[RFC PATCH 2/2] RDMA/efa: Add support for dmabuf memory regions
Gal Pressman
galpress at amazon.com
Thu Oct 7 10:43:00 UTC 2021
Implement a dmabuf importer for the EFA driver. As ODP is not supported,
the dmabuf memory regions always pin the buffers to prevent the
move_notify callback from being called.
Signed-off-by: Gal Pressman <galpress at amazon.com>
---
drivers/infiniband/hw/efa/efa.h | 4 +
drivers/infiniband/hw/efa/efa_main.c | 1 +
drivers/infiniband/hw/efa/efa_verbs.c | 166 +++++++++++++++++++++-----
3 files changed, 141 insertions(+), 30 deletions(-)
diff --git a/drivers/infiniband/hw/efa/efa.h b/drivers/infiniband/hw/efa/efa.h
index 2b8ca099b381..407d7c4baa16 100644
--- a/drivers/infiniband/hw/efa/efa.h
+++ b/drivers/infiniband/hw/efa/efa.h
@@ -141,6 +141,10 @@ int efa_create_cq(struct ib_cq *ibcq, const struct ib_cq_init_attr *attr,
struct ib_mr *efa_reg_mr(struct ib_pd *ibpd, u64 start, u64 length,
u64 virt_addr, int access_flags,
struct ib_udata *udata);
+struct ib_mr *efa_reg_user_mr_dmabuf(struct ib_pd *ibpd, u64 start,
+ u64 length, u64 virt_addr,
+ int fd, int access_flags,
+ struct ib_udata *udata);
int efa_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata);
int efa_get_port_immutable(struct ib_device *ibdev, u32 port_num,
struct ib_port_immutable *immutable);
diff --git a/drivers/infiniband/hw/efa/efa_main.c b/drivers/infiniband/hw/efa/efa_main.c
index 203e6ddcacbc..72cd7d952a07 100644
--- a/drivers/infiniband/hw/efa/efa_main.c
+++ b/drivers/infiniband/hw/efa/efa_main.c
@@ -267,6 +267,7 @@ static const struct ib_device_ops efa_dev_ops = {
.query_port = efa_query_port,
.query_qp = efa_query_qp,
.reg_user_mr = efa_reg_mr,
+ .reg_user_mr_dmabuf = efa_reg_user_mr_dmabuf,
INIT_RDMA_OBJ_SIZE(ib_ah, efa_ah, ibah),
INIT_RDMA_OBJ_SIZE(ib_cq, efa_cq, ibcq),
diff --git a/drivers/infiniband/hw/efa/efa_verbs.c b/drivers/infiniband/hw/efa/efa_verbs.c
index be6d3ff0f1be..ca907853a84f 100644
--- a/drivers/infiniband/hw/efa/efa_verbs.c
+++ b/drivers/infiniband/hw/efa/efa_verbs.c
@@ -3,6 +3,8 @@
* Copyright 2018-2020 Amazon.com, Inc. or its affiliates. All rights reserved.
*/
+#include <linux/dma-buf.h>
+#include <linux/dma-resv.h>
#include <linux/vmalloc.h>
#include <linux/log2.h>
@@ -1491,26 +1493,29 @@ static int efa_create_pbl(struct efa_dev *dev,
return 0;
}
-struct ib_mr *efa_reg_mr(struct ib_pd *ibpd, u64 start, u64 length,
- u64 virt_addr, int access_flags,
- struct ib_udata *udata)
+static void efa_dmabuf_invalidate_cb(struct dma_buf_attachment *attach)
+{
+ WARN_ON_ONCE(1,
+ "Invalidate callback should not be called when memory is pinned\n");
+}
+
+static struct dma_buf_attach_ops efa_dmabuf_attach_ops = {
+ .allow_peer2peer = true,
+ .move_notify = efa_dmabuf_invalidate_cb,
+};
+
+static struct efa_mr *efa_alloc_mr(struct ib_pd *ibpd, int access_flags,
+ struct ib_udata *udata)
{
struct efa_dev *dev = to_edev(ibpd->device);
- struct efa_com_reg_mr_params params = {};
- struct efa_com_reg_mr_result result = {};
- struct pbl_context pbl;
int supp_access_flags;
- unsigned int pg_sz;
struct efa_mr *mr;
- int inline_size;
- int err;
if (udata && udata->inlen &&
!ib_is_udata_cleared(udata, 0, sizeof(udata->inlen))) {
ibdev_dbg(&dev->ibdev,
"Incompatible ABI params, udata not cleared\n");
- err = -EINVAL;
- goto err_out;
+ return ERR_PTR(-EINVAL);
}
supp_access_flags =
@@ -1522,23 +1527,26 @@ struct ib_mr *efa_reg_mr(struct ib_pd *ibpd, u64 start, u64 length,
ibdev_dbg(&dev->ibdev,
"Unsupported access flags[%#x], supported[%#x]\n",
access_flags, supp_access_flags);
- err = -EOPNOTSUPP;
- goto err_out;
+ return ERR_PTR(-EOPNOTSUPP);
}
mr = kzalloc(sizeof(*mr), GFP_KERNEL);
- if (!mr) {
- err = -ENOMEM;
- goto err_out;
- }
+ if (!mr)
+ return ERR_PTR(-ENOMEM);
- mr->umem = ib_umem_get(ibpd->device, start, length, access_flags);
- if (IS_ERR(mr->umem)) {
- err = PTR_ERR(mr->umem);
- ibdev_dbg(&dev->ibdev,
- "Failed to pin and map user space memory[%d]\n", err);
- goto err_free;
- }
+ return mr;
+}
+
+static int efa_register_mr(struct ib_pd *ibpd, struct efa_mr *mr, u64 start,
+ u64 length, u64 virt_addr, int access_flags)
+{
+ struct efa_dev *dev = to_edev(ibpd->device);
+ struct efa_com_reg_mr_params params = {};
+ struct efa_com_reg_mr_result result = {};
+ struct pbl_context pbl;
+ unsigned int pg_sz;
+ int inline_size;
+ int err;
params.pd = to_epd(ibpd)->pdn;
params.iova = virt_addr;
@@ -1549,10 +1557,9 @@ struct ib_mr *efa_reg_mr(struct ib_pd *ibpd, u64 start, u64 length,
dev->dev_attr.page_size_cap,
virt_addr);
if (!pg_sz) {
- err = -EOPNOTSUPP;
ibdev_dbg(&dev->ibdev, "Failed to find a suitable page size in page_size_cap %#llx\n",
dev->dev_attr.page_size_cap);
- goto err_unmap;
+ return -EOPNOTSUPP;
}
params.page_shift = order_base_2(pg_sz);
@@ -1566,21 +1573,21 @@ struct ib_mr *efa_reg_mr(struct ib_pd *ibpd, u64 start, u64 length,
if (params.page_num <= inline_size) {
err = efa_create_inline_pbl(dev, mr, ¶ms);
if (err)
- goto err_unmap;
+ return err;
err = efa_com_register_mr(&dev->edev, ¶ms, &result);
if (err)
- goto err_unmap;
+ return err;
} else {
err = efa_create_pbl(dev, &pbl, mr, ¶ms);
if (err)
- goto err_unmap;
+ return err;
err = efa_com_register_mr(&dev->edev, ¶ms, &result);
pbl_destroy(dev, &pbl);
if (err)
- goto err_unmap;
+ return err;
}
mr->ibmr.lkey = result.l_key;
@@ -1588,9 +1595,98 @@ struct ib_mr *efa_reg_mr(struct ib_pd *ibpd, u64 start, u64 length,
mr->ibmr.length = length;
ibdev_dbg(&dev->ibdev, "Registered mr[%d]\n", mr->ibmr.lkey);
+ return 0;
+}
+
+struct ib_mr *efa_reg_user_mr_dmabuf(struct ib_pd *ibpd, u64 start,
+ u64 length, u64 virt_addr,
+ int fd, int access_flags,
+ struct ib_udata *udata)
+{
+ struct efa_dev *dev = to_edev(ibpd->device);
+ struct ib_umem_dmabuf *umem_dmabuf;
+ struct efa_mr *mr;
+ int err;
+
+ mr = efa_alloc_mr(ibpd, access_flags, udata);
+ if (IS_ERR(mr)) {
+ err = PTR_ERR(mr);
+ goto err_out;
+ }
+
+ umem_dmabuf = ib_umem_dmabuf_get(ibpd->device, start, length, fd,
+ access_flags, &efa_dmabuf_attach_ops);
+ if (IS_ERR(umem_dmabuf)) {
+ ibdev_dbg(&dev->ibdev, "Failed to get dmabuf[%d]\n", err);
+ err = PTR_ERR(umem_dmabuf);
+ goto err_free;
+ }
+
+ dma_resv_lock(umem_dmabuf->attach->dmabuf->resv, NULL);
+ err = dma_buf_pin(umem_dmabuf->attach);
+ if (err) {
+ ibdev_dbg(&dev->ibdev, "Failed to pin dmabuf memory\n");
+ goto err_release;
+ }
+
+ err = ib_umem_dmabuf_map_pages(umem_dmabuf);
+ if (err) {
+ ibdev_dbg(&dev->ibdev, "Failed to map dmabuf pages\n");
+ goto err_unpin;
+ }
+ dma_resv_unlock(umem_dmabuf->attach->dmabuf->resv);
+
+ mr->umem = &umem_dmabuf->umem;
+ err = efa_register_mr(ibpd, mr, start, length, virt_addr, access_flags);
+ if (err)
+ goto err_unmap;
+
return &mr->ibmr;
err_unmap:
+ dma_resv_lock(umem_dmabuf->attach->dmabuf->resv, NULL);
+ ib_umem_dmabuf_unmap_pages(umem_dmabuf);
+err_unpin:
+ dma_buf_unpin(umem_dmabuf->attach);
+err_release:
+ dma_resv_unlock(umem_dmabuf->attach->dmabuf->resv);
+ ib_umem_release(mr->umem);
+err_free:
+ kfree(mr);
+err_out:
+ atomic64_inc(&dev->stats.reg_mr_err);
+ return ERR_PTR(err);
+}
+
+struct ib_mr *efa_reg_mr(struct ib_pd *ibpd, u64 start, u64 length,
+ u64 virt_addr, int access_flags,
+ struct ib_udata *udata)
+{
+ struct efa_dev *dev = to_edev(ibpd->device);
+ struct efa_mr *mr;
+ int err;
+
+ mr = efa_alloc_mr(ibpd, access_flags, udata);
+ if (IS_ERR(mr)) {
+ err = PTR_ERR(mr);
+ goto err_out;
+ }
+
+ mr->umem = ib_umem_get(ibpd->device, start, length, access_flags);
+ if (IS_ERR(mr->umem)) {
+ err = PTR_ERR(mr->umem);
+ ibdev_dbg(&dev->ibdev,
+ "Failed to pin and map user space memory[%d]\n", err);
+ goto err_free;
+ }
+
+ err = efa_register_mr(ibpd, mr, start, length, virt_addr, access_flags);
+ if (err)
+ goto err_release;
+
+ return &mr->ibmr;
+
+err_release:
ib_umem_release(mr->umem);
err_free:
kfree(mr);
@@ -1603,6 +1699,7 @@ int efa_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata)
{
struct efa_dev *dev = to_edev(ibmr->device);
struct efa_com_dereg_mr_params params;
+ struct ib_umem_dmabuf *umem_dmabuf;
struct efa_mr *mr = to_emr(ibmr);
int err;
@@ -1613,6 +1710,15 @@ int efa_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata)
if (err)
return err;
+ if (mr->umem->is_dmabuf) {
+ umem_dmabuf = to_ib_umem_dmabuf(mr->umem);
+
+ dma_resv_lock(umem_dmabuf->attach->dmabuf->resv, NULL);
+ ib_umem_dmabuf_unmap_pages(umem_dmabuf);
+ dma_buf_unpin(umem_dmabuf->attach);
+ dma_resv_unlock(umem_dmabuf->attach->dmabuf->resv);
+ }
+
ib_umem_release(mr->umem);
kfree(mr);
--
2.33.0
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