Commit a834a36b authored by Uma Krishnan's avatar Uma Krishnan Committed by Martin K. Petersen
Browse files

scsi: cxlflash: Create character device to provide host management interface 



The cxlflash driver currently lacks host management interface. Future
devices supported by cxlflash will provide a variety of host-wide
management functions. Examples include LUN provisioning, hardware debug
support, and firmware download.

In order to provide a way to manage the device, a character device will
be created during probe of each adapter. This device will support a set of
ioctls defined in the SISLite specification from which administrators can
manage the adapter.

Signed-off-by: default avatarUma Krishnan <ukrishn@linux.vnet.ibm.com>
Acked-by: default avatarMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 7c4c41f1

drivers/scsi/cxlflash/common.h

+5 −1
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
#define _CXLFLASH_COMMON_H



#include <linux/async.h>

#include <linux/cdev.h>

#include <linux/irq_poll.h>

#include <linux/list.h>

#include <linux/rwsem.h>
@@ -86,7 +87,8 @@ enum cxlflash_init_state { 
	INIT_STATE_NONE,

	INIT_STATE_PCI,

	INIT_STATE_AFU,

	INIT_STATE_SCSI

	INIT_STATE_SCSI,

	INIT_STATE_CDEV

};



enum cxlflash_state {
@@ -116,6 +118,8 @@ struct cxlflash_cfg { 
	struct pci_device_id *dev_id;

	struct Scsi_Host *host;

	int num_fc_ports;

	struct cdev cdev;

	struct device *chardev;



	ulong cxlflash_regs_pci;

drivers/scsi/cxlflash/main.c

+206 −1
Original line number Diff line number Diff line
@@ -34,6 +34,10 @@ MODULE_AUTHOR("Manoj N. Kumar <manoj@linux.vnet.ibm.com>"); 
MODULE_AUTHOR("Matthew R. Ochs <mrochs@linux.vnet.ibm.com>");

MODULE_LICENSE("GPL");



static struct class *cxlflash_class;

static u32 cxlflash_major;

static DECLARE_BITMAP(cxlflash_minor, CXLFLASH_MAX_ADAPTERS);



/**

 * process_cmd_err() - command error handler

 * @cmd:	AFU command that experienced the error.
@@ -862,6 +866,47 @@ static void notify_shutdown(struct cxlflash_cfg *cfg, bool wait) 
	}

}



/**

 * cxlflash_get_minor() - gets the first available minor number

 *

 * Return: Unique minor number that can be used to create the character device.

 */

static int cxlflash_get_minor(void)

{

	int minor;

	long bit;



	bit = find_first_zero_bit(cxlflash_minor, CXLFLASH_MAX_ADAPTERS);

	if (bit >= CXLFLASH_MAX_ADAPTERS)

		return -1;



	minor = bit & MINORMASK;

	set_bit(minor, cxlflash_minor);

	return minor;

}



/**

 * cxlflash_put_minor() - releases the minor number

 * @minor:	Minor number that is no longer needed.

 */

static void cxlflash_put_minor(int minor)

{

	clear_bit(minor, cxlflash_minor);

}



/**

 * cxlflash_release_chrdev() - release the character device for the host

 * @cfg:	Internal structure associated with the host.

 */

static void cxlflash_release_chrdev(struct cxlflash_cfg *cfg)

{

	put_device(cfg->chardev);

	device_unregister(cfg->chardev);

	cfg->chardev = NULL;

	cdev_del(&cfg->cdev);

	cxlflash_put_minor(MINOR(cfg->cdev.dev));

}



/**

 * cxlflash_remove() - PCI entry point to tear down host

 * @pdev:	PCI device associated with the host.
@@ -897,6 +942,8 @@ static void cxlflash_remove(struct pci_dev *pdev) 
	cxlflash_stop_term_user_contexts(cfg);



	switch (cfg->init_state) {

	case INIT_STATE_CDEV:

		cxlflash_release_chrdev(cfg);

	case INIT_STATE_SCSI:

		cxlflash_term_local_luns(cfg);

		scsi_remove_host(cfg->host);
@@ -3119,6 +3166,86 @@ static void cxlflash_worker_thread(struct work_struct *work) 
		scsi_scan_host(cfg->host);

}



/**

 * cxlflash_chr_open() - character device open handler

 * @inode:	Device inode associated with this character device.

 * @file:	File pointer for this device.

 *

 * Only users with admin privileges are allowed to open the character device.

 *

 * Return: 0 on success, -errno on failure

 */

static int cxlflash_chr_open(struct inode *inode, struct file *file)

{

	struct cxlflash_cfg *cfg;



	if (!capable(CAP_SYS_ADMIN))

		return -EACCES;



	cfg = container_of(inode->i_cdev, struct cxlflash_cfg, cdev);

	file->private_data = cfg;



	return 0;

}



/*

 * Character device file operations

 */

static const struct file_operations cxlflash_chr_fops = {

	.owner          = THIS_MODULE,

	.open           = cxlflash_chr_open,

};



/**

 * init_chrdev() - initialize the character device for the host

 * @cfg:	Internal structure associated with the host.

 *

 * Return: 0 on success, -errno on failure

 */

static int init_chrdev(struct cxlflash_cfg *cfg)

{

	struct device *dev = &cfg->dev->dev;

	struct device *char_dev;

	dev_t devno;

	int minor;

	int rc = 0;



	minor = cxlflash_get_minor();

	if (unlikely(minor < 0)) {

		dev_err(dev, "%s: Exhausted allowed adapters\n", __func__);

		rc = -ENOSPC;

		goto out;

	}



	devno = MKDEV(cxlflash_major, minor);

	cdev_init(&cfg->cdev, &cxlflash_chr_fops);



	rc = cdev_add(&cfg->cdev, devno, 1);

	if (rc) {

		dev_err(dev, "%s: cdev_add failed rc=%d\n", __func__, rc);

		goto err1;

	}



	char_dev = device_create(cxlflash_class, NULL, devno,

				 NULL, "cxlflash%d", minor);

	if (IS_ERR(char_dev)) {

		rc = PTR_ERR(char_dev);

		dev_err(dev, "%s: device_create failed rc=%d\n",

			__func__, rc);

		goto err2;

	}



	cfg->chardev = char_dev;

out:

	dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc);

	return rc;

err2:

	cdev_del(&cfg->cdev);

err1:

	cxlflash_put_minor(minor);

	goto out;

}



/**

 * cxlflash_probe() - PCI entry point to add host

 * @pdev:	PCI device associated with the host.
@@ -3229,6 +3356,13 @@ static int cxlflash_probe(struct pci_dev *pdev, 
	}

	cfg->init_state = INIT_STATE_SCSI;



	rc = init_chrdev(cfg);

	if (rc) {

		dev_err(dev, "%s: init_chrdev failed rc=%d\n", __func__, rc);

		goto out_remove;

	}

	cfg->init_state = INIT_STATE_CDEV;



	if (wq_has_sleeper(&cfg->reset_waitq)) {

		cfg->state = STATE_PROBED;

		wake_up_all(&cfg->reset_waitq);
@@ -3331,6 +3465,63 @@ static void cxlflash_pci_resume(struct pci_dev *pdev) 
	scsi_unblock_requests(cfg->host);

}



/**

 * cxlflash_devnode() - provides devtmpfs for devices in the cxlflash class

 * @dev:	Character device.

 * @mode:	Mode that can be used to verify access.

 *

 * Return: Allocated string describing the devtmpfs structure.

 */

static char *cxlflash_devnode(struct device *dev, umode_t *mode)

{

	return kasprintf(GFP_KERNEL, "cxlflash/%s", dev_name(dev));

}



/**

 * cxlflash_class_init() - create character device class

 *

 * Return: 0 on success, -errno on failure

 */

static int cxlflash_class_init(void)

{

	dev_t devno;

	int rc = 0;



	rc = alloc_chrdev_region(&devno, 0, CXLFLASH_MAX_ADAPTERS, "cxlflash");

	if (unlikely(rc)) {

		pr_err("%s: alloc_chrdev_region failed rc=%d\n", __func__, rc);

		goto out;

	}



	cxlflash_major = MAJOR(devno);



	cxlflash_class = class_create(THIS_MODULE, "cxlflash");

	if (IS_ERR(cxlflash_class)) {

		rc = PTR_ERR(cxlflash_class);

		pr_err("%s: class_create failed rc=%d\n", __func__, rc);

		goto err;

	}



	cxlflash_class->devnode = cxlflash_devnode;

out:

	pr_debug("%s: returning rc=%d\n", __func__, rc);

	return rc;

err:

	unregister_chrdev_region(devno, CXLFLASH_MAX_ADAPTERS);

	goto out;

}



/**

 * cxlflash_class_exit() - destroy character device class

 */

static void cxlflash_class_exit(void)

{

	dev_t devno = MKDEV(cxlflash_major, 0);



	class_destroy(cxlflash_class);

	unregister_chrdev_region(devno, CXLFLASH_MAX_ADAPTERS);

}



static const struct pci_error_handlers cxlflash_err_handler = {

	.error_detected = cxlflash_pci_error_detected,

	.slot_reset = cxlflash_pci_slot_reset,
@@ -3356,10 +3547,23 @@ static struct pci_driver cxlflash_driver = { 
 */

static int __init init_cxlflash(void)

{

	int rc;



	check_sizes();

	cxlflash_list_init();

	rc = cxlflash_class_init();

	if (unlikely(rc))

		goto out;



	return pci_register_driver(&cxlflash_driver);

	rc = pci_register_driver(&cxlflash_driver);

	if (unlikely(rc))

		goto err;

out:

	pr_debug("%s: returning rc=%d\n", __func__, rc);

	return rc;

err:

	cxlflash_class_exit();

	goto out;

}



/**
@@ -3371,6 +3575,7 @@ static void __exit exit_cxlflash(void) 
	cxlflash_free_errpage();



	pci_unregister_driver(&cxlflash_driver);

	cxlflash_class_exit();

}



module_init(init_cxlflash);

drivers/scsi/cxlflash/main.h

+1 −0
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ 


#define CXLFLASH_NAME		"cxlflash"

#define CXLFLASH_ADAPTER_NAME	"IBM POWER CXL Flash Adapter"

#define CXLFLASH_MAX_ADAPTERS	32



#define PCI_DEVICE_ID_IBM_CORSA		0x04F0

#define PCI_DEVICE_ID_IBM_FLASH_GT	0x0600

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