_intr() will try to start it
+ * in case it is not running.
*
- * NOTE : NCR5380_main exits with interrupts *disabled*, the caller should
- * reenable them. This prevents reentrancy and kernel stack overflow.
+ * Locks: called as its own thread with no locks held.
*/
static void NCR5380_main(struct work_struct *work)
#endif /* REAL_DMA */
-/*
- * Function : void NCR5380_intr (int irq)
- *
- * Purpose : handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
- * from the disconnected queue, and restarting NCR5380_main()
- * as required.
- *
- * Inputs : int irq, irq that caused this interrupt.
+/**
+ * NCR5380_intr - generic NCR5380 irq handler
+ * @irq: interrupt number
+ * @dev_id: device info
*
+ * Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
+ * from the disconnected queue, and restarting NCR5380_main()
+ * as required.
*/
static irqreturn_t NCR5380_intr(int irq, void *dev_id)
* selection.
*/
- timeout = jiffies + 25;
+ timeout = jiffies + (250 * HZ / 1000);
/*
* XXX very interesting - we're seeing a bounce where the BSY we
* If the watchdog timer fires, all future
* accesses to this device will use the
* polled-IO. */
- printk(KERN_NOTICE "scsi%d: switching target %d "
- "lun %llu to slow handshake\n", HOSTNO,
- cmd->device->id, cmd->device->lun);
+ scmd_printk(KERN_INFO, cmd,
+ "switching to slow handshake\n");
cmd->device->borken = 1;
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
ICR_ASSERT_ATN);
*/
default:
if (!tmp) {
- printk(KERN_DEBUG "scsi%d: rejecting message ", HOSTNO);
+ printk(KERN_INFO "scsi%d: rejecting message ",
+ instance->host_no);
spi_print_msg(extended_msg);
printk("\n");
} else if (tmp != EXTENDED_MESSAGE)
- printk(KERN_DEBUG "scsi%d: rejecting unknown "
- "message %02x from target %d, lun %llu\n",
- HOSTNO, tmp, cmd->device->id, cmd->device->lun);
+ scmd_printk(KERN_INFO, cmd,
+ "rejecting unknown message %02x\n",
+ tmp);
else
- printk(KERN_DEBUG "scsi%d: rejecting unknown "
- "extended message "
- "code %02x, length %d from target %d, lun %llu\n",
- HOSTNO, extended_msg[1], extended_msg[0],
- cmd->device->id, cmd->device->lun);
-
+ scmd_printk(KERN_INFO, cmd,
+ "rejecting unknown extended message code %02x, length %d\n",
+ extended_msg[1], extended_msg[0]);
msgout = MESSAGE_REJECT;
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
projects / linux-beck.git / commitdiff