[mirror_ubuntu-artful-kernel.git] / drivers / char / tile-srom.c

/*
 * Copyright 2011 Tilera Corporation. All Rights Reserved.
 *
 *   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, version 2.
 *
 *   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, GOOD TITLE or
 *   NON INFRINGEMENT.  See the GNU General Public License for
 *   more details.
 *
 * SPI Flash ROM driver
 *
 * This source code is derived from code provided in "Linux Device
 * Drivers, Third Edition", by Jonathan Corbet, Alessandro Rubini, and
 * Greg Kroah-Hartman, published by O'Reilly Media, Inc.
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>	/* printk() */
#include <linux/slab.h>		/* kmalloc() */
#include <linux/fs.h>		/* everything... */
#include <linux/errno.h>	/* error codes */
#include <linux/types.h>	/* size_t */
#include <linux/proc_fs.h>
#include <linux/fcntl.h>	/* O_ACCMODE */
#include <linux/pagemap.h>
#include <linux/hugetlb.h>
#include <linux/uaccess.h>
#include <linux/platform_device.h>
#include <hv/hypervisor.h>
#include <linux/ioctl.h>
#include <linux/cdev.h>
#include <linux/delay.h>
#include <hv/drv_srom_intf.h>

/*
 * Size of our hypervisor I/O requests.  We break up large transfers
 * so that we don't spend large uninterrupted spans of time in the
 * hypervisor.  Erasing an SROM sector takes a significant fraction of
 * a second, so if we allowed the user to, say, do one I/O to write the
 * entire ROM, we'd get soft lockup timeouts, or worse.
 */
#define SROM_CHUNK_SIZE ((size_t)4096)

/*
 * When hypervisor is busy (e.g. erasing), poll the status periodically.
 */

/*
 * Interval to poll the state in msec
 */
#define SROM_WAIT_TRY_INTERVAL 20

/*
 * Maximum times to poll the state
 */
#define SROM_MAX_WAIT_TRY_TIMES 1000

struct srom_dev {
	int hv_devhdl;			/* Handle for hypervisor device */
	u32 total_size;			/* Size of this device */
	u32 sector_size;		/* Size of a sector */
	u32 page_size;			/* Size of a page */
	struct mutex lock;		/* Allow only one accessor at a time */
};

static int srom_major;			/* Dynamic major by default */
module_param(srom_major, int, 0);
MODULE_AUTHOR("Tilera Corporation");
MODULE_LICENSE("GPL");

static int srom_devs;			/* Number of SROM partitions */
static struct cdev srom_cdev;
static struct platform_device *srom_parent;
static struct class *srom_class;
static struct srom_dev *srom_devices;

/*
 * Handle calling the hypervisor and managing EAGAIN/EBUSY.
 */

static ssize_t _srom_read(int hv_devhdl, void *buf,
			  loff_t off, size_t count)
{
	int retval, retries = SROM_MAX_WAIT_TRY_TIMES;
	for (;;) {
		retval = hv_dev_pread(hv_devhdl, 0, (HV_VirtAddr)buf,
				      count, off);
		if (retval >= 0)
			return retval;
		if (retval == HV_EAGAIN)
			continue;
		if (retval == HV_EBUSY && --retries > 0) {
			msleep(SROM_WAIT_TRY_INTERVAL);
			continue;
		}
		pr_err("_srom_read: error %d\n", retval);
		return -EIO;
	}
}

static ssize_t _srom_write(int hv_devhdl, const void *buf,
			   loff_t off, size_t count)
{
	int retval, retries = SROM_MAX_WAIT_TRY_TIMES;
	for (;;) {
		retval = hv_dev_pwrite(hv_devhdl, 0, (HV_VirtAddr)buf,
				       count, off);
		if (retval >= 0)
			return retval;
		if (retval == HV_EAGAIN)
			continue;
		if (retval == HV_EBUSY && --retries > 0) {
			msleep(SROM_WAIT_TRY_INTERVAL);
			continue;
		}
		pr_err("_srom_write: error %d\n", retval);
		return -EIO;
	}
}

/**
 * srom_open() - Device open routine.
 * @inode: Inode for this device.
 * @filp: File for this specific open of the device.
 *
 * Returns zero, or an error code.
 */
static int srom_open(struct inode *inode, struct file *filp)
{
	filp->private_data = &srom_devices[iminor(inode)];
	return 0;
}


/**
 * srom_release() - Device release routine.
 * @inode: Inode for this device.
 * @filp: File for this specific open of the device.
 *
 * Returns zero, or an error code.
 */
static int srom_release(struct inode *inode, struct file *filp)
{
	struct srom_dev *srom = filp->private_data;
	char dummy;

	/* Make sure we've flushed anything written to the ROM. */
	mutex_lock(&srom->lock);
	if (srom->hv_devhdl >= 0)
		_srom_write(srom->hv_devhdl, &dummy, SROM_FLUSH_OFF, 1);
	mutex_unlock(&srom->lock);

	filp->private_data = NULL;

	return 0;
}


/**
 * srom_read() - Read data from the device.
 * @filp: File for this specific open of the device.
 * @buf: User's data buffer.
 * @count: Number of bytes requested.
 * @f_pos: File position.
 *
 * Returns number of bytes read, or an error code.
 */
static ssize_t srom_read(struct file *filp, char __user *buf,
			 size_t count, loff_t *f_pos)
{
	int retval = 0;
	void *kernbuf;
	struct srom_dev *srom = filp->private_data;

	kernbuf = kmalloc(SROM_CHUNK_SIZE, GFP_KERNEL);
	if (!kernbuf)
		return -ENOMEM;

	if (mutex_lock_interruptible(&srom->lock)) {
		retval = -ERESTARTSYS;
		kfree(kernbuf);
		return retval;
	}

	while (count) {
		int hv_retval;
		int bytes_this_pass = min(count, SROM_CHUNK_SIZE);

		hv_retval = _srom_read(srom->hv_devhdl, kernbuf,
				       *f_pos, bytes_this_pass);
		if (hv_retval <= 0) {
			if (retval == 0)
				retval = hv_retval;
			break;
		}

		if (copy_to_user(buf, kernbuf, hv_retval) != 0) {
			retval = -EFAULT;
			break;
		}

		retval += hv_retval;
		*f_pos += hv_retval;
		buf += hv_retval;
		count -= hv_retval;
	}

	mutex_unlock(&srom->lock);
	kfree(kernbuf);

	return retval;
}

/**
 * srom_write() - Write data to the device.
 * @filp: File for this specific open of the device.
 * @buf: User's data buffer.
 * @count: Number of bytes requested.
 * @f_pos: File position.
 *
 * Returns number of bytes written, or an error code.
 */
static ssize_t srom_write(struct file *filp, const char __user *buf,
			  size_t count, loff_t *f_pos)
{
	int retval = 0;
	void *kernbuf;
	struct srom_dev *srom = filp->private_data;

	kernbuf = kmalloc(SROM_CHUNK_SIZE, GFP_KERNEL);
	if (!kernbuf)
		return -ENOMEM;

	if (mutex_lock_interruptible(&srom->lock)) {
		retval = -ERESTARTSYS;
		kfree(kernbuf);
		return retval;
	}

	while (count) {
		int hv_retval;
		int bytes_this_pass = min(count, SROM_CHUNK_SIZE);

		if (copy_from_user(kernbuf, buf, bytes_this_pass) != 0) {
			retval = -EFAULT;
			break;
		}

		hv_retval = _srom_write(srom->hv_devhdl, kernbuf,
					*f_pos, bytes_this_pass);
		if (hv_retval <= 0) {
			if (retval == 0)
				retval = hv_retval;
			break;
		}

		retval += hv_retval;
		*f_pos += hv_retval;
		buf += hv_retval;
		count -= hv_retval;
	}

	mutex_unlock(&srom->lock);
	kfree(kernbuf);

	return retval;
}

/* Provide our own implementation so we can use srom->total_size. */
loff_t srom_llseek(struct file *file, loff_t offset, int origin)
{
	struct srom_dev *srom = file->private_data;
	return fixed_size_llseek(file, offset, origin, srom->total_size);
}

static ssize_t total_size_show(struct device *dev,
			       struct device_attribute *attr, char *buf)
{
	struct srom_dev *srom = dev_get_drvdata(dev);
	return sprintf(buf, "%u\n", srom->total_size);
}
static DEVICE_ATTR_RO(total_size);

static ssize_t sector_size_show(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct srom_dev *srom = dev_get_drvdata(dev);
	return sprintf(buf, "%u\n", srom->sector_size);
}
static DEVICE_ATTR_RO(sector_size);

static ssize_t page_size_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
	struct srom_dev *srom = dev_get_drvdata(dev);
	return sprintf(buf, "%u\n", srom->page_size);
}
static DEVICE_ATTR_RO(page_size);

static struct attribute *srom_dev_attrs[] = {
	&dev_attr_total_size.attr,
	&dev_attr_sector_size.attr,
	&dev_attr_page_size.attr,
	NULL,
};
ATTRIBUTE_GROUPS(srom_dev);

static char *srom_devnode(struct device *dev, umode_t *mode)
{
	if (mode)
		*mode = 0644;
	return kasprintf(GFP_KERNEL, "srom/%s", dev_name(dev));
}

/*
 * The fops
 */
static const struct file_operations srom_fops = {
	.owner =     THIS_MODULE,
	.llseek =    srom_llseek,
	.read =	     srom_read,
	.write =     srom_write,
	.open =	     srom_open,
	.release =   srom_release,
};

/**
 * srom_setup_minor() - Initialize per-minor information.
 * @srom: Per-device SROM state.
 * @devhdl: Partition device handle.
 */
static int srom_setup_minor(struct srom_dev *srom, int devhdl)
{
	srom->hv_devhdl = devhdl;
	mutex_init(&srom->lock);

	if (_srom_read(devhdl, &srom->total_size,
		       SROM_TOTAL_SIZE_OFF, sizeof(srom->total_size)) < 0)
		return -EIO;
	if (_srom_read(devhdl, &srom->sector_size,
		       SROM_SECTOR_SIZE_OFF, sizeof(srom->sector_size)) < 0)
		return -EIO;
	if (_srom_read(devhdl, &srom->page_size,
		       SROM_PAGE_SIZE_OFF, sizeof(srom->page_size)) < 0)
		return -EIO;

	return 0;
}

/** srom_init() - Initialize the driver's module. */
static int srom_init(void)
{
	int result, i;
	dev_t dev = MKDEV(srom_major, 0);

	/*
	 * Start with a plausible number of partitions; the krealloc() call
	 * below will yield about log(srom_devs) additional allocations.
	 */
	srom_devices = kmalloc(4 * sizeof(struct srom_dev), GFP_KERNEL);

	/* Discover the number of srom partitions. */
	for (i = 0; ; i++) {
		int devhdl;
		char buf[20];
		struct srom_dev *new_srom_devices =
			krealloc(srom_devices, (i+1) * sizeof(struct srom_dev),
				 GFP_KERNEL);
		if (!new_srom_devices) {
			result = -ENOMEM;
			goto fail_mem;
		}
		srom_devices = new_srom_devices;
		sprintf(buf, "srom/0/%d", i);
		devhdl = hv_dev_open((HV_VirtAddr)buf, 0);
		if (devhdl < 0) {
			if (devhdl != HV_ENODEV)
				pr_notice("srom/%d: hv_dev_open failed: %d.\n",
					  i, devhdl);
			break;
		}
		result = srom_setup_minor(&srom_devices[i], devhdl);
		if (result != 0)
			goto fail_mem;
	}
	srom_devs = i;

	/* Bail out early if we have no partitions at all. */
	if (srom_devs == 0) {
		result = -ENODEV;
		goto fail_mem;
	}

	/* Register our major, and accept a dynamic number. */
	if (srom_major)
		result = register_chrdev_region(dev, srom_devs, "srom");
	else {
		result = alloc_chrdev_region(&dev, 0, srom_devs, "srom");
		srom_major = MAJOR(dev);
	}
	if (result < 0)
		goto fail_mem;

	/* Register a character device. */
	cdev_init(&srom_cdev, &srom_fops);
	srom_cdev.owner = THIS_MODULE;
	srom_cdev.ops = &srom_fops;
	result = cdev_add(&srom_cdev, dev, srom_devs);
	if (result < 0)
		goto fail_chrdev;

	/* Create a parent device */
	srom_parent = platform_device_register_simple("srom", -1, NULL, 0);
	if (IS_ERR(srom_parent)) {
		result = PTR_ERR(srom_parent);
		goto fail_pdev;
	}

	/* Create a sysfs class. */
	srom_class = class_create(THIS_MODULE, "srom");
	if (IS_ERR(srom_class)) {
		result = PTR_ERR(srom_class);
		goto fail_cdev;
	}
	srom_class->dev_groups = srom_dev_groups;
	srom_class->devnode = srom_devnode;

	/* Create per-partition devices */
	for (i = 0; i < srom_devs; i++) {
		struct device *dev =
			device_create(srom_class, &srom_parent->dev,
				      MKDEV(srom_major, i), srom_devices + i,
				      "%d", i);
		result = PTR_ERR_OR_ZERO(dev);
		if (result < 0)
			goto fail_class;
	}

	return 0;

fail_class:
	for (i = 0; i < srom_devs; i++)
		device_destroy(srom_class, MKDEV(srom_major, i));
	class_destroy(srom_class);
fail_cdev:
	platform_device_unregister(srom_parent);
fail_pdev:
	cdev_del(&srom_cdev);
fail_chrdev:
	unregister_chrdev_region(dev, srom_devs);
fail_mem:
	kfree(srom_devices);
	return result;
}

/** srom_cleanup() - Clean up the driver's module. */
static void srom_cleanup(void)
{
	int i;
	for (i = 0; i < srom_devs; i++)
		device_destroy(srom_class, MKDEV(srom_major, i));
	class_destroy(srom_class);
	cdev_del(&srom_cdev);
	platform_device_unregister(srom_parent);
	unregister_chrdev_region(MKDEV(srom_major, 0), srom_devs);
	kfree(srom_devices);
}

module_init(srom_init);
module_exit(srom_cleanup);
Commit	Line	Data
dbcb4a1a CM	1	/*
	2	* Copyright 2011 Tilera Corporation. All Rights Reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public License
	6	* as published by the Free Software Foundation, version 2.
	7	*
	8	* This program is distributed in the hope that it will be useful, but
	9	* WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
	11	* NON INFRINGEMENT. See the GNU General Public License for
	12	* more details.
	13	*
	14	* SPI Flash ROM driver
	15	*
	16	* This source code is derived from code provided in "Linux Device
	17	* Drivers, Third Edition", by Jonathan Corbet, Alessandro Rubini, and
	18	* Greg Kroah-Hartman, published by O'Reilly Media, Inc.
	19	*/
	20
	21	#include <linux/module.h>
	22	#include <linux/moduleparam.h>
dbcb4a1a CM	23	#include <linux/kernel.h> /* printk() */
	24	#include <linux/slab.h> /* kmalloc() */
	25	#include <linux/fs.h> /* everything... */
	26	#include <linux/errno.h> /* error codes */
	27	#include <linux/types.h> /* size_t */
	28	#include <linux/proc_fs.h>
	29	#include <linux/fcntl.h> /* O_ACCMODE */
dbcb4a1a CM	30	#include <linux/pagemap.h>
	31	#include <linux/hugetlb.h>
	32	#include <linux/uaccess.h>
	33	#include <linux/platform_device.h>
	34	#include <hv/hypervisor.h>
	35	#include <linux/ioctl.h>
	36	#include <linux/cdev.h>
	37	#include <linux/delay.h>
	38	#include <hv/drv_srom_intf.h>
	39
	40	/*
	41	* Size of our hypervisor I/O requests. We break up large transfers
	42	* so that we don't spend large uninterrupted spans of time in the
	43	* hypervisor. Erasing an SROM sector takes a significant fraction of
	44	* a second, so if we allowed the user to, say, do one I/O to write the
	45	* entire ROM, we'd get soft lockup timeouts, or worse.
	46	*/
	47	#define SROM_CHUNK_SIZE ((size_t)4096)
	48
	49	/*
	50	* When hypervisor is busy (e.g. erasing), poll the status periodically.
	51	*/
	52
	53	/*
	54	* Interval to poll the state in msec
	55	*/
	56	#define SROM_WAIT_TRY_INTERVAL 20
	57
	58	/*
	59	* Maximum times to poll the state
	60	*/
	61	#define SROM_MAX_WAIT_TRY_TIMES 1000
	62
	63	struct srom_dev {
	64	int hv_devhdl; /* Handle for hypervisor device */
	65	u32 total_size; /* Size of this device */
	66	u32 sector_size; /* Size of a sector */
	67	u32 page_size; /* Size of a page */
	68	struct mutex lock; /* Allow only one accessor at a time */
	69	};
	70
	71	static int srom_major; /* Dynamic major by default */
	72	module_param(srom_major, int, 0);
	73	MODULE_AUTHOR("Tilera Corporation");
	74	MODULE_LICENSE("GPL");
	75
	76	static int srom_devs; /* Number of SROM partitions */
	77	static struct cdev srom_cdev;
514b82a5	78	static struct platform_device *srom_parent;
dbcb4a1a CM	79	static struct class *srom_class;
	80	static struct srom_dev *srom_devices;
	81
	82	/*
	83	* Handle calling the hypervisor and managing EAGAIN/EBUSY.
	84	*/
	85
	86	static ssize_t _srom_read(int hv_devhdl, void *buf,
	87	loff_t off, size_t count)
	88	{
	89	int retval, retries = SROM_MAX_WAIT_TRY_TIMES;
	90	for (;;) {
	91	retval = hv_dev_pread(hv_devhdl, 0, (HV_VirtAddr)buf,
	92	count, off);
	93	if (retval >= 0)
	94	return retval;
	95	if (retval == HV_EAGAIN)
	96	continue;
	97	if (retval == HV_EBUSY && --retries > 0) {
	98	msleep(SROM_WAIT_TRY_INTERVAL);
	99	continue;
	100	}
	101	pr_err("_srom_read: error %d\n", retval);
	102	return -EIO;
	103	}
	104	}
	105
	106	static ssize_t _srom_write(int hv_devhdl, const void *buf,
	107	loff_t off, size_t count)
	108	{
	109	int retval, retries = SROM_MAX_WAIT_TRY_TIMES;
	110	for (;;) {
	111	retval = hv_dev_pwrite(hv_devhdl, 0, (HV_VirtAddr)buf,
	112	count, off);
	113	if (retval >= 0)
	114	return retval;
	115	if (retval == HV_EAGAIN)
	116	continue;
	117	if (retval == HV_EBUSY && --retries > 0) {
	118	msleep(SROM_WAIT_TRY_INTERVAL);
	119	continue;
	120	}
	121	pr_err("_srom_write: error %d\n", retval);
	122	return -EIO;
	123	}
	124	}
	125
	126	/**
	127	* srom_open() - Device open routine.
	128	* @inode: Inode for this device.
	129	* @filp: File for this specific open of the device.
	130	*
	131	* Returns zero, or an error code.
	132	*/
	133	static int srom_open(struct inode inode, struct file filp)
	134	{
	135	filp->private_data = &srom_devices[iminor(inode)];
	136	return 0;
	137	}
	138
	139
	140	/**
	141	* srom_release() - Device release routine.
	142	* @inode: Inode for this device.
143	* @filp: File for this specific open of the device.
144	*
145	* Returns zero, or an error code.
146	*/
147	static int srom_release(struct inode inode, struct file filp)
148	{
149	struct srom_dev *srom = filp->private_data;
150	char dummy;
151
152	/* Make sure we've flushed anything written to the ROM. */
153	mutex_lock(&srom->lock);
154	if (srom->hv_devhdl >= 0)
155	_srom_write(srom->hv_devhdl, &dummy, SROM_FLUSH_OFF, 1);
156	mutex_unlock(&srom->lock);
157
158	filp->private_data = NULL;
159
160	return 0;
161	}
162
163
164	/**
165	* srom_read() - Read data from the device.
166	* @filp: File for this specific open of the device.
167	* @buf: User's data buffer.
168	* @count: Number of bytes requested.
169	* @f_pos: File position.
170	*
171	* Returns number of bytes read, or an error code.
172	*/
173	static ssize_t srom_read(struct file filp, char __user buf,
174	size_t count, loff_t *f_pos)
175	{
176	int retval = 0;
177	void *kernbuf;
178	struct srom_dev *srom = filp->private_data;
179
180	kernbuf = kmalloc(SROM_CHUNK_SIZE, GFP_KERNEL);
181	if (!kernbuf)
182	return -ENOMEM;
183
184	if (mutex_lock_interruptible(&srom->lock)) {
185	retval = -ERESTARTSYS;
186	kfree(kernbuf);
187	return retval;
188	}
189
190	while (count) {
191	int hv_retval;
192	int bytes_this_pass = min(count, SROM_CHUNK_SIZE);
193
194	hv_retval = _srom_read(srom->hv_devhdl, kernbuf,
195	*f_pos, bytes_this_pass);
16418bb1	196	if (hv_retval <= 0) {
dbcb4a1a CM	197	if (retval == 0)
	198	retval = hv_retval;
	199	break;
	200	}
	201
16418bb1 CM	202	if (copy_to_user(buf, kernbuf, hv_retval) != 0) {
	203	retval = -EFAULT;
	204	break;
	205	}
	206
dbcb4a1a CM	207	retval += hv_retval;
	208	*f_pos += hv_retval;
	209	buf += hv_retval;
	210	count -= hv_retval;
	211	}
	212
	213	mutex_unlock(&srom->lock);
	214	kfree(kernbuf);
	215
	216	return retval;
	217	}
	218
	219	/**
	220	* srom_write() - Write data to the device.
	221	* @filp: File for this specific open of the device.
	222	* @buf: User's data buffer.
	223	* @count: Number of bytes requested.
	224	* @f_pos: File position.
	225	*
	226	* Returns number of bytes written, or an error code.
	227	*/
	228	static ssize_t srom_write(struct file filp, const char __user buf,
	229	size_t count, loff_t *f_pos)
	230	{
	231	int retval = 0;
	232	void *kernbuf;
	233	struct srom_dev *srom = filp->private_data;
	234
	235	kernbuf = kmalloc(SROM_CHUNK_SIZE, GFP_KERNEL);
	236	if (!kernbuf)
	237	return -ENOMEM;
	238
	239	if (mutex_lock_interruptible(&srom->lock)) {
	240	retval = -ERESTARTSYS;
	241	kfree(kernbuf);
	242	return retval;
	243	}
	244
	245	while (count) {
	246	int hv_retval;
	247	int bytes_this_pass = min(count, SROM_CHUNK_SIZE);
	248
	249	if (copy_from_user(kernbuf, buf, bytes_this_pass) != 0) {
	250	retval = -EFAULT;
	251	break;
	252	}
	253
	254	hv_retval = _srom_write(srom->hv_devhdl, kernbuf,
	255	*f_pos, bytes_this_pass);
	256	if (hv_retval <= 0) {
	257	if (retval == 0)
	258	retval = hv_retval;
	259	break;
	260	}
	261
	262	retval += hv_retval;
	263	*f_pos += hv_retval;
	264	buf += hv_retval;
	265	count -= hv_retval;
	266	}
	267
	268	mutex_unlock(&srom->lock);
	269	kfree(kernbuf);
	270
271	return retval;
272	}
273
274	/* Provide our own implementation so we can use srom->total_size. */
914961aa	275	loff_t srom_llseek(struct file *file, loff_t offset, int origin)
dbcb4a1a	276	{
914961aa AV	277	struct srom_dev *srom = file->private_data;
914961aa AV	278	return fixed_size_llseek(file, offset, origin, srom->total_size);
dbcb4a1a CM	279	}
dbcb4a1a CM	280
e017a84b GKH	281	static ssize_t total_size_show(struct device *dev,
e017a84b GKH	282	struct device_attribute attr, char buf)
dbcb4a1a CM	283	{
	284	struct srom_dev *srom = dev_get_drvdata(dev);
	285	return sprintf(buf, "%u\n", srom->total_size);
	286	}
e017a84b	287	static DEVICE_ATTR_RO(total_size);
dbcb4a1a	288
e017a84b GKH	289	static ssize_t sector_size_show(struct device *dev,
e017a84b GKH	290	struct device_attribute attr, char buf)
dbcb4a1a CM	291	{
	292	struct srom_dev *srom = dev_get_drvdata(dev);
	293	return sprintf(buf, "%u\n", srom->sector_size);
	294	}
e017a84b	295	static DEVICE_ATTR_RO(sector_size);
dbcb4a1a	296
e017a84b GKH	297	static ssize_t page_size_show(struct device *dev,
e017a84b GKH	298	struct device_attribute attr, char buf)
dbcb4a1a CM	299	{
	300	struct srom_dev *srom = dev_get_drvdata(dev);
	301	return sprintf(buf, "%u\n", srom->page_size);
	302	}
e017a84b	303	static DEVICE_ATTR_RO(page_size);
dbcb4a1a	304
7c42721f	305	static struct attribute *srom_dev_attrs[] = {
e017a84b GKH	306	&dev_attr_total_size.attr,
	307	&dev_attr_sector_size.attr,
	308	&dev_attr_page_size.attr,
	309	NULL,
dbcb4a1a	310	};
e017a84b	311	ATTRIBUTE_GROUPS(srom_dev);
dbcb4a1a	312
2c9ede55	313	static char srom_devnode(struct device dev, umode_t *mode)
dbcb4a1a	314	{
71aeebff CM	315	if (mode)
71aeebff CM	316	*mode = 0644;
dbcb4a1a CM	317	return kasprintf(GFP_KERNEL, "srom/%s", dev_name(dev));
	318	}
	319
	320	/*
	321	* The fops
	322	*/
	323	static const struct file_operations srom_fops = {
	324	.owner = THIS_MODULE,
	325	.llseek = srom_llseek,
	326	.read = srom_read,
	327	.write = srom_write,
	328	.open = srom_open,
	329	.release = srom_release,
	330	};
	331
	332	/**
	333	* srom_setup_minor() - Initialize per-minor information.
	334	* @srom: Per-device SROM state.
069b188f	335	* @devhdl: Partition device handle.
dbcb4a1a	336	*/
069b188f	337	static int srom_setup_minor(struct srom_dev *srom, int devhdl)
dbcb4a1a	338	{
069b188f	339	srom->hv_devhdl = devhdl;
dbcb4a1a CM	340	mutex_init(&srom->lock);
	341
	342	if (_srom_read(devhdl, &srom->total_size,
	343	SROM_TOTAL_SIZE_OFF, sizeof(srom->total_size)) < 0)
	344	return -EIO;
	345	if (_srom_read(devhdl, &srom->sector_size,
	346	SROM_SECTOR_SIZE_OFF, sizeof(srom->sector_size)) < 0)
	347	return -EIO;
	348	if (_srom_read(devhdl, &srom->page_size,
	349	SROM_PAGE_SIZE_OFF, sizeof(srom->page_size)) < 0)
	350	return -EIO;
	351
069b188f	352	return 0;
dbcb4a1a CM	353	}
	354
	355	/** srom_init() - Initialize the driver's module. */
	356	static int srom_init(void)
	357	{
	358	int result, i;
	359	dev_t dev = MKDEV(srom_major, 0);
	360
	361	/*
	362	* Start with a plausible number of partitions; the krealloc() call
	363	* below will yield about log(srom_devs) additional allocations.
	364	*/
069b188f	365	srom_devices = kmalloc(4 * sizeof(struct srom_dev), GFP_KERNEL);
dbcb4a1a CM	366
	367	/* Discover the number of srom partitions. */
	368	for (i = 0; ; i++) {
	369	int devhdl;
	370	char buf[20];
	371	struct srom_dev *new_srom_devices =
	372	krealloc(srom_devices, (i+1) * sizeof(struct srom_dev),
069b188f	373	GFP_KERNEL);
dbcb4a1a CM	374	if (!new_srom_devices) {
	375	result = -ENOMEM;
	376	goto fail_mem;
	377	}
	378	srom_devices = new_srom_devices;
	379	sprintf(buf, "srom/0/%d", i);
	380	devhdl = hv_dev_open((HV_VirtAddr)buf, 0);
	381	if (devhdl < 0) {
	382	if (devhdl != HV_ENODEV)
	383	pr_notice("srom/%d: hv_dev_open failed: %d.\n",
	384	i, devhdl);
	385	break;
	386	}
069b188f CM	387	result = srom_setup_minor(&srom_devices[i], devhdl);
	388	if (result != 0)
	389	goto fail_mem;
dbcb4a1a CM	390	}
	391	srom_devs = i;
	392
	393	/* Bail out early if we have no partitions at all. */
	394	if (srom_devs == 0) {
	395	result = -ENODEV;
	396	goto fail_mem;
	397	}
	398
	399	/* Register our major, and accept a dynamic number. */
	400	if (srom_major)
	401	result = register_chrdev_region(dev, srom_devs, "srom");
	402	else {
	403	result = alloc_chrdev_region(&dev, 0, srom_devs, "srom");
	404	srom_major = MAJOR(dev);
	405	}
	406	if (result < 0)
	407	goto fail_mem;
	408
	409	/* Register a character device. */
	410	cdev_init(&srom_cdev, &srom_fops);
	411	srom_cdev.owner = THIS_MODULE;
	412	srom_cdev.ops = &srom_fops;
	413	result = cdev_add(&srom_cdev, dev, srom_devs);
	414	if (result < 0)
	415	goto fail_chrdev;
	416
514b82a5 PM	417	/* Create a parent device */
	418	srom_parent = platform_device_register_simple("srom", -1, NULL, 0);
	419	if (IS_ERR(srom_parent)) {
	420	result = PTR_ERR(srom_parent);
	421	goto fail_pdev;
	422	}
	423
dbcb4a1a CM	424	/* Create a sysfs class. */
	425	srom_class = class_create(THIS_MODULE, "srom");
	426	if (IS_ERR(srom_class)) {
	427	result = PTR_ERR(srom_class);
	428	goto fail_cdev;
	429	}
e017a84b	430	srom_class->dev_groups = srom_dev_groups;
dbcb4a1a CM	431	srom_class->devnode = srom_devnode;
dbcb4a1a CM	432
069b188f	433	/* Create per-partition devices */
dbcb4a1a	434	for (i = 0; i < srom_devs; i++) {
069b188f CM	435	struct device *dev =
	436	device_create(srom_class, &srom_parent->dev,
	437	MKDEV(srom_major, i), srom_devices + i,
	438	"%d", i);
	439	result = PTR_ERR_OR_ZERO(dev);
dbcb4a1a CM	440	if (result < 0)
	441	goto fail_class;
	442	}
	443
	444	return 0;
	445
	446	fail_class:
	447	for (i = 0; i < srom_devs; i++)
	448	device_destroy(srom_class, MKDEV(srom_major, i));
	449	class_destroy(srom_class);
	450	fail_cdev:
514b82a5 PM	451	platform_device_unregister(srom_parent);
514b82a5 PM	452	fail_pdev:
dbcb4a1a CM	453	cdev_del(&srom_cdev);
	454	fail_chrdev:
	455	unregister_chrdev_region(dev, srom_devs);
	456	fail_mem:
	457	kfree(srom_devices);
	458	return result;
	459	}
	460
	461	/** srom_cleanup() - Clean up the driver's module. */
	462	static void srom_cleanup(void)
	463	{
	464	int i;
	465	for (i = 0; i < srom_devs; i++)
	466	device_destroy(srom_class, MKDEV(srom_major, i));
	467	class_destroy(srom_class);
	468	cdev_del(&srom_cdev);
514b82a5	469	platform_device_unregister(srom_parent);
dbcb4a1a CM	470	unregister_chrdev_region(MKDEV(srom_major, 0), srom_devs);
	471	kfree(srom_devices);
	472	}
	473
	474	module_init(srom_init);
	475	module_exit(srom_cleanup);