cpqarray.c

Linux块设备驱动源码

	/* Now do all the DMA Mappings */
	if (rq_data_dir(creq) == READ)
		dir = PCI_DMA_FROMDEVICE;
	else
		dir = PCI_DMA_TODEVICE;
	for( i=0; i < seg; i++)
	{
		c->req.sg[i].size = tmp_sg[i].length;
		c->req.sg[i].addr = (__u32) pci_map_page(h->pci_dev,
						 tmp_sg[i].page,
						 tmp_sg[i].offset,
						 tmp_sg[i].length, dir);
	}
DBGPX(	printk("Submitting %d sectors in %d segments\n", creq->nr_sectors, seg); );
	c->req.hdr.sg_cnt = seg;
	c->req.hdr.blk_cnt = creq->nr_sectors;
	c->req.hdr.cmd = (rq_data_dir(creq) == READ) ? IDA_READ : IDA_WRITE;
	c->type = CMD_RWREQ;

	/* Put the request on the tail of the request queue */
	addQ(&h->reqQ, c);
	h->Qdepth++;
	if (h->Qdepth > h->maxQsinceinit) 
		h->maxQsinceinit = h->Qdepth;

	goto queue_next;

startio:
	start_io(h);
}

/* 
 * start_io submits everything on a controller's request queue
 * and moves it to the completion queue.
 *
 * Interrupts had better be off if you're in here
 */
static void start_io(ctlr_info_t *h)
{
	cmdlist_t *c;

	while((c = h->reqQ) != NULL) {
		/* Can't do anything if we're busy */
		if (h->access.fifo_full(h) == 0)
			return;

		/* Get the first entry from the request Q */
		removeQ(&h->reqQ, c);
		h->Qdepth--;
	
		/* Tell the controller to do our bidding */
		h->access.submit_command(h, c);

		/* Get onto the completion Q */
		addQ(&h->cmpQ, c);
	}
}

static inline void complete_buffers(struct bio *bio, int ok)
{
	struct bio *xbh;
	while(bio) {
		int nr_sectors = bio_sectors(bio);

		xbh = bio->bi_next;
		bio->bi_next = NULL;
		
		blk_finished_io(nr_sectors);
		bio_endio(bio, nr_sectors << 9, ok ? 0 : -EIO);

		bio = xbh;
	}
}
/*
 * Mark all buffers that cmd was responsible for
 */
static inline void complete_command(cmdlist_t *cmd, int timeout)
{
	int ok=1;
	int i, ddir;

	if (cmd->req.hdr.rcode & RCODE_NONFATAL &&
	   (hba[cmd->ctlr]->misc_tflags & MISC_NONFATAL_WARN) == 0) {
		printk(KERN_NOTICE "Non Fatal error on ida/c%dd%d\n",
				cmd->ctlr, cmd->hdr.unit);
		hba[cmd->ctlr]->misc_tflags |= MISC_NONFATAL_WARN;
	}
	if (cmd->req.hdr.rcode & RCODE_FATAL) {
		printk(KERN_WARNING "Fatal error on ida/c%dd%d\n",
				cmd->ctlr, cmd->hdr.unit);
		ok = 0;
	}
	if (cmd->req.hdr.rcode & RCODE_INVREQ) {
				printk(KERN_WARNING "Invalid request on ida/c%dd%d = (cmd=%x sect=%d cnt=%d sg=%d ret=%x)\n",
				cmd->ctlr, cmd->hdr.unit, cmd->req.hdr.cmd,
				cmd->req.hdr.blk, cmd->req.hdr.blk_cnt,
				cmd->req.hdr.sg_cnt, cmd->req.hdr.rcode);
		ok = 0;	
	}
	if (timeout) ok = 0;
	/* unmap the DMA mapping for all the scatter gather elements */
	if (cmd->req.hdr.cmd == IDA_READ)
		ddir = PCI_DMA_FROMDEVICE;
	else
		ddir = PCI_DMA_TODEVICE;
        for(i=0; i<cmd->req.hdr.sg_cnt; i++)
                pci_unmap_page(hba[cmd->ctlr]->pci_dev, cmd->req.sg[i].addr,
				cmd->req.sg[i].size, ddir);

	complete_buffers(cmd->rq->bio, ok);

        DBGPX(printk("Done with %p\n", cmd->rq););
	end_that_request_last(cmd->rq);
}

/*
 *  The controller will interrupt us upon completion of commands.
 *  Find the command on the completion queue, remove it, tell the OS and
 *  try to queue up more IO
 */
static irqreturn_t do_ida_intr(int irq, void *dev_id, struct pt_regs *regs)
{
	ctlr_info_t *h = dev_id;
	cmdlist_t *c;
	unsigned long istat;
	unsigned long flags;
	__u32 a,a1;

	istat = h->access.intr_pending(h);
	/* Is this interrupt for us? */
	if (istat == 0)
		return IRQ_NONE;

	/*
	 * If there are completed commands in the completion queue,
	 * we had better do something about it.
	 */
	spin_lock_irqsave(IDA_LOCK(h->ctlr), flags);
	if (istat & FIFO_NOT_EMPTY) {
		while((a = h->access.command_completed(h))) {
			a1 = a; a &= ~3;
			if ((c = h->cmpQ) == NULL)
			{  
				printk(KERN_WARNING "cpqarray: Completion of %08lx ignored\n", (unsigned long)a1);
				continue;	
			} 
			while(c->busaddr != a) {
				c = c->next;
				if (c == h->cmpQ) 
					break;
			}
			/*
			 * If we've found the command, take it off the
			 * completion Q and free it
			 */
			if (c->busaddr == a) {
				removeQ(&h->cmpQ, c);
				/*  Check for invalid command.
                                 *  Controller returns command error,
                                 *  But rcode = 0.
                                 */

				if((a1 & 0x03) && (c->req.hdr.rcode == 0))
                                {
                                	c->req.hdr.rcode = RCODE_INVREQ;
                                }
				if (c->type == CMD_RWREQ) {
					complete_command(c, 0);
					cmd_free(h, c, 1);
				} else if (c->type == CMD_IOCTL_PEND) {
					c->type = CMD_IOCTL_DONE;
				}
				continue;
			}
		}
	}

	/*
	 * See if we can queue up some more IO
	 */
	do_ida_request(h->queue);
	spin_unlock_irqrestore(IDA_LOCK(h->ctlr), flags); 
	return IRQ_HANDLED;
}

/*
 * This timer was for timing out requests that haven't happened after
 * IDA_TIMEOUT.  That wasn't such a good idea.  This timer is used to
 * reset a flags structure so we don't flood the user with
 * "Non-Fatal error" messages.
 */
static void ida_timer(unsigned long tdata)
{
	ctlr_info_t *h = (ctlr_info_t*)tdata;

	h->timer.expires = jiffies + IDA_TIMER;
	add_timer(&h->timer);
	h->misc_tflags = 0;
}

/*
 *  ida_ioctl does some miscellaneous stuff like reporting drive geometry,
 *  setting readahead and submitting commands from userspace to the controller.
 */
static int ida_ioctl(struct inode *inode, struct file *filep, unsigned int cmd, unsigned long arg)
{
	drv_info_t *drv = get_drv(inode->i_bdev->bd_disk);
	ctlr_info_t *host = get_host(inode->i_bdev->bd_disk);
	int error;
	int diskinfo[4];
	struct hd_geometry __user *geo = (struct hd_geometry __user *)arg;
	ida_ioctl_t __user *io = (ida_ioctl_t __user *)arg;
	ida_ioctl_t *my_io;

	switch(cmd) {
	case HDIO_GETGEO:
		if (drv->cylinders) {
			diskinfo[0] = drv->heads;
			diskinfo[1] = drv->sectors;
			diskinfo[2] = drv->cylinders;
		} else {
			diskinfo[0] = 0xff;
			diskinfo[1] = 0x3f;
			diskinfo[2] = drv->nr_blks / (0xff*0x3f);
		}
		put_user(diskinfo[0], &geo->heads);
		put_user(diskinfo[1], &geo->sectors);
		put_user(diskinfo[2], &geo->cylinders);
		put_user(get_start_sect(inode->i_bdev), &geo->start);
		return 0;
	case IDAGETDRVINFO:
		if (copy_to_user(&io->c.drv, drv, sizeof(drv_info_t)))
			return -EFAULT;
		return 0;
	case IDAPASSTHRU:
		if (!capable(CAP_SYS_RAWIO))
			return -EPERM;
		my_io = kmalloc(sizeof(ida_ioctl_t), GFP_KERNEL);
		if (!my_io)
			return -ENOMEM;
		error = -EFAULT;
		if (copy_from_user(my_io, io, sizeof(*my_io)))
			goto out_passthru;
		error = ida_ctlr_ioctl(host, drv - host->drv, my_io);
		if (error)
			goto out_passthru;
		error = -EFAULT;
		if (copy_to_user(io, my_io, sizeof(*my_io)))
			goto out_passthru;
		error = 0;
out_passthru:
		kfree(my_io);
		return error;
	case IDAGETCTLRSIG:
		if (!arg) return -EINVAL;
		put_user(host->ctlr_sig, (int __user *)arg);
		return 0;
	case IDAREVALIDATEVOLS:
		if (iminor(inode) != 0)
			return -ENXIO;
		return revalidate_allvol(host);
	case IDADRIVERVERSION:
		if (!arg) return -EINVAL;
		put_user(DRIVER_VERSION, (unsigned long __user *)arg);
		return 0;
	case IDAGETPCIINFO:
	{
		
		ida_pci_info_struct pciinfo;

		if (!arg) return -EINVAL;
		pciinfo.bus = host->pci_dev->bus->number;
		pciinfo.dev_fn = host->pci_dev->devfn;
		pciinfo.board_id = host->board_id;
		if(copy_to_user((void __user *) arg, &pciinfo,  
			sizeof( ida_pci_info_struct)))
				return -EFAULT;
		return(0);
	}	

	default:
		return -EINVAL;
	}
		
}
/*
 * ida_ctlr_ioctl is for passing commands to the controller from userspace.
 * The command block (io) has already been copied to kernel space for us,
 * however, any elements in the sglist need to be copied to kernel space
 * or copied back to userspace.
 *
 * Only root may perform a controller passthru command, however I'm not doing
 * any serious sanity checking on the arguments.  Doing an IDA_WRITE_MEDIA and
 * putting a 64M buffer in the sglist is probably a *bad* idea.
 */
static int ida_ctlr_ioctl(ctlr_info_t *h, int dsk, ida_ioctl_t *io)
{
	int ctlr = h->ctlr;
	cmdlist_t *c;
	void *p = NULL;
	unsigned long flags;
	int error;

	if ((c = cmd_alloc(h, 0)) == NULL)
		return -ENOMEM;
	c->ctlr = ctlr;
	c->hdr.unit = (io->unit & UNITVALID) ? (io->unit & ~UNITVALID) : dsk;
	c->hdr.size = sizeof(rblk_t) >> 2;
	c->size += sizeof(rblk_t);

	c->req.hdr.cmd = io->cmd;
	c->req.hdr.blk = io->blk;
	c->req.hdr.blk_cnt = io->blk_cnt;
	c->type = CMD_IOCTL_PEND;

	/* Pre submit processing */
	switch(io->cmd) {
	case PASSTHRU_A:
		p = kmalloc(io->sg[0].size, GFP_KERNEL);
		if (!p) 
		{ 
			error = -ENOMEM; 
			cmd_free(h, c, 0); 
			return(error);
		}
		if (copy_from_user(p, io->sg[0].addr, io->sg[0].size)) {
			kfree(p);
			cmd_free(h, c, 0); 
			return -EFAULT;
		}
		c->req.hdr.blk = pci_map_single(h->pci_dev, &(io->c), 
				sizeof(ida_ioctl_t), 
				PCI_DMA_BIDIRECTIONAL);
		c->req.sg[0].size = io->sg[0].size;
		c->req.sg[0].addr = pci_map_single(h->pci_dev, p, 
			c->req.sg[0].size, PCI_DMA_BIDIRECTIONAL);
		c->req.hdr.sg_cnt = 1;
		break;
	case IDA_READ:
	case READ_FLASH_ROM:
	case SENSE_CONTROLLER_PERFORMANCE:
		p = kmalloc(io->sg[0].size, GFP_KERNEL);
		if (!p) 
		{ 
                        error = -ENOMEM; 
                        cmd_free(h, c, 0);
                        return(error);
                }

		c->req.sg[0].size = io->sg[0].size;
		c->req.sg[0].addr = pci_map_single(h->pci_dev, p, 
			c->req.sg[0].size, PCI_DMA_BIDIRECTIONAL); 
		c->req.hdr.sg_cnt = 1;
		break;
	case IDA_WRITE:
	case IDA_WRITE_MEDIA:
	case DIAG_PASS_THRU:
	case COLLECT_BUFFER:
	case WRITE_FLASH_ROM:
		p = kmalloc(io->sg[0].size, GFP_KERNEL);
		if (!p) 
 		{ 
                        error = -ENOMEM; 
                        cmd_free(h, c, 0);
                        return(error);
                }
		if (copy_from_user(p, io->sg[0].addr, io->sg[0].size)) {
			kfree(p);
                        cmd_free(h, c, 0);
			return -EFAULT;
		}
		c->req.sg[0].size = io->sg[0].size;
		c->req.sg[0].addr = pci_map_single(h->pci_dev, p, 
			c->req.sg[0].size, PCI_DMA_BIDIRECTIONAL); 
		c->req.hdr.sg_cnt = 1;
		break;
	default:
		c->req.sg[0].size = sizeof(io->c);
		c->req.sg[0].addr = pci_map_single(h->pci_dev,&io->c, 
			c->req.sg[0].size, PCI_DMA_BIDIRECTIONAL);
		c->req.hdr.sg_cnt = 1;
	}
	
	/* Put the request on the tail of the request queue */
	spin_lock_irqsave(IDA_LOCK(ctlr), flags);
	addQ(&h->reqQ, c);
	h->Qdepth++;
	start_io(h);
	spin_unlock_irqrestore(IDA_LOCK(ctlr), flags);

	/* Wait for completion */
	while(c->type != CMD_IOCTL_DONE)
		schedule();

	/* Unmap the DMA  */
	pci_unmap_single(h->pci_dev, c->req.sg[0].addr, c->req.sg[0].size, 
		PCI_DMA_BIDIRECTIONAL);
	/* Post submit processing */
	switch(io->cmd) {
	case PASSTHRU_A:
		pci_unmap_single(h->pci_dev, c->req.hdr.blk,
                                sizeof(ida_ioctl_t),
                                PCI_DMA_BIDIRECTIONAL);
	case IDA_READ:
	case DIAG_PASS_THRU:
	case SENSE_CONTROLLER_PERFORMANCE:
	case READ_FLASH_ROM:
		if (copy_to_user(io->sg[0].addr, p, io->sg[0].size)) {
			kfree(p);
			return -EFAULT;
		}
		/* fall through and free p */
	case IDA_WRITE:
	case IDA_WRITE_MEDIA:
	case COLLECT_BUFFER:
	case WRITE_FLASH_ROM:
		kfree(p);
		break;
	default:;
		/* Nothing to do */
	}

	io->rcode = c->req.hdr.rcode;
	cmd_free(h, c, 0);
	return(0);
}

/*
 * Commands are pre-allocated in a large block.  Here we use a simple bitmap
 * scheme to suballocte them to the driver.  Operations that are not time
 * critical (and can wait for kmalloc and possibly sleep) can pass in NULL
 * as the first argument to get a new command.
 */
static cmdlist_t * cmd_alloc(ctlr_info_t *h, int get_from_pool)
{
	cmdlist_t * c;
	int i;
	dma_addr_t cmd_dhandle;

	if (!get_from_pool) {
		c = (cmdlist_t*)pci_alloc_consistent(h->pci_dev, 
			sizeof(cmdlist_t), &cmd_dhandle);
		if(c==NULL)
			return NULL;
	} else {
		do {
			i = find_first_zero_bit(h->cmd_pool_bits, NR_CMDS);
			if (i == NR_CMDS)
				return NULL;
		} while(test_and_set_bit(i&(BITS_PER_LONG-1), h->cmd_pool_bits+(i/BITS_PER_LONG)) != 0);
		c = h->cmd_pool + i;
		cmd_dhandle = h->cmd_pool_dhandle + i*sizeof(cmdlist_t);
		h->nr_allocs++;
	}

	memset(c, 0, sizeof(cmdlist_t));
	c->busaddr = cmd_dhandle; 
	return c;
}

static void cmd_free(ctlr_info_t *h, cmdlist_t *c, int got_from_pool)
{
	int i;