sfc: add functions to allocate/free MAE counters
authorEdward Cree <ecree.xilinx@gmail.com>
Mon, 14 Nov 2022 13:15:57 +0000 (13:15 +0000)
committerDavid S. Miller <davem@davemloft.net>
Wed, 16 Nov 2022 09:07:02 +0000 (09:07 +0000)
efx_tc_flower_get_counter_index() will create an MAE counter mapped to
 the passed (TC filter) cookie, or increment the reference if one already
 exists for that cookie.

Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/ethernet/sfc/mae.c
drivers/net/ethernet/sfc/mae.h
drivers/net/ethernet/sfc/tc_counters.c
drivers/net/ethernet/sfc/tc_counters.h

index 3772234..f227b4f 100644 (file)
@@ -434,6 +434,57 @@ int efx_mae_match_check_caps(struct efx_nic *efx,
 #undef CHECK_BIT
 #undef CHECK
 
+int efx_mae_allocate_counter(struct efx_nic *efx, struct efx_tc_counter *cnt)
+{
+       MCDI_DECLARE_BUF(outbuf, MC_CMD_MAE_COUNTER_ALLOC_OUT_LEN(1));
+       MCDI_DECLARE_BUF(inbuf, MC_CMD_MAE_COUNTER_ALLOC_V2_IN_LEN);
+       size_t outlen;
+       int rc;
+
+       if (!cnt)
+               return -EINVAL;
+
+       MCDI_SET_DWORD(inbuf, MAE_COUNTER_ALLOC_V2_IN_REQUESTED_COUNT, 1);
+       MCDI_SET_DWORD(inbuf, MAE_COUNTER_ALLOC_V2_IN_COUNTER_TYPE, cnt->type);
+       rc = efx_mcdi_rpc(efx, MC_CMD_MAE_COUNTER_ALLOC, inbuf, sizeof(inbuf),
+                         outbuf, sizeof(outbuf), &outlen);
+       if (rc)
+               return rc;
+       /* pcol says this can't happen, since count is 1 */
+       if (outlen < sizeof(outbuf))
+               return -EIO;
+       cnt->fw_id = MCDI_DWORD(outbuf, MAE_COUNTER_ALLOC_OUT_COUNTER_ID);
+       cnt->gen = MCDI_DWORD(outbuf, MAE_COUNTER_ALLOC_OUT_GENERATION_COUNT);
+       return 0;
+}
+
+int efx_mae_free_counter(struct efx_nic *efx, struct efx_tc_counter *cnt)
+{
+       MCDI_DECLARE_BUF(outbuf, MC_CMD_MAE_COUNTER_FREE_OUT_LEN(1));
+       MCDI_DECLARE_BUF(inbuf, MC_CMD_MAE_COUNTER_FREE_V2_IN_LEN);
+       size_t outlen;
+       int rc;
+
+       MCDI_SET_DWORD(inbuf, MAE_COUNTER_FREE_V2_IN_COUNTER_ID_COUNT, 1);
+       MCDI_SET_DWORD(inbuf, MAE_COUNTER_FREE_V2_IN_FREE_COUNTER_ID, cnt->fw_id);
+       MCDI_SET_DWORD(inbuf, MAE_COUNTER_FREE_V2_IN_COUNTER_TYPE, cnt->type);
+       rc = efx_mcdi_rpc(efx, MC_CMD_MAE_COUNTER_FREE, inbuf, sizeof(inbuf),
+                         outbuf, sizeof(outbuf), &outlen);
+       if (rc)
+               return rc;
+       /* pcol says this can't happen, since count is 1 */
+       if (outlen < sizeof(outbuf))
+               return -EIO;
+       /* FW freed a different ID than we asked for, should also never happen.
+        * Warn because it means we've now got a different idea to the FW of
+        * what counters exist, which could cause mayhem later.
+        */
+       if (WARN_ON(MCDI_DWORD(outbuf, MAE_COUNTER_FREE_OUT_FREED_COUNTER_ID) !=
+                   cnt->fw_id))
+               return -EIO;
+       return 0;
+}
+
 static bool efx_mae_asl_id(u32 id)
 {
        return !!(id & BIT(31));
index 8f5de01..72343e9 100644 (file)
@@ -45,6 +45,9 @@ int efx_mae_match_check_caps(struct efx_nic *efx,
                             const struct efx_tc_match_fields *mask,
                             struct netlink_ext_ack *extack);
 
+int efx_mae_allocate_counter(struct efx_nic *efx, struct efx_tc_counter *cnt);
+int efx_mae_free_counter(struct efx_nic *efx, struct efx_tc_counter *cnt);
+
 int efx_mae_alloc_action_set(struct efx_nic *efx, struct efx_tc_action_set *act);
 int efx_mae_free_action_set(struct efx_nic *efx, u32 fw_id);
 
index 9a4d1d2..6fd07ce 100644 (file)
@@ -74,6 +74,115 @@ void efx_tc_fini_counters(struct efx_nic *efx)
        rhashtable_free_and_destroy(&efx->tc->counter_ht, efx_tc_counter_free, NULL);
 }
 
+/* Counter allocation */
+
+static struct efx_tc_counter *efx_tc_flower_allocate_counter(struct efx_nic *efx,
+                                                            int type)
+{
+       struct efx_tc_counter *cnt;
+       int rc, rc2;
+
+       cnt = kzalloc(sizeof(*cnt), GFP_USER);
+       if (!cnt)
+               return ERR_PTR(-ENOMEM);
+
+       cnt->type = type;
+
+       rc = efx_mae_allocate_counter(efx, cnt);
+       if (rc)
+               goto fail1;
+       rc = rhashtable_insert_fast(&efx->tc->counter_ht, &cnt->linkage,
+                                   efx_tc_counter_ht_params);
+       if (rc)
+               goto fail2;
+       return cnt;
+fail2:
+       /* If we get here, it implies that we couldn't insert into the table,
+        * which in turn probably means that the fw_id was already taken.
+        * In that case, it's unclear whether we really 'own' the fw_id; but
+        * the firmware seemed to think we did, so it's proper to free it.
+        */
+       rc2 = efx_mae_free_counter(efx, cnt);
+       if (rc2)
+               netif_warn(efx, hw, efx->net_dev,
+                          "Failed to free MAE counter %u, rc %d\n",
+                          cnt->fw_id, rc2);
+fail1:
+       kfree(cnt);
+       return ERR_PTR(rc > 0 ? -EIO : rc);
+}
+
+static void efx_tc_flower_release_counter(struct efx_nic *efx,
+                                         struct efx_tc_counter *cnt)
+{
+       int rc;
+
+       rhashtable_remove_fast(&efx->tc->counter_ht, &cnt->linkage,
+                              efx_tc_counter_ht_params);
+       rc = efx_mae_free_counter(efx, cnt);
+       if (rc)
+               netif_warn(efx, hw, efx->net_dev,
+                          "Failed to free MAE counter %u, rc %d\n",
+                          cnt->fw_id, rc);
+       /* This doesn't protect counter updates coming in arbitrarily long
+        * after we deleted the counter.  The RCU just ensures that we won't
+        * free the counter while another thread has a pointer to it.
+        * Ensuring we don't update the wrong counter if the ID gets re-used
+        * is handled by the generation count.
+        */
+       synchronize_rcu();
+       kfree(cnt);
+}
+
+/* TC cookie to counter mapping */
+
+void efx_tc_flower_put_counter_index(struct efx_nic *efx,
+                                    struct efx_tc_counter_index *ctr)
+{
+       if (!refcount_dec_and_test(&ctr->ref))
+               return; /* still in use */
+       rhashtable_remove_fast(&efx->tc->counter_id_ht, &ctr->linkage,
+                              efx_tc_counter_id_ht_params);
+       efx_tc_flower_release_counter(efx, ctr->cnt);
+       kfree(ctr);
+}
+
+struct efx_tc_counter_index *efx_tc_flower_get_counter_index(
+                               struct efx_nic *efx, unsigned long cookie,
+                               enum efx_tc_counter_type type)
+{
+       struct efx_tc_counter_index *ctr, *old;
+       struct efx_tc_counter *cnt;
+
+       ctr = kzalloc(sizeof(*ctr), GFP_USER);
+       if (!ctr)
+               return ERR_PTR(-ENOMEM);
+       ctr->cookie = cookie;
+       old = rhashtable_lookup_get_insert_fast(&efx->tc->counter_id_ht,
+                                               &ctr->linkage,
+                                               efx_tc_counter_id_ht_params);
+       if (old) {
+               /* don't need our new entry */
+               kfree(ctr);
+               if (!refcount_inc_not_zero(&old->ref))
+                       return ERR_PTR(-EAGAIN);
+               /* existing entry found */
+               ctr = old;
+       } else {
+               cnt = efx_tc_flower_allocate_counter(efx, type);
+               if (IS_ERR(cnt)) {
+                       rhashtable_remove_fast(&efx->tc->counter_id_ht,
+                                              &ctr->linkage,
+                                              efx_tc_counter_id_ht_params);
+                       kfree(ctr);
+                       return (void *)cnt; /* it's an ERR_PTR */
+               }
+               ctr->cnt = cnt;
+               refcount_set(&ctr->ref, 1);
+       }
+       return ctr;
+}
+
 /* TC Channel.  Counter updates are delivered on this channel's RXQ. */
 
 static void efx_tc_handle_no_channel(struct efx_nic *efx)
index f998cee..85f4919 100644 (file)
@@ -26,6 +26,7 @@ struct efx_tc_counter {
        u32 fw_id; /* index in firmware counter table */
        enum efx_tc_counter_type type;
        struct rhash_head linkage; /* efx->tc->counter_ht */
+       u32 gen; /* Generation count at which this counter is current */
 };
 
 struct efx_tc_counter_index {
@@ -40,6 +41,12 @@ int efx_tc_init_counters(struct efx_nic *efx);
 void efx_tc_destroy_counters(struct efx_nic *efx);
 void efx_tc_fini_counters(struct efx_nic *efx);
 
+struct efx_tc_counter_index *efx_tc_flower_get_counter_index(
+                               struct efx_nic *efx, unsigned long cookie,
+                               enum efx_tc_counter_type type);
+void efx_tc_flower_put_counter_index(struct efx_nic *efx,
+                                    struct efx_tc_counter_index *ctr);
+
 extern const struct efx_channel_type efx_tc_channel_type;
 
 #endif /* EFX_TC_COUNTERS_H */