mesh.c

linux 内核源代码

			}
			ms->msgphase = msg_out;
			/*
			 * We need to wait for REQ before dropping ATN.
			 * We wait for at most 30us, then fall back to
			 * a scheme where we issue a SEQ_COMMAND with ATN,
			 * which will give us a phase mismatch interrupt
			 * when REQ does come, and then we send the message.
			 */
			t = 230;		/* wait up to 230us */
			while ((in_8(&mr->bus_status0) & BS0_REQ) == 0) {
				if (--t < 0) {
					dlog(ms, "impatient for req", ms->n_msgout);
					ms->msgphase = msg_none;
					break;
				}
				udelay(1);
			}
			break;
		case dataing:
			if (ms->dma_count != 0) {
				start_phase(ms);
				return;
			}
			/*
			 * We can get a phase mismatch here if the target
			 * changes to the status phase, even though we have
			 * had a command complete interrupt.  Then, if we
			 * issue the SEQ_STATUS command, we'll get a sequence
			 * error interrupt.  Which isn't so bad except that
			 * occasionally the mesh actually executes the
			 * SEQ_STATUS *as well as* giving us the sequence
			 * error and phase mismatch exception.
			 */
			out_8(&mr->sequence, 0);
			out_8(&mr->interrupt,
			      INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
			halt_dma(ms);
			break;
		case statusing:
			if (cmd) {
				cmd->SCp.Status = mr->fifo;
				if (DEBUG_TARGET(cmd))
					printk(KERN_DEBUG "mesh: status is %x\n",
					       cmd->SCp.Status);
			}
			ms->msgphase = msg_in;
			break;
		case busfreeing:
			mesh_done(ms, 1);
			return;
		case disconnecting:
			ms->current_req = NULL;
			ms->phase = idle;
			mesh_start(ms);
			return;
		default:
			break;
		}
		++ms->phase;
		start_phase(ms);
		break;
	}
}


/*
 * Called by midlayer with host locked to queue a new
 * request
 */
static int mesh_queue(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
{
	struct mesh_state *ms;

	cmd->scsi_done = done;
	cmd->host_scribble = NULL;

	ms = (struct mesh_state *) cmd->device->host->hostdata;

	if (ms->request_q == NULL)
		ms->request_q = cmd;
	else
		ms->request_qtail->host_scribble = (void *) cmd;
	ms->request_qtail = cmd;

	if (ms->phase == idle)
		mesh_start(ms);

	return 0;
}

/*
 * Called to handle interrupts, either call by the interrupt
 * handler (do_mesh_interrupt) or by other functions in
 * exceptional circumstances
 */
static void mesh_interrupt(struct mesh_state *ms)
{
	volatile struct mesh_regs __iomem *mr = ms->mesh;
	int intr;

#if 0
	if (ALLOW_DEBUG(ms->conn_tgt))
		printk(KERN_DEBUG "mesh_intr, bs0=%x int=%x exc=%x err=%x "
		       "phase=%d msgphase=%d\n", mr->bus_status0,
		       mr->interrupt, mr->exception, mr->error,
		       ms->phase, ms->msgphase);
#endif
	while ((intr = in_8(&mr->interrupt)) != 0) {
		dlog(ms, "interrupt intr/err/exc/seq=%.8x", 
		     MKWORD(intr, mr->error, mr->exception, mr->sequence));
		if (intr & INT_ERROR) {
			handle_error(ms);
		} else if (intr & INT_EXCEPTION) {
			handle_exception(ms);
		} else if (intr & INT_CMDDONE) {
			out_8(&mr->interrupt, INT_CMDDONE);
			cmd_complete(ms);
		}
	}
}

/* Todo: here we can at least try to remove the command from the
 * queue if it isn't connected yet, and for pending command, assert
 * ATN until the bus gets freed.
 */
static int mesh_abort(struct scsi_cmnd *cmd)
{
	struct mesh_state *ms = (struct mesh_state *) cmd->device->host->hostdata;

	printk(KERN_DEBUG "mesh_abort(%p)\n", cmd);
	mesh_dump_regs(ms);
	dumplog(ms, cmd->device->id);
	dumpslog(ms);
	return FAILED;
}

/*
 * Called by the midlayer with the lock held to reset the
 * SCSI host and bus.
 * The midlayer will wait for devices to come back, we don't need
 * to do that ourselves
 */
static int mesh_host_reset(struct scsi_cmnd *cmd)
{
	struct mesh_state *ms = (struct mesh_state *) cmd->device->host->hostdata;
	volatile struct mesh_regs __iomem *mr = ms->mesh;
	volatile struct dbdma_regs __iomem *md = ms->dma;
	unsigned long flags;

	printk(KERN_DEBUG "mesh_host_reset\n");

	spin_lock_irqsave(ms->host->host_lock, flags);

	/* Reset the controller & dbdma channel */
	out_le32(&md->control, (RUN|PAUSE|FLUSH|WAKE) << 16);	/* stop dma */
	out_8(&mr->exception, 0xff);	/* clear all exception bits */
	out_8(&mr->error, 0xff);	/* clear all error bits */
	out_8(&mr->sequence, SEQ_RESETMESH);
       	mesh_flush_io(mr);
	udelay(1);
	out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
	out_8(&mr->source_id, ms->host->this_id);
	out_8(&mr->sel_timeout, 25);	/* 250ms */
	out_8(&mr->sync_params, ASYNC_PARAMS);

	/* Reset the bus */
	out_8(&mr->bus_status1, BS1_RST);	/* assert RST */
       	mesh_flush_io(mr);
	udelay(30);			/* leave it on for >= 25us */
	out_8(&mr->bus_status1, 0);	/* negate RST */

	/* Complete pending commands */
	handle_reset(ms);
	
	spin_unlock_irqrestore(ms->host->host_lock, flags);
	return SUCCESS;
}

static void set_mesh_power(struct mesh_state *ms, int state)
{
	if (!machine_is(powermac))
		return;
	if (state) {
		pmac_call_feature(PMAC_FTR_MESH_ENABLE, macio_get_of_node(ms->mdev), 0, 1);
		msleep(200);
	} else {
		pmac_call_feature(PMAC_FTR_MESH_ENABLE, macio_get_of_node(ms->mdev), 0, 0);
		msleep(10);
	}
}


#ifdef CONFIG_PM
static int mesh_suspend(struct macio_dev *mdev, pm_message_t mesg)
{
	struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
	unsigned long flags;

	switch (mesg.event) {
	case PM_EVENT_SUSPEND:
	case PM_EVENT_FREEZE:
		break;
	default:
		return 0;
	}
	if (mesg.event == mdev->ofdev.dev.power.power_state.event)
		return 0;

	scsi_block_requests(ms->host);
	spin_lock_irqsave(ms->host->host_lock, flags);
	while(ms->phase != idle) {
		spin_unlock_irqrestore(ms->host->host_lock, flags);
		msleep(10);
		spin_lock_irqsave(ms->host->host_lock, flags);
	}
	ms->phase = sleeping;
	spin_unlock_irqrestore(ms->host->host_lock, flags);
	disable_irq(ms->meshintr);
	set_mesh_power(ms, 0);

	mdev->ofdev.dev.power.power_state = mesg;

	return 0;
}

static int mesh_resume(struct macio_dev *mdev)
{
	struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
	unsigned long flags;

	if (mdev->ofdev.dev.power.power_state.event == PM_EVENT_ON)
		return 0;

	set_mesh_power(ms, 1);
	mesh_init(ms);
	spin_lock_irqsave(ms->host->host_lock, flags);
	mesh_start(ms);
	spin_unlock_irqrestore(ms->host->host_lock, flags);
	enable_irq(ms->meshintr);
	scsi_unblock_requests(ms->host);

	mdev->ofdev.dev.power.power_state.event = PM_EVENT_ON;

	return 0;
}

#endif /* CONFIG_PM */

/*
 * If we leave drives set for synchronous transfers (especially
 * CDROMs), and reboot to MacOS, it gets confused, poor thing.
 * So, on reboot we reset the SCSI bus.
 */
static int mesh_shutdown(struct macio_dev *mdev)
{
	struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
	volatile struct mesh_regs __iomem *mr;
	unsigned long flags;

       	printk(KERN_INFO "resetting MESH scsi bus(es)\n");
	spin_lock_irqsave(ms->host->host_lock, flags);
       	mr = ms->mesh;
	out_8(&mr->intr_mask, 0);
	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
	out_8(&mr->bus_status1, BS1_RST);
	mesh_flush_io(mr);
	udelay(30);
	out_8(&mr->bus_status1, 0);
	spin_unlock_irqrestore(ms->host->host_lock, flags);

	return 0;
}

static struct scsi_host_template mesh_template = {
	.proc_name			= "mesh",
	.name				= "MESH",
	.queuecommand			= mesh_queue,
	.eh_abort_handler		= mesh_abort,
	.eh_host_reset_handler		= mesh_host_reset,
	.can_queue			= 20,
	.this_id			= 7,
	.sg_tablesize			= SG_ALL,
	.cmd_per_lun			= 2,
	.use_clustering			= DISABLE_CLUSTERING,
	.use_sg_chaining		= ENABLE_SG_CHAINING,
};

static int mesh_probe(struct macio_dev *mdev, const struct of_device_id *match)
{
	struct device_node *mesh = macio_get_of_node(mdev);
	struct pci_dev* pdev = macio_get_pci_dev(mdev);
	int tgt, minper;
	const int *cfp;
	struct mesh_state *ms;
	struct Scsi_Host *mesh_host;
	void *dma_cmd_space;
	dma_addr_t dma_cmd_bus;

	switch (mdev->bus->chip->type) {
	case macio_heathrow:
	case macio_gatwick:
	case macio_paddington:
		use_active_neg = 0;
		break;
	default:
		use_active_neg = SEQ_ACTIVE_NEG;
	}

	if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {
       		printk(KERN_ERR "mesh: expected 2 addrs and 2 intrs"
	       	       " (got %d,%d)\n", macio_resource_count(mdev),
		       macio_irq_count(mdev));
		return -ENODEV;
	}

	if (macio_request_resources(mdev, "mesh") != 0) {
       		printk(KERN_ERR "mesh: unable to request memory resources");
		return -EBUSY;
	}
       	mesh_host = scsi_host_alloc(&mesh_template, sizeof(struct mesh_state));
	if (mesh_host == NULL) {
		printk(KERN_ERR "mesh: couldn't register host");
		goto out_release;
	}
	
	/* Old junk for root discovery, that will die ultimately */
#if !defined(MODULE)
       	note_scsi_host(mesh, mesh_host);
#endif

	mesh_host->base = macio_resource_start(mdev, 0);
	mesh_host->irq = macio_irq(mdev, 0);
       	ms = (struct mesh_state *) mesh_host->hostdata;
	macio_set_drvdata(mdev, ms);
	ms->host = mesh_host;
	ms->mdev = mdev;
	ms->pdev = pdev;
	
	ms->mesh = ioremap(macio_resource_start(mdev, 0), 0x1000);
	if (ms->mesh == NULL) {
		printk(KERN_ERR "mesh: can't map registers\n");
		goto out_free;
	}		
	ms->dma = ioremap(macio_resource_start(mdev, 1), 0x1000);
	if (ms->dma == NULL) {
		printk(KERN_ERR "mesh: can't map registers\n");
		iounmap(ms->mesh);
		goto out_free;
	}

       	ms->meshintr = macio_irq(mdev, 0);
       	ms->dmaintr = macio_irq(mdev, 1);

       	/* Space for dma command list: +1 for stop command,
       	 * +1 to allow for aligning.
	 */
	ms->dma_cmd_size = (mesh_host->sg_tablesize + 2) * sizeof(struct dbdma_cmd);

	/* We use the PCI APIs for now until the generic one gets fixed
	 * enough or until we get some macio-specific versions
	 */
	dma_cmd_space = pci_alloc_consistent(macio_get_pci_dev(mdev),
					     ms->dma_cmd_size,
					     &dma_cmd_bus);
	if (dma_cmd_space == NULL) {
		printk(KERN_ERR "mesh: can't allocate DMA table\n");
		goto out_unmap;
	}
	memset(dma_cmd_space, 0, ms->dma_cmd_size);

	ms->dma_cmds = (struct dbdma_cmd *) DBDMA_ALIGN(dma_cmd_space);
       	ms->dma_cmd_space = dma_cmd_space;
	ms->dma_cmd_bus = dma_cmd_bus + ((unsigned long)ms->dma_cmds)
		- (unsigned long)dma_cmd_space;
	ms->current_req = NULL;
       	for (tgt = 0; tgt < 8; ++tgt) {
	       	ms->tgts[tgt].sdtr_state = do_sdtr;
	       	ms->tgts[tgt].sync_params = ASYNC_PARAMS;
	       	ms->tgts[tgt].current_req = NULL;
       	}

	if ((cfp = of_get_property(mesh, "clock-frequency", NULL)))
       		ms->clk_freq = *cfp;
	else {
       		printk(KERN_INFO "mesh: assuming 50MHz clock frequency\n");
	       	ms->clk_freq = 50000000;
       	}

       	/* The maximum sync rate is clock / 5; increase
       	 * mesh_sync_period if necessary.
	 */
	minper = 1000000000 / (ms->clk_freq / 5); /* ns */
	if (mesh_sync_period < minper)
		mesh_sync_period = minper;

	/* Power up the chip */
	set_mesh_power(ms, 1);

	/* Set it up */
       	mesh_init(ms);

	/* Request interrupt */
       	if (request_irq(ms->meshintr, do_mesh_interrupt, 0, "MESH", ms)) {
	       	printk(KERN_ERR "MESH: can't get irq %d\n", ms->meshintr);
		goto out_shutdown;
	}

	/* Add scsi host & scan */
	if (scsi_add_host(mesh_host, &mdev->ofdev.dev))
		goto out_release_irq;
	scsi_scan_host(mesh_host);

	return 0;

 out_release_irq:
	free_irq(ms->meshintr, ms);
 out_shutdown:
	/* shutdown & reset bus in case of error or macos can be confused
	 * at reboot if the bus was set to synchronous mode already
	 */
	mesh_shutdown(mdev);
	set_mesh_power(ms, 0);
	pci_free_consistent(macio_get_pci_dev(mdev), ms->dma_cmd_size,
			    ms->dma_cmd_space, ms->dma_cmd_bus);
 out_unmap:
	iounmap(ms->dma);
	iounmap(ms->mesh);
 out_free:
	scsi_host_put(mesh_host);
 out_release:
	macio_release_resources(mdev);

	return -ENODEV;
}

static int mesh_remove(struct macio_dev *mdev)
{
	struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
	struct Scsi_Host *mesh_host = ms->host;

	scsi_remove_host(mesh_host);

	free_irq(ms->meshintr, ms);

	/* Reset scsi bus */
	mesh_shutdown(mdev);

	/* Shut down chip & termination */
	set_mesh_power(ms, 0);

	/* Unmap registers & dma controller */
	iounmap(ms->mesh);
       	iounmap(ms->dma);

	/* Free DMA commands memory */
	pci_free_consistent(macio_get_pci_dev(mdev), ms->dma_cmd_size,
			    ms->dma_cmd_space, ms->dma_cmd_bus);

	/* Release memory resources */
	macio_release_resources(mdev);

	scsi_host_put(mesh_host);

	return 0;
}


static struct of_device_id mesh_match[] = 
{
	{
	.name 		= "mesh",
	},
	{
	.type		= "scsi",
	.compatible	= "chrp,mesh0"
	},
	{},
};
MODULE_DEVICE_TABLE (of, mesh_match);

static struct macio_driver mesh_driver = 
{
	.name 		= "mesh",
	.match_table	= mesh_match,
	.probe		= mesh_probe,
	.remove		= mesh_remove,
	.shutdown	= mesh_shutdown,
#ifdef CONFIG_PM
	.suspend	= mesh_suspend,
	.resume		= mesh_resume,
#endif
};


static int __init init_mesh(void)
{

	/* Calculate sync rate from module parameters */
	if (sync_rate > 10)
		sync_rate = 10;
	if (sync_rate > 0) {
		printk(KERN_INFO "mesh: configured for synchronous %d MB/s\n", sync_rate);
		mesh_sync_period = 1000 / sync_rate;	/* ns */
		mesh_sync_offset = 15;
	} else
		printk(KERN_INFO "mesh: configured for asynchronous\n");

	return macio_register_driver(&mesh_driver);
}

static void __exit exit_mesh(void)
{
	return macio_unregister_driver(&mesh_driver);
}

module_init(init_mesh);
module_exit(exit_mesh);