[PATCH 06/12] IB/core: Add optional PCI P2P flag to rdma_rw_ctx_[init|destroy]()

Logan Gunthorpe
2018-01-04T19:01:31Z

In order to use PCI P2P memory pci_p2pmem_[un]map_sg() functions must be
called to map the correct DMA address. To do this, we add a flags
variable and the RDMA_RW_CTX_FLAG_PCI_P2P flag. When the flag is
specified use the appropriate map function.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
---
drivers/infiniband/core/rw.c | 22 +++++++++++++++++-----
drivers/infiniband/ulp/isert/ib_isert.c | 5 +++--
drivers/infiniband/ulp/srpt/ib_srpt.c | 7 ++++---
drivers/nvme/target/rdma.c | 6 +++---
include/rdma/rw.h | 7 +++++--
net/sunrpc/xprtrdma/svc_rdma_rw.c | 6 +++---
6 files changed, 35 insertions(+), 18 deletions(-)

diff --git a/drivers/infiniband/core/rw.c b/drivers/infiniband/core/rw.c
index c8963e91f92a..7956484da082 100644
--- a/drivers/infiniband/core/rw.c
+++ b/drivers/infiniband/core/rw.c
@@ -12,6 +12,7 @@
*/
#include <linux/moduleparam.h>
#include <linux/slab.h>
+#include <linux/pci-p2p.h>
#include <rdma/mr_pool.h>
#include <rdma/rw.h>

@@ -269,18 +270,24 @@ static int rdma_rw_init_single_wr(struct rdma_rw_ctx *ctx, struct ib_qp *qp,
* @remote_addr:remote address to read/write (relative to @rkey)
* @rkey: remote key to operate on
* @dir: %DMA_TO_DEVICE for RDMA WRITE, %DMA_FROM_DEVICE for RDMA READ
+ * @flags: any of the RDMA_RW_CTX_FLAG_* flags
*
* Returns the number of WQEs that will be needed on the workqueue if
* successful, or a negative error code.
*/
int rdma_rw_ctx_init(struct rdma_rw_ctx *ctx, struct ib_qp *qp, u8 port_num,
struct scatterlist *sg, u32 sg_cnt, u32 sg_offset,
- u64 remote_addr, u32 rkey, enum dma_data_direction dir)
+ u64 remote_addr, u32 rkey, enum dma_data_direction dir,
+ unsigned int flags)
{
struct ib_device *dev = qp->pd->device;
int ret;

- ret = ib_dma_map_sg(dev, sg, sg_cnt, dir);
+ if (flags & RDMA_RW_CTX_FLAG_PCI_P2P)
+ ret = pci_p2pmem_map_sg(sg, sg_cnt);
+ else
+ ret = ib_dma_map_sg(dev, sg, sg_cnt, dir);
+
if (!ret)
return -ENOMEM;
sg_cnt = ret;
@@ -499,7 +506,7 @@ struct ib_send_wr *rdma_rw_ctx_wrs(struct rdma_rw_ctx *ctx, struct ib_qp *qp,
rdma_rw_update_lkey(&ctx->sig->data, true);
if (ctx->sig->prot.mr)
rdma_rw_update_lkey(&ctx->sig->prot, true);
-
+
ctx->sig->sig_mr->need_inval = true;
ib_update_fast_reg_key(ctx->sig->sig_mr,
ib_inc_rkey(ctx->sig->sig_mr->lkey));
@@ -579,9 +586,11 @@ EXPORT_SYMBOL(rdma_rw_ctx_post);
* @sg: scatterlist that was used for the READ/WRITE
* @sg_cnt: number of entries in @sg
* @dir: %DMA_TO_DEVICE for RDMA WRITE, %DMA_FROM_DEVICE for RDMA READ
+ * @flags: the same flags used to init the context
*/
void rdma_rw_ctx_destroy(struct rdma_rw_ctx *ctx, struct ib_qp *qp, u8 port_num,
- struct scatterlist *sg, u32 sg_cnt, enum dma_data_direction dir)
+ struct scatterlist *sg, u32 sg_cnt, enum dma_data_direction dir,
+ unsigned int flags)
{
int i;

@@ -602,7 +611,10 @@ void rdma_rw_ctx_destroy(struct rdma_rw_ctx *ctx, struct ib_qp *qp, u8 port_num,
break;
}

- ib_dma_unmap_sg(qp->pd->device, sg, sg_cnt, dir);
+ if (flags & RDMA_RW_CTX_FLAG_PCI_P2P)
+ pci_p2pmem_unmap_sg(sg, sg_cnt);
+ else
+ ib_dma_unmap_sg(qp->pd->device, sg, sg_cnt, dir);
}
EXPORT_SYMBOL(rdma_rw_ctx_destroy);

diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index 720dfb3a1ac2..a076da2ead16 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -1496,7 +1496,8 @@ isert_rdma_rw_ctx_destroy(struct isert_cmd *cmd, struct isert_conn *conn)
se_cmd->t_prot_nents, dir);
} else {
rdma_rw_ctx_destroy(&cmd->rw, conn->qp, conn->cm_id->port_num,
- se_cmd->t_data_sg, se_cmd->t_data_nents, dir);
+ se_cmd->t_data_sg, se_cmd->t_data_nents,
+ dir, 0);
}

cmd->rw.nr_ops = 0;
@@ -2148,7 +2149,7 @@ isert_rdma_rw_ctx_post(struct isert_cmd *cmd, struct isert_conn *conn,
} else {
ret = rdma_rw_ctx_init(&cmd->rw, conn->qp, port_num,
se_cmd->t_data_sg, se_cmd->t_data_nents,
- offset, addr, rkey, dir);
+ offset, addr, rkey, dir, 0);
}
if (ret < 0) {
isert_err("Cmd: %p failed to prepare RDMA res\n", cmd);
diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c
index 8a1bd354b1cc..c5371ab2e47d 100644
--- a/drivers/infiniband/ulp/srpt/ib_srpt.c
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
@@ -854,7 +854,8 @@ static int srpt_alloc_rw_ctxs(struct srpt_send_ioctx *ioctx,
goto unwind;

ret = rdma_rw_ctx_init(&ctx->rw, ch->qp, ch->sport->port,
- ctx->sg, ctx->nents, 0, remote_addr, rkey, dir);
+ ctx->sg, ctx->nents, 0, remote_addr, rkey,
+ dir, 0);
if (ret < 0) {
target_free_sgl(ctx->sg, ctx->nents);
goto unwind;
@@ -883,7 +884,7 @@ static int srpt_alloc_rw_ctxs(struct srpt_send_ioctx *ioctx,
struct srpt_rw_ctx *ctx = &ioctx->rw_ctxs[i];

rdma_rw_ctx_destroy(&ctx->rw, ch->qp, ch->sport->port,
- ctx->sg, ctx->nents, dir);
+ ctx->sg, ctx->nents, dir, 0);
target_free_sgl(ctx->sg, ctx->nents);
}
if (ioctx->rw_ctxs != &ioctx->s_rw_ctx)
@@ -901,7 +902,7 @@ static void srpt_free_rw_ctxs(struct srpt_rdma_ch *ch,
struct srpt_rw_ctx *ctx = &ioctx->rw_ctxs[i];

rdma_rw_ctx_destroy(&ctx->rw, ch->qp, ch->sport->port,
- ctx->sg, ctx->nents, dir);
+ ctx->sg, ctx->nents, dir, 0);
target_free_sgl(ctx->sg, ctx->nents);
}

diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c
index 49912909c298..d4d0662ab071 100644
--- a/drivers/nvme/target/rdma.c
+++ b/drivers/nvme/target/rdma.c
@@ -480,7 +480,7 @@ static void nvmet_rdma_release_rsp(struct nvmet_rdma_rsp *rsp)
if (rsp->n_rdma) {
rdma_rw_ctx_destroy(&rsp->rw, queue->cm_id->qp,
queue->cm_id->port_num, rsp->req.sg,
- rsp->req.sg_cnt, nvmet_data_dir(&rsp->req));
+ rsp->req.sg_cnt, nvmet_data_dir(&rsp->req), 0);
}

if (rsp->req.sg != &rsp->cmd->inline_sg)
@@ -563,7 +563,7 @@ static void nvmet_rdma_read_data_done(struct ib_cq *cq, struct ib_wc *wc)
atomic_add(rsp->n_rdma, &queue->sq_wr_avail);
rdma_rw_ctx_destroy(&rsp->rw, queue->cm_id->qp,
queue->cm_id->port_num, rsp->req.sg,
- rsp->req.sg_cnt, nvmet_data_dir(&rsp->req));
+ rsp->req.sg_cnt, nvmet_data_dir(&rsp->req), 0);
rsp->n_rdma = 0;

if (unlikely(wc->status != IB_WC_SUCCESS)) {
@@ -634,7 +634,7 @@ static u16 nvmet_rdma_map_sgl_keyed(struct nvmet_rdma_rsp *rsp,

ret = rdma_rw_ctx_init(&rsp->rw, cm_id->qp, cm_id->port_num,
rsp->req.sg, rsp->req.sg_cnt, 0, addr, key,
- nvmet_data_dir(&rsp->req));
+ nvmet_data_dir(&rsp->req), 0);
if (ret < 0)
return NVME_SC_INTERNAL;
rsp->req.transfer_len += len;
diff --git a/include/rdma/rw.h b/include/rdma/rw.h
index a3cbbc7b6417..ba8050434667 100644
--- a/include/rdma/rw.h
+++ b/include/rdma/rw.h
@@ -59,12 +59,15 @@ struct rdma_rw_ctx {
};
};

+#define RDMA_RW_CTX_FLAG_PCI_P2P (1 << 0)
+
int rdma_rw_ctx_init(struct rdma_rw_ctx *ctx, struct ib_qp *qp, u8 port_num,
struct scatterlist *sg, u32 sg_cnt, u32 sg_offset,
- u64 remote_addr, u32 rkey, enum dma_data_direction dir);
+ u64 remote_addr, u32 rkey, enum dma_data_direction dir,
+ unsigned int flags);
void rdma_rw_ctx_destroy(struct rdma_rw_ctx *ctx, struct ib_qp *qp, u8 port_num,
struct scatterlist *sg, u32 sg_cnt,
- enum dma_data_direction dir);
+ enum dma_data_direction dir, unsigned int flags);

int rdma_rw_ctx_signature_init(struct rdma_rw_ctx *ctx, struct ib_qp *qp,
u8 port_num, struct scatterlist *sg, u32 sg_cnt,
diff --git a/net/sunrpc/xprtrdma/svc_rdma_rw.c b/net/sunrpc/xprtrdma/svc_rdma_rw.c
index 9bd04549a1ad..5f46c35e6707 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_rw.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_rw.c
@@ -140,7 +140,7 @@ static void svc_rdma_cc_release(struct svc_rdma_chunk_ctxt *cc,

rdma_rw_ctx_destroy(&ctxt->rw_ctx, rdma->sc_qp,
rdma->sc_port_num, ctxt->rw_sg_table.sgl,
- ctxt->rw_nents, dir);
+ ctxt->rw_nents, dir, 0);
svc_rdma_put_rw_ctxt(rdma, ctxt);
}
svc_xprt_put(&rdma->sc_xprt);
@@ -433,7 +433,7 @@ svc_rdma_build_writes(struct svc_rdma_write_info *info,
ret = rdma_rw_ctx_init(&ctxt->rw_ctx, rdma->sc_qp,
rdma->sc_port_num, ctxt->rw_sg_table.sgl,
ctxt->rw_nents, 0, seg_offset,
- seg_handle, DMA_TO_DEVICE);
+ seg_handle, DMA_TO_DEVICE, 0);
if (ret < 0)
goto out_initerr;

@@ -639,7 +639,7 @@ static int svc_rdma_build_read_segment(struct svc_rdma_read_info *info,
ret = rdma_rw_ctx_init(&ctxt->rw_ctx, cc->cc_rdma->sc_qp,
cc->cc_rdma->sc_port_num,
ctxt->rw_sg_table.sgl, ctxt->rw_nents,
- 0, offset, rkey, DMA_FROM_DEVICE);
+ 0, offset, rkey, DMA_FROM_DEVICE, 0);
if (ret < 0)
goto out_initerr;

--
2.11.0