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-rw-r--r--drivers/nvdimm/Makefile1
-rw-r--r--drivers/nvdimm/nd_virtio.c125
-rw-r--r--drivers/nvdimm/virtio_pmem.c122
-rw-r--r--drivers/nvdimm/virtio_pmem.h55
4 files changed, 303 insertions, 0 deletions
diff --git a/drivers/nvdimm/Makefile b/drivers/nvdimm/Makefile
index 6f2a088afad6..cefe233e0b52 100644
--- a/drivers/nvdimm/Makefile
+++ b/drivers/nvdimm/Makefile
@@ -5,6 +5,7 @@ obj-$(CONFIG_ND_BTT) += nd_btt.o
obj-$(CONFIG_ND_BLK) += nd_blk.o
obj-$(CONFIG_X86_PMEM_LEGACY) += nd_e820.o
obj-$(CONFIG_OF_PMEM) += of_pmem.o
+obj-$(CONFIG_VIRTIO_PMEM) += virtio_pmem.o nd_virtio.o
nd_pmem-y := pmem.o
diff --git a/drivers/nvdimm/nd_virtio.c b/drivers/nvdimm/nd_virtio.c
new file mode 100644
index 000000000000..8645275c08c2
--- /dev/null
+++ b/drivers/nvdimm/nd_virtio.c
@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * virtio_pmem.c: Virtio pmem Driver
+ *
+ * Discovers persistent memory range information
+ * from host and provides a virtio based flushing
+ * interface.
+ */
+#include "virtio_pmem.h"
+#include "nd.h"
+
+ /* The interrupt handler */
+void virtio_pmem_host_ack(struct virtqueue *vq)
+{
+ struct virtio_pmem *vpmem = vq->vdev->priv;
+ struct virtio_pmem_request *req_data, *req_buf;
+ unsigned long flags;
+ unsigned int len;
+
+ spin_lock_irqsave(&vpmem->pmem_lock, flags);
+ while ((req_data = virtqueue_get_buf(vq, &len)) != NULL) {
+ req_data->done = true;
+ wake_up(&req_data->host_acked);
+
+ if (!list_empty(&vpmem->req_list)) {
+ req_buf = list_first_entry(&vpmem->req_list,
+ struct virtio_pmem_request, list);
+ req_buf->wq_buf_avail = true;
+ wake_up(&req_buf->wq_buf);
+ list_del(&req_buf->list);
+ }
+ }
+ spin_unlock_irqrestore(&vpmem->pmem_lock, flags);
+}
+EXPORT_SYMBOL_GPL(virtio_pmem_host_ack);
+
+ /* The request submission function */
+static int virtio_pmem_flush(struct nd_region *nd_region)
+{
+ struct virtio_device *vdev = nd_region->provider_data;
+ struct virtio_pmem *vpmem = vdev->priv;
+ struct virtio_pmem_request *req_data;
+ struct scatterlist *sgs[2], sg, ret;
+ unsigned long flags;
+ int err, err1;
+
+ might_sleep();
+ req_data = kmalloc(sizeof(*req_data), GFP_KERNEL);
+ if (!req_data)
+ return -ENOMEM;
+
+ req_data->done = false;
+ init_waitqueue_head(&req_data->host_acked);
+ init_waitqueue_head(&req_data->wq_buf);
+ INIT_LIST_HEAD(&req_data->list);
+ req_data->req.type = cpu_to_virtio32(vdev, VIRTIO_PMEM_REQ_TYPE_FLUSH);
+ sg_init_one(&sg, &req_data->req, sizeof(req_data->req));
+ sgs[0] = &sg;
+ sg_init_one(&ret, &req_data->resp.ret, sizeof(req_data->resp));
+ sgs[1] = &ret;
+
+ spin_lock_irqsave(&vpmem->pmem_lock, flags);
+ /*
+ * If virtqueue_add_sgs returns -ENOSPC then req_vq virtual
+ * queue does not have free descriptor. We add the request
+ * to req_list and wait for host_ack to wake us up when free
+ * slots are available.
+ */
+ while ((err = virtqueue_add_sgs(vpmem->req_vq, sgs, 1, 1, req_data,
+ GFP_ATOMIC)) == -ENOSPC) {
+
+ dev_info(&vdev->dev, "failed to send command to virtio pmem device, no free slots in the virtqueue\n");
+ req_data->wq_buf_avail = false;
+ list_add_tail(&req_data->list, &vpmem->req_list);
+ spin_unlock_irqrestore(&vpmem->pmem_lock, flags);
+
+ /* A host response results in "host_ack" getting called */
+ wait_event(req_data->wq_buf, req_data->wq_buf_avail);
+ spin_lock_irqsave(&vpmem->pmem_lock, flags);
+ }
+ err1 = virtqueue_kick(vpmem->req_vq);
+ spin_unlock_irqrestore(&vpmem->pmem_lock, flags);
+ /*
+ * virtqueue_add_sgs failed with error different than -ENOSPC, we can't
+ * do anything about that.
+ */
+ if (err || !err1) {
+ dev_info(&vdev->dev, "failed to send command to virtio pmem device\n");
+ err = -EIO;
+ } else {
+ /* A host repsonse results in "host_ack" getting called */
+ wait_event(req_data->host_acked, req_data->done);
+ err = virtio32_to_cpu(vdev, req_data->resp.ret);
+ }
+
+ kfree(req_data);
+ return err;
+};
+
+/* The asynchronous flush callback function */
+int async_pmem_flush(struct nd_region *nd_region, struct bio *bio)
+{
+ /*
+ * Create child bio for asynchronous flush and chain with
+ * parent bio. Otherwise directly call nd_region flush.
+ */
+ if (bio && bio->bi_iter.bi_sector != -1) {
+ struct bio *child = bio_alloc(GFP_ATOMIC, 0);
+
+ if (!child)
+ return -ENOMEM;
+ bio_copy_dev(child, bio);
+ child->bi_opf = REQ_PREFLUSH;
+ child->bi_iter.bi_sector = -1;
+ bio_chain(child, bio);
+ submit_bio(child);
+ return 0;
+ }
+ if (virtio_pmem_flush(nd_region))
+ return -EIO;
+
+ return 0;
+};
+EXPORT_SYMBOL_GPL(async_pmem_flush);
+MODULE_LICENSE("GPL");
diff --git a/drivers/nvdimm/virtio_pmem.c b/drivers/nvdimm/virtio_pmem.c
new file mode 100644
index 000000000000..5e3d07b47e0c
--- /dev/null
+++ b/drivers/nvdimm/virtio_pmem.c
@@ -0,0 +1,122 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * virtio_pmem.c: Virtio pmem Driver
+ *
+ * Discovers persistent memory range information
+ * from host and registers the virtual pmem device
+ * with libnvdimm core.
+ */
+#include "virtio_pmem.h"
+#include "nd.h"
+
+static struct virtio_device_id id_table[] = {
+ { VIRTIO_ID_PMEM, VIRTIO_DEV_ANY_ID },
+ { 0 },
+};
+
+ /* Initialize virt queue */
+static int init_vq(struct virtio_pmem *vpmem)
+{
+ /* single vq */
+ vpmem->req_vq = virtio_find_single_vq(vpmem->vdev,
+ virtio_pmem_host_ack, "flush_queue");
+ if (IS_ERR(vpmem->req_vq))
+ return PTR_ERR(vpmem->req_vq);
+
+ spin_lock_init(&vpmem->pmem_lock);
+ INIT_LIST_HEAD(&vpmem->req_list);
+
+ return 0;
+};
+
+static int virtio_pmem_probe(struct virtio_device *vdev)
+{
+ struct nd_region_desc ndr_desc = {};
+ int nid = dev_to_node(&vdev->dev);
+ struct nd_region *nd_region;
+ struct virtio_pmem *vpmem;
+ struct resource res;
+ int err = 0;
+
+ if (!vdev->config->get) {
+ dev_err(&vdev->dev, "%s failure: config access disabled\n",
+ __func__);
+ return -EINVAL;
+ }
+
+ vpmem = devm_kzalloc(&vdev->dev, sizeof(*vpmem), GFP_KERNEL);
+ if (!vpmem) {
+ err = -ENOMEM;
+ goto out_err;
+ }
+
+ vpmem->vdev = vdev;
+ vdev->priv = vpmem;
+ err = init_vq(vpmem);
+ if (err) {
+ dev_err(&vdev->dev, "failed to initialize virtio pmem vq's\n");
+ goto out_err;
+ }
+
+ virtio_cread(vpmem->vdev, struct virtio_pmem_config,
+ start, &vpmem->start);
+ virtio_cread(vpmem->vdev, struct virtio_pmem_config,
+ size, &vpmem->size);
+
+ res.start = vpmem->start;
+ res.end = vpmem->start + vpmem->size - 1;
+ vpmem->nd_desc.provider_name = "virtio-pmem";
+ vpmem->nd_desc.module = THIS_MODULE;
+
+ vpmem->nvdimm_bus = nvdimm_bus_register(&vdev->dev,
+ &vpmem->nd_desc);
+ if (!vpmem->nvdimm_bus) {
+ dev_err(&vdev->dev, "failed to register device with nvdimm_bus\n");
+ err = -ENXIO;
+ goto out_vq;
+ }
+
+ dev_set_drvdata(&vdev->dev, vpmem->nvdimm_bus);
+
+ ndr_desc.res = &res;
+ ndr_desc.numa_node = nid;
+ ndr_desc.flush = async_pmem_flush;
+ set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
+ set_bit(ND_REGION_ASYNC, &ndr_desc.flags);
+ nd_region = nvdimm_pmem_region_create(vpmem->nvdimm_bus, &ndr_desc);
+ if (!nd_region) {
+ dev_err(&vdev->dev, "failed to create nvdimm region\n");
+ err = -ENXIO;
+ goto out_nd;
+ }
+ nd_region->provider_data = dev_to_virtio(nd_region->dev.parent->parent);
+ return 0;
+out_nd:
+ nvdimm_bus_unregister(vpmem->nvdimm_bus);
+out_vq:
+ vdev->config->del_vqs(vdev);
+out_err:
+ return err;
+}
+
+static void virtio_pmem_remove(struct virtio_device *vdev)
+{
+ struct nvdimm_bus *nvdimm_bus = dev_get_drvdata(&vdev->dev);
+
+ nvdimm_bus_unregister(nvdimm_bus);
+ vdev->config->del_vqs(vdev);
+ vdev->config->reset(vdev);
+}
+
+static struct virtio_driver virtio_pmem_driver = {
+ .driver.name = KBUILD_MODNAME,
+ .driver.owner = THIS_MODULE,
+ .id_table = id_table,
+ .probe = virtio_pmem_probe,
+ .remove = virtio_pmem_remove,
+};
+
+module_virtio_driver(virtio_pmem_driver);
+MODULE_DEVICE_TABLE(virtio, id_table);
+MODULE_DESCRIPTION("Virtio pmem driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/nvdimm/virtio_pmem.h b/drivers/nvdimm/virtio_pmem.h
new file mode 100644
index 000000000000..0dddefe594c4
--- /dev/null
+++ b/drivers/nvdimm/virtio_pmem.h
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * virtio_pmem.h: virtio pmem Driver
+ *
+ * Discovers persistent memory range information
+ * from host and provides a virtio based flushing
+ * interface.
+ **/
+
+#ifndef _LINUX_VIRTIO_PMEM_H
+#define _LINUX_VIRTIO_PMEM_H
+
+#include <linux/module.h>
+#include <uapi/linux/virtio_pmem.h>
+#include <linux/libnvdimm.h>
+#include <linux/spinlock.h>
+
+struct virtio_pmem_request {
+ struct virtio_pmem_req req;
+ struct virtio_pmem_resp resp;
+
+ /* Wait queue to process deferred work after ack from host */
+ wait_queue_head_t host_acked;
+ bool done;
+
+ /* Wait queue to process deferred work after virt queue buffer avail */
+ wait_queue_head_t wq_buf;
+ bool wq_buf_avail;
+ struct list_head list;
+};
+
+struct virtio_pmem {
+ struct virtio_device *vdev;
+
+ /* Virtio pmem request queue */
+ struct virtqueue *req_vq;
+
+ /* nvdimm bus registers virtio pmem device */
+ struct nvdimm_bus *nvdimm_bus;
+ struct nvdimm_bus_descriptor nd_desc;
+
+ /* List to store deferred work if virtqueue is full */
+ struct list_head req_list;
+
+ /* Synchronize virtqueue data */
+ spinlock_t pmem_lock;
+
+ /* Memory region information */
+ __u64 start;
+ __u64 size;
+};
+
+void virtio_pmem_host_ack(struct virtqueue *vq);
+int async_pmem_flush(struct nd_region *nd_region, struct bio *bio);
+#endif
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-21 10:41:41 +0100