RDMA/mana_ib: Support memory windows

Implement .alloc_mw() and .dealloc_mw() for mana device.

This is just the basic infrastructure, MW is not practically usable until
additional kernel support for allowing user space to submit MW work
requests is completed.

Link: https://patch.msgid.link/r/20260331090851.2276205-1-kotaranov@linux.microsoft.com
Signed-off-by: Konstantin Taranov <kotaranov@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

4 files changed, 69 insertions, 1 deletions

diff --git a/drivers/infiniband/hw/mana/device.c b/drivers/infiniband/hw/mana/device.c
index ccc2279ca63c..9811570ab8f8 100644
--- a/drivers/infiniband/hw/mana/device.c
+++ b/drivers/infiniband/hw/mana/device.c
@@ -17,6 +17,7 @@ static const struct ib_device_ops mana_ib_dev_ops = {
 	.uverbs_abi_ver = MANA_IB_UVERBS_ABI_VERSION,
 
 	.add_gid = mana_ib_gd_add_gid,
+	.alloc_mw = mana_ib_alloc_mw,
 	.alloc_pd = mana_ib_alloc_pd,
 	.alloc_ucontext = mana_ib_alloc_ucontext,
 	.create_ah = mana_ib_create_ah,
@@ -24,6 +25,7 @@ static const struct ib_device_ops mana_ib_dev_ops = {
 	.create_qp = mana_ib_create_qp,
 	.create_rwq_ind_table = mana_ib_create_rwq_ind_table,
 	.create_wq = mana_ib_create_wq,
+	.dealloc_mw = mana_ib_dealloc_mw,
 	.dealloc_pd = mana_ib_dealloc_pd,
 	.dealloc_ucontext = mana_ib_dealloc_ucontext,
 	.del_gid = mana_ib_gd_del_gid,
@@ -53,6 +55,7 @@ static const struct ib_device_ops mana_ib_dev_ops = {
 
 	INIT_RDMA_OBJ_SIZE(ib_ah, mana_ib_ah, ibah),
 	INIT_RDMA_OBJ_SIZE(ib_cq, mana_ib_cq, ibcq),
+	INIT_RDMA_OBJ_SIZE(ib_mw, mana_ib_mw, ibmw),
 	INIT_RDMA_OBJ_SIZE(ib_pd, mana_ib_pd, ibpd),
 	INIT_RDMA_OBJ_SIZE(ib_qp, mana_ib_qp, ibqp),
 	INIT_RDMA_OBJ_SIZE(ib_ucontext, mana_ib_ucontext, ibucontext),
diff --git a/drivers/infiniband/hw/mana/mana_ib.h b/drivers/infiniband/hw/mana/mana_ib.h
index a7c8c0fd7019..c9c94e86a72b 100644
--- a/drivers/infiniband/hw/mana/mana_ib.h
+++ b/drivers/infiniband/hw/mana/mana_ib.h
@@ -125,6 +125,11 @@ struct mana_ib_ah {
 	dma_addr_t dma_handle;
 };
 
+struct mana_ib_mw {
+	struct ib_mw ibmw;
+	mana_handle_t mw_handle;
+};
+
 struct mana_ib_mr {
 	struct ib_mr ibmr;
 	struct ib_umem *umem;
@@ -736,6 +741,9 @@ void mana_drain_gsi_sqs(struct mana_ib_dev *mdev);
 int mana_ib_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *wc);
 int mana_ib_arm_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags flags);
 
+int mana_ib_alloc_mw(struct ib_mw *mw, struct ib_udata *udata);
+int mana_ib_dealloc_mw(struct ib_mw *mw);
+
 struct ib_mr *mana_ib_reg_user_mr_dmabuf(struct ib_pd *ibpd, u64 start, u64 length,
 					 u64 iova, int fd, int mr_access_flags,
 					 struct ib_dmah *dmah,
diff --git a/drivers/infiniband/hw/mana/mr.c b/drivers/infiniband/hw/mana/mr.c
index 9bae99c8e846..8092a7bb785b 100644
--- a/drivers/infiniband/hw/mana/mr.c
+++ b/drivers/infiniband/hw/mana/mr.c
@@ -6,7 +6,7 @@
 #include "mana_ib.h"
 
 #define VALID_MR_FLAGS (IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_WRITE | IB_ACCESS_REMOTE_READ |\
-			IB_ACCESS_REMOTE_ATOMIC | IB_ZERO_BASED)
+			IB_ACCESS_REMOTE_ATOMIC | IB_ACCESS_MW_BIND | IB_ZERO_BASED)
 
 #define VALID_DMA_MR_FLAGS (IB_ACCESS_LOCAL_WRITE)
 
@@ -27,6 +27,9 @@ mana_ib_verbs_to_gdma_access_flags(int access_flags)
 	if (access_flags & IB_ACCESS_REMOTE_ATOMIC)
 		flags |= GDMA_ACCESS_FLAG_REMOTE_ATOMIC;
 
+	if (access_flags & IB_ACCESS_MW_BIND)
+		flags |= GDMA_ACCESS_FLAG_BIND_MW;
+
 	return flags;
 }
 
@@ -287,6 +290,55 @@ err_free:
 	return ERR_PTR(err);
 }
 
+static int mana_ib_gd_create_mw(struct mana_ib_dev *dev, struct mana_ib_pd *pd, struct ib_mw *ibmw)
+{
+	struct mana_ib_mw *mw = container_of(ibmw, struct mana_ib_mw, ibmw);
+	struct gdma_context *gc = mdev_to_gc(dev);
+	struct gdma_create_mr_response resp = {};
+	struct gdma_create_mr_request req = {};
+	int err;
+
+	mana_gd_init_req_hdr(&req.hdr, GDMA_CREATE_MR, sizeof(req), sizeof(resp));
+	req.hdr.req.msg_version = GDMA_MESSAGE_V2;
+	req.pd_handle = pd->pd_handle;
+
+	switch (mw->ibmw.type) {
+	case IB_MW_TYPE_1:
+		req.mr_type = GDMA_MR_TYPE_MW1;
+		break;
+	case IB_MW_TYPE_2:
+		req.mr_type = GDMA_MR_TYPE_MW2;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	err = mana_gd_send_request(gc, sizeof(req), &req, sizeof(resp), &resp);
+	if (err)
+		return err;
+
+	mw->ibmw.rkey = resp.rkey;
+	mw->mw_handle = resp.mr_handle;
+
+	return 0;
+}
+
+int mana_ib_alloc_mw(struct ib_mw *ibmw, struct ib_udata *udata)
+{
+	struct mana_ib_dev *mdev = container_of(ibmw->device, struct mana_ib_dev, ib_dev);
+	struct mana_ib_pd *pd = container_of(ibmw->pd, struct mana_ib_pd, ibpd);
+
+	return mana_ib_gd_create_mw(mdev, pd, ibmw);
+}
+
+int mana_ib_dealloc_mw(struct ib_mw *ibmw)
+{
+	struct mana_ib_dev *dev = container_of(ibmw->device, struct mana_ib_dev, ib_dev);
+	struct mana_ib_mw *mw = container_of(ibmw, struct mana_ib_mw, ibmw);
+
+	return mana_ib_gd_destroy_mr(dev, mw->mw_handle);
+}
+
 int mana_ib_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata)
 {
 	struct mana_ib_mr *mr = container_of(ibmr, struct mana_ib_mr, ibmr);
diff --git a/include/net/mana/gdma.h b/include/net/mana/gdma.h
index 766f4fb25e26..fc6468ac7a6f 100644
--- a/include/net/mana/gdma.h
+++ b/include/net/mana/gdma.h
@@ -778,6 +778,7 @@ enum gdma_mr_access_flags {
 	GDMA_ACCESS_FLAG_REMOTE_READ = BIT_ULL(2),
 	GDMA_ACCESS_FLAG_REMOTE_WRITE = BIT_ULL(3),
 	GDMA_ACCESS_FLAG_REMOTE_ATOMIC = BIT_ULL(4),
+	GDMA_ACCESS_FLAG_BIND_MW = BIT_ULL(5),
 };
 
 /* GDMA_CREATE_DMA_REGION */
@@ -870,6 +871,10 @@ enum gdma_mr_type {
 	GDMA_MR_TYPE_ZBVA = 4,
 	/* Device address MRs */
 	GDMA_MR_TYPE_DM = 5,
+	/* Memory Window type 1 */
+	GDMA_MR_TYPE_MW1 = 6,
+	/* Memory Window type 2 */
+	GDMA_MR_TYPE_MW2 = 7,
 };
 
 struct gdma_create_mr_params {