[PATCH 4/7] nvmet-fc: use feature flag for virtual LLDD
James Smart
james.smart at broadcom.com
Mon Oct 5 13:37:11 EDT 2020
On 9/22/2020 5:14 AM, Hannes Reinecke wrote:
> Virtual LLDDs like fcloop don't need to do DMA, but still
> might want to expose a device. So add a new feature flag
> to mark these LLDDs instead of relying on a non-existing
> struct device.
>
> Signed-off-by: Hannes Reinecke <hare at suse.de>
> ---
> drivers/nvme/target/fc.c | 93 +++++++++++++++++++++++-------------------
> drivers/nvme/target/fcloop.c | 2 +-
> include/linux/nvme-fc-driver.h | 2 +
> 3 files changed, 55 insertions(+), 42 deletions(-)
>
> diff --git a/drivers/nvme/target/fc.c b/drivers/nvme/target/fc.c
> index 63f5deb3b68a..6f5784767d35 100644
> --- a/drivers/nvme/target/fc.c
> +++ b/drivers/nvme/target/fc.c
> @@ -273,41 +273,50 @@ static void nvmet_fc_xmt_ls_rsp(struct nvmet_fc_tgtport *tgtport,
> * in the scatter list, setting all dma addresses to 0.
> */
>
> +static bool fc_lldd_is_virtual(struct nvmet_fc_tgtport *tgtport)
> +{
> + return !!(tgtport->ops->target_features & NVMET_FCTGTFEAT_VIRTUAL_DMA);
> +}
> +
> static inline dma_addr_t
> -fc_dma_map_single(struct device *dev, void *ptr, size_t size,
> +fc_dma_map_single(struct nvmet_fc_tgtport *tgtport, void *ptr, size_t size,
> enum dma_data_direction dir)
> {
> - return dev ? dma_map_single(dev, ptr, size, dir) : (dma_addr_t)0L;
> + if (fc_lldd_is_virtual(tgtport))
> + return (dma_addr_t)0L;
> + return dma_map_single(tgtport->dev, ptr, size, dir);
> }
>
> static inline int
> -fc_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
> +fc_dma_mapping_error(struct nvmet_fc_tgtport *tgtport, dma_addr_t dma_addr)
> {
> - return dev ? dma_mapping_error(dev, dma_addr) : 0;
> + if (fc_lldd_is_virtual(tgtport))
> + return 0;
> + return dma_mapping_error(tgtport->dev, dma_addr);
> }
>
> static inline void
> -fc_dma_unmap_single(struct device *dev, dma_addr_t addr, size_t size,
> - enum dma_data_direction dir)
> +fc_dma_unmap_single(struct nvmet_fc_tgtport *tgtport, dma_addr_t addr,
> + size_t size, enum dma_data_direction dir)
> {
> - if (dev)
> - dma_unmap_single(dev, addr, size, dir);
> + if (!fc_lldd_is_virtual(tgtport))
> + dma_unmap_single(tgtport->dev, addr, size, dir);
> }
>
> static inline void
> -fc_dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size,
> - enum dma_data_direction dir)
> +fc_dma_sync_single_for_cpu(struct nvmet_fc_tgtport *tgtport, dma_addr_t addr,
> + size_t size, enum dma_data_direction dir)
> {
> - if (dev)
> - dma_sync_single_for_cpu(dev, addr, size, dir);
> + if (!fc_lldd_is_virtual(tgtport))
> + dma_sync_single_for_cpu(tgtport->dev, addr, size, dir);
> }
>
> static inline void
> -fc_dma_sync_single_for_device(struct device *dev, dma_addr_t addr, size_t size,
> - enum dma_data_direction dir)
> +fc_dma_sync_single_for_device(struct nvmet_fc_tgtport *tgtport, dma_addr_t addr,
> + size_t size, enum dma_data_direction dir)
> {
> - if (dev)
> - dma_sync_single_for_device(dev, addr, size, dir);
> + if (!fc_lldd_is_virtual(tgtport))
> + dma_sync_single_for_device(tgtport->dev, addr, size, dir);
> }
>
> /* pseudo dma_map_sg call */
> @@ -329,18 +338,20 @@ fc_map_sg(struct scatterlist *sg, int nents)
> }
>
> static inline int
> -fc_dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
> - enum dma_data_direction dir)
> +fc_dma_map_sg(struct nvmet_fc_tgtport *tgtport, struct scatterlist *sg,
> + int nents, enum dma_data_direction dir)
> {
> - return dev ? dma_map_sg(dev, sg, nents, dir) : fc_map_sg(sg, nents);
> + if (fc_lldd_is_virtual(tgtport))
> + return fc_map_sg(sg, nents);
> + return dma_map_sg(tgtport->dev, sg, nents, dir);
> }
>
> static inline void
> -fc_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
> - enum dma_data_direction dir)
> +fc_dma_unmap_sg(struct nvmet_fc_tgtport *tgtport, struct scatterlist *sg,
> + int nents, enum dma_data_direction dir)
> {
> - if (dev)
> - dma_unmap_sg(dev, sg, nents, dir);
> + if (!fc_lldd_is_virtual(tgtport))
> + dma_unmap_sg(tgtport->dev, sg, nents, dir);
> }
>
>
> @@ -368,7 +379,7 @@ __nvmet_fc_finish_ls_req(struct nvmet_fc_ls_req_op *lsop)
>
> spin_unlock_irqrestore(&tgtport->lock, flags);
>
> - fc_dma_unmap_single(tgtport->dev, lsreq->rqstdma,
> + fc_dma_unmap_single(tgtport, lsreq->rqstdma,
> (lsreq->rqstlen + lsreq->rsplen),
> DMA_BIDIRECTIONAL);
>
> @@ -391,10 +402,10 @@ __nvmet_fc_send_ls_req(struct nvmet_fc_tgtport *tgtport,
> lsop->req_queued = false;
> INIT_LIST_HEAD(&lsop->lsreq_list);
>
> - lsreq->rqstdma = fc_dma_map_single(tgtport->dev, lsreq->rqstaddr,
> + lsreq->rqstdma = fc_dma_map_single(tgtport, lsreq->rqstaddr,
> lsreq->rqstlen + lsreq->rsplen,
> DMA_BIDIRECTIONAL);
> - if (fc_dma_mapping_error(tgtport->dev, lsreq->rqstdma))
> + if (fc_dma_mapping_error(tgtport, lsreq->rqstdma))
> return -EFAULT;
>
> lsreq->rspdma = lsreq->rqstdma + lsreq->rqstlen;
> @@ -420,7 +431,7 @@ __nvmet_fc_send_ls_req(struct nvmet_fc_tgtport *tgtport,
> lsop->req_queued = false;
> list_del(&lsop->lsreq_list);
> spin_unlock_irqrestore(&tgtport->lock, flags);
> - fc_dma_unmap_single(tgtport->dev, lsreq->rqstdma,
> + fc_dma_unmap_single(tgtport, lsreq->rqstdma,
> (lsreq->rqstlen + lsreq->rsplen),
> DMA_BIDIRECTIONAL);
> return ret;
> @@ -555,10 +566,10 @@ nvmet_fc_alloc_ls_iodlist(struct nvmet_fc_tgtport *tgtport)
>
> iod->rspbuf = (union nvmefc_ls_responses *)&iod->rqstbuf[1];
>
> - iod->rspdma = fc_dma_map_single(tgtport->dev, iod->rspbuf,
> + iod->rspdma = fc_dma_map_single(tgtport, iod->rspbuf,
> sizeof(*iod->rspbuf),
> DMA_TO_DEVICE);
> - if (fc_dma_mapping_error(tgtport->dev, iod->rspdma))
> + if (fc_dma_mapping_error(tgtport, iod->rspdma))
> goto out_fail;
> }
>
> @@ -568,7 +579,7 @@ nvmet_fc_alloc_ls_iodlist(struct nvmet_fc_tgtport *tgtport)
> kfree(iod->rqstbuf);
> list_del(&iod->ls_rcv_list);
> for (iod--, i--; i >= 0; iod--, i--) {
> - fc_dma_unmap_single(tgtport->dev, iod->rspdma,
> + fc_dma_unmap_single(tgtport, iod->rspdma,
> sizeof(*iod->rspbuf), DMA_TO_DEVICE);
> kfree(iod->rqstbuf);
> list_del(&iod->ls_rcv_list);
> @@ -586,7 +597,7 @@ nvmet_fc_free_ls_iodlist(struct nvmet_fc_tgtport *tgtport)
> int i;
>
> for (i = 0; i < NVMET_LS_CTX_COUNT; iod++, i++) {
> - fc_dma_unmap_single(tgtport->dev,
> + fc_dma_unmap_single(tgtport,
> iod->rspdma, sizeof(*iod->rspbuf),
> DMA_TO_DEVICE);
> kfree(iod->rqstbuf);
> @@ -640,12 +651,12 @@ nvmet_fc_prep_fcp_iodlist(struct nvmet_fc_tgtport *tgtport,
> list_add_tail(&fod->fcp_list, &queue->fod_list);
> spin_lock_init(&fod->flock);
>
> - fod->rspdma = fc_dma_map_single(tgtport->dev, &fod->rspiubuf,
> + fod->rspdma = fc_dma_map_single(tgtport, &fod->rspiubuf,
> sizeof(fod->rspiubuf), DMA_TO_DEVICE);
> - if (fc_dma_mapping_error(tgtport->dev, fod->rspdma)) {
> + if (fc_dma_mapping_error(tgtport, fod->rspdma)) {
> list_del(&fod->fcp_list);
> for (fod--, i--; i >= 0; fod--, i--) {
> - fc_dma_unmap_single(tgtport->dev, fod->rspdma,
> + fc_dma_unmap_single(tgtport, fod->rspdma,
> sizeof(fod->rspiubuf),
> DMA_TO_DEVICE);
> fod->rspdma = 0L;
> @@ -666,7 +677,7 @@ nvmet_fc_destroy_fcp_iodlist(struct nvmet_fc_tgtport *tgtport,
>
> for (i = 0; i < queue->sqsize; fod++, i++) {
> if (fod->rspdma)
> - fc_dma_unmap_single(tgtport->dev, fod->rspdma,
> + fc_dma_unmap_single(tgtport, fod->rspdma,
> sizeof(fod->rspiubuf), DMA_TO_DEVICE);
> }
> }
> @@ -730,7 +741,7 @@ nvmet_fc_free_fcp_iod(struct nvmet_fc_tgt_queue *queue,
> struct nvmet_fc_defer_fcp_req *deferfcp;
> unsigned long flags;
>
> - fc_dma_sync_single_for_cpu(tgtport->dev, fod->rspdma,
> + fc_dma_sync_single_for_cpu(tgtport, fod->rspdma,
> sizeof(fod->rspiubuf), DMA_TO_DEVICE);
>
> fcpreq->nvmet_fc_private = NULL;
> @@ -1925,7 +1936,7 @@ nvmet_fc_xmt_ls_rsp_done(struct nvmefc_ls_rsp *lsrsp)
> struct nvmet_fc_ls_iod *iod = lsrsp->nvme_fc_private;
> struct nvmet_fc_tgtport *tgtport = iod->tgtport;
>
> - fc_dma_sync_single_for_cpu(tgtport->dev, iod->rspdma,
> + fc_dma_sync_single_for_cpu(tgtport, iod->rspdma,
> sizeof(*iod->rspbuf), DMA_TO_DEVICE);
> nvmet_fc_free_ls_iod(tgtport, iod);
> nvmet_fc_tgtport_put(tgtport);
> @@ -1937,7 +1948,7 @@ nvmet_fc_xmt_ls_rsp(struct nvmet_fc_tgtport *tgtport,
> {
> int ret;
>
> - fc_dma_sync_single_for_device(tgtport->dev, iod->rspdma,
> + fc_dma_sync_single_for_device(tgtport, iod->rspdma,
> sizeof(*iod->rspbuf), DMA_TO_DEVICE);
>
> ret = tgtport->ops->xmt_ls_rsp(&tgtport->fc_target_port, iod->lsrsp);
> @@ -2091,7 +2102,7 @@ nvmet_fc_alloc_tgt_pgs(struct nvmet_fc_fcp_iod *fod)
>
> fod->data_sg = sg;
> fod->data_sg_cnt = nent;
> - fod->data_sg_cnt = fc_dma_map_sg(fod->tgtport->dev, sg, nent,
> + fod->data_sg_cnt = fc_dma_map_sg(fod->tgtport, sg, nent,
> ((fod->io_dir == NVMET_FCP_WRITE) ?
> DMA_FROM_DEVICE : DMA_TO_DEVICE));
> /* note: write from initiator perspective */
> @@ -2109,7 +2120,7 @@ nvmet_fc_free_tgt_pgs(struct nvmet_fc_fcp_iod *fod)
> if (!fod->data_sg || !fod->data_sg_cnt)
> return;
>
> - fc_dma_unmap_sg(fod->tgtport->dev, fod->data_sg, fod->data_sg_cnt,
> + fc_dma_unmap_sg(fod->tgtport, fod->data_sg, fod->data_sg_cnt,
> ((fod->io_dir == NVMET_FCP_WRITE) ?
> DMA_FROM_DEVICE : DMA_TO_DEVICE));
> sgl_free(fod->data_sg);
> @@ -2193,7 +2204,7 @@ nvmet_fc_prep_fcp_rsp(struct nvmet_fc_tgtport *tgtport,
> fod->fcpreq->rsplen = sizeof(*ersp);
> }
>
> - fc_dma_sync_single_for_device(tgtport->dev, fod->rspdma,
> + fc_dma_sync_single_for_device(tgtport, fod->rspdma,
> sizeof(fod->rspiubuf), DMA_TO_DEVICE);
> }
>
> diff --git a/drivers/nvme/target/fcloop.c b/drivers/nvme/target/fcloop.c
> index e56f323fa7d4..2ccb941efb21 100644
> --- a/drivers/nvme/target/fcloop.c
> +++ b/drivers/nvme/target/fcloop.c
> @@ -1043,7 +1043,7 @@ static struct nvmet_fc_target_template tgttemplate = {
> .max_dif_sgl_segments = FCLOOP_SGL_SEGS,
> .dma_boundary = FCLOOP_DMABOUND_4G,
> /* optional features */
> - .target_features = 0,
> + .target_features = NVMET_FCTGTFEAT_VIRTUAL_DMA,
> /* sizes of additional private data for data structures */
> .target_priv_sz = sizeof(struct fcloop_tport),
> .lsrqst_priv_sz = sizeof(struct fcloop_lsreq),
> diff --git a/include/linux/nvme-fc-driver.h b/include/linux/nvme-fc-driver.h
> index 2a38f2b477a5..675c7ef6df17 100644
> --- a/include/linux/nvme-fc-driver.h
> +++ b/include/linux/nvme-fc-driver.h
> @@ -707,6 +707,8 @@ enum {
> * sequence in one LLDD operation. Errors during Data
> * sequence transmit must not allow RSP sequence to be sent.
> */
> + NVMET_FCTGTFEAT_VIRTUAL_DMA = (1 << 1),
> + /* Bit 1: Virtual LLDD with no DMA support */
> };
>
>
Ok.
Reviewed-by: James Smart <james.smart at broadcom.com>
-- james
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