umem.c

Linux块设备驱动源码

	desc = &p->desc[p->cnt];
	p->cnt++;
	if ((p->biotail) != &bio->bi_next) {
		*(p->biotail) = bio;
		p->biotail = &(bio->bi_next);
		bio->bi_next = NULL;
	}

	desc->data_dma_handle = dma_handle;

	desc->pci_addr = cpu_to_le64((u64)desc->data_dma_handle);
	desc->local_addr= cpu_to_le64(bio->bi_sector << 9);
	desc->transfer_size = cpu_to_le32(len);
	offset = ( ((char*)&desc->sem_control_bits) - ((char*)p->desc));
	desc->sem_addr = cpu_to_le64((u64)(p->page_dma+offset));
	desc->zero1 = desc->zero2 = 0;
	offset = ( ((char*)(desc+1)) - ((char*)p->desc));
	desc->next_desc_addr = cpu_to_le64(p->page_dma+offset);
	desc->control_bits = cpu_to_le32(DMASCR_GO|DMASCR_ERR_INT_EN|
					 DMASCR_PARITY_INT_EN|
					 DMASCR_CHAIN_EN |
					 DMASCR_SEM_EN |
					 pci_cmds);
	if (rw == WRITE)
		desc->control_bits |= cpu_to_le32(DMASCR_TRANSFER_READ);
	desc->sem_control_bits = desc->control_bits;

	bio->bi_sector += (len>>9);
	bio->bi_size -= len;
	bio->bi_idx++;
	if (bio->bi_idx >= bio->bi_vcnt) 
		card->currentbio = NULL;

	return 1;
}

static void process_page(unsigned long data)
{
	/* check if any of the requests in the page are DMA_COMPLETE,
	 * and deal with them appropriately.
	 * If we find a descriptor without DMA_COMPLETE in the semaphore, then
	 * dma must have hit an error on that descriptor, so use dma_status instead
	 * and assume that all following descriptors must be re-tried.
	 */
	struct mm_page *page;
	struct bio *return_bio=NULL;
	struct cardinfo *card = (struct cardinfo *)data;
	unsigned int dma_status = card->dma_status;

	spin_lock_bh(&card->lock);
	if (card->Active < 0)
		goto out_unlock;
	page = &card->mm_pages[card->Active];
	
	while (page->headcnt < page->cnt) {
		struct bio *bio = page->bio;
		struct mm_dma_desc *desc = &page->desc[page->headcnt];
		int control = le32_to_cpu(desc->sem_control_bits);
		int last=0;
		int idx;

		if (!(control & DMASCR_DMA_COMPLETE)) {
			control = dma_status;
			last=1; 
		}
		page->headcnt++;
		idx = bio->bi_phys_segments;
		bio->bi_phys_segments++;
		if (bio->bi_phys_segments >= bio->bi_vcnt)
			page->bio = bio->bi_next;

		pci_unmap_page(card->dev, desc->data_dma_handle, 
			       bio_iovec_idx(bio,idx)->bv_len,
				 (control& DMASCR_TRANSFER_READ) ?
				PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);
		if (control & DMASCR_HARD_ERROR) {
			/* error */
			clear_bit(BIO_UPTODATE, &bio->bi_flags);
			printk(KERN_WARNING "MM%d: I/O error on sector %d/%d\n",
			       card->card_number, 
			       le32_to_cpu(desc->local_addr)>>9,
			       le32_to_cpu(desc->transfer_size));
			dump_dmastat(card, control);
		} else if (test_bit(BIO_RW, &bio->bi_rw) &&
			   le32_to_cpu(desc->local_addr)>>9 == card->init_size) {
			card->init_size += le32_to_cpu(desc->transfer_size)>>9;
			if (card->init_size>>1 >= card->mm_size) {
				printk(KERN_INFO "MM%d: memory now initialised\n",
				       card->card_number);
				set_userbit(card, MEMORY_INITIALIZED, 1);
			}
		}
		if (bio != page->bio) {
			bio->bi_next = return_bio;
			return_bio = bio;
		}

		if (last) break;
	}

	if (debug & DEBUG_LED_ON_TRANSFER)
		set_led(card, LED_REMOVE, LED_OFF);

	if (card->check_batteries) {
		card->check_batteries = 0;
		check_batteries(card);
	}
	if (page->headcnt >= page->cnt) {
		reset_page(page);
		card->Active = -1;
		activate(card);
	} else {
		/* haven't finished with this one yet */
		pr_debug("do some more\n");
		mm_start_io(card);
	}
 out_unlock:
	spin_unlock_bh(&card->lock);

	while(return_bio) {
		struct bio *bio = return_bio;

		return_bio = bio->bi_next;
		bio->bi_next = NULL;
		bio_endio(bio, bio->bi_size, 0);
	}
}

/*
-----------------------------------------------------------------------------------
--                              mm_make_request
-----------------------------------------------------------------------------------
*/
static int mm_make_request(request_queue_t *q, struct bio *bio)
{
	struct cardinfo *card = q->queuedata;
	pr_debug("mm_make_request %ld %d\n", bh->b_rsector, bh->b_size);

	bio->bi_phys_segments = bio->bi_idx; /* count of completed segments*/
	spin_lock_irq(&card->lock);
	*card->biotail = bio;
	bio->bi_next = NULL;
	card->biotail = &bio->bi_next;
	blk_plug_device(q);
	spin_unlock_irq(&card->lock);

	return 0;
}

/*
-----------------------------------------------------------------------------------
--                              mm_interrupt
-----------------------------------------------------------------------------------
*/
static irqreturn_t mm_interrupt(int irq, void *__card, struct pt_regs *regs)
{
	struct cardinfo *card = (struct cardinfo *) __card;
	unsigned int dma_status;
	unsigned short cfg_status;

HW_TRACE(0x30);

	dma_status = le32_to_cpu(readl(card->csr_remap + DMA_STATUS_CTRL));

	if (!(dma_status & (DMASCR_ERROR_MASK | DMASCR_CHAIN_COMPLETE))) {
		/* interrupt wasn't for me ... */
		return IRQ_NONE;
        }

	/* clear COMPLETION interrupts */
	if (card->flags & UM_FLAG_NO_BYTE_STATUS)
		writel(cpu_to_le32(DMASCR_DMA_COMPLETE|DMASCR_CHAIN_COMPLETE),
		       card->csr_remap+ DMA_STATUS_CTRL);
	else
		writeb((DMASCR_DMA_COMPLETE|DMASCR_CHAIN_COMPLETE) >> 16,
		       card->csr_remap+ DMA_STATUS_CTRL + 2);
	
	/* log errors and clear interrupt status */
	if (dma_status & DMASCR_ANY_ERR) {
		unsigned int	data_log1, data_log2;
		unsigned int	addr_log1, addr_log2;
		unsigned char	stat, count, syndrome, check;

		stat = readb(card->csr_remap + MEMCTRLCMD_ERRSTATUS);

		data_log1 = le32_to_cpu(readl(card->csr_remap + ERROR_DATA_LOG));
		data_log2 = le32_to_cpu(readl(card->csr_remap + ERROR_DATA_LOG + 4));
		addr_log1 = le32_to_cpu(readl(card->csr_remap + ERROR_ADDR_LOG));
		addr_log2 = readb(card->csr_remap + ERROR_ADDR_LOG + 4);

		count = readb(card->csr_remap + ERROR_COUNT);
		syndrome = readb(card->csr_remap + ERROR_SYNDROME);
		check = readb(card->csr_remap + ERROR_CHECK);

		dump_dmastat(card, dma_status);

		if (stat & 0x01)
			printk(KERN_ERR "MM%d*: Memory access error detected (err count %d)\n",
				card->card_number, count);
		if (stat & 0x02)
			printk(KERN_ERR "MM%d*: Multi-bit EDC error\n",
				card->card_number);

		printk(KERN_ERR "MM%d*: Fault Address 0x%02x%08x, Fault Data 0x%08x%08x\n",
			card->card_number, addr_log2, addr_log1, data_log2, data_log1);
		printk(KERN_ERR "MM%d*: Fault Check 0x%02x, Fault Syndrome 0x%02x\n",
			card->card_number, check, syndrome);

		writeb(0, card->csr_remap + ERROR_COUNT);
	}

	if (dma_status & DMASCR_PARITY_ERR_REP) {
		printk(KERN_ERR "MM%d*: PARITY ERROR REPORTED\n", card->card_number);
		pci_read_config_word(card->dev, PCI_STATUS, &cfg_status);
		pci_write_config_word(card->dev, PCI_STATUS, cfg_status);
	}

	if (dma_status & DMASCR_PARITY_ERR_DET) {
		printk(KERN_ERR "MM%d*: PARITY ERROR DETECTED\n", card->card_number); 
		pci_read_config_word(card->dev, PCI_STATUS, &cfg_status);
		pci_write_config_word(card->dev, PCI_STATUS, cfg_status);
	}

	if (dma_status & DMASCR_SYSTEM_ERR_SIG) {
		printk(KERN_ERR "MM%d*: SYSTEM ERROR\n", card->card_number); 
		pci_read_config_word(card->dev, PCI_STATUS, &cfg_status);
		pci_write_config_word(card->dev, PCI_STATUS, cfg_status);
	}

	if (dma_status & DMASCR_TARGET_ABT) {
		printk(KERN_ERR "MM%d*: TARGET ABORT\n", card->card_number); 
		pci_read_config_word(card->dev, PCI_STATUS, &cfg_status);
		pci_write_config_word(card->dev, PCI_STATUS, cfg_status);
	}

	if (dma_status & DMASCR_MASTER_ABT) {
		printk(KERN_ERR "MM%d*: MASTER ABORT\n", card->card_number); 
		pci_read_config_word(card->dev, PCI_STATUS, &cfg_status);
		pci_write_config_word(card->dev, PCI_STATUS, cfg_status);
	}

	/* and process the DMA descriptors */
	card->dma_status = dma_status;
	tasklet_schedule(&card->tasklet);

HW_TRACE(0x36);

	return IRQ_HANDLED; 
}
/*
-----------------------------------------------------------------------------------
--                         set_fault_to_battery_status
-----------------------------------------------------------------------------------
*/
/*
 * If both batteries are good, no LED
 * If either battery has been warned, solid LED
 * If both batteries are bad, flash the LED quickly
 * If either battery is bad, flash the LED semi quickly
 */
static void set_fault_to_battery_status(struct cardinfo *card)
{
	if (card->battery[0].good && card->battery[1].good)
		set_led(card, LED_FAULT, LED_OFF);
	else if (card->battery[0].warned || card->battery[1].warned)
		set_led(card, LED_FAULT, LED_ON);
	else if (!card->battery[0].good && !card->battery[1].good)
		set_led(card, LED_FAULT, LED_FLASH_7_0);
	else
		set_led(card, LED_FAULT, LED_FLASH_3_5);
}

static void init_battery_timer(void);


/*
-----------------------------------------------------------------------------------
--                            check_battery
-----------------------------------------------------------------------------------
*/
static int check_battery(struct cardinfo *card, int battery, int status)
{
	if (status != card->battery[battery].good) {
		card->battery[battery].good = !card->battery[battery].good;
		card->battery[battery].last_change = jiffies;

		if (card->battery[battery].good) {
			printk(KERN_ERR "MM%d: Battery %d now good\n",
				card->card_number, battery + 1);
			card->battery[battery].warned = 0;
		} else
			printk(KERN_ERR "MM%d: Battery %d now FAILED\n",
				card->card_number, battery + 1);

		return 1;
	} else if (!card->battery[battery].good &&
		   !card->battery[battery].warned &&
		   time_after_eq(jiffies, card->battery[battery].last_change +
				 (HZ * 60 * 60 * 5))) {
		printk(KERN_ERR "MM%d: Battery %d still FAILED after 5 hours\n",
			card->card_number, battery + 1);
		card->battery[battery].warned = 1;

		return 1;
	}

	return 0;
}
/*
-----------------------------------------------------------------------------------
--                              check_batteries
-----------------------------------------------------------------------------------
*/
static void check_batteries(struct cardinfo *card)
{
	/* NOTE: this must *never* be called while the card
	 * is doing (bus-to-card) DMA, or you will need the
	 * reset switch
	 */
	unsigned char status;
	int ret1, ret2;

	status = readb(card->csr_remap + MEMCTRLSTATUS_BATTERY);
	if (debug & DEBUG_BATTERY_POLLING)
		printk(KERN_DEBUG "MM%d: checking battery status, 1 = %s, 2 = %s\n",
		       card->card_number,
		       (status & BATTERY_1_FAILURE) ? "FAILURE" : "OK",
		       (status & BATTERY_2_FAILURE) ? "FAILURE" : "OK");

	ret1 = check_battery(card, 0, !(status & BATTERY_1_FAILURE));
	ret2 = check_battery(card, 1, !(status & BATTERY_2_FAILURE));

	if (ret1 || ret2)
		set_fault_to_battery_status(card);
}

static void check_all_batteries(unsigned long ptr)
{
	int i;

	for (i = 0; i < num_cards; i++) 
		if (!(cards[i].flags & UM_FLAG_NO_BATT)) {
			struct cardinfo *card = &cards[i];
			spin_lock_bh(&card->lock);
			if (card->Active >= 0)
				card->check_batteries = 1;
			else
				check_batteries(card);
			spin_unlock_bh(&card->lock);
		}

	init_battery_timer();
}
/*
-----------------------------------------------------------------------------------
--                            init_battery_timer
-----------------------------------------------------------------------------------
*/
static void init_battery_timer(void)
{
	init_timer(&battery_timer);
	battery_timer.function = check_all_batteries;
	battery_timer.expires = jiffies + (HZ * 60);
	add_timer(&battery_timer);
}
/*
-----------------------------------------------------------------------------------
--                              del_battery_timer
-----------------------------------------------------------------------------------
*/
static void del_battery_timer(void)
{
	del_timer(&battery_timer);
}
/*
-----------------------------------------------------------------------------------
--                                mm_revalidate
-----------------------------------------------------------------------------------
*/
/*
 * Note no locks taken out here.  In a worst case scenario, we could drop
 * a chunk of system memory.  But that should never happen, since validation
 * happens at open or mount time, when locks are held.
 *
 *	That's crap, since doing that while some partitions are opened
 * or mounted will give you really nasty results.
 */
static int mm_revalidate(struct gendisk *disk)
{
	struct cardinfo *card = disk->private_data;
	set_capacity(disk, card->mm_size << 1);
	return 0;
}
/*
-----------------------------------------------------------------------------------
--                            mm_ioctl
-----------------------------------------------------------------------------------
*/
static int mm_ioctl(struct inode *i, struct file *f, unsigned int cmd, unsigned long arg)
{
	if (cmd == HDIO_GETGEO) {
		struct cardinfo *card = i->i_bdev->bd_disk->private_data;
		int size = card->mm_size * (1024 / MM_HARDSECT);
		struct hd_geometry geo;
		/*
		 * get geometry: we have to fake one...  trim the size to a
		 * multiple of 2048 (1M): tell we have 32 sectors, 64 heads,
		 * whatever cylinders.
		 */
		geo.heads     = 64;
		geo.sectors   = 32;
		geo.start     = get_start_sect(i->i_bdev);
		geo.cylinders = size / (geo.heads * geo.sectors);

		if (copy_to_user((void __user *) arg, &geo, sizeof(geo)))
			return -EFAULT;
		return 0;
	}