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path: root/drivers/s390/crypto/zcrypt_api.c
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Diffstat (limited to 'drivers/s390/crypto/zcrypt_api.c')
-rw-r--r--drivers/s390/crypto/zcrypt_api.c181
1 files changed, 165 insertions, 16 deletions
diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c
index e3625a47a596..4d36e805a234 100644
--- a/drivers/s390/crypto/zcrypt_api.c
+++ b/drivers/s390/crypto/zcrypt_api.c
@@ -36,10 +36,11 @@
#include <linux/compat.h>
#include <asm/atomic.h>
#include <asm/uaccess.h>
+#include <linux/hw_random.h>
#include "zcrypt_api.h"
-/**
+/*
* Module description.
*/
MODULE_AUTHOR("IBM Corporation");
@@ -52,7 +53,10 @@ static LIST_HEAD(zcrypt_device_list);
static int zcrypt_device_count = 0;
static atomic_t zcrypt_open_count = ATOMIC_INIT(0);
-/**
+static int zcrypt_rng_device_add(void);
+static void zcrypt_rng_device_remove(void);
+
+/*
* Device attributes common for all crypto devices.
*/
static ssize_t zcrypt_type_show(struct device *dev,
@@ -99,6 +103,9 @@ static struct attribute_group zcrypt_device_attr_group = {
};
/**
+ * __zcrypt_increase_preference(): Increase preference of a crypto device.
+ * @zdev: Pointer the crypto device
+ *
* 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.
@@ -125,6 +132,9 @@ static void __zcrypt_increase_preference(struct zcrypt_device *zdev)
}
/**
+ * __zcrypt_decrease_preference(): Decrease preference of a crypto device.
+ * @zdev: Pointer to a crypto device.
+ *
* 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.
@@ -198,7 +208,10 @@ void zcrypt_device_free(struct zcrypt_device *zdev)
EXPORT_SYMBOL(zcrypt_device_free);
/**
- * Register a crypto device.
+ * zcrypt_device_register() - Register a crypto device.
+ * @zdev: Pointer to a crypto device
+ *
+ * Register a crypto device. Returns 0 if successful.
*/
int zcrypt_device_register(struct zcrypt_device *zdev)
{
@@ -216,16 +229,37 @@ int zcrypt_device_register(struct zcrypt_device *zdev)
__zcrypt_increase_preference(zdev);
zcrypt_device_count++;
spin_unlock_bh(&zcrypt_device_lock);
+ if (zdev->ops->rng) {
+ rc = zcrypt_rng_device_add();
+ if (rc)
+ goto out_unregister;
+ }
+ return 0;
+
+out_unregister:
+ 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);
out:
return rc;
}
EXPORT_SYMBOL(zcrypt_device_register);
/**
+ * zcrypt_device_unregister(): Unregister a crypto device.
+ * @zdev: Pointer to crypto device
+ *
* Unregister a crypto device.
*/
void zcrypt_device_unregister(struct zcrypt_device *zdev)
{
+ if (zdev->ops->rng)
+ zcrypt_rng_device_remove();
spin_lock_bh(&zcrypt_device_lock);
zcrypt_device_count--;
list_del_init(&zdev->list);
@@ -238,7 +272,9 @@ void zcrypt_device_unregister(struct zcrypt_device *zdev)
EXPORT_SYMBOL(zcrypt_device_unregister);
/**
- * zcrypt_read is not be supported beyond zcrypt 1.3.1
+ * zcrypt_read (): Not supported beyond zcrypt 1.3.1.
+ *
+ * This function is not supported beyond zcrypt 1.3.1.
*/
static ssize_t zcrypt_read(struct file *filp, char __user *buf,
size_t count, loff_t *f_pos)
@@ -247,6 +283,8 @@ static ssize_t zcrypt_read(struct file *filp, char __user *buf,
}
/**
+ * zcrypt_write(): Not allowed.
+ *
* Write is is not allowed
*/
static ssize_t zcrypt_write(struct file *filp, const char __user *buf,
@@ -256,7 +294,9 @@ static ssize_t zcrypt_write(struct file *filp, const char __user *buf,
}
/**
- * Device open/close functions to count number of users.
+ * zcrypt_open(): Count number of users.
+ *
+ * Device open function to count number of users.
*/
static int zcrypt_open(struct inode *inode, struct file *filp)
{
@@ -264,13 +304,18 @@ static int zcrypt_open(struct inode *inode, struct file *filp)
return 0;
}
+/**
+ * zcrypt_release(): Count number of users.
+ *
+ * Device close function to count number of users.
+ */
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)
@@ -280,7 +325,7 @@ static long zcrypt_rsa_modexpo(struct ica_rsa_modexpo *mex)
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
@@ -326,7 +371,7 @@ static long zcrypt_rsa_crt(struct ica_rsa_modexpo_crt *crt)
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
@@ -343,7 +388,7 @@ static long zcrypt_rsa_crt(struct ica_rsa_modexpo_crt *crt)
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.
@@ -359,7 +404,7 @@ static long zcrypt_rsa_crt(struct ica_rsa_modexpo_crt *crt)
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.
*/
@@ -427,6 +472,37 @@ static long zcrypt_send_cprb(struct ica_xcRB *xcRB)
return -ENODEV;
}
+static long zcrypt_rng(char *buffer)
+{
+ 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->rng)
+ 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->rng(zdev, buffer);
+ 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;
@@ -514,6 +590,8 @@ static int zcrypt_count_type(int type)
}
/**
+ * zcrypt_ica_status(): Old, depracted combi status call.
+ *
* Old, deprecated combi status call.
*/
static long zcrypt_ica_status(struct file *filp, unsigned long arg)
@@ -615,7 +693,7 @@ static long zcrypt_unlocked_ioctl(struct file *filp, unsigned int cmd,
(int __user *) arg);
case Z90STAT_DOMAIN_INDEX:
return put_user(ap_domain_index, (int __user *) arg);
- /**
+ /*
* Deprecated ioctls. Don't add another device count ioctl,
* you can count them yourself in the user space with the
* output of the Z90STAT_STATUS_MASK ioctl.
@@ -653,7 +731,7 @@ static long zcrypt_unlocked_ioctl(struct file *filp, unsigned int cmd,
}
#ifdef CONFIG_COMPAT
-/**
+/*
* ioctl32 conversion routines
*/
struct compat_ica_rsa_modexpo {
@@ -804,7 +882,7 @@ static long zcrypt_compat_ioctl(struct file *filp, unsigned int cmd,
}
#endif
-/**
+/*
* Misc device file operations.
*/
static const struct file_operations zcrypt_fops = {
@@ -819,7 +897,7 @@ static const struct file_operations zcrypt_fops = {
.release = zcrypt_release
};
-/**
+/*
* Misc device.
*/
static struct miscdevice zcrypt_misc_device = {
@@ -828,7 +906,7 @@ static struct miscdevice zcrypt_misc_device = {
.fops = &zcrypt_fops,
};
-/**
+/*
* Deprecated /proc entry support.
*/
static struct proc_dir_entry *zcrypt_entry;
@@ -1022,7 +1100,7 @@ static int zcrypt_status_write(struct file *file, const char __user *buffer,
}
for (j = 0; j < 64 && *ptr; ptr++) {
- /**
+ /*
* '0' for no device, '1' for PCICA, '2' for PCICC,
* '3' for PCIXCC_MCL2, '4' for PCIXCC_MCL3,
* '5' for CEX2C and '6' for CEX2A'
@@ -1041,7 +1119,76 @@ out:
return count;
}
+static int zcrypt_rng_device_count;
+static u32 *zcrypt_rng_buffer;
+static int zcrypt_rng_buffer_index;
+static DEFINE_MUTEX(zcrypt_rng_mutex);
+
+static int zcrypt_rng_data_read(struct hwrng *rng, u32 *data)
+{
+ int rc;
+
+ /*
+ * We don't need locking here because the RNG API guarantees serialized
+ * read method calls.
+ */
+ if (zcrypt_rng_buffer_index == 0) {
+ rc = zcrypt_rng((char *) zcrypt_rng_buffer);
+ if (rc < 0)
+ return -EIO;
+ zcrypt_rng_buffer_index = rc / sizeof *data;
+ }
+ *data = zcrypt_rng_buffer[--zcrypt_rng_buffer_index];
+ return sizeof *data;
+}
+
+static struct hwrng zcrypt_rng_dev = {
+ .name = "zcrypt",
+ .data_read = zcrypt_rng_data_read,
+};
+
+static int zcrypt_rng_device_add(void)
+{
+ int rc = 0;
+
+ mutex_lock(&zcrypt_rng_mutex);
+ if (zcrypt_rng_device_count == 0) {
+ zcrypt_rng_buffer = (u32 *) get_zeroed_page(GFP_KERNEL);
+ if (!zcrypt_rng_buffer) {
+ rc = -ENOMEM;
+ goto out;
+ }
+ zcrypt_rng_buffer_index = 0;
+ rc = hwrng_register(&zcrypt_rng_dev);
+ if (rc)
+ goto out_free;
+ zcrypt_rng_device_count = 1;
+ } else
+ zcrypt_rng_device_count++;
+ mutex_unlock(&zcrypt_rng_mutex);
+ return 0;
+
+out_free:
+ free_page((unsigned long) zcrypt_rng_buffer);
+out:
+ mutex_unlock(&zcrypt_rng_mutex);
+ return rc;
+}
+
+static void zcrypt_rng_device_remove(void)
+{
+ mutex_lock(&zcrypt_rng_mutex);
+ zcrypt_rng_device_count--;
+ if (zcrypt_rng_device_count == 0) {
+ hwrng_unregister(&zcrypt_rng_dev);
+ free_page((unsigned long) zcrypt_rng_buffer);
+ }
+ mutex_unlock(&zcrypt_rng_mutex);
+}
+
/**
+ * zcrypt_api_init(): Module initialization.
+ *
* The module initialization code.
*/
int __init zcrypt_api_init(void)
@@ -1076,6 +1223,8 @@ out:
}
/**
+ * zcrypt_api_exit(): Module termination.
+ *
* The module termination code.
*/
void zcrypt_api_exit(void)