lpm: implement RCU rule reclamation
[dpdk.git] / lib / librte_lpm / rte_lpm.c
index 38ab512..126fc5a 100644 (file)
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: BSD-3-Clause
  * Copyright(c) 2010-2014 Intel Corporation
+ * Copyright(c) 2020 Arm Limited
  */
 
 #include <string.h>
@@ -39,6 +40,17 @@ enum valid_flag {
        VALID
 };
 
+/** @internal LPM structure. */
+struct __rte_lpm {
+       /* LPM metadata. */
+       struct rte_lpm lpm;
+
+       /* RCU config. */
+       struct rte_rcu_qsbr *v;         /* RCU QSBR variable. */
+       enum rte_lpm_qsbr_mode rcu_mode;/* Blocking, defer queue. */
+       struct rte_rcu_qsbr_dq *dq;     /* RCU QSBR defer queue. */
+};
+
 /* Macro to enable/disable run-time checks. */
 #if defined(RTE_LIBRTE_LPM_DEBUG)
 #include <rte_debug.h>
@@ -122,6 +134,7 @@ rte_lpm_create(const char *name, int socket_id,
                const struct rte_lpm_config *config)
 {
        char mem_name[RTE_LPM_NAMESIZE];
+       struct __rte_lpm *internal_lpm;
        struct rte_lpm *lpm = NULL;
        struct rte_tailq_entry *te;
        uint32_t mem_size, rules_size, tbl8s_size;
@@ -140,12 +153,6 @@ rte_lpm_create(const char *name, int socket_id,
 
        snprintf(mem_name, sizeof(mem_name), "LPM_%s", name);
 
-       /* Determine the amount of memory to allocate. */
-       mem_size = sizeof(*lpm);
-       rules_size = sizeof(struct rte_lpm_rule) * config->max_rules;
-       tbl8s_size = (sizeof(struct rte_lpm_tbl_entry) *
-                       RTE_LPM_TBL8_GROUP_NUM_ENTRIES * config->number_tbl8s);
-
        rte_mcfg_tailq_write_lock();
 
        /* guarantee there's no existing */
@@ -161,6 +168,12 @@ rte_lpm_create(const char *name, int socket_id,
                goto exit;
        }
 
+       /* Determine the amount of memory to allocate. */
+       mem_size = sizeof(*internal_lpm);
+       rules_size = sizeof(struct rte_lpm_rule) * config->max_rules;
+       tbl8s_size = sizeof(struct rte_lpm_tbl_entry) *
+                       RTE_LPM_TBL8_GROUP_NUM_ENTRIES * config->number_tbl8s;
+
        /* allocate tailq entry */
        te = rte_zmalloc("LPM_TAILQ_ENTRY", sizeof(*te), 0);
        if (te == NULL) {
@@ -170,21 +183,23 @@ rte_lpm_create(const char *name, int socket_id,
        }
 
        /* Allocate memory to store the LPM data structures. */
-       lpm = rte_zmalloc_socket(mem_name, mem_size,
+       internal_lpm = rte_zmalloc_socket(mem_name, mem_size,
                        RTE_CACHE_LINE_SIZE, socket_id);
-       if (lpm == NULL) {
+       if (internal_lpm == NULL) {
                RTE_LOG(ERR, LPM, "LPM memory allocation failed\n");
                rte_free(te);
                rte_errno = ENOMEM;
                goto exit;
        }
 
+       lpm = &internal_lpm->lpm;
        lpm->rules_tbl = rte_zmalloc_socket(NULL,
                        (size_t)rules_size, RTE_CACHE_LINE_SIZE, socket_id);
 
        if (lpm->rules_tbl == NULL) {
                RTE_LOG(ERR, LPM, "LPM rules_tbl memory allocation failed\n");
-               rte_free(lpm);
+               rte_free(internal_lpm);
+               internal_lpm = NULL;
                lpm = NULL;
                rte_free(te);
                rte_errno = ENOMEM;
@@ -197,7 +212,8 @@ rte_lpm_create(const char *name, int socket_id,
        if (lpm->tbl8 == NULL) {
                RTE_LOG(ERR, LPM, "LPM tbl8 memory allocation failed\n");
                rte_free(lpm->rules_tbl);
-               rte_free(lpm);
+               rte_free(internal_lpm);
+               internal_lpm = NULL;
                lpm = NULL;
                rte_free(te);
                rte_errno = ENOMEM;
@@ -225,6 +241,7 @@ exit:
 void
 rte_lpm_free(struct rte_lpm *lpm)
 {
+       struct __rte_lpm *internal_lpm;
        struct rte_lpm_list *lpm_list;
        struct rte_tailq_entry *te;
 
@@ -246,12 +263,84 @@ rte_lpm_free(struct rte_lpm *lpm)
 
        rte_mcfg_tailq_write_unlock();
 
+       internal_lpm = container_of(lpm, struct __rte_lpm, lpm);
+       if (internal_lpm->dq != NULL)
+               rte_rcu_qsbr_dq_delete(internal_lpm->dq);
        rte_free(lpm->tbl8);
        rte_free(lpm->rules_tbl);
        rte_free(lpm);
        rte_free(te);
 }
 
+static void
+__lpm_rcu_qsbr_free_resource(void *p, void *data, unsigned int n)
+{
+       struct rte_lpm_tbl_entry *tbl8 = ((struct rte_lpm *)p)->tbl8;
+       struct rte_lpm_tbl_entry zero_tbl8_entry = {0};
+       uint32_t tbl8_group_index = *(uint32_t *)data;
+
+       RTE_SET_USED(n);
+       /* Set tbl8 group invalid */
+       __atomic_store(&tbl8[tbl8_group_index], &zero_tbl8_entry,
+               __ATOMIC_RELAXED);
+}
+
+/* Associate QSBR variable with an LPM object.
+ */
+int
+rte_lpm_rcu_qsbr_add(struct rte_lpm *lpm, struct rte_lpm_rcu_config *cfg,
+       struct rte_rcu_qsbr_dq **dq)
+{
+       struct rte_rcu_qsbr_dq_parameters params = {0};
+       char rcu_dq_name[RTE_RCU_QSBR_DQ_NAMESIZE];
+       struct __rte_lpm *internal_lpm;
+
+       if (lpm == NULL || cfg == NULL) {
+               rte_errno = EINVAL;
+               return 1;
+       }
+
+       internal_lpm = container_of(lpm, struct __rte_lpm, lpm);
+       if (internal_lpm->v != NULL) {
+               rte_errno = EEXIST;
+               return 1;
+       }
+
+       if (cfg->mode == RTE_LPM_QSBR_MODE_SYNC) {
+               /* No other things to do. */
+       } else if (cfg->mode == RTE_LPM_QSBR_MODE_DQ) {
+               /* Init QSBR defer queue. */
+               snprintf(rcu_dq_name, sizeof(rcu_dq_name),
+                               "LPM_RCU_%s", lpm->name);
+               params.name = rcu_dq_name;
+               params.size = cfg->dq_size;
+               if (params.size == 0)
+                       params.size = lpm->number_tbl8s;
+               params.trigger_reclaim_limit = cfg->reclaim_thd;
+               params.max_reclaim_size = cfg->reclaim_max;
+               if (params.max_reclaim_size == 0)
+                       params.max_reclaim_size = RTE_LPM_RCU_DQ_RECLAIM_MAX;
+               params.esize = sizeof(uint32_t);        /* tbl8 group index */
+               params.free_fn = __lpm_rcu_qsbr_free_resource;
+               params.p = lpm;
+               params.v = cfg->v;
+               internal_lpm->dq = rte_rcu_qsbr_dq_create(&params);
+               if (internal_lpm->dq == NULL) {
+                       RTE_LOG(ERR, LPM, "LPM defer queue creation failed\n");
+                       return 1;
+               }
+               if (dq != NULL)
+                       *dq = internal_lpm->dq;
+       } else {
+               rte_errno = EINVAL;
+               return 1;
+       }
+       internal_lpm->rcu_mode = cfg->mode;
+       internal_lpm->v = cfg->v;
+
+       return 0;
+}
+
 /*
  * Adds a rule to the rule table.
  *
@@ -394,14 +483,15 @@ rule_find(struct rte_lpm *lpm, uint32_t ip_masked, uint8_t depth)
  * Find, clean and allocate a tbl8.
  */
 static int32_t
-tbl8_alloc(struct rte_lpm_tbl_entry *tbl8, uint32_t number_tbl8s)
+_tbl8_alloc(struct rte_lpm *lpm)
 {
        uint32_t group_idx; /* tbl8 group index. */
        struct rte_lpm_tbl_entry *tbl8_entry;
 
        /* Scan through tbl8 to find a free (i.e. INVALID) tbl8 group. */
-       for (group_idx = 0; group_idx < number_tbl8s; group_idx++) {
-               tbl8_entry = &tbl8[group_idx * RTE_LPM_TBL8_GROUP_NUM_ENTRIES];
+       for (group_idx = 0; group_idx < lpm->number_tbl8s; group_idx++) {
+               tbl8_entry = &lpm->tbl8[group_idx *
+                                       RTE_LPM_TBL8_GROUP_NUM_ENTRIES];
                /* If a free tbl8 group is found clean it and set as VALID. */
                if (!tbl8_entry->valid_group) {
                        struct rte_lpm_tbl_entry new_tbl8_entry = {
@@ -427,14 +517,47 @@ tbl8_alloc(struct rte_lpm_tbl_entry *tbl8, uint32_t number_tbl8s)
        return -ENOSPC;
 }
 
+static int32_t
+tbl8_alloc(struct rte_lpm *lpm)
+{
+       int32_t group_idx; /* tbl8 group index. */
+       struct __rte_lpm *internal_lpm;
+
+       internal_lpm = container_of(lpm, struct __rte_lpm, lpm);
+       group_idx = _tbl8_alloc(lpm);
+       if (group_idx == -ENOSPC && internal_lpm->dq != NULL) {
+               /* If there are no tbl8 groups try to reclaim one. */
+               if (rte_rcu_qsbr_dq_reclaim(internal_lpm->dq, 1,
+                               NULL, NULL, NULL) == 0)
+                       group_idx = _tbl8_alloc(lpm);
+       }
+
+       return group_idx;
+}
+
 static void
-tbl8_free(struct rte_lpm_tbl_entry *tbl8, uint32_t tbl8_group_start)
+tbl8_free(struct rte_lpm *lpm, uint32_t tbl8_group_start)
 {
-       /* Set tbl8 group invalid*/
        struct rte_lpm_tbl_entry zero_tbl8_entry = {0};
+       struct __rte_lpm *internal_lpm;
 
-       __atomic_store(&tbl8[tbl8_group_start], &zero_tbl8_entry,
-                       __ATOMIC_RELAXED);
+       internal_lpm = container_of(lpm, struct __rte_lpm, lpm);
+       if (internal_lpm->v == NULL) {
+               /* Set tbl8 group invalid*/
+               __atomic_store(&lpm->tbl8[tbl8_group_start], &zero_tbl8_entry,
+                               __ATOMIC_RELAXED);
+       } else if (internal_lpm->rcu_mode == RTE_LPM_QSBR_MODE_SYNC) {
+               /* Wait for quiescent state change. */
+               rte_rcu_qsbr_synchronize(internal_lpm->v,
+                       RTE_QSBR_THRID_INVALID);
+               /* Set tbl8 group invalid*/
+               __atomic_store(&lpm->tbl8[tbl8_group_start], &zero_tbl8_entry,
+                               __ATOMIC_RELAXED);
+       } else if (internal_lpm->rcu_mode == RTE_LPM_QSBR_MODE_DQ) {
+               /* Push into QSBR defer queue. */
+               rte_rcu_qsbr_dq_enqueue(internal_lpm->dq,
+                               (void *)&tbl8_group_start);
+       }
 }
 
 static __rte_noinline int32_t
@@ -523,7 +646,7 @@ add_depth_big(struct rte_lpm *lpm, uint32_t ip_masked, uint8_t depth,
 
        if (!lpm->tbl24[tbl24_index].valid) {
                /* Search for a free tbl8 group. */
-               tbl8_group_index = tbl8_alloc(lpm->tbl8, lpm->number_tbl8s);
+               tbl8_group_index = tbl8_alloc(lpm);
 
                /* Check tbl8 allocation was successful. */
                if (tbl8_group_index < 0) {
@@ -569,7 +692,7 @@ add_depth_big(struct rte_lpm *lpm, uint32_t ip_masked, uint8_t depth,
        } /* If valid entry but not extended calculate the index into Table8. */
        else if (lpm->tbl24[tbl24_index].valid_group == 0) {
                /* Search for free tbl8 group. */
-               tbl8_group_index = tbl8_alloc(lpm->tbl8, lpm->number_tbl8s);
+               tbl8_group_index = tbl8_alloc(lpm);
 
                if (tbl8_group_index < 0) {
                        return tbl8_group_index;
@@ -977,7 +1100,7 @@ delete_depth_big(struct rte_lpm *lpm, uint32_t ip_masked,
                 */
                lpm->tbl24[tbl24_index].valid = 0;
                __atomic_thread_fence(__ATOMIC_RELEASE);
-               tbl8_free(lpm->tbl8, tbl8_group_start);
+               tbl8_free(lpm, tbl8_group_start);
        } else if (tbl8_recycle_index > -1) {
                /* Update tbl24 entry. */
                struct rte_lpm_tbl_entry new_tbl24_entry = {
@@ -993,7 +1116,7 @@ delete_depth_big(struct rte_lpm *lpm, uint32_t ip_masked,
                __atomic_store(&lpm->tbl24[tbl24_index], &new_tbl24_entry,
                                __ATOMIC_RELAXED);
                __atomic_thread_fence(__ATOMIC_RELEASE);
-               tbl8_free(lpm->tbl8, tbl8_group_start);
+               tbl8_free(lpm, tbl8_group_start);
        }
 #undef group_idx
        return 0;