drivers/block/rsxx/dev.c - third_party/linux - Git at Google

 /*
 * Filename: dev.c
 *
 *
 * Authors: Joshua Morris <josh.h.morris@us.ibm.com>
 *	Philip Kelleher <pjk1939@linux.vnet.ibm.com>
 *
 * (C) Copyright 2013 IBM Corporation
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

 #include <linux/kernel.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/slab.h>

 #include <linux/hdreg.h>
 #include <linux/genhd.h>
 #include <linux/blkdev.h>
 #include <linux/bio.h>

 #include <linux/fs.h>

 #include "rsxx_priv.h"

 static unsigned int blkdev_minors = 64;
 module_param(blkdev_minors, uint, 0444);
 MODULE_PARM_DESC(blkdev_minors, "Number of minors(partitions)");

 /*
  * For now I'm making this tweakable in case any applications hit this limit.
  * If you see a "bio too big" error in the log you will need to raise this
  * value.
  */
 static unsigned int blkdev_max_hw_sectors = 1024;
 module_param(blkdev_max_hw_sectors, uint, 0444);
 MODULE_PARM_DESC(blkdev_max_hw_sectors, "Max hw sectors for a single BIO");

 static unsigned int enable_blkdev = 1;
 module_param(enable_blkdev , uint, 0444);
 MODULE_PARM_DESC(enable_blkdev, "Enable block device interfaces");


 struct rsxx_bio_meta {
 	struct bio	*bio;
 	atomic_t	pending_dmas;
 	atomic_t	error;
 	unsigned long	start_time;
 };

 static struct kmem_cache *bio_meta_pool;

 /*----------------- Block Device Operations -----------------*/
 static int rsxx_blkdev_ioctl(struct block_device *bdev,
 				 fmode_t mode,
 				 unsigned int cmd,
 				 unsigned long arg)
 {
 	struct rsxx_cardinfo *card = bdev->bd_disk->private_data;

 	switch (cmd) {
 	case RSXX_GETREG:
 		return rsxx_reg_access(card, (void __user *)arg, 1);
 	case RSXX_SETREG:
 		return rsxx_reg_access(card, (void __user *)arg, 0);
 	}

 	return -ENOTTY;
 }

 static int rsxx_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 {
 	struct rsxx_cardinfo *card = bdev->bd_disk->private_data;
 	u64 blocks = card->size8 >> 9;

 	/*
 	 * get geometry: Fake it. I haven't found any drivers that set
 	 * geo->start, so we won't either.
 	 */
 	if (card->size8) {
 		geo->heads = 64;
 		geo->sectors = 16;
 		do_div(blocks, (geo->heads * geo->sectors));
 		geo->cylinders = blocks;
 	} else {
 		geo->heads = 0;
 		geo->sectors = 0;
 		geo->cylinders = 0;
 	}
 	return 0;
 }

 static const struct block_device_operations rsxx_fops = {
 	.owner		= THIS_MODULE,
 	.getgeo		= rsxx_getgeo,
 	.ioctl		= rsxx_blkdev_ioctl,
 };

 static void disk_stats_start(struct rsxx_cardinfo *card, struct bio *bio)
 {
 	generic_start_io_acct(card->queue, bio_data_dir(bio), bio_sectors(bio),
 			     &card->gendisk->part0);
 }

 static void disk_stats_complete(struct rsxx_cardinfo *card,
 				struct bio *bio,
 				unsigned long start_time)
 {
 	generic_end_io_acct(card->queue, bio_data_dir(bio),
 				&card->gendisk->part0, start_time);
 }

 static void bio_dma_done_cb(struct rsxx_cardinfo *card,
 			    void *cb_data,
 			    unsigned int error)
 {
 	struct rsxx_bio_meta *meta = cb_data;

 	if (error)
 		atomic_set(&meta->error, 1);

 	if (atomic_dec_and_test(&meta->pending_dmas)) {
 		if (!card->eeh_state && card->gendisk)
 			disk_stats_complete(card, meta->bio, meta->start_time);

 		if (atomic_read(&meta->error))
 			bio_io_error(meta->bio);
 		else
 			bio_endio(meta->bio);
 		kmem_cache_free(bio_meta_pool, meta);
 	}
 }

 static blk_qc_t rsxx_make_request(struct request_queue *q, struct bio *bio)
 {
 	struct rsxx_cardinfo *card = q->queuedata;
 	struct rsxx_bio_meta *bio_meta;
 	blk_status_t st = BLK_STS_IOERR;

 	blk_queue_split(q, &bio);

 	might_sleep();

 	if (!card)
 		goto req_err;

 	if (bio_end_sector(bio) > get_capacity(card->gendisk))
 		goto req_err;

 	if (unlikely(card->halt))
 		goto req_err;

 	if (unlikely(card->dma_fault))
 		goto req_err;

 	if (bio->bi_iter.bi_size == 0) {
 		dev_err(CARD_TO_DEV(card), "size zero BIO!\n");
 		goto req_err;
 	}

 	bio_meta = kmem_cache_alloc(bio_meta_pool, GFP_KERNEL);
 	if (!bio_meta) {
 		st = BLK_STS_RESOURCE;
 		goto req_err;
 	}

 	bio_meta->bio = bio;
 	atomic_set(&bio_meta->error, 0);
 	atomic_set(&bio_meta->pending_dmas, 0);
 	bio_meta->start_time = jiffies;

 	if (!unlikely(card->halt))
 		disk_stats_start(card, bio);

 	dev_dbg(CARD_TO_DEV(card), "BIO[%c]: meta: %p addr8: x%llx size: %d\n",
 		 bio_data_dir(bio) ? 'W' : 'R', bio_meta,
 		 (u64)bio->bi_iter.bi_sector << 9, bio->bi_iter.bi_size);

 	st = rsxx_dma_queue_bio(card, bio, &bio_meta->pending_dmas,
 				    bio_dma_done_cb, bio_meta);
 	if (st)
 		goto queue_err;

 	return BLK_QC_T_NONE;

 queue_err:
 	kmem_cache_free(bio_meta_pool, bio_meta);
 req_err:
 	if (st)
 		bio->bi_status = st;
 	bio_endio(bio);
 	return BLK_QC_T_NONE;
 }

 /*----------------- Device Setup -------------------*/
 static bool rsxx_discard_supported(struct rsxx_cardinfo *card)
 {
 	unsigned char pci_rev;

 	pci_read_config_byte(card->dev, PCI_REVISION_ID, &pci_rev);

 	return (pci_rev >= RSXX_DISCARD_SUPPORT);
 }

 int rsxx_attach_dev(struct rsxx_cardinfo *card)
 {
 	mutex_lock(&card->dev_lock);

 	/* The block device requires the stripe size from the config. */
 	if (enable_blkdev) {
 		if (card->config_valid)
 			set_capacity(card->gendisk, card->size8 >> 9);
 		else
 			set_capacity(card->gendisk, 0);
 		device_add_disk(CARD_TO_DEV(card), card->gendisk);
 		card->bdev_attached = 1;
 	}

 	mutex_unlock(&card->dev_lock);

 	return 0;
 }

 void rsxx_detach_dev(struct rsxx_cardinfo *card)
 {
 	mutex_lock(&card->dev_lock);

 	if (card->bdev_attached) {
 		del_gendisk(card->gendisk);
 		card->bdev_attached = 0;
 	}

 	mutex_unlock(&card->dev_lock);
 }

 int rsxx_setup_dev(struct rsxx_cardinfo *card)
 {
 	unsigned short blk_size;

 	mutex_init(&card->dev_lock);

 	if (!enable_blkdev)
 		return 0;

 	card->major = register_blkdev(0, DRIVER_NAME);
 	if (card->major < 0) {
 		dev_err(CARD_TO_DEV(card), "Failed to get major number\n");
 		return -ENOMEM;
 	}

 	card->queue = blk_alloc_queue(GFP_KERNEL);
 	if (!card->queue) {
 		dev_err(CARD_TO_DEV(card), "Failed queue alloc\n");
 		unregister_blkdev(card->major, DRIVER_NAME);
 		return -ENOMEM;
 	}

 	card->gendisk = alloc_disk(blkdev_minors);
 	if (!card->gendisk) {
 		dev_err(CARD_TO_DEV(card), "Failed disk alloc\n");
 		blk_cleanup_queue(card->queue);
 		unregister_blkdev(card->major, DRIVER_NAME);
 		return -ENOMEM;
 	}

 	if (card->config_valid) {
 		blk_size = card->config.data.block_size;
 		blk_queue_dma_alignment(card->queue, blk_size - 1);
 		blk_queue_logical_block_size(card->queue, blk_size);
 	}

 	blk_queue_make_request(card->queue, rsxx_make_request);
 	blk_queue_max_hw_sectors(card->queue, blkdev_max_hw_sectors);
 	blk_queue_physical_block_size(card->queue, RSXX_HW_BLK_SIZE);

 	blk_queue_flag_set(QUEUE_FLAG_NONROT, card->queue);
 	blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, card->queue);
 	if (rsxx_discard_supported(card)) {
 		blk_queue_flag_set(QUEUE_FLAG_DISCARD, card->queue);
 		blk_queue_max_discard_sectors(card->queue,
 						RSXX_HW_BLK_SIZE >> 9);
 		card->queue->limits.discard_granularity = RSXX_HW_BLK_SIZE;
 		card->queue->limits.discard_alignment   = RSXX_HW_BLK_SIZE;
 	}

 	card->queue->queuedata = card;

 	snprintf(card->gendisk->disk_name, sizeof(card->gendisk->disk_name),
 		 "rsxx%d", card->disk_id);
 	card->gendisk->major = card->major;
 	card->gendisk->first_minor = 0;
 	card->gendisk->fops = &rsxx_fops;
 	card->gendisk->private_data = card;
 	card->gendisk->queue = card->queue;

 	return 0;
 }

 void rsxx_destroy_dev(struct rsxx_cardinfo *card)
 {
 	if (!enable_blkdev)
 		return;

 	put_disk(card->gendisk);
 	card->gendisk = NULL;

 	blk_cleanup_queue(card->queue);
 	card->queue->queuedata = NULL;
 	unregister_blkdev(card->major, DRIVER_NAME);
 }

 int rsxx_dev_init(void)
 {
 	bio_meta_pool = KMEM_CACHE(rsxx_bio_meta, SLAB_HWCACHE_ALIGN);
 	if (!bio_meta_pool)
 		return -ENOMEM;

 	return 0;
 }

 void rsxx_dev_cleanup(void)
 {
 	kmem_cache_destroy(bio_meta_pool);
 }
	/*
	* Filename: dev.c
	*
	*
	* Authors: Joshua Morris <josh.h.morris@us.ibm.com>
	* Philip Kelleher <pjk1939@linux.vnet.ibm.com>
	*
	* (C) Copyright 2013 IBM Corporation
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License as
	* published by the Free Software Foundation; either version 2 of the
	* License, or (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful, but
	* WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software Foundation,
	* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	#include <linux/kernel.h>
	#include <linux/interrupt.h>
	#include <linux/module.h>
	#include <linux/pci.h>
	#include <linux/slab.h>

	#include <linux/hdreg.h>
	#include <linux/genhd.h>
	#include <linux/blkdev.h>
	#include <linux/bio.h>

	#include <linux/fs.h>

	#include "rsxx_priv.h"

	static unsigned int blkdev_minors = 64;
	module_param(blkdev_minors, uint, 0444);
	MODULE_PARM_DESC(blkdev_minors, "Number of minors(partitions)");

	/*
	* For now I'm making this tweakable in case any applications hit this limit.
	* If you see a "bio too big" error in the log you will need to raise this
	* value.
	*/
	static unsigned int blkdev_max_hw_sectors = 1024;
	module_param(blkdev_max_hw_sectors, uint, 0444);
	MODULE_PARM_DESC(blkdev_max_hw_sectors, "Max hw sectors for a single BIO");

	static unsigned int enable_blkdev = 1;
	module_param(enable_blkdev , uint, 0444);
	MODULE_PARM_DESC(enable_blkdev, "Enable block device interfaces");


	struct rsxx_bio_meta {
	struct bio *bio;
	atomic_t pending_dmas;
	atomic_t error;
	unsigned long start_time;
	};

	static struct kmem_cache *bio_meta_pool;

	/----------------- Block Device Operations -----------------/
	static int rsxx_blkdev_ioctl(struct block_device *bdev,
	fmode_t mode,
	unsigned int cmd,
	unsigned long arg)
	{
	struct rsxx_cardinfo *card = bdev->bd_disk->private_data;

	switch (cmd) {
	case RSXX_GETREG:
	return rsxx_reg_access(card, (void __user *)arg, 1);
	case RSXX_SETREG:
	return rsxx_reg_access(card, (void __user *)arg, 0);
	}

	return -ENOTTY;
	}

	static int rsxx_getgeo(struct block_device bdev, struct hd_geometry geo)
	{
	struct rsxx_cardinfo *card = bdev->bd_disk->private_data;
	u64 blocks = card->size8 >> 9;

	/*
	* get geometry: Fake it. I haven't found any drivers that set
	* geo->start, so we won't either.
	*/
	if (card->size8) {
	geo->heads = 64;
	geo->sectors = 16;
	do_div(blocks, (geo->heads * geo->sectors));
	geo->cylinders = blocks;
	} else {
	geo->heads = 0;
	geo->sectors = 0;
	geo->cylinders = 0;
	}
	return 0;
	}

	static const struct block_device_operations rsxx_fops = {
	.owner = THIS_MODULE,
	.getgeo = rsxx_getgeo,
	.ioctl = rsxx_blkdev_ioctl,
	};

	static void disk_stats_start(struct rsxx_cardinfo card, struct bio bio)
	{
	generic_start_io_acct(card->queue, bio_data_dir(bio), bio_sectors(bio),
	&card->gendisk->part0);
	}

	static void disk_stats_complete(struct rsxx_cardinfo *card,
	struct bio *bio,
	unsigned long start_time)
	{
	generic_end_io_acct(card->queue, bio_data_dir(bio),
	&card->gendisk->part0, start_time);
	}

	static void bio_dma_done_cb(struct rsxx_cardinfo *card,
	void *cb_data,
	unsigned int error)
	{
	struct rsxx_bio_meta *meta = cb_data;

	if (error)
	atomic_set(&meta->error, 1);

	if (atomic_dec_and_test(&meta->pending_dmas)) {
	if (!card->eeh_state && card->gendisk)
	disk_stats_complete(card, meta->bio, meta->start_time);

	if (atomic_read(&meta->error))
	bio_io_error(meta->bio);
	else
	bio_endio(meta->bio);
	kmem_cache_free(bio_meta_pool, meta);
	}
	}

	static blk_qc_t rsxx_make_request(struct request_queue q, struct bio bio)
	{
	struct rsxx_cardinfo *card = q->queuedata;
	struct rsxx_bio_meta *bio_meta;
	blk_status_t st = BLK_STS_IOERR;

	blk_queue_split(q, &bio);

	might_sleep();

	if (!card)
	goto req_err;

	if (bio_end_sector(bio) > get_capacity(card->gendisk))
	goto req_err;

	if (unlikely(card->halt))
	goto req_err;

	if (unlikely(card->dma_fault))
	goto req_err;

	if (bio->bi_iter.bi_size == 0) {
	dev_err(CARD_TO_DEV(card), "size zero BIO!\n");
	goto req_err;
	}

	bio_meta = kmem_cache_alloc(bio_meta_pool, GFP_KERNEL);
	if (!bio_meta) {
	st = BLK_STS_RESOURCE;
	goto req_err;
	}

	bio_meta->bio = bio;
	atomic_set(&bio_meta->error, 0);
	atomic_set(&bio_meta->pending_dmas, 0);
	bio_meta->start_time = jiffies;

	if (!unlikely(card->halt))
	disk_stats_start(card, bio);

	dev_dbg(CARD_TO_DEV(card), "BIO[%c]: meta: %p addr8: x%llx size: %d\n",
	bio_data_dir(bio) ? 'W' : 'R', bio_meta,
	(u64)bio->bi_iter.bi_sector << 9, bio->bi_iter.bi_size);

	st = rsxx_dma_queue_bio(card, bio, &bio_meta->pending_dmas,
	bio_dma_done_cb, bio_meta);
	if (st)
	goto queue_err;

	return BLK_QC_T_NONE;

	queue_err:
	kmem_cache_free(bio_meta_pool, bio_meta);
	req_err:
	if (st)
	bio->bi_status = st;
	bio_endio(bio);
	return BLK_QC_T_NONE;
	}

	/----------------- Device Setup -------------------/
	static bool rsxx_discard_supported(struct rsxx_cardinfo *card)
	{
	unsigned char pci_rev;

	pci_read_config_byte(card->dev, PCI_REVISION_ID, &pci_rev);

	return (pci_rev >= RSXX_DISCARD_SUPPORT);
	}

	int rsxx_attach_dev(struct rsxx_cardinfo *card)
	{
	mutex_lock(&card->dev_lock);

	/* The block device requires the stripe size from the config. */
	if (enable_blkdev) {
	if (card->config_valid)
	set_capacity(card->gendisk, card->size8 >> 9);
	else
	set_capacity(card->gendisk, 0);
	device_add_disk(CARD_TO_DEV(card), card->gendisk);
	card->bdev_attached = 1;
	}

	mutex_unlock(&card->dev_lock);

	return 0;
	}

	void rsxx_detach_dev(struct rsxx_cardinfo *card)
	{
	mutex_lock(&card->dev_lock);

	if (card->bdev_attached) {
	del_gendisk(card->gendisk);
	card->bdev_attached = 0;
	}

	mutex_unlock(&card->dev_lock);
	}

	int rsxx_setup_dev(struct rsxx_cardinfo *card)
	{
	unsigned short blk_size;

	mutex_init(&card->dev_lock);

	if (!enable_blkdev)
	return 0;

	card->major = register_blkdev(0, DRIVER_NAME);
	if (card->major < 0) {
	dev_err(CARD_TO_DEV(card), "Failed to get major number\n");
	return -ENOMEM;
	}

	card->queue = blk_alloc_queue(GFP_KERNEL);
	if (!card->queue) {
	dev_err(CARD_TO_DEV(card), "Failed queue alloc\n");
	unregister_blkdev(card->major, DRIVER_NAME);
	return -ENOMEM;
	}

	card->gendisk = alloc_disk(blkdev_minors);
	if (!card->gendisk) {
	dev_err(CARD_TO_DEV(card), "Failed disk alloc\n");
	blk_cleanup_queue(card->queue);
	unregister_blkdev(card->major, DRIVER_NAME);
	return -ENOMEM;
	}

	if (card->config_valid) {
	blk_size = card->config.data.block_size;
	blk_queue_dma_alignment(card->queue, blk_size - 1);
	blk_queue_logical_block_size(card->queue, blk_size);
	}

	blk_queue_make_request(card->queue, rsxx_make_request);
	blk_queue_max_hw_sectors(card->queue, blkdev_max_hw_sectors);
	blk_queue_physical_block_size(card->queue, RSXX_HW_BLK_SIZE);

	blk_queue_flag_set(QUEUE_FLAG_NONROT, card->queue);
	blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, card->queue);
	if (rsxx_discard_supported(card)) {
	blk_queue_flag_set(QUEUE_FLAG_DISCARD, card->queue);
	blk_queue_max_discard_sectors(card->queue,
	RSXX_HW_BLK_SIZE >> 9);
	card->queue->limits.discard_granularity = RSXX_HW_BLK_SIZE;
	card->queue->limits.discard_alignment = RSXX_HW_BLK_SIZE;
	}

	card->queue->queuedata = card;

	snprintf(card->gendisk->disk_name, sizeof(card->gendisk->disk_name),
	"rsxx%d", card->disk_id);
	card->gendisk->major = card->major;
	card->gendisk->first_minor = 0;
	card->gendisk->fops = &rsxx_fops;
	card->gendisk->private_data = card;
	card->gendisk->queue = card->queue;

	return 0;
	}

	void rsxx_destroy_dev(struct rsxx_cardinfo *card)
	{
	if (!enable_blkdev)
	return;

	put_disk(card->gendisk);
	card->gendisk = NULL;

	blk_cleanup_queue(card->queue);
	card->queue->queuedata = NULL;
	unregister_blkdev(card->major, DRIVER_NAME);
	}

	int rsxx_dev_init(void)
	{
	bio_meta_pool = KMEM_CACHE(rsxx_bio_meta, SLAB_HWCACHE_ALIGN);
	if (!bio_meta_pool)
	return -ENOMEM;

	return 0;
	}

	void rsxx_dev_cleanup(void)
	{
	kmem_cache_destroy(bio_meta_pool);
	}