tailq: introduce dynamic register system

[dpdk.git] / lib / librte_eal / common / eal_common_tailqs.c

diff --git a/lib/librte_eal/common/eal_common_tailqs.c b/lib/librte_eal/common/eal_common_tailqs.c
index 975ee74..3c4e70d 100644 (file)
--- a/lib/librte_eal/common/eal_common_tailqs.c
+++ b/lib/librte_eal/common/eal_common_tailqs.c
@@ -51,6 +51,7 @@
 #include <rte_branch_prediction.h>
 #include <rte_log.h>
 #include <rte_string_fns.h>
+#include <rte_debug.h>
 
 #include "eal_private.h"
 
@@ -62,6 +63,14 @@ const char* rte_tailq_names[RTE_MAX_TAILQ] = {
 #include <rte_tailq_elem.h>
 };
 
+TAILQ_HEAD(rte_tailq_elem_head, rte_tailq_elem);
+/* local tailq list */
+static struct rte_tailq_elem_head rte_tailq_elem_head =
+       TAILQ_HEAD_INITIALIZER(rte_tailq_elem_head);
+
+/* number of tailqs registered, -1 before call to rte_eal_tailqs_init */
+static int rte_tailqs_count = -1;
+
 struct rte_tailq_head *
 rte_eal_tailq_lookup(const char *name)
 {
@@ -72,9 +81,13 @@ rte_eal_tailq_lookup(const char *name)
                return NULL;
 
        for (i = 0; i < RTE_MAX_TAILQ; i++) {
-               if (rte_tailq_names[i] == NULL)
-                       continue;
-               if (!strncmp(name, rte_tailq_names[i], RTE_TAILQ_NAMESIZE-1))
+               if (i < RTE_TAILQ_NUM &&
+                   !strncmp(name, rte_tailq_names[i], RTE_TAILQ_NAMESIZE-1))
+                       return &mcfg->tailq_head[i];
+
+               /* if past static entries, look at shared mem for names */
+               if (!strncmp(name, mcfg->tailq_head[i].name,
+                            RTE_TAILQ_NAMESIZE-1))
                        return &mcfg->tailq_head[i];
        }
 
@@ -103,31 +116,130 @@ rte_dump_tailq(FILE *f)
        mcfg = rte_eal_get_configuration()->mem_config;
 
        rte_rwlock_read_lock(&mcfg->qlock);
-       for (i=0; i < RTE_MAX_TAILQ; i++) {
+       for (i = 0; i < RTE_MAX_TAILQ; i++) {
                const struct rte_tailq_head *tailq = &mcfg->tailq_head[i];
                const struct rte_tailq_entry_head *head = &tailq->tailq_head;
+               const char *name = "nil";
 
-               fprintf(f, "Tailq %u: qname:<%s>, tqh_first:%p, tqh_last:%p\n", i,
-                      (rte_tailq_names[i] != NULL ? rte_tailq_names[i]:"nil"),
-                      head->tqh_first, head->tqh_last);
+               if (rte_tailq_names[i])
+                       name = rte_tailq_names[i];
+               else if (tailq->name)
+                       name = tailq->name;
+
+               fprintf(f, "Tailq %u: qname:<%s>, tqh_first:%p, tqh_last:%p\n",
+                       i, name, head->tqh_first, head->tqh_last);
        }
        rte_rwlock_read_unlock(&mcfg->qlock);
 }
 
+static struct rte_tailq_head *
+rte_eal_tailq_create(const char *name)
+{
+       struct rte_tailq_head *head = NULL;
+
+       if (!rte_eal_tailq_lookup(name) &&
+           (rte_tailqs_count + 1 < RTE_MAX_TAILQ)) {
+               struct rte_mem_config *mcfg;
+
+               mcfg = rte_eal_get_configuration()->mem_config;
+               head = &mcfg->tailq_head[rte_tailqs_count];
+               snprintf(head->name, sizeof(head->name) - 1, "%s", name);
+               TAILQ_INIT(&head->tailq_head);
+               rte_tailqs_count++;
+       }
+
+       return head;
+}
+
+/* local register, used to store "early" tailqs before rte_eal_init() and to
+ * ensure secondary process only registers tailqs once. */
+static int
+rte_eal_tailq_local_register(struct rte_tailq_elem *t)
+{
+       struct rte_tailq_elem *temp;
+
+       TAILQ_FOREACH(temp, &rte_tailq_elem_head, next) {
+               if (!strncmp(t->name, temp->name, sizeof(temp->name)))
+                       return -1;
+       }
+
+       TAILQ_INSERT_TAIL(&rte_tailq_elem_head, t, next);
+       return 0;
+}
+
+static void
+rte_eal_tailq_update(struct rte_tailq_elem *t)
+{
+       if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
+               /* primary process is the only one that creates */
+               t->head = rte_eal_tailq_create(t->name);
+       } else {
+               t->head = rte_eal_tailq_lookup(t->name);
+       }
+}
+
+int
+rte_eal_tailq_register(struct rte_tailq_elem *t)
+{
+       if (rte_eal_tailq_local_register(t) < 0) {
+               rte_log(RTE_LOG_ERR, RTE_LOGTYPE_EAL,
+                       "%s tailq is already registered\n", t->name);
+               goto error;
+       }
+
+       /* if a register happens after rte_eal_tailqs_init(), then we can update
+        * tailq head */
+       if (rte_tailqs_count >= 0) {
+               rte_eal_tailq_update(t);
+               if (t->head == NULL) {
+                       rte_log(RTE_LOG_ERR, RTE_LOGTYPE_EAL,
+                               "Cannot initialize tailq: %s\n", t->name);
+                       TAILQ_REMOVE(&rte_tailq_elem_head, t, next);
+                       goto error;
+               }
+       }
+
+       return 0;
+
+error:
+       t->head = NULL;
+       return -1;
+}
+
 int
 rte_eal_tailqs_init(void)
 {
        unsigned i;
        struct rte_mem_config *mcfg = NULL;
+       struct rte_tailq_elem *t;
 
        RTE_BUILD_BUG_ON(RTE_MAX_TAILQ < RTE_TAILQ_NUM);
 
        if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
                mcfg = rte_eal_get_configuration()->mem_config;
-               for (i = 0; i < RTE_MAX_TAILQ; i++)
+               for (i = 0; i < RTE_TAILQ_NUM; i++)
                        TAILQ_INIT(&mcfg->tailq_head[i].tailq_head);
        }
 
+       /* mark those static entries as already taken */
+       rte_tailqs_count = RTE_TAILQ_NUM;
+
+       TAILQ_FOREACH(t, &rte_tailq_elem_head, next) {
+               /* second part of register job for "early" tailqs, see
+                * rte_eal_tailq_register and EAL_REGISTER_TAILQ */
+               rte_eal_tailq_update(t);
+               if (t->head == NULL) {
+                       rte_log(RTE_LOG_ERR, RTE_LOGTYPE_EAL,
+                               "Cannot initialize tailq: %s\n", t->name);
+                       /* no need to TAILQ_REMOVE, we are going to panic in
+                        * rte_eal_init() */
+                       goto fail;
+               }
+       }
+
        return 0;
-}
 
+fail:
+       rte_dump_tailq(stderr);
+       return -1;
+}