// SPDX-License-Identifier: GPL-2.0-or-later
 /* Driver for Virtio crypto device.
  *
  * Copyright 2016 HUAWEI TECHNOLOGIES CO., LTD.
  */

#include <linux/err.h>
#include <linux/module.h>
#include <linux/virtio_config.h>
#include <linux/cpu.h>

#include <uapi/linux/virtio_crypto.h>
#include "virtio_crypto_common.h"


void
virtcrypto_clear_request(struct virtio_crypto_request *vc_req)
{
        if (vc_req) {
                kfree_sensitive(vc_req->req_data);
                kfree(vc_req->sgs);
        }
}

static void virtio_crypto_ctrlq_callback(struct virtio_crypto_ctrl_request *vc_ctrl_req)
{
        complete(&vc_ctrl_req->compl);
}

static void virtcrypto_ctrlq_callback(struct virtqueue *vq)
{
        struct virtio_crypto *vcrypto = vq->vdev->priv;
        struct virtio_crypto_ctrl_request *vc_ctrl_req;
        unsigned long flags;
        unsigned int len;

        spin_lock_irqsave(&vcrypto->ctrl_lock, flags);
        do {
                virtqueue_disable_cb(vq);
                while ((vc_ctrl_req = virtqueue_get_buf(vq, &len)) != NULL) {
                        spin_unlock_irqrestore(&vcrypto->ctrl_lock, flags);
                        virtio_crypto_ctrlq_callback(vc_ctrl_req);
                        spin_lock_irqsave(&vcrypto->ctrl_lock, flags);
                }
        } while (!virtqueue_enable_cb(vq));
        spin_unlock_irqrestore(&vcrypto->ctrl_lock, flags);
}

int virtio_crypto_ctrl_vq_request(struct virtio_crypto *vcrypto, struct scatterlist *sgs[],
                unsigned int out_sgs, unsigned int in_sgs,
                struct virtio_crypto_ctrl_request *vc_ctrl_req)
{
        int err;
        unsigned long flags;

        init_completion(&vc_ctrl_req->compl);

        spin_lock_irqsave(&vcrypto->ctrl_lock, flags);
        err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, out_sgs, in_sgs, vc_ctrl_req, GFP_ATOMIC);
        if (err < 0) {
                spin_unlock_irqrestore(&vcrypto->ctrl_lock, flags);
                return err;
        }

        virtqueue_kick(vcrypto->ctrl_vq);
        spin_unlock_irqrestore(&vcrypto->ctrl_lock, flags);

        wait_for_completion(&vc_ctrl_req->compl);

        return 0;
}

static void virtcrypto_done_task(unsigned long data)
{
        struct data_queue *data_vq = (struct data_queue *)data;
        struct virtqueue *vq = data_vq->vq;
        struct virtio_crypto_request *vc_req;
        unsigned long flags;
        unsigned int len;

        spin_lock_irqsave(&data_vq->lock, flags);
        do {
                virtqueue_disable_cb(vq);
                while ((vc_req = virtqueue_get_buf(vq, &len)) != NULL) {
                        spin_unlock_irqrestore(&data_vq->lock, flags);
                        if (vc_req->alg_cb)
                                vc_req->alg_cb(vc_req, len);
                        spin_lock_irqsave(&data_vq->lock, flags);
                }
        } while (!virtqueue_enable_cb(vq));
        spin_unlock_irqrestore(&data_vq->lock, flags);
}

static void virtcrypto_dataq_callback(struct virtqueue *vq)
{
        struct virtio_crypto *vcrypto = vq->vdev->priv;
        struct data_queue *dq = &vcrypto->data_vq[vq->index];

        tasklet_schedule(&dq->done_task);
}

static int virtcrypto_find_vqs(struct virtio_crypto *vi)
{
        struct virtqueue_info *vqs_info;
        struct virtqueue **vqs;
        int ret = -ENOMEM;
        int i, total_vqs;
        struct device *dev = &vi->vdev->dev;

        /*
         * We expect 1 data virtqueue, followed by
         * possible N-1 data queues used in multiqueue mode,
         * followed by control vq.
         */
        total_vqs = vi->max_data_queues + 1;

        /* Allocate space for find_vqs parameters */
        vqs = kzalloc_objs(*vqs, total_vqs);
        if (!vqs)
                goto err_vq;
        vqs_info = kzalloc_objs(*vqs_info, total_vqs);
        if (!vqs_info)
                goto err_vqs_info;

        /* Parameters for control virtqueue */
        vqs_info[total_vqs - 1].callback = virtcrypto_ctrlq_callback;
        vqs_info[total_vqs - 1].name = "controlq";

        /* Allocate/initialize parameters for data virtqueues */
        for (i = 0; i < vi->max_data_queues; i++) {
                vqs_info[i].callback = virtcrypto_dataq_callback;
                snprintf(vi->data_vq[i].name, sizeof(vi->data_vq[i].name),
                                "dataq.%d", i);
                vqs_info[i].name = vi->data_vq[i].name;
        }

        ret = virtio_find_vqs(vi->vdev, total_vqs, vqs, vqs_info, NULL);
        if (ret)
                goto err_find;

        vi->ctrl_vq = vqs[total_vqs - 1];

        for (i = 0; i < vi->max_data_queues; i++) {
                spin_lock_init(&vi->data_vq[i].lock);
                vi->data_vq[i].vq = vqs[i];
                /* Initialize crypto engine */
                vi->data_vq[i].engine = crypto_engine_alloc_init_and_set(dev, true, true,
                                                virtqueue_get_vring_size(vqs[i]));
                if (!vi->data_vq[i].engine) {
                        ret = -ENOMEM;
                        goto err_engine;
                }
                tasklet_init(&vi->data_vq[i].done_task, virtcrypto_done_task,
                                (unsigned long)&vi->data_vq[i]);
        }

        kfree(vqs_info);
        kfree(vqs);

        return 0;

err_engine:
err_find:
        kfree(vqs_info);
err_vqs_info:
        kfree(vqs);
err_vq:
        return ret;
}

static int virtcrypto_alloc_queues(struct virtio_crypto *vi)
{
        vi->data_vq = kzalloc_objs(*vi->data_vq, vi->max_data_queues);
        if (!vi->data_vq)
                return -ENOMEM;

        return 0;
}

static void virtcrypto_clean_affinity(struct virtio_crypto *vi, long hcpu)
{
        int i;

        if (vi->affinity_hint_set) {
                for (i = 0; i < vi->max_data_queues; i++)
                        virtqueue_set_affinity(vi->data_vq[i].vq, NULL);

                vi->affinity_hint_set = false;
        }
}

static void virtcrypto_set_affinity(struct virtio_crypto *vcrypto)
{
        int i = 0;
        int cpu;

        /*
         * In single queue mode, we don't set the cpu affinity.
         */
        if (vcrypto->curr_queue == 1 || vcrypto->max_data_queues == 1) {
                virtcrypto_clean_affinity(vcrypto, -1);
                return;
        }

        /*
         * In multiqueue mode, we let the queue to be private to one cpu
         * by setting the affinity hint to eliminate the contention.
         *
         * TODO: adds cpu hotplug support by register cpu notifier.
         *
         */
        for_each_online_cpu(cpu) {
                virtqueue_set_affinity(vcrypto->data_vq[i].vq, cpumask_of(cpu));
                if (++i >= vcrypto->max_data_queues)
                        break;
        }

        vcrypto->affinity_hint_set = true;
}

static void virtcrypto_free_queues(struct virtio_crypto *vi)
{
        kfree(vi->data_vq);
}

static int virtcrypto_init_vqs(struct virtio_crypto *vi)
{
        int ret;

        /* Allocate send & receive queues */
        ret = virtcrypto_alloc_queues(vi);
        if (ret)
                goto err;

        ret = virtcrypto_find_vqs(vi);
        if (ret)
                goto err_free;

        cpus_read_lock();
        virtcrypto_set_affinity(vi);
        cpus_read_unlock();

        return 0;

err_free:
        virtcrypto_free_queues(vi);
err:
        return ret;
}

static int virtcrypto_update_status(struct virtio_crypto *vcrypto)
{
        u32 status;
        int err;

        virtio_cread_le(vcrypto->vdev,
                        struct virtio_crypto_config, status, &status);

        /*
         * Unknown status bits would be a host error and the driver
         * should consider the device to be broken.
         */
        if (status & (~VIRTIO_CRYPTO_S_HW_READY)) {
                dev_warn(&vcrypto->vdev->dev,
                                "Unknown status bits: 0x%x\n", status);

                virtio_break_device(vcrypto->vdev);
                return -EPERM;
        }

        if (vcrypto->status == status)
                return 0;

        vcrypto->status = status;

        if (vcrypto->status & VIRTIO_CRYPTO_S_HW_READY) {
                err = virtcrypto_dev_start(vcrypto);
                if (err) {
                        dev_err(&vcrypto->vdev->dev,
                                "Failed to start virtio crypto device.\n");

                        return -EPERM;
                }
                dev_info(&vcrypto->vdev->dev, "Accelerator device is ready\n");
        } else {
                virtcrypto_dev_stop(vcrypto);
                dev_info(&vcrypto->vdev->dev, "Accelerator is not ready\n");
        }

        return 0;
}

static int virtcrypto_start_crypto_engines(struct virtio_crypto *vcrypto)
{
        int32_t i;
        int ret;

        for (i = 0; i < vcrypto->max_data_queues; i++) {
                if (vcrypto->data_vq[i].engine) {
                        ret = crypto_engine_start(vcrypto->data_vq[i].engine);
                        if (ret)
                                goto err;
                }
        }

        return 0;

err:
        while (--i >= 0)
                if (vcrypto->data_vq[i].engine)
                        crypto_engine_exit(vcrypto->data_vq[i].engine);

        return ret;
}

static void virtcrypto_clear_crypto_engines(struct virtio_crypto *vcrypto)
{
        u32 i;

        for (i = 0; i < vcrypto->max_data_queues; i++)
                if (vcrypto->data_vq[i].engine)
                        crypto_engine_exit(vcrypto->data_vq[i].engine);
}

static void virtcrypto_del_vqs(struct virtio_crypto *vcrypto)
{
        struct virtio_device *vdev = vcrypto->vdev;

        virtcrypto_clean_affinity(vcrypto, -1);

        vdev->config->del_vqs(vdev);

        virtcrypto_free_queues(vcrypto);
}

static void vcrypto_config_changed_work(struct work_struct *work)
{
        struct virtio_crypto *vcrypto =
                container_of(work, struct virtio_crypto, config_work);

        virtcrypto_update_status(vcrypto);
}

static int virtcrypto_probe(struct virtio_device *vdev)
{
        int err = -EFAULT;
        struct virtio_crypto *vcrypto;
        u32 max_data_queues = 0, max_cipher_key_len = 0;
        u32 max_auth_key_len = 0;
        u64 max_size = 0;
        u32 cipher_algo_l = 0;
        u32 cipher_algo_h = 0;
        u32 hash_algo = 0;
        u32 mac_algo_l = 0;
        u32 mac_algo_h = 0;
        u32 aead_algo = 0;
        u32 akcipher_algo = 0;
        u32 crypto_services = 0;

        if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
                return -ENODEV;

        if (!vdev->config->get) {
                dev_err(&vdev->dev, "%s failure: config access disabled\n",
                        __func__);
                return -EINVAL;
        }

        if (num_possible_nodes() > 1 && dev_to_node(&vdev->dev) < 0) {
                /*
                 * If the accelerator is connected to a node with no memory
                 * there is no point in using the accelerator since the remote
                 * memory transaction will be very slow.
                 */
                dev_err(&vdev->dev, "Invalid NUMA configuration.\n");
                return -EINVAL;
        }

        vcrypto = kzalloc_node(sizeof(*vcrypto), GFP_KERNEL,
                                        dev_to_node(&vdev->dev));
        if (!vcrypto)
                return -ENOMEM;

        virtio_cread_le(vdev, struct virtio_crypto_config,
                        max_dataqueues, &max_data_queues);
        if (max_data_queues < 1)
                max_data_queues = 1;

        virtio_cread_le(vdev, struct virtio_crypto_config,
                        max_cipher_key_len, &max_cipher_key_len);
        virtio_cread_le(vdev, struct virtio_crypto_config,
                        max_auth_key_len, &max_auth_key_len);
        virtio_cread_le(vdev, struct virtio_crypto_config,
                        max_size, &max_size);
        virtio_cread_le(vdev, struct virtio_crypto_config,
                        crypto_services, &crypto_services);
        virtio_cread_le(vdev, struct virtio_crypto_config,
                        cipher_algo_l, &cipher_algo_l);
        virtio_cread_le(vdev, struct virtio_crypto_config,
                        cipher_algo_h, &cipher_algo_h);
        virtio_cread_le(vdev, struct virtio_crypto_config,
                        hash_algo, &hash_algo);
        virtio_cread_le(vdev, struct virtio_crypto_config,
                        mac_algo_l, &mac_algo_l);
        virtio_cread_le(vdev, struct virtio_crypto_config,
                        mac_algo_h, &mac_algo_h);
        virtio_cread_le(vdev, struct virtio_crypto_config,
                        aead_algo, &aead_algo);
        if (crypto_services & (1 << VIRTIO_CRYPTO_SERVICE_AKCIPHER))
                virtio_cread_le(vdev, struct virtio_crypto_config,
                                akcipher_algo, &akcipher_algo);

        /* Add virtio crypto device to global table */
        err = virtcrypto_devmgr_add_dev(vcrypto);
        if (err) {
                dev_err(&vdev->dev, "Failed to add new virtio crypto device.\n");
                goto free;
        }
        vcrypto->owner = THIS_MODULE;
        vcrypto = vdev->priv = vcrypto;
        vcrypto->vdev = vdev;

        spin_lock_init(&vcrypto->ctrl_lock);

        /* Use single data queue as default */
        vcrypto->curr_queue = 1;
        vcrypto->max_data_queues = max_data_queues;
        vcrypto->max_cipher_key_len = max_cipher_key_len;
        vcrypto->max_auth_key_len = max_auth_key_len;
        vcrypto->max_size = max_size;
        vcrypto->crypto_services = crypto_services;
        vcrypto->cipher_algo_l = cipher_algo_l;
        vcrypto->cipher_algo_h = cipher_algo_h;
        vcrypto->mac_algo_l = mac_algo_l;
        vcrypto->mac_algo_h = mac_algo_h;
        vcrypto->hash_algo = hash_algo;
        vcrypto->aead_algo = aead_algo;
        vcrypto->akcipher_algo = akcipher_algo;

        dev_info(&vdev->dev,
                "max_queues: %u, max_cipher_key_len: %u, max_auth_key_len: %u, max_size 0x%llx\n",
                vcrypto->max_data_queues,
                vcrypto->max_cipher_key_len,
                vcrypto->max_auth_key_len,
                vcrypto->max_size);

        err = virtcrypto_init_vqs(vcrypto);
        if (err) {
                dev_err(&vdev->dev, "Failed to initialize vqs.\n");
                goto free_dev;
        }

        err = virtcrypto_start_crypto_engines(vcrypto);
        if (err)
                goto free_vqs;

        virtio_device_ready(vdev);

        err = virtcrypto_update_status(vcrypto);
        if (err)
                goto free_engines;

        INIT_WORK(&vcrypto->config_work, vcrypto_config_changed_work);

        return 0;

free_engines:
        virtcrypto_clear_crypto_engines(vcrypto);
free_vqs:
        virtio_reset_device(vdev);
        virtcrypto_del_vqs(vcrypto);
free_dev:
        virtcrypto_devmgr_rm_dev(vcrypto);
free:
        kfree(vcrypto);
        return err;
}

static void virtcrypto_free_unused_reqs(struct virtio_crypto *vcrypto)
{
        struct virtio_crypto_request *vc_req;
        int i;
        struct virtqueue *vq;

        for (i = 0; i < vcrypto->max_data_queues; i++) {
                vq = vcrypto->data_vq[i].vq;
                while ((vc_req = virtqueue_detach_unused_buf(vq)) != NULL)
                        virtcrypto_clear_request(vc_req);
                cond_resched();
        }
}

static void virtcrypto_remove(struct virtio_device *vdev)
{
        struct virtio_crypto *vcrypto = vdev->priv;
        int i;

        dev_info(&vdev->dev, "Start virtcrypto_remove.\n");

        flush_work(&vcrypto->config_work);
        if (virtcrypto_dev_started(vcrypto))
                virtcrypto_dev_stop(vcrypto);
        for (i = 0; i < vcrypto->max_data_queues; i++)
                tasklet_kill(&vcrypto->data_vq[i].done_task);
        virtio_reset_device(vdev);
        virtcrypto_free_unused_reqs(vcrypto);
        virtcrypto_clear_crypto_engines(vcrypto);
        virtcrypto_del_vqs(vcrypto);
        virtcrypto_devmgr_rm_dev(vcrypto);
        kfree(vcrypto);
}

static void virtcrypto_config_changed(struct virtio_device *vdev)
{
        struct virtio_crypto *vcrypto = vdev->priv;

        schedule_work(&vcrypto->config_work);
}

#ifdef CONFIG_PM_SLEEP
static int virtcrypto_freeze(struct virtio_device *vdev)
{
        struct virtio_crypto *vcrypto = vdev->priv;

        flush_work(&vcrypto->config_work);
        virtio_reset_device(vdev);
        virtcrypto_free_unused_reqs(vcrypto);
        if (virtcrypto_dev_started(vcrypto))
                virtcrypto_dev_stop(vcrypto);

        virtcrypto_clear_crypto_engines(vcrypto);
        virtcrypto_del_vqs(vcrypto);
        return 0;
}

static int virtcrypto_restore(struct virtio_device *vdev)
{
        struct virtio_crypto *vcrypto = vdev->priv;
        int err;

        err = virtcrypto_init_vqs(vcrypto);
        if (err)
                return err;

        err = virtcrypto_start_crypto_engines(vcrypto);
        if (err)
                goto free_vqs;

        virtio_device_ready(vdev);

        err = virtcrypto_dev_start(vcrypto);
        if (err) {
                dev_err(&vdev->dev, "Failed to start virtio crypto device.\n");
                goto free_engines;
        }

        return 0;

free_engines:
        virtcrypto_clear_crypto_engines(vcrypto);
free_vqs:
        virtio_reset_device(vdev);
        virtcrypto_del_vqs(vcrypto);
        return err;
}
#endif

static const unsigned int features[] = {
        /* none */
};

static const struct virtio_device_id id_table[] = {
        { VIRTIO_ID_CRYPTO, VIRTIO_DEV_ANY_ID },
        { 0 },
};

static struct virtio_driver virtio_crypto_driver = {
        .driver.name         = KBUILD_MODNAME,
        .feature_table       = features,
        .feature_table_size  = ARRAY_SIZE(features),
        .id_table            = id_table,
        .probe               = virtcrypto_probe,
        .remove              = virtcrypto_remove,
        .config_changed = virtcrypto_config_changed,
#ifdef CONFIG_PM_SLEEP
        .freeze = virtcrypto_freeze,
        .restore = virtcrypto_restore,
#endif
};

module_virtio_driver(virtio_crypto_driver);

MODULE_DEVICE_TABLE(virtio, id_table);
MODULE_DESCRIPTION("virtio crypto device driver");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Gonglei <arei.gonglei@huawei.com>");