[PATCH for-next v5 3/6] RDMA-rxe: Isolate mr code from atomic_reply()

[Bob Pearson <rpearsonhpe@gmail.com>]

Isolate mr specific code from atomic_reply() in rxe_resp.c into
a subroutine rxe_mr_do_atomic_op() in rxe_mr.c.

Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
---
 drivers/infiniband/sw/rxe/rxe_loc.h   |  2 +
 drivers/infiniband/sw/rxe/rxe_mr.c    | 83 ++++++++++++++++++---------
 drivers/infiniband/sw/rxe/rxe_resp.c  | 49 +++++-----------
 drivers/infiniband/sw/rxe/rxe_verbs.h |  5 ++
 4 files changed, 76 insertions(+), 63 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_loc.h b/drivers/infiniband/sw/rxe/rxe_loc.h
index 29b6c2143045..bcb1bbcf50df 100644
--- a/drivers/infiniband/sw/rxe/rxe_loc.h
+++ b/drivers/infiniband/sw/rxe/rxe_loc.h
@@ -72,6 +72,8 @@ int copy_data(struct rxe_pd *pd, int access, struct rxe_dma_info *dma,
 int rxe_map_mr_sg(struct ib_mr *ibmr, struct scatterlist *sg,
 		  int sg_nents, unsigned int *sg_offset);
 void *iova_to_vaddr(struct rxe_mr *mr, u64 iova, int length);
+int rxe_mr_do_atomic_op(struct rxe_mr *mr, u64 iova, int opcode,
+			u64 compare, u64 swap_add, u64 *orig_val);
 struct rxe_mr *lookup_mr(struct rxe_pd *pd, int access, u32 key,
 			 enum rxe_mr_lookup_type type);
 int mr_check_range(struct rxe_mr *mr, u64 iova, size_t length);
diff --git a/drivers/infiniband/sw/rxe/rxe_mr.c b/drivers/infiniband/sw/rxe/rxe_mr.c
index 229c7259644c..15a8d44daa35 100644
--- a/drivers/infiniband/sw/rxe/rxe_mr.c
+++ b/drivers/infiniband/sw/rxe/rxe_mr.c
@@ -32,13 +32,15 @@ int mr_check_range(struct rxe_mr *mr, u64 iova, size_t length)
 
 	case IB_MR_TYPE_USER:
 	case IB_MR_TYPE_MEM_REG:
-		if (iova < mr->ibmr.iova || length > mr->ibmr.length ||
-		    iova > mr->ibmr.iova + mr->ibmr.length - length)
-			return -EFAULT;
+		if (iova < mr->ibmr.iova ||
+		    iova + length > mr->ibmr.iova + mr->ibmr.length) {
+			rxe_dbg_mr(mr, "iova/length out of range");
+			return -ERANGE;
+		}
 		return 0;
 
 	default:
-		rxe_dbg_mr(mr, "type (%d) not supported\n", mr->ibmr.type);
+		rxe_dbg_mr(mr, "mr type not supported\n");
 		return -EINVAL;
 	}
 }
@@ -299,37 +301,22 @@ void *iova_to_vaddr(struct rxe_mr *mr, u64 iova, int length)
 {
 	size_t offset;
 	int m, n;
-	void *addr;
 
-	if (mr->state != RXE_MR_STATE_VALID) {
-		rxe_dbg_mr(mr, "Not in valid state\n");
-		addr = NULL;
-		goto out;
-	}
+	if (mr->state != RXE_MR_STATE_VALID)
+		return NULL;
 
-	if (!mr->map) {
-		addr = (void *)(uintptr_t)iova;
-		goto out;
-	}
+	if (mr->ibmr.type == IB_MR_TYPE_DMA)
+		return (void *)(uintptr_t)iova;
 
-	if (mr_check_range(mr, iova, length)) {
-		rxe_dbg_mr(mr, "Range violation\n");
-		addr = NULL;
-		goto out;
-	}
+	if (mr_check_range(mr, iova, length))
+		return NULL;
 
 	lookup_iova(mr, iova, &m, &n, &offset);
 
-	if (offset + length > mr->map[m]->buf[n].size) {
-		rxe_dbg_mr(mr, "Crosses page boundary\n");
-		addr = NULL;
-		goto out;
-	}
-
-	addr = (void *)(uintptr_t)mr->map[m]->buf[n].addr + offset;
+	if (offset + length > mr->map[m]->buf[n].size)
+		return NULL;
 
-out:
-	return addr;
+	return (void *)(uintptr_t)mr->map[m]->buf[n].addr + offset;
 }
 
 int rxe_flush_pmem_iova(struct rxe_mr *mr, u64 iova, int length)
@@ -538,6 +525,46 @@ int copy_data(
 	return err;
 }
 
+/* Guarantee atomicity of atomic operations at the machine level. */
+static DEFINE_SPINLOCK(atomic_ops_lock);
+
+int rxe_mr_do_atomic_op(struct rxe_mr *mr, u64 iova, int opcode,
+			u64 compare, u64 swap_add, u64 *orig_val)
+{
+	u64 *va;
+	u64 value;
+
+	if (mr->state != RXE_MR_STATE_VALID) {
+		rxe_dbg_mr(mr, "mr not in valid state");
+		return -EINVAL;
+	}
+
+	va = iova_to_vaddr(mr, iova, sizeof(u64));
+	if (!va) {
+		rxe_dbg_mr(mr, "iova out of range");
+		return -ERANGE;
+	}
+
+	if ((uintptr_t)va & 0x7) {
+		rxe_dbg_mr(mr, "iova not aligned");
+		return RXE_ERR_NOT_ALIGNED;
+	}
+
+	spin_lock_bh(&atomic_ops_lock);
+	value = *orig_val = *va;
+
+	if (opcode == IB_OPCODE_RC_COMPARE_SWAP) {
+		if (value == compare)
+			*va = swap_add;
+	} else {
+		value += swap_add;
+		*va = value;
+	}
+	spin_unlock_bh(&atomic_ops_lock);
+
+	return 0;
+}
+
 int advance_dma_data(struct rxe_dma_info *dma, unsigned int length)
 {
 	struct rxe_sge		*sge	= &dma->sge[dma->cur_sge];
diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
index c74972244f08..1e38e5da1f4c 100644
--- a/drivers/infiniband/sw/rxe/rxe_resp.c
+++ b/drivers/infiniband/sw/rxe/rxe_resp.c
@@ -725,17 +725,12 @@ static enum resp_states process_flush(struct rxe_qp *qp,
 	return RESPST_ACKNOWLEDGE;
 }
 
-/* Guarantee atomicity of atomic operations at the machine level. */
-static DEFINE_SPINLOCK(atomic_ops_lock);
-
 static enum resp_states atomic_reply(struct rxe_qp *qp,
-					 struct rxe_pkt_info *pkt)
+				     struct rxe_pkt_info *pkt)
 {
-	u64 *vaddr;
-	enum resp_states ret;
 	struct rxe_mr *mr = qp->resp.mr;
 	struct resp_res *res = qp->resp.res;
-	u64 value;
+	int err;
 
 	if (!res) {
 		res = rxe_prepare_res(qp, pkt, RXE_ATOMIC_MASK);
@@ -743,33 +738,19 @@ static enum resp_states atomic_reply(struct rxe_qp *qp,
 	}
 
 	if (!res->replay) {
-		if (mr->state != RXE_MR_STATE_VALID) {
-			ret = RESPST_ERR_RKEY_VIOLATION;
-			goto out;
-		}
-
-		vaddr = iova_to_vaddr(mr, qp->resp.va + qp->resp.offset,
-					sizeof(u64));
-
-		/* check vaddr is 8 bytes aligned. */
-		if (!vaddr || (uintptr_t)vaddr & 7) {
-			ret = RESPST_ERR_MISALIGNED_ATOMIC;
-			goto out;
-		}
-
-		spin_lock_bh(&atomic_ops_lock);
-		res->atomic.orig_val = value = *vaddr;
-
-		if (pkt->opcode == IB_OPCODE_RC_COMPARE_SWAP) {
-			if (value == atmeth_comp(pkt))
-				value = atmeth_swap_add(pkt);
-		} else {
-			value += atmeth_swap_add(pkt);
+		u64 iova = qp->resp.va + qp->resp.offset;
+
+		err = rxe_mr_do_atomic_op(mr, iova, pkt->opcode,
+					  atmeth_comp(pkt),
+					  atmeth_swap_add(pkt),
+					  &res->atomic.orig_val);
+		if (unlikely(err)) {
+			if (err == -RXE_ERR_NOT_ALIGNED)
+				return RESPST_ERR_MISALIGNED_ATOMIC;
+			else
+				return RESPST_ERR_RKEY_VIOLATION;
 		}
 
-		*vaddr = value;
-		spin_unlock_bh(&atomic_ops_lock);
-
 		qp->resp.msn++;
 
 		/* next expected psn, read handles this separately */
@@ -780,9 +761,7 @@ static enum resp_states atomic_reply(struct rxe_qp *qp,
 		qp->resp.status = IB_WC_SUCCESS;
 	}
 
-	ret = RESPST_ACKNOWLEDGE;
-out:
-	return ret;
+	return RESPST_ACKNOWLEDGE;
 }
 
 #ifdef CONFIG_64BIT
diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
index 19ddfa890480..691200d99d6b 100644
--- a/drivers/infiniband/sw/rxe/rxe_verbs.h
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
@@ -273,6 +273,11 @@ enum rxe_mr_state {
 	RXE_MR_STATE_VALID,
 };
 
+/* some rxe specific error conditions */
+enum rxe_mr_error {
+	RXE_ERR_NOT_ALIGNED = 0x1001,	/* misaligned address */
+};
+
 enum rxe_mr_copy_dir {
 	RXE_TO_MR_OBJ,
 	RXE_FROM_MR_OBJ,
-- 
2.37.2