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path: root/drivers/crypto/virtio/virtio_crypto_mgr.c
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Diffstat (limited to 'drivers/crypto/virtio/virtio_crypto_mgr.c')
-rw-r--r--drivers/crypto/virtio/virtio_crypto_mgr.c264
1 files changed, 264 insertions, 0 deletions
diff --git a/drivers/crypto/virtio/virtio_crypto_mgr.c b/drivers/crypto/virtio/virtio_crypto_mgr.c
new file mode 100644
index 000000000000..a69ff71de2c4
--- /dev/null
+++ b/drivers/crypto/virtio/virtio_crypto_mgr.c
@@ -0,0 +1,264 @@
+ /* Management for virtio crypto devices (refer to adf_dev_mgr.c)
+ *
+ * Copyright 2016 HUAWEI TECHNOLOGIES CO., LTD.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/mutex.h>
+#include <linux/list.h>
+#include <linux/module.h>
+
+#include <uapi/linux/virtio_crypto.h>
+#include "virtio_crypto_common.h"
+
+static LIST_HEAD(virtio_crypto_table);
+static uint32_t num_devices;
+
+/* The table_lock protects the above global list and num_devices */
+static DEFINE_MUTEX(table_lock);
+
+#define VIRTIO_CRYPTO_MAX_DEVICES 32
+
+
+/*
+ * virtcrypto_devmgr_add_dev() - Add vcrypto_dev to the acceleration
+ * framework.
+ * @vcrypto_dev: Pointer to virtio crypto device.
+ *
+ * Function adds virtio crypto device to the global list.
+ * To be used by virtio crypto device specific drivers.
+ *
+ * Return: 0 on success, error code othewise.
+ */
+int virtcrypto_devmgr_add_dev(struct virtio_crypto *vcrypto_dev)
+{
+ struct list_head *itr;
+
+ mutex_lock(&table_lock);
+ if (num_devices == VIRTIO_CRYPTO_MAX_DEVICES) {
+ pr_info("virtio_crypto: only support up to %d devices\n",
+ VIRTIO_CRYPTO_MAX_DEVICES);
+ mutex_unlock(&table_lock);
+ return -EFAULT;
+ }
+
+ list_for_each(itr, &virtio_crypto_table) {
+ struct virtio_crypto *ptr =
+ list_entry(itr, struct virtio_crypto, list);
+
+ if (ptr == vcrypto_dev) {
+ mutex_unlock(&table_lock);
+ return -EEXIST;
+ }
+ }
+ atomic_set(&vcrypto_dev->ref_count, 0);
+ list_add_tail(&vcrypto_dev->list, &virtio_crypto_table);
+ vcrypto_dev->dev_id = num_devices++;
+ mutex_unlock(&table_lock);
+ return 0;
+}
+
+struct list_head *virtcrypto_devmgr_get_head(void)
+{
+ return &virtio_crypto_table;
+}
+
+/*
+ * virtcrypto_devmgr_rm_dev() - Remove vcrypto_dev from the acceleration
+ * framework.
+ * @vcrypto_dev: Pointer to virtio crypto device.
+ *
+ * Function removes virtio crypto device from the acceleration framework.
+ * To be used by virtio crypto device specific drivers.
+ *
+ * Return: void
+ */
+void virtcrypto_devmgr_rm_dev(struct virtio_crypto *vcrypto_dev)
+{
+ mutex_lock(&table_lock);
+ list_del(&vcrypto_dev->list);
+ num_devices--;
+ mutex_unlock(&table_lock);
+}
+
+/*
+ * virtcrypto_devmgr_get_first()
+ *
+ * Function returns the first virtio crypto device from the acceleration
+ * framework.
+ *
+ * To be used by virtio crypto device specific drivers.
+ *
+ * Return: pointer to vcrypto_dev or NULL if not found.
+ */
+struct virtio_crypto *virtcrypto_devmgr_get_first(void)
+{
+ struct virtio_crypto *dev = NULL;
+
+ mutex_lock(&table_lock);
+ if (!list_empty(&virtio_crypto_table))
+ dev = list_first_entry(&virtio_crypto_table,
+ struct virtio_crypto,
+ list);
+ mutex_unlock(&table_lock);
+ return dev;
+}
+
+/*
+ * virtcrypto_dev_in_use() - Check whether vcrypto_dev is currently in use
+ * @vcrypto_dev: Pointer to virtio crypto device.
+ *
+ * To be used by virtio crypto device specific drivers.
+ *
+ * Return: 1 when device is in use, 0 otherwise.
+ */
+int virtcrypto_dev_in_use(struct virtio_crypto *vcrypto_dev)
+{
+ return atomic_read(&vcrypto_dev->ref_count) != 0;
+}
+
+/*
+ * virtcrypto_dev_get() - Increment vcrypto_dev reference count
+ * @vcrypto_dev: Pointer to virtio crypto device.
+ *
+ * Increment the vcrypto_dev refcount and if this is the first time
+ * incrementing it during this period the vcrypto_dev is in use,
+ * increment the module refcount too.
+ * To be used by virtio crypto device specific drivers.
+ *
+ * Return: 0 when successful, EFAULT when fail to bump module refcount
+ */
+int virtcrypto_dev_get(struct virtio_crypto *vcrypto_dev)
+{
+ if (atomic_add_return(1, &vcrypto_dev->ref_count) == 1)
+ if (!try_module_get(vcrypto_dev->owner))
+ return -EFAULT;
+ return 0;
+}
+
+/*
+ * virtcrypto_dev_put() - Decrement vcrypto_dev reference count
+ * @vcrypto_dev: Pointer to virtio crypto device.
+ *
+ * Decrement the vcrypto_dev refcount and if this is the last time
+ * decrementing it during this period the vcrypto_dev is in use,
+ * decrement the module refcount too.
+ * To be used by virtio crypto device specific drivers.
+ *
+ * Return: void
+ */
+void virtcrypto_dev_put(struct virtio_crypto *vcrypto_dev)
+{
+ if (atomic_sub_return(1, &vcrypto_dev->ref_count) == 0)
+ module_put(vcrypto_dev->owner);
+}
+
+/*
+ * virtcrypto_dev_started() - Check whether device has started
+ * @vcrypto_dev: Pointer to virtio crypto device.
+ *
+ * To be used by virtio crypto device specific drivers.
+ *
+ * Return: 1 when the device has started, 0 otherwise
+ */
+int virtcrypto_dev_started(struct virtio_crypto *vcrypto_dev)
+{
+ return (vcrypto_dev->status & VIRTIO_CRYPTO_S_HW_READY);
+}
+
+/*
+ * virtcrypto_get_dev_node() - Get vcrypto_dev on the node.
+ * @node: Node id the driver works.
+ *
+ * Function returns the virtio crypto device used fewest on the node.
+ *
+ * To be used by virtio crypto device specific drivers.
+ *
+ * Return: pointer to vcrypto_dev or NULL if not found.
+ */
+struct virtio_crypto *virtcrypto_get_dev_node(int node)
+{
+ struct virtio_crypto *vcrypto_dev = NULL, *tmp_dev;
+ unsigned long best = ~0;
+ unsigned long ctr;
+
+ mutex_lock(&table_lock);
+ list_for_each_entry(tmp_dev, virtcrypto_devmgr_get_head(), list) {
+
+ if ((node == dev_to_node(&tmp_dev->vdev->dev) ||
+ dev_to_node(&tmp_dev->vdev->dev) < 0) &&
+ virtcrypto_dev_started(tmp_dev)) {
+ ctr = atomic_read(&tmp_dev->ref_count);
+ if (best > ctr) {
+ vcrypto_dev = tmp_dev;
+ best = ctr;
+ }
+ }
+ }
+
+ if (!vcrypto_dev) {
+ pr_info("virtio_crypto: Could not find a device on node %d\n",
+ node);
+ /* Get any started device */
+ list_for_each_entry(tmp_dev,
+ virtcrypto_devmgr_get_head(), list) {
+ if (virtcrypto_dev_started(tmp_dev)) {
+ vcrypto_dev = tmp_dev;
+ break;
+ }
+ }
+ }
+ mutex_unlock(&table_lock);
+ if (!vcrypto_dev)
+ return NULL;
+
+ virtcrypto_dev_get(vcrypto_dev);
+ return vcrypto_dev;
+}
+
+/*
+ * virtcrypto_dev_start() - Start virtio crypto device
+ * @vcrypto: Pointer to virtio crypto device.
+ *
+ * Function notifies all the registered services that the virtio crypto device
+ * is ready to be used.
+ * To be used by virtio crypto device specific drivers.
+ *
+ * Return: 0 on success, EFAULT when fail to register algorithms
+ */
+int virtcrypto_dev_start(struct virtio_crypto *vcrypto)
+{
+ if (virtio_crypto_algs_register()) {
+ pr_err("virtio_crypto: Failed to register crypto algs\n");
+ return -EFAULT;
+ }
+
+ return 0;
+}
+
+/*
+ * virtcrypto_dev_stop() - Stop virtio crypto device
+ * @vcrypto: Pointer to virtio crypto device.
+ *
+ * Function notifies all the registered services that the virtio crypto device
+ * is ready to be used.
+ * To be used by virtio crypto device specific drivers.
+ *
+ * Return: void
+ */
+void virtcrypto_dev_stop(struct virtio_crypto *vcrypto)
+{
+ virtio_crypto_algs_unregister();
+}