^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * virtio_pmem.c: Virtio pmem Driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Discovers persistent memory range information
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * from host and provides a virtio based flushing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * interface.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include "virtio_pmem.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include "nd.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) /* The interrupt handler */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) void virtio_pmem_host_ack(struct virtqueue *vq)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) struct virtio_pmem *vpmem = vq->vdev->priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) struct virtio_pmem_request *req_data, *req_buf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) unsigned int len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) spin_lock_irqsave(&vpmem->pmem_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) while ((req_data = virtqueue_get_buf(vq, &len)) != NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) req_data->done = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) wake_up(&req_data->host_acked);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) if (!list_empty(&vpmem->req_list)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) req_buf = list_first_entry(&vpmem->req_list,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) struct virtio_pmem_request, list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) req_buf->wq_buf_avail = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) wake_up(&req_buf->wq_buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) list_del(&req_buf->list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) spin_unlock_irqrestore(&vpmem->pmem_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) EXPORT_SYMBOL_GPL(virtio_pmem_host_ack);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) /* The request submission function */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) static int virtio_pmem_flush(struct nd_region *nd_region)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) struct virtio_device *vdev = nd_region->provider_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) struct virtio_pmem *vpmem = vdev->priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) struct virtio_pmem_request *req_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) struct scatterlist *sgs[2], sg, ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) int err, err1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) might_sleep();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) req_data = kmalloc(sizeof(*req_data), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) if (!req_data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) req_data->done = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) init_waitqueue_head(&req_data->host_acked);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) init_waitqueue_head(&req_data->wq_buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) INIT_LIST_HEAD(&req_data->list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) req_data->req.type = cpu_to_le32(VIRTIO_PMEM_REQ_TYPE_FLUSH);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) sg_init_one(&sg, &req_data->req, sizeof(req_data->req));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) sgs[0] = &sg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) sg_init_one(&ret, &req_data->resp.ret, sizeof(req_data->resp));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) sgs[1] = &ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) spin_lock_irqsave(&vpmem->pmem_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) * If virtqueue_add_sgs returns -ENOSPC then req_vq virtual
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) * queue does not have free descriptor. We add the request
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) * to req_list and wait for host_ack to wake us up when free
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) * slots are available.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) while ((err = virtqueue_add_sgs(vpmem->req_vq, sgs, 1, 1, req_data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) GFP_ATOMIC)) == -ENOSPC) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) dev_info(&vdev->dev, "failed to send command to virtio pmem device, no free slots in the virtqueue\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) req_data->wq_buf_avail = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) list_add_tail(&req_data->list, &vpmem->req_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) spin_unlock_irqrestore(&vpmem->pmem_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) /* A host response results in "host_ack" getting called */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) wait_event(req_data->wq_buf, req_data->wq_buf_avail);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) spin_lock_irqsave(&vpmem->pmem_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) err1 = virtqueue_kick(vpmem->req_vq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) spin_unlock_irqrestore(&vpmem->pmem_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) * virtqueue_add_sgs failed with error different than -ENOSPC, we can't
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) * do anything about that.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) if (err || !err1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) dev_info(&vdev->dev, "failed to send command to virtio pmem device\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) err = -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) /* A host repsonse results in "host_ack" getting called */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) wait_event(req_data->host_acked, req_data->done);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) err = le32_to_cpu(req_data->resp.ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) kfree(req_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) /* The asynchronous flush callback function */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) int async_pmem_flush(struct nd_region *nd_region, struct bio *bio)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) * Create child bio for asynchronous flush and chain with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) * parent bio. Otherwise directly call nd_region flush.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) if (bio && bio->bi_iter.bi_sector != -1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) struct bio *child = bio_alloc(GFP_ATOMIC, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) if (!child)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) bio_copy_dev(child, bio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) child->bi_opf = REQ_PREFLUSH;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) child->bi_iter.bi_sector = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) bio_chain(child, bio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) submit_bio(child);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) if (virtio_pmem_flush(nd_region))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) EXPORT_SYMBOL_GPL(async_pmem_flush);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) MODULE_LICENSE("GPL");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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