zcrypt_api.c

来自「linux 内核源代码」· C语言 代码 · 共 1,091 行 · 第 1/2 页

/*
 *  linux/drivers/s390/crypto/zcrypt_api.c
 *
 *  zcrypt 2.1.0
 *
 *  Copyright (C)  2001, 2006 IBM Corporation
 *  Author(s): Robert Burroughs
 *	       Eric Rossman ([e-mail])
 *	       Cornelia Huck <[e-mail]>
 *
 *  Hotplug & misc device support: Jochen Roehrig ([e-mail])
 *  Major cleanup & driver split: Martin Schwidefsky <[e-mail]>
 *				  Ralph Wuerthner <[e-mail]>
 *
 * 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, 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/miscdevice.h>
#include <linux/fs.h>
#include <linux/proc_fs.h>
#include <linux/compat.h>
#include <asm/atomic.h>
#include <asm/uaccess.h>

#include "zcrypt_api.h"

/**
 * Module description.
 */
MODULE_AUTHOR("IBM Corporation");
MODULE_DESCRIPTION("Cryptographic Coprocessor interface, "
		   "Copyright 2001, 2006 IBM Corporation");
MODULE_LICENSE("GPL");

static DEFINE_SPINLOCK(zcrypt_device_lock);
static LIST_HEAD(zcrypt_device_list);
static int zcrypt_device_count = 0;
static atomic_t zcrypt_open_count = ATOMIC_INIT(0);

/**
 * Device attributes common for all crypto devices.
 */
static ssize_t zcrypt_type_show(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct zcrypt_device *zdev = to_ap_dev(dev)->private;
	return snprintf(buf, PAGE_SIZE, "%s\n", zdev->type_string);
}

static DEVICE_ATTR(type, 0444, zcrypt_type_show, NULL);

static ssize_t zcrypt_online_show(struct device *dev,
				  struct device_attribute *attr, char *buf)
{
	struct zcrypt_device *zdev = to_ap_dev(dev)->private;
	return snprintf(buf, PAGE_SIZE, "%d\n", zdev->online);
}

static ssize_t zcrypt_online_store(struct device *dev,
				   struct device_attribute *attr,
				   const char *buf, size_t count)
{
	struct zcrypt_device *zdev = to_ap_dev(dev)->private;
	int online;

	if (sscanf(buf, "%d\n", &online) != 1 || online < 0 || online > 1)
		return -EINVAL;
	zdev->online = online;
	if (!online)
		ap_flush_queue(zdev->ap_dev);
	return count;
}

static DEVICE_ATTR(online, 0644, zcrypt_online_show, zcrypt_online_store);

static struct attribute * zcrypt_device_attrs[] = {
	&dev_attr_type.attr,
	&dev_attr_online.attr,
	NULL,
};

static struct attribute_group zcrypt_device_attr_group = {
	.attrs = zcrypt_device_attrs,
};

/**
 * Move the device towards the head of the device list.
 * Need to be called while holding the zcrypt device list lock.
 * Note: cards with speed_rating of 0 are kept at the end of the list.
 */
static void __zcrypt_increase_preference(struct zcrypt_device *zdev)
{
	struct zcrypt_device *tmp;
	struct list_head *l;

	if (zdev->speed_rating == 0)
		return;
	for (l = zdev->list.prev; l != &zcrypt_device_list; l = l->prev) {
		tmp = list_entry(l, struct zcrypt_device, list);
		if ((tmp->request_count + 1) * tmp->speed_rating <=
		    (zdev->request_count + 1) * zdev->speed_rating &&
		    tmp->speed_rating != 0)
			break;
	}
	if (l == zdev->list.prev)
		return;
	/* Move zdev behind l */
	list_del(&zdev->list);
	list_add(&zdev->list, l);
}

/**
 * Move the device towards the tail of the device list.
 * Need to be called while holding the zcrypt device list lock.
 * Note: cards with speed_rating of 0 are kept at the end of the list.
 */
static void __zcrypt_decrease_preference(struct zcrypt_device *zdev)
{
	struct zcrypt_device *tmp;
	struct list_head *l;

	if (zdev->speed_rating == 0)
		return;
	for (l = zdev->list.next; l != &zcrypt_device_list; l = l->next) {
		tmp = list_entry(l, struct zcrypt_device, list);
		if ((tmp->request_count + 1) * tmp->speed_rating >
		    (zdev->request_count + 1) * zdev->speed_rating ||
		    tmp->speed_rating == 0)
			break;
	}
	if (l == zdev->list.next)
		return;
	/* Move zdev before l */
	list_del(&zdev->list);
	list_add_tail(&zdev->list, l);
}

static void zcrypt_device_release(struct kref *kref)
{
	struct zcrypt_device *zdev =
		container_of(kref, struct zcrypt_device, refcount);
	zcrypt_device_free(zdev);
}

void zcrypt_device_get(struct zcrypt_device *zdev)
{
	kref_get(&zdev->refcount);
}
EXPORT_SYMBOL(zcrypt_device_get);

int zcrypt_device_put(struct zcrypt_device *zdev)
{
	return kref_put(&zdev->refcount, zcrypt_device_release);
}
EXPORT_SYMBOL(zcrypt_device_put);

struct zcrypt_device *zcrypt_device_alloc(size_t max_response_size)
{
	struct zcrypt_device *zdev;

	zdev = kzalloc(sizeof(struct zcrypt_device), GFP_KERNEL);
	if (!zdev)
		return NULL;
	zdev->reply.message = kmalloc(max_response_size, GFP_KERNEL);
	if (!zdev->reply.message)
		goto out_free;
	zdev->reply.length = max_response_size;
	spin_lock_init(&zdev->lock);
	INIT_LIST_HEAD(&zdev->list);
	return zdev;

out_free:
	kfree(zdev);
	return NULL;
}
EXPORT_SYMBOL(zcrypt_device_alloc);

void zcrypt_device_free(struct zcrypt_device *zdev)
{
	kfree(zdev->reply.message);
	kfree(zdev);
}
EXPORT_SYMBOL(zcrypt_device_free);

/**
 * Register a crypto device.
 */
int zcrypt_device_register(struct zcrypt_device *zdev)
{
	int rc;

	rc = sysfs_create_group(&zdev->ap_dev->device.kobj,
				&zcrypt_device_attr_group);
	if (rc)
		goto out;
	get_device(&zdev->ap_dev->device);
	kref_init(&zdev->refcount);
	spin_lock_bh(&zcrypt_device_lock);
	zdev->online = 1;	/* New devices are online by default. */
	list_add_tail(&zdev->list, &zcrypt_device_list);
	__zcrypt_increase_preference(zdev);
	zcrypt_device_count++;
	spin_unlock_bh(&zcrypt_device_lock);
out:
	return rc;
}
EXPORT_SYMBOL(zcrypt_device_register);

/**
 * Unregister a crypto device.
 */
void zcrypt_device_unregister(struct zcrypt_device *zdev)
{
	spin_lock_bh(&zcrypt_device_lock);
	zcrypt_device_count--;
	list_del_init(&zdev->list);
	spin_unlock_bh(&zcrypt_device_lock);
	sysfs_remove_group(&zdev->ap_dev->device.kobj,
			   &zcrypt_device_attr_group);
	put_device(&zdev->ap_dev->device);
	zcrypt_device_put(zdev);
}
EXPORT_SYMBOL(zcrypt_device_unregister);

/**
 * zcrypt_read is not be supported beyond zcrypt 1.3.1
 */
static ssize_t zcrypt_read(struct file *filp, char __user *buf,
			   size_t count, loff_t *f_pos)
{
	return -EPERM;
}

/**
 * Write is is not allowed
 */
static ssize_t zcrypt_write(struct file *filp, const char __user *buf,
			    size_t count, loff_t *f_pos)
{
	return -EPERM;
}

/**
 * Device open/close functions to count number of users.
 */
static int zcrypt_open(struct inode *inode, struct file *filp)
{
	atomic_inc(&zcrypt_open_count);
	return 0;
}

static int zcrypt_release(struct inode *inode, struct file *filp)
{
	atomic_dec(&zcrypt_open_count);
	return 0;
}

/**
 * zcrypt ioctls.
 */
static long zcrypt_rsa_modexpo(struct ica_rsa_modexpo *mex)
{
	struct zcrypt_device *zdev;
	int rc;

	if (mex->outputdatalength < mex->inputdatalength)
		return -EINVAL;
	/**
	 * As long as outputdatalength is big enough, we can set the
	 * outputdatalength equal to the inputdatalength, since that is the
	 * number of bytes we will copy in any case
	 */
	mex->outputdatalength = mex->inputdatalength;

	spin_lock_bh(&zcrypt_device_lock);
	list_for_each_entry(zdev, &zcrypt_device_list, list) {
		if (!zdev->online ||
		    !zdev->ops->rsa_modexpo ||
		    zdev->min_mod_size > mex->inputdatalength ||
		    zdev->max_mod_size < mex->inputdatalength)
			continue;
		zcrypt_device_get(zdev);
		get_device(&zdev->ap_dev->device);
		zdev->request_count++;
		__zcrypt_decrease_preference(zdev);
		if (try_module_get(zdev->ap_dev->drv->driver.owner)) {
			spin_unlock_bh(&zcrypt_device_lock);
			rc = zdev->ops->rsa_modexpo(zdev, mex);
			spin_lock_bh(&zcrypt_device_lock);
			module_put(zdev->ap_dev->drv->driver.owner);
		}
		else
			rc = -EAGAIN;
		zdev->request_count--;
		__zcrypt_increase_preference(zdev);
		put_device(&zdev->ap_dev->device);
		zcrypt_device_put(zdev);
		spin_unlock_bh(&zcrypt_device_lock);
		return rc;
	}
	spin_unlock_bh(&zcrypt_device_lock);
	return -ENODEV;
}

static long zcrypt_rsa_crt(struct ica_rsa_modexpo_crt *crt)
{
	struct zcrypt_device *zdev;
	unsigned long long z1, z2, z3;
	int rc, copied;

	if (crt->outputdatalength < crt->inputdatalength ||
	    (crt->inputdatalength & 1))
		return -EINVAL;
	/**
	 * As long as outputdatalength is big enough, we can set the
	 * outputdatalength equal to the inputdatalength, since that is the
	 * number of bytes we will copy in any case
	 */
	crt->outputdatalength = crt->inputdatalength;

	copied = 0;
 restart:
	spin_lock_bh(&zcrypt_device_lock);
	list_for_each_entry(zdev, &zcrypt_device_list, list) {
		if (!zdev->online ||
		    !zdev->ops->rsa_modexpo_crt ||
		    zdev->min_mod_size > crt->inputdatalength ||
		    zdev->max_mod_size < crt->inputdatalength)
			continue;
		if (zdev->short_crt && crt->inputdatalength > 240) {
			/**
			 * Check inputdata for leading zeros for cards
			 * that can't handle np_prime, bp_key, or
			 * u_mult_inv > 128 bytes.
			 */
			if (copied == 0) {
				int len;
				spin_unlock_bh(&zcrypt_device_lock);
				/* len is max 256 / 2 - 120 = 8 */
				len = crt->inputdatalength / 2 - 120;
				z1 = z2 = z3 = 0;
				if (copy_from_user(&z1, crt->np_prime, len) ||
				    copy_from_user(&z2, crt->bp_key, len) ||
				    copy_from_user(&z3, crt->u_mult_inv, len))
					return -EFAULT;
				copied = 1;
				/**
				 * We have to restart device lookup -
				 * the device list may have changed by now.
				 */
				goto restart;
			}
			if (z1 != 0ULL || z2 != 0ULL || z3 != 0ULL)
				/* The device can't handle this request. */
				continue;
		}
		zcrypt_device_get(zdev);
		get_device(&zdev->ap_dev->device);
		zdev->request_count++;
		__zcrypt_decrease_preference(zdev);
		if (try_module_get(zdev->ap_dev->drv->driver.owner)) {
			spin_unlock_bh(&zcrypt_device_lock);
			rc = zdev->ops->rsa_modexpo_crt(zdev, crt);
			spin_lock_bh(&zcrypt_device_lock);
			module_put(zdev->ap_dev->drv->driver.owner);
		}
		else
			rc = -EAGAIN;
		zdev->request_count--;
		__zcrypt_increase_preference(zdev);
		put_device(&zdev->ap_dev->device);
		zcrypt_device_put(zdev);
		spin_unlock_bh(&zcrypt_device_lock);
		return rc;
	}
	spin_unlock_bh(&zcrypt_device_lock);
	return -ENODEV;
}

static long zcrypt_send_cprb(struct ica_xcRB *xcRB)
{
	struct zcrypt_device *zdev;
	int rc;

	spin_lock_bh(&zcrypt_device_lock);
	list_for_each_entry(zdev, &zcrypt_device_list, list) {
		if (!zdev->online || !zdev->ops->send_cprb ||
		    (xcRB->user_defined != AUTOSELECT &&
			AP_QID_DEVICE(zdev->ap_dev->qid) != xcRB->user_defined)
		    )
			continue;
		zcrypt_device_get(zdev);
		get_device(&zdev->ap_dev->device);
		zdev->request_count++;
		__zcrypt_decrease_preference(zdev);
		if (try_module_get(zdev->ap_dev->drv->driver.owner)) {
			spin_unlock_bh(&zcrypt_device_lock);
			rc = zdev->ops->send_cprb(zdev, xcRB);
			spin_lock_bh(&zcrypt_device_lock);
			module_put(zdev->ap_dev->drv->driver.owner);
		}
		else
			rc = -EAGAIN;
		zdev->request_count--;
		__zcrypt_increase_preference(zdev);
		put_device(&zdev->ap_dev->device);
		zcrypt_device_put(zdev);
		spin_unlock_bh(&zcrypt_device_lock);
		return rc;
	}
	spin_unlock_bh(&zcrypt_device_lock);
	return -ENODEV;
}

static void zcrypt_status_mask(char status[AP_DEVICES])
{
	struct zcrypt_device *zdev;

	memset(status, 0, sizeof(char) * AP_DEVICES);
	spin_lock_bh(&zcrypt_device_lock);
	list_for_each_entry(zdev, &zcrypt_device_list, list)
		status[AP_QID_DEVICE(zdev->ap_dev->qid)] =
			zdev->online ? zdev->user_space_type : 0x0d;
	spin_unlock_bh(&zcrypt_device_lock);
}

static void zcrypt_qdepth_mask(char qdepth[AP_DEVICES])
{
	struct zcrypt_device *zdev;

	memset(qdepth, 0, sizeof(char)	* AP_DEVICES);
	spin_lock_bh(&zcrypt_device_lock);
	list_for_each_entry(zdev, &zcrypt_device_list, list) {
		spin_lock(&zdev->ap_dev->lock);
		qdepth[AP_QID_DEVICE(zdev->ap_dev->qid)] =
			zdev->ap_dev->pendingq_count +
			zdev->ap_dev->requestq_count;
		spin_unlock(&zdev->ap_dev->lock);
	}
	spin_unlock_bh(&zcrypt_device_lock);
}

static void zcrypt_perdev_reqcnt(int reqcnt[AP_DEVICES])
{
	struct zcrypt_device *zdev;

	memset(reqcnt, 0, sizeof(int) * AP_DEVICES);
	spin_lock_bh(&zcrypt_device_lock);
	list_for_each_entry(zdev, &zcrypt_device_list, list) {
		spin_lock(&zdev->ap_dev->lock);
		reqcnt[AP_QID_DEVICE(zdev->ap_dev->qid)] =
			zdev->ap_dev->total_request_count;
		spin_unlock(&zdev->ap_dev->lock);
	}
	spin_unlock_bh(&zcrypt_device_lock);
}

static int zcrypt_pendingq_count(void)
{
	struct zcrypt_device *zdev;
	int pendingq_count = 0;

	spin_lock_bh(&zcrypt_device_lock);
	list_for_each_entry(zdev, &zcrypt_device_list, list) {
		spin_lock(&zdev->ap_dev->lock);
		pendingq_count += zdev->ap_dev->pendingq_count;
		spin_unlock(&zdev->ap_dev->lock);
	}
	spin_unlock_bh(&zcrypt_device_lock);
	return pendingq_count;
}

static int zcrypt_requestq_count(void)
{
	struct zcrypt_device *zdev;
	int requestq_count = 0;

	spin_lock_bh(&zcrypt_device_lock);
	list_for_each_entry(zdev, &zcrypt_device_list, list) {
		spin_lock(&zdev->ap_dev->lock);
		requestq_count += zdev->ap_dev->requestq_count;
		spin_unlock(&zdev->ap_dev->lock);
	}
	spin_unlock_bh(&zcrypt_device_lock);
	return requestq_count;
}

static int zcrypt_count_type(int type)
{
	struct zcrypt_device *zdev;
	int device_count = 0;

	spin_lock_bh(&zcrypt_device_lock);
	list_for_each_entry(zdev, &zcrypt_device_list, list)
		if (zdev->user_space_type == type)
			device_count++;
	spin_unlock_bh(&zcrypt_device_lock);
	return device_count;
}

/**
 * Old, deprecated combi status call.
 */
static long zcrypt_ica_status(struct file *filp, unsigned long arg)
{
	struct ica_z90_status *pstat;
	int ret;

	pstat = kzalloc(sizeof(*pstat), GFP_KERNEL);
	if (!pstat)
		return -ENOMEM;
	pstat->totalcount = zcrypt_device_count;
	pstat->leedslitecount = zcrypt_count_type(ZCRYPT_PCICA);
	pstat->leeds2count = zcrypt_count_type(ZCRYPT_PCICC);
	pstat->requestqWaitCount = zcrypt_requestq_count();
	pstat->pendingqWaitCount = zcrypt_pendingq_count();
	pstat->totalOpenCount = atomic_read(&zcrypt_open_count);
	pstat->cryptoDomain = ap_domain_index;
	zcrypt_status_mask(pstat->status);
	zcrypt_qdepth_mask(pstat->qdepth);
	ret = 0;
	if (copy_to_user((void __user *) arg, pstat, sizeof(*pstat)))
		ret = -EFAULT;
	kfree(pstat);
	return ret;
}

static long zcrypt_unlocked_ioctl(struct file *filp, unsigned int cmd,
				  unsigned long arg)
{
	int rc;