[PATCH AUTOSEL 5.15 01/50] IB/hfi1: Update RMT size calculation

Sasha Levin
2023-03-03T22:02:03Z

From: Dean Luick <dean.luick@cornelisnetworks.com>

[ Upstream commit 892ede5a77f337831609fb9c248ac60948061894 ]

Fix possible RMT overflow: Use the correct netdev size.
Don't allow adjusted user contexts to go negative.

Fix QOS calculation: Send kernel context count as an argument since
dd->n_krcv_queues is not yet set up in earliest call. Do not include
the control context in the QOS calculation. Use the same sized
variable to find the max of krcvq[] entries.

Update the RMT count explanation to make more sense.

Signed-off-by: Dean Luick <dean.luick@cornelisnetworks.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Link: https://lore.kernel.org/r/167329106946.1472990.18385495251650939054.stgit@awfm-02.cornelisnetworks.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/infiniband/hw/hfi1/chip.c | 59 +++++++++++++++++--------------
1 file changed, 32 insertions(+), 27 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/chip.c b/drivers/infiniband/hw/hfi1/chip.c
index b0d587254fe66..689921dc3d4a8 100644
--- a/drivers/infiniband/hw/hfi1/chip.c
+++ b/drivers/infiniband/hw/hfi1/chip.c
@@ -1055,7 +1055,7 @@ static void read_link_down_reason(struct hfi1_devdata *dd, u8 *ldr);
static void handle_temp_err(struct hfi1_devdata *dd);
static void dc_shutdown(struct hfi1_devdata *dd);
static void dc_start(struct hfi1_devdata *dd);
-static int qos_rmt_entries(struct hfi1_devdata *dd, unsigned int *mp,
+static int qos_rmt_entries(unsigned int n_krcv_queues, unsigned int *mp,
unsigned int *np);
static void clear_full_mgmt_pkey(struct hfi1_pportdata *ppd);
static int wait_link_transfer_active(struct hfi1_devdata *dd, int wait_ms);
@@ -13361,7 +13361,6 @@ static int set_up_context_variables(struct hfi1_devdata *dd)
int ret;
unsigned ngroups;
int rmt_count;
- int user_rmt_reduced;
u32 n_usr_ctxts;
u32 send_contexts = chip_send_contexts(dd);
u32 rcv_contexts = chip_rcv_contexts(dd);
@@ -13420,28 +13419,34 @@ static int set_up_context_variables(struct hfi1_devdata *dd)
(num_kernel_contexts + n_usr_ctxts),
&node_affinity.real_cpu_mask);
/*
- * The RMT entries are currently allocated as shown below:
- * 1. QOS (0 to 128 entries);
- * 2. FECN (num_kernel_context - 1 + num_user_contexts +
- * num_netdev_contexts);
- * 3. netdev (num_netdev_contexts).
- * It should be noted that FECN oversubscribe num_netdev_contexts
- * entries of RMT because both netdev 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 entries are allocated as follows:
+ * 1. QOS (0 to 128 entries)
+ * 2. FECN (num_kernel_context - 1 [a] + num_user_contexts +
+ * num_netdev_contexts [b])
+ * 3. netdev (NUM_NETDEV_MAP_ENTRIES)
+ *
+ * Notes:
+ * [a] Kernel contexts (except control) are included in FECN if kernel
+ * TID_RDMA is active.
+ * [b] Netdev and user contexts are randomly allocated from the same
+ * context pool, so FECN must cover all contexts in the pool.
*/
- rmt_count = qos_rmt_entries(dd, NULL, NULL) + (num_netdev_contexts * 2);
- if (HFI1_CAP_IS_KSET(TID_RDMA))
- rmt_count += num_kernel_contexts - 1;
- 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,
- user_rmt_reduced);
- /* recalculate */
- n_usr_ctxts = user_rmt_reduced;
+ rmt_count = qos_rmt_entries(num_kernel_contexts - 1, NULL, NULL)
+ + (HFI1_CAP_IS_KSET(TID_RDMA) ? num_kernel_contexts - 1
+ : 0)
+ + n_usr_ctxts
+ + num_netdev_contexts
+ + NUM_NETDEV_MAP_ENTRIES;
+ if (rmt_count > NUM_MAP_ENTRIES) {
+ int over = rmt_count - NUM_MAP_ENTRIES;
+ /* try to squish user contexts, minimum of 1 */
+ if (over >= n_usr_ctxts) {
+ dd_dev_err(dd, "RMT overflow: reduce the requested number of contexts\n");
+ return -EINVAL;
+ }
+ dd_dev_err(dd, "RMT overflow: reducing # user contexts from %u to %u\n",
+ n_usr_ctxts, n_usr_ctxts - over);
+ n_usr_ctxts -= over;
}

/* the first N are kernel contexts, the rest are user/netdev contexts */
@@ -14298,15 +14303,15 @@ static void clear_rsm_rule(struct hfi1_devdata *dd, u8 rule_index)
}

/* return the number of RSM map table entries that will be used for QOS */
-static int qos_rmt_entries(struct hfi1_devdata *dd, unsigned int *mp,
+static int qos_rmt_entries(unsigned int n_krcv_queues, unsigned int *mp,
unsigned int *np)
{
int i;
unsigned int m, n;
- u8 max_by_vl = 0;
+ uint max_by_vl = 0;

/* is QOS active at all? */
- if (dd->n_krcv_queues <= MIN_KERNEL_KCTXTS ||
+ if (n_krcv_queues < MIN_KERNEL_KCTXTS ||
num_vls == 1 ||
krcvqsset <= 1)
goto no_qos;
@@ -14364,7 +14369,7 @@ static void init_qos(struct hfi1_devdata *dd, struct rsm_map_table *rmt)

if (!rmt)
goto bail;
- rmt_entries = qos_rmt_entries(dd, &m, &n);
+ rmt_entries = qos_rmt_entries(dd->n_krcv_queues - 1, &m, &n);
if (rmt_entries == 0)
goto bail;
qpns_per_vl = 1 << m;
--
2.39.2