diff options
Diffstat (limited to 'drivers/nvdimm')
| -rw-r--r-- | drivers/nvdimm/Makefile | 1 | ||||
| -rw-r--r-- | drivers/nvdimm/nd_virtio.c | 125 | ||||
| -rw-r--r-- | drivers/nvdimm/virtio_pmem.c | 122 | ||||
| -rw-r--r-- | drivers/nvdimm/virtio_pmem.h | 55 |
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 |