RDMA/rxe: Implement flush execution in responder side

Only the requested placement types that also registered in the destination
memory region are acceptable.
Otherwise, responder will also reply NAK "Remote Access Error" if it
found a placement type violation.

We will persist data via arch_wb_cache_pmem(), which could be
architecture specific.

This commit also adds 2 helpers to update qp.resp from the incoming packet.

Link: https://lore.kernel.org/r/20221206130201.30986-8-lizhijian@fujitsu.comReviewed-by: Zhu Yanjun <zyjzyj2000@gmail.com>
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/sw/rxe/rxe_loc.h

@@ -64,6 +64,7 @@ void rxe_mr_init_dma(int access, struct rxe_mr *mr);
 int rxe_mr_init_user(struct rxe_dev *rxe, u64 start, u64 length, u64 iova,
 		     int access, struct rxe_mr *mr);
 int rxe_mr_init_fast(int max_pages, struct rxe_mr *mr);
+int rxe_flush_pmem_iova(struct rxe_mr *mr, u64 iova, int length);
 int rxe_mr_copy(struct rxe_mr *mr, u64 iova, void *addr, int length,
 		enum rxe_mr_copy_dir dir);
 int copy_data(struct rxe_pd *pd, int access, struct rxe_dma_info *dma,

drivers/infiniband/sw/rxe/rxe_mr.c

@@ -4,6 +4,8 @@
  * Copyright (c) 2015 System Fabric Works, Inc. All rights reserved.
  */
 
+#include <linux/libnvdimm.h>
+
 #include "rxe.h"
 #include "rxe_loc.h"
 
@@ -192,6 +194,7 @@ int rxe_mr_init_user(struct rxe_dev *rxe, u64 start, u64 length, u64 iova,
 	mr->offset = ib_umem_offset(umem);
 	mr->state = RXE_MR_STATE_VALID;
 	mr->ibmr.type = IB_MR_TYPE_USER;
+	mr->ibmr.page_size = PAGE_SIZE;
 
 	return 0;
 
@@ -295,6 +298,39 @@ void *iova_to_vaddr(struct rxe_mr *mr, u64 iova, int length)
 	return addr;
 }
 
+int rxe_flush_pmem_iova(struct rxe_mr *mr, u64 iova, int length)
+{
+	size_t offset;
+
+	if (length == 0)
+		return 0;
+
+	if (mr->ibmr.type == IB_MR_TYPE_DMA)
+		return -EFAULT;
+
+	offset = (iova - mr->ibmr.iova + mr->offset) & mr->page_mask;
+	while (length > 0) {
+		u8 *va;
+		int bytes;
+
+		bytes = mr->ibmr.page_size - offset;
+		if (bytes > length)
+			bytes = length;
+
+		va = iova_to_vaddr(mr, iova, length);
+		if (!va)
+			return -EFAULT;
+
+		arch_wb_cache_pmem(va, bytes);
+
+		length -= bytes;
+		iova += bytes;
+		offset = 0;
+	}
+
+	return 0;
+}
+
 /* copy data from a range (vaddr, vaddr+length-1) to or from
  * a mr object starting at iova.
  */

drivers/infiniband/sw/rxe/rxe_resp.c

@@ -23,6 +23,7 @@ enum resp_states {
 	RESPST_READ_REPLY,
 	RESPST_ATOMIC_REPLY,
 	RESPST_ATOMIC_WRITE_REPLY,
+	RESPST_PROCESS_FLUSH,
 	RESPST_COMPLETE,
 	RESPST_ACKNOWLEDGE,
 	RESPST_CLEANUP,
@@ -59,6 +60,7 @@ static char *resp_state_name[] = {
 	[RESPST_READ_REPLY]			= "READ_REPLY",
 	[RESPST_ATOMIC_REPLY]			= "ATOMIC_REPLY",
 	[RESPST_ATOMIC_WRITE_REPLY]		= "ATOMIC_WRITE_REPLY",
+	[RESPST_PROCESS_FLUSH]			= "PROCESS_FLUSH",
 	[RESPST_COMPLETE]			= "COMPLETE",
 	[RESPST_ACKNOWLEDGE]			= "ACKNOWLEDGE",
 	[RESPST_CLEANUP]			= "CLEANUP",
@@ -258,19 +260,37 @@ static enum resp_states check_op_seq(struct rxe_qp *qp,
 	}
 }
 
+static bool check_qp_attr_access(struct rxe_qp *qp,
+				 struct rxe_pkt_info *pkt)
+{
+	if (((pkt->mask & RXE_READ_MASK) &&
+	     !(qp->attr.qp_access_flags & IB_ACCESS_REMOTE_READ)) ||
+	    ((pkt->mask & (RXE_WRITE_MASK | RXE_ATOMIC_WRITE_MASK)) &&
+	     !(qp->attr.qp_access_flags & IB_ACCESS_REMOTE_WRITE)) ||
+	    ((pkt->mask & RXE_ATOMIC_MASK) &&
+	     !(qp->attr.qp_access_flags & IB_ACCESS_REMOTE_ATOMIC)))
+		return false;
+
+	if (pkt->mask & RXE_FLUSH_MASK) {
+		u32 flush_type = feth_plt(pkt);
+
+		if ((flush_type & IB_FLUSH_GLOBAL &&
+		     !(qp->attr.qp_access_flags & IB_ACCESS_FLUSH_GLOBAL)) ||
+		    (flush_type & IB_FLUSH_PERSISTENT &&
+		     !(qp->attr.qp_access_flags & IB_ACCESS_FLUSH_PERSISTENT)))
+			return false;
+	}
+
+	return true;
+}
+
 static enum resp_states check_op_valid(struct rxe_qp *qp,
 				       struct rxe_pkt_info *pkt)
 {
 	switch (qp_type(qp)) {
 	case IB_QPT_RC:
-		if (((pkt->mask & RXE_READ_MASK) &&
-		     !(qp->attr.qp_access_flags & IB_ACCESS_REMOTE_READ)) ||
-		    ((pkt->mask & (RXE_WRITE_MASK | RXE_ATOMIC_WRITE_MASK)) &&
-		     !(qp->attr.qp_access_flags & IB_ACCESS_REMOTE_WRITE)) ||
-		    ((pkt->mask & RXE_ATOMIC_MASK) &&
-		     !(qp->attr.qp_access_flags & IB_ACCESS_REMOTE_ATOMIC))) {
+		if (!check_qp_attr_access(qp, pkt))
 			return RESPST_ERR_UNSUPPORTED_OPCODE;
-		}
 
 		break;
 
@@ -437,6 +457,23 @@ static enum resp_states rxe_resp_check_length(struct rxe_qp *qp,
 	return RESPST_CHK_RKEY;
 }
 
+static void qp_resp_from_reth(struct rxe_qp *qp, struct rxe_pkt_info *pkt)
+{
+	qp->resp.va = reth_va(pkt);
+	qp->resp.offset = 0;
+	qp->resp.rkey = reth_rkey(pkt);
+	qp->resp.resid = reth_len(pkt);
+	qp->resp.length = reth_len(pkt);
+}
+
+static void qp_resp_from_atmeth(struct rxe_qp *qp, struct rxe_pkt_info *pkt)
+{
+	qp->resp.va = atmeth_va(pkt);
+	qp->resp.offset = 0;
+	qp->resp.rkey = atmeth_rkey(pkt);
+	qp->resp.resid = sizeof(u64);
+}
+
 static enum resp_states check_rkey(struct rxe_qp *qp,
 				   struct rxe_pkt_info *pkt)
 {
@@ -448,23 +485,26 @@ static enum resp_states check_rkey(struct rxe_qp *qp,
 	u32 pktlen;
 	int mtu = qp->mtu;
 	enum resp_states state;
-	int access;
+	int access = 0;
 
 	if (pkt->mask & (RXE_READ_OR_WRITE_MASK | RXE_ATOMIC_WRITE_MASK)) {
-		if (pkt->mask & RXE_RETH_MASK) {
-			qp->resp.va = reth_va(pkt);
-			qp->resp.offset = 0;
-			qp->resp.rkey = reth_rkey(pkt);
-			qp->resp.resid = reth_len(pkt);
-			qp->resp.length = reth_len(pkt);
-		}
+		if (pkt->mask & RXE_RETH_MASK)
+			qp_resp_from_reth(qp, pkt);
+
 		access = (pkt->mask & RXE_READ_MASK) ? IB_ACCESS_REMOTE_READ
 						     : IB_ACCESS_REMOTE_WRITE;
+	} else if (pkt->mask & RXE_FLUSH_MASK) {
+		u32 flush_type = feth_plt(pkt);
+
+		if (pkt->mask & RXE_RETH_MASK)
+			qp_resp_from_reth(qp, pkt);
+
+		if (flush_type & IB_FLUSH_GLOBAL)
+			access |= IB_ACCESS_FLUSH_GLOBAL;
+		if (flush_type & IB_FLUSH_PERSISTENT)
+			access |= IB_ACCESS_FLUSH_PERSISTENT;
 	} else if (pkt->mask & RXE_ATOMIC_MASK) {
-		qp->resp.va = atmeth_va(pkt);
-		qp->resp.offset = 0;
-		qp->resp.rkey = atmeth_rkey(pkt);
-		qp->resp.resid = sizeof(u64);
+		qp_resp_from_atmeth(qp, pkt);
 		access = IB_ACCESS_REMOTE_ATOMIC;
 	} else {
 		return RESPST_EXECUTE;
@@ -511,11 +551,20 @@ static enum resp_states check_rkey(struct rxe_qp *qp,
 		}
 	}
 
+	if (pkt->mask & RXE_FLUSH_MASK) {
+		/* FLUSH MR may not set va or resid
+		 * no need to check range since we will flush whole mr
+		 */
+		if (feth_sel(pkt) == IB_FLUSH_MR)
+			goto skip_check_range;
+	}
+
 	if (mr_check_range(mr, va + qp->resp.offset, resid)) {
 		state = RESPST_ERR_RKEY_VIOLATION;
 		goto err;
 	}
 
+skip_check_range:
 	if (pkt->mask & (RXE_WRITE_MASK | RXE_ATOMIC_WRITE_MASK)) {
 		if (resid > mtu) {
 			if (pktlen != mtu || bth_pad(pkt)) {
@@ -621,11 +670,61 @@ static struct resp_res *rxe_prepare_res(struct rxe_qp *qp,
 		res->last_psn = pkt->psn;
 		res->cur_psn = pkt->psn;
 		break;
+	case RXE_FLUSH_MASK:
+		res->flush.va = qp->resp.va + qp->resp.offset;
+		res->flush.length = qp->resp.length;
+		res->flush.type = feth_plt(pkt);
+		res->flush.level = feth_sel(pkt);
 	}
 
 	return res;
 }
 
+static enum resp_states process_flush(struct rxe_qp *qp,
+				       struct rxe_pkt_info *pkt)
+{
+	u64 length, start;
+	struct rxe_mr *mr = qp->resp.mr;
+	struct resp_res *res = qp->resp.res;
+
+	/* oA19-14, oA19-15 */
+	if (res && res->replay)
+		return RESPST_ACKNOWLEDGE;
+	else if (!res) {
+		res = rxe_prepare_res(qp, pkt, RXE_FLUSH_MASK);
+		qp->resp.res = res;
+	}
+
+	if (res->flush.level == IB_FLUSH_RANGE) {
+		start = res->flush.va;
+		length = res->flush.length;
+	} else { /* level == IB_FLUSH_MR */
+		start = mr->ibmr.iova;
+		length = mr->ibmr.length;
+	}
+
+	if (res->flush.type & IB_FLUSH_PERSISTENT) {
+		if (rxe_flush_pmem_iova(mr, start, length))
+			return RESPST_ERR_RKEY_VIOLATION;
+		/* Make data persistent. */
+		wmb();
+	} else if (res->flush.type & IB_FLUSH_GLOBAL) {
+		/* Make data global visibility. */
+		wmb();
+	}
+
+	qp->resp.msn++;
+
+	/* next expected psn, read handles this separately */
+	qp->resp.psn = (pkt->psn + 1) & BTH_PSN_MASK;
+	qp->resp.ack_psn = qp->resp.psn;
+
+	qp->resp.opcode = pkt->opcode;
+	qp->resp.status = IB_WC_SUCCESS;
+
+	return RESPST_ACKNOWLEDGE;
+}
+
 /* Guarantee atomicity of atomic operations at the machine level. */
 static DEFINE_SPINLOCK(atomic_ops_lock);
 
@@ -980,6 +1079,8 @@ static enum resp_states execute(struct rxe_qp *qp, struct rxe_pkt_info *pkt)
 		return RESPST_ATOMIC_REPLY;
 	} else if (pkt->mask & RXE_ATOMIC_WRITE_MASK) {
 		return RESPST_ATOMIC_WRITE_REPLY;
+	} else if (pkt->mask & RXE_FLUSH_MASK) {
+		return RESPST_PROCESS_FLUSH;
 	} else {
 		/* Unreachable */
 		WARN_ON_ONCE(1);
@@ -1176,7 +1277,7 @@ static enum resp_states acknowledge(struct rxe_qp *qp,
 		send_ack(qp, qp->resp.aeth_syndrome, pkt->psn);
 	else if (pkt->mask & RXE_ATOMIC_MASK)
 		send_atomic_ack(qp, AETH_ACK_UNLIMITED, pkt->psn);
-	else if (pkt->mask & RXE_ATOMIC_WRITE_MASK)
+	else if (pkt->mask & (RXE_FLUSH_MASK | RXE_ATOMIC_WRITE_MASK))
 		send_read_response_ack(qp, AETH_ACK_UNLIMITED, pkt->psn);
 	else if (bth_ack(pkt))
 		send_ack(qp, AETH_ACK_UNLIMITED, pkt->psn);
@@ -1234,6 +1335,22 @@ static enum resp_states duplicate_request(struct rxe_qp *qp,
 		/* SEND. Ack again and cleanup. C9-105. */
 		send_ack(qp, AETH_ACK_UNLIMITED, prev_psn);
 		return RESPST_CLEANUP;
+	} else if (pkt->mask & RXE_FLUSH_MASK) {
+		struct resp_res *res;
+
+		/* Find the operation in our list of responder resources. */
+		res = find_resource(qp, pkt->psn);
+		if (res) {
+			res->replay = 1;
+			res->cur_psn = pkt->psn;
+			qp->resp.res = res;
+			rc = RESPST_PROCESS_FLUSH;
+			goto out;
+		}
+
+		/* Resource not found. Class D error. Drop the request. */
+		rc = RESPST_CLEANUP;
+		goto out;
 	} else if (pkt->mask & RXE_READ_MASK) {
 		struct resp_res *res;
 
@@ -1431,6 +1548,9 @@ int rxe_responder(void *arg)
 		case RESPST_ATOMIC_WRITE_REPLY:
 			state = atomic_write_reply(qp, pkt);
 			break;
+		case RESPST_PROCESS_FLUSH:
+			state = process_flush(qp, pkt);
+			break;
 		case RESPST_ACKNOWLEDGE:
 			state = acknowledge(qp, pkt);
 			break;

drivers/infiniband/sw/rxe/rxe_verbs.h

@@ -165,6 +165,12 @@ struct resp_res {
 			u64		va;
 			u32		resid;
 		} read;
+		struct {
+			u32		length;
+			u64		va;
+			u8		type;
+			u8		level;
+		} flush;
 	};
 };