[PATCH AUTOSEL 4.19 20/53] IB/hfi1: Fix the allocation of RSM table

Sasha Levin
2019-04-27T01:50:46Z

From: Kaike Wan <kaike.wan@intel.com>

[ Upstream commit d0294344470e6b52d097aa7369173f32d11f2f52 ]

The receive side mapping (RSM) on hfi1 hardware is a special
matching mechanism to direct an incoming packet to a given
hardware receive context. It has 4 instances of matching capabilities
(RSM0 - RSM3) that share the same RSM table (RMT). The RMT has a total of
256 entries, each of which points to a receive context.

Currently, three instances of RSM have been used:
1. RSM0 by QOS;
2. RSM1 by PSM FECN;
3. RSM2 by VNIC.

Each RSM instance should reserve enough entries in RMT to function
properly. Since both PSM and VNIC could allocate any receive context
between dd->first_dyn_alloc_ctxt and dd->num_rcv_contexts, PSM FECN must
reserve enough RMT entries to cover the entire receive context index
range (dd->num_rcv_contexts - dd->first_dyn_alloc_ctxt) instead of only
the user receive contexts allocated for PSM
(dd->num_user_contexts). Consequently, the sizing of
dd->num_user_contexts in set_up_context_variables is incorrect.

Fixes: 2280740f01ae ("IB/hfi1: Virtual Network Interface Controller (VNIC) HW support")
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/infiniband/hw/hfi1/chip.c | 26 +++++++++++++++++++-------
1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/chip.c b/drivers/infiniband/hw/hfi1/chip.c
index 902d12d6d88b..b12c8ff8ed66 100644
--- a/drivers/infiniband/hw/hfi1/chip.c
+++ b/drivers/infiniband/hw/hfi1/chip.c
@@ -13388,7 +13388,7 @@ static int set_up_context_variables(struct hfi1_devdata *dd)
int total_contexts;
int ret;
unsigned ngroups;
- int qos_rmt_count;
+ int rmt_count;
int user_rmt_reduced;
u32 n_usr_ctxts;
u32 send_contexts = chip_send_contexts(dd);
@@ -13450,10 +13450,20 @@ static int set_up_context_variables(struct hfi1_devdata *dd)
n_usr_ctxts = rcv_contexts - total_contexts;
}

- /* each user context requires an entry in the RMT */
- qos_rmt_count = qos_rmt_entries(dd, NULL, NULL);
- if (qos_rmt_count + n_usr_ctxts > NUM_MAP_ENTRIES) {
- user_rmt_reduced = NUM_MAP_ENTRIES - qos_rmt_count;
+ /*
+ * The RMT entries are currently allocated as shown below:
+ * 1. QOS (0 to 128 entries);
+ * 2. FECN for PSM (num_user_contexts + num_vnic_contexts);
+ * 3. VNIC (num_vnic_contexts).
+ * It should be noted that PSM FECN oversubscribe num_vnic_contexts
+ * entries of RMT because both VNIC and PSM could allocate any receive
+ * context between dd->first_dyn_alloc_text and dd->num_rcv_contexts,
+ * and PSM FECN must reserve an RMT entry for each possible PSM receive
+ * context.
+ */
+ rmt_count = qos_rmt_entries(dd, NULL, NULL) + (num_vnic_contexts * 2);
+ if (rmt_count + n_usr_ctxts > NUM_MAP_ENTRIES) {
+ user_rmt_reduced = NUM_MAP_ENTRIES - rmt_count;
dd_dev_err(dd,
"RMT size is reducing the number of user receive contexts from %u to %d\n",
n_usr_ctxts,
@@ -14441,9 +14451,11 @@ static void init_user_fecn_handling(struct hfi1_devdata *dd,
u64 reg;
int i, idx, regoff, regidx;
u8 offset;
+ u32 total_cnt;

/* there needs to be enough room in the map table */
- if (rmt->used + dd->num_user_contexts >= NUM_MAP_ENTRIES) {
+ total_cnt = dd->num_rcv_contexts - dd->first_dyn_alloc_ctxt;
+ if (rmt->used + total_cnt >= NUM_MAP_ENTRIES) {
dd_dev_err(dd, "User FECN handling disabled - too many user contexts allocated\n");
return;
}
@@ -14497,7 +14509,7 @@ static void init_user_fecn_handling(struct hfi1_devdata *dd,
/* add rule 1 */
add_rsm_rule(dd, RSM_INS_FECN, &rrd);

- rmt->used += dd->num_user_contexts;
+ rmt->used += total_cnt;
}

/* Initialize RSM for VNIC */
--
2.19.1