[PATCH 12/15] IB/hfi1: Immediately apply congestion setting MAD

Dennis Dalessandro
2016-05-12T17:23:41Z

From: Dean Luick <dean.luick-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

The handling of the congestion setting MAD packet only
saved off the values, waiting for a congestion control
table packet before going active. Instead, immediately
apply the values.

Reviewed-by: Dennis Dalessandro <dennis.dalessandro-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Dean Luick <dean.luick-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
drivers/staging/rdma/hfi1/mad.c | 93 +++++++++++++++++++++++++--------------
1 files changed, 60 insertions(+), 33 deletions(-)

diff --git a/drivers/staging/rdma/hfi1/mad.c b/drivers/staging/rdma/hfi1/mad.c
index ed58cf2..17882dc 100644
--- a/drivers/staging/rdma/hfi1/mad.c
+++ b/drivers/staging/rdma/hfi1/mad.c
@@ -3363,6 +3363,50 @@ static int __subn_get_opa_cong_setting(struct opa_smp *smp, u32 am,
return reply((struct ib_mad_hdr *)smp);
}

+/*
+ * Apply congestion control information stored in the ppd to the
+ * active structure.
+ */
+static void apply_cc_state(struct hfi1_pportdata *ppd)
+{
+ struct cc_state *old_cc_state, *new_cc_state;
+
+ new_cc_state = kzalloc(sizeof(*new_cc_state), GFP_KERNEL);
+ if (!new_cc_state)
+ return;
+
+ /*
+ * Hold the lock for updating *and* to prevent ppd information
+ * from changing during the update.
+ */
+ spin_lock(&ppd->cc_state_lock);
+
+ old_cc_state = get_cc_state(ppd);
+ if (!old_cc_state) {
+ /* never active, or shutting down */
+ spin_unlock(&ppd->cc_state_lock);
+ kfree(new_cc_state);
+ return;
+ }
+
+ *new_cc_state = *old_cc_state;
+
+ new_cc_state->cct.ccti_limit = ppd->total_cct_entry - 1;
+ memcpy(new_cc_state->cct.entries, ppd->ccti_entries,
+ ppd->total_cct_entry * sizeof(struct ib_cc_table_entry));
+
+ new_cc_state->cong_setting.port_control = IB_CC_CCS_PC_SL_BASED;
+ new_cc_state->cong_setting.control_map = ppd->cc_sl_control_map;
+ memcpy(new_cc_state->cong_setting.entries, ppd->congestion_entries,
+ OPA_MAX_SLS * sizeof(struct opa_congestion_setting_entry));
+
+ rcu_assign_pointer(ppd->cc_state, new_cc_state);
+
+ spin_unlock(&ppd->cc_state_lock);
+
+ call_rcu(&old_cc_state->rcu, cc_state_reclaim);
+}
+
static int __subn_set_opa_cong_setting(struct opa_smp *smp, u32 am, u8 *data,
struct ib_device *ibdev, u8 port,
u32 *resp_len)
@@ -3374,6 +3418,11 @@ static int __subn_set_opa_cong_setting(struct opa_smp *smp, u32 am, u8 *data,
struct opa_congestion_setting_entry_shadow *entries;
int i;

+ /*
+ * Save details from packet into the ppd. Hold the cc_state_lock so
+ * our information is consistent with anyone trying to apply the state.
+ */
+ spin_lock(&ppd->cc_state_lock);
ppd->cc_sl_control_map = be32_to_cpu(p->control_map);

entries = ppd->congestion_entries;
@@ -3384,6 +3433,10 @@ static int __subn_set_opa_cong_setting(struct opa_smp *smp, u32 am, u8 *data,
p->entries[i].trigger_threshold;
entries[i].ccti_min = p->entries[i].ccti_min;
}
+ spin_unlock(&ppd->cc_state_lock);
+
+ /* now apply the information */
+ apply_cc_state(ppd);

return __subn_get_opa_cong_setting(smp, am, data, ibdev, port,
resp_len);
@@ -3526,7 +3579,6 @@ static int __subn_set_opa_cc_table(struct opa_smp *smp, u32 am, u8 *data,
int i, j;
u32 sentry, eentry;
u16 ccti_limit;
- struct cc_state *old_cc_state, *new_cc_state;

/* sanity check n_blocks, start_block */
if (n_blocks == 0 ||
@@ -3546,45 +3598,20 @@ static int __subn_set_opa_cc_table(struct opa_smp *smp, u32 am, u8 *data,
return reply((struct ib_mad_hdr *)smp);
}

- new_cc_state = kzalloc(sizeof(*new_cc_state), GFP_KERNEL);
- if (!new_cc_state)
- goto getit;
-
+ /*
+ * Save details from packet into the ppd. Hold the cc_state_lock so
+ * our information is consistent with anyone trying to apply the state.
+ */
spin_lock(&ppd->cc_state_lock);
-
- old_cc_state = get_cc_state(ppd);
-
- if (!old_cc_state) {
- spin_unlock(&ppd->cc_state_lock);
- kfree(new_cc_state);
- return reply((struct ib_mad_hdr *)smp);
- }
-
- *new_cc_state = *old_cc_state;
-
- new_cc_state->cct.ccti_limit = ccti_limit;
-
- entries = ppd->ccti_entries;
ppd->total_cct_entry = ccti_limit + 1;
-
+ entries = ppd->ccti_entries;
for (j = 0, i = sentry; i < eentry; j++, i++)
entries[i].entry = be16_to_cpu(p->ccti_entries[j].entry);
-
- memcpy(new_cc_state->cct.entries, entries,
- eentry * sizeof(struct ib_cc_table_entry));
-
- new_cc_state->cong_setting.port_control = IB_CC_CCS_PC_SL_BASED;
- new_cc_state->cong_setting.control_map = ppd->cc_sl_control_map;
- memcpy(new_cc_state->cong_setting.entries, ppd->congestion_entries,
- OPA_MAX_SLS * sizeof(struct opa_congestion_setting_entry));
-
- rcu_assign_pointer(ppd->cc_state, new_cc_state);
-
spin_unlock(&ppd->cc_state_lock);

- call_rcu(&old_cc_state->rcu, cc_state_reclaim);
+ /* now apply the information */
+ apply_cc_state(ppd);

-getit:
return __subn_get_opa_cc_table(smp, am, data, ibdev, port, resp_len);
}