Fwd: [PATCH for-next v5 09/10] RDMA/rxe: Implement memory access through MWs

["Pearson, Robert B" <rpearsonhpe@gmail.com>]

On 4/24/2021 11:23 PM, Zhu Yanjun wrote:
> On Fri, Apr 23, 2021 at 12:13 AM Bob Pearson <rpearsonhpe@gmail.com> 
> wrote:
>> Add code to implement memory access through memory windows.
>>
>> Signed-off-by: Bob Pearson <rpearson@hpe.com>
>> ---
>> v3:
>> Adjusted patch for collisions with v3 of "RDMA/rxe: Implement
>> invalidate MW operations" patch.
>> v2:
>> Removed a copy of changes in ea4922518940 "Fix missing acks from 
>> responder"
>> that was submitted separately.
>> ---
>> drivers/infiniband/sw/rxe/rxe_loc.h | 1 +
>> drivers/infiniband/sw/rxe/rxe_mw.c | 23 +++++++++++
>> drivers/infiniband/sw/rxe/rxe_resp.c | 55 +++++++++++++++++++--------
>> drivers/infiniband/sw/rxe/rxe_verbs.h | 11 ++++++
>> 4 files changed, 75 insertions(+), 15 deletions(-)
>>
>> diff --git a/drivers/infiniband/sw/rxe/rxe_loc.h 
>> b/drivers/infiniband/sw/rxe/rxe_loc.h
>> index bc0e484f8cde..076e1460577f 100644
>> --- a/drivers/infiniband/sw/rxe/rxe_loc.h
>> +++ b/drivers/infiniband/sw/rxe/rxe_loc.h
>> @@ -94,6 +94,7 @@ int rxe_alloc_mw(struct ib_mw *ibmw, struct 
>> ib_udata *udata);
>> int rxe_dealloc_mw(struct ib_mw *ibmw);
>> int rxe_bind_mw(struct rxe_qp *qp, struct rxe_send_wqe *wqe);
>> int rxe_invalidate_mw(struct rxe_qp *qp, u32 rkey);
>> +struct rxe_mw *lookup_mw(struct rxe_qp *qp, int access, u32 rkey);
>> void rxe_mw_cleanup(struct rxe_pool_entry *arg);
>>
>> /* rxe_net.c */
>> diff --git a/drivers/infiniband/sw/rxe/rxe_mw.c 
>> b/drivers/infiniband/sw/rxe/rxe_mw.c
>> index 00490f232fde..6ed36845c693 100644
>> --- a/drivers/infiniband/sw/rxe/rxe_mw.c
>> +++ b/drivers/infiniband/sw/rxe/rxe_mw.c
>> @@ -312,6 +312,29 @@ int rxe_invalidate_mw(struct rxe_qp *qp, u32 rkey)
>> return ret;
>> }
>>
>> +struct rxe_mw *lookup_mw(struct rxe_qp *qp, int access, u32 rkey)
> will this function lookup_mw be used outside of softroce?
> If not, how about changing the name from lookup_mw to rxe_lookup_mw?
>
> Thanks
> Zhu Yanjun

I would think the opposite is correct. If a name is used outside of the 
driver then the prefix reduces the chance

of a collision with some more global name. If it is only used locally in 
the driver this is less of an issue. Mostly

I have been following the rule that if a name is shared between files in 
rxe then add the prefix and if it is local

to a file (e.g. static) then drop it. Here I broke that and will make 
this change. If a routine is frequently used

for example to_rdev() then the prefix just gets in the way of clarity. 
The shared names are declared in rxe_loc.h.

The common names are defined in rxe_verbs.h.

Bob

>
>> +{
>> + struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
>> + struct rxe_pd *pd = to_rpd(qp->ibqp.pd);
>> + struct rxe_mw *mw;
>> + int index = rkey >> 8;
>> +
>> + mw = rxe_pool_get_index(&rxe->mw_pool, index);
>> + if (!mw)
>> + return NULL;
>> +
>> + if (unlikely((mw_rkey(mw) != rkey) || mw_pd(mw) != pd ||
>> + (mw->ibmw.type == IB_MW_TYPE_2 && mw->qp != qp) ||
>> + (mw->length == 0) ||
>> + (access && !(access & mw->access)) ||
>> + mw->state != RXE_MW_STATE_VALID)) {
>> + rxe_drop_ref(mw);
>> + return NULL;
>> + }
>> +
>> + return mw;
>> +}
>> +
>> void rxe_mw_cleanup(struct rxe_pool_entry *elem)
>> {
>> struct rxe_mw *mw = container_of(elem, typeof(*mw), pelem);
>> diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c 
>> b/drivers/infiniband/sw/rxe/rxe_resp.c
>> index 759e9789cd4d..9c8cbfbc8820 100644
>> --- a/drivers/infiniband/sw/rxe/rxe_resp.c
>> +++ b/drivers/infiniband/sw/rxe/rxe_resp.c
>> @@ -394,6 +394,7 @@ static enum resp_states check_rkey(struct rxe_qp *qp,
>> struct rxe_pkt_info *pkt)
>> {
>> struct rxe_mr *mr = NULL;
>> + struct rxe_mw *mw = NULL;
>> u64 va;
>> u32 rkey;
>> u32 resid;
>> @@ -405,6 +406,7 @@ static enum resp_states check_rkey(struct rxe_qp *qp,
>> if (pkt->mask & (RXE_READ_MASK | RXE_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);
>> @@ -413,6 +415,7 @@ static enum resp_states check_rkey(struct rxe_qp *qp,
>> : IB_ACCESS_REMOTE_WRITE;
>> } 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);
>> access = IB_ACCESS_REMOTE_ATOMIC;
>> @@ -432,18 +435,36 @@ static enum resp_states check_rkey(struct 
>> rxe_qp *qp,
>> resid = qp->resp.resid;
>> pktlen = payload_size(pkt);
>>
>> - mr = lookup_mr(qp->pd, access, rkey, RXE_LOOKUP_REMOTE);
>> - if (!mr) {
>> - state = RESPST_ERR_RKEY_VIOLATION;
>> - goto err;
>> - }
>> + if (rkey_is_mw(rkey)) {
>> + mw = lookup_mw(qp, access, rkey);
>> + if (!mw) {
>> + pr_err("%s: no MW matches rkey %#x\n", __func__, rkey);
>> + state = RESPST_ERR_RKEY_VIOLATION;
>> + goto err;
>> + }
>>
>> - if (unlikely(mr->state == RXE_MR_STATE_FREE)) {
>> - state = RESPST_ERR_RKEY_VIOLATION;
>> - goto err;
>> + mr = mw->mr;
>> + if (!mr) {
>> + pr_err("%s: MW doesn't have an MR\n", __func__);
>> + state = RESPST_ERR_RKEY_VIOLATION;
>> + goto err;
>> + }
>> +
>> + if (mw->access & IB_ZERO_BASED)
>> + qp->resp.offset = mw->addr;
>> +
>> + rxe_drop_ref(mw);
>> + rxe_add_ref(mr);
>> + } else {
>> + mr = lookup_mr(qp->pd, access, rkey, RXE_LOOKUP_REMOTE);
>> + if (!mr) {
>> + pr_err("%s: no MR matches rkey %#x\n", __func__, rkey);
>> + state = RESPST_ERR_RKEY_VIOLATION;
>> + goto err;
>> + }
>> }
>>
>> - if (mr_check_range(mr, va, resid)) {
>> + if (mr_check_range(mr, va + qp->resp.offset, resid)) {
>> state = RESPST_ERR_RKEY_VIOLATION;
>> goto err;
>> }
>> @@ -477,6 +498,9 @@ static enum resp_states check_rkey(struct rxe_qp *qp,
>> err:
>> if (mr)
>> rxe_drop_ref(mr);
>> + if (mw)
>> + rxe_drop_ref(mw);
>> +
>> return state;
>> }
>>
>> @@ -501,8 +525,8 @@ static enum resp_states write_data_in(struct 
>> rxe_qp *qp,
>> int err;
>> int data_len = payload_size(pkt);
>>
>> - err = rxe_mr_copy(qp->resp.mr, qp->resp.va, payload_addr(pkt), 
>> data_len,
>> - RXE_TO_MR_OBJ, NULL);
>> + err = rxe_mr_copy(qp->resp.mr, qp->resp.va + qp->resp.offset,
>> + payload_addr(pkt), data_len, RXE_TO_MR_OBJ, NULL);
>> if (err) {
>> rc = RESPST_ERR_RKEY_VIOLATION;
>> goto out;
>> @@ -521,7 +545,6 @@ static DEFINE_SPINLOCK(atomic_ops_lock);
>> static enum resp_states process_atomic(struct rxe_qp *qp,
>> struct rxe_pkt_info *pkt)
>> {
>> - u64 iova = atmeth_va(pkt);
>> u64 *vaddr;
>> enum resp_states ret;
>> struct rxe_mr *mr = qp->resp.mr;
>> @@ -531,7 +554,7 @@ static enum resp_states process_atomic(struct 
>> rxe_qp *qp,
>> goto out;
>> }
>>
>> - vaddr = iova_to_vaddr(mr, iova, sizeof(u64));
>> + 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) {
>> @@ -655,8 +678,10 @@ static enum resp_states read_reply(struct rxe_qp 
>> *qp,
>> res->type = RXE_READ_MASK;
>> res->replay = 0;
>>
>> - res->read.va = qp->resp.va;
>> - res->read.va_org = qp->resp.va;
>> + res->read.va = qp->resp.va +
>> + qp->resp.offset;
>> + res->read.va_org = qp->resp.va +
>> + qp->resp.offset;
>>
>> res->first_psn = req_pkt->psn;
>>
>> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h 
>> b/drivers/infiniband/sw/rxe/rxe_verbs.h
>> index 74fcd871757d..f426bf30f86a 100644
>> --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
>> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
>> @@ -183,6 +183,7 @@ struct rxe_resp_info {
>>
>> /* RDMA read / atomic only */
>> u64 va;
>> + u64 offset;
>> struct rxe_mr *mr;
>> u32 resid;
>> u32 rkey;
>> @@ -480,6 +481,16 @@ static inline u32 mr_rkey(struct rxe_mr *mr)
>> return mr->ibmr.rkey;
>> }
>>
>> +static inline struct rxe_pd *mw_pd(struct rxe_mw *mw)
> rxe_mw_pd
No. See above.
>
>> +{
>> + return to_rpd(mw->ibmw.pd);
>> +}
>> +
>> +static inline u32 mw_rkey(struct rxe_mw *mw)
> rxe_mw_rkey
No.
>
>> +{
>> + return mw->ibmw.rkey;
>> +}
>> +
>> int rxe_register_device(struct rxe_dev *rxe, const char *ibdev_name);
>>
>> void rxe_mc_cleanup(struct rxe_pool_entry *arg);
>> --
>> 2.27.0
>>