eal: implement device iteration

Use the iteration hooks in the abstraction layers to perform the
requested filtering on the internal device lists.

Signed-off-by: Gaetan Rivet <gaetan.rivet@6wind.com>

diff --git a/lib/librte_eal/common/eal_common_dev.c b/lib/librte_eal/common/eal_common_dev.c
index 63e329b..b78845f 100644 (file)
--- a/lib/librte_eal/common/eal_common_dev.c
+++ b/lib/librte_eal/common/eal_common_dev.c
@@ -45,6 +45,28 @@ static struct dev_event_cb_list dev_event_cbs;
 /* spinlock for device callbacks */
 static rte_spinlock_t dev_event_lock = RTE_SPINLOCK_INITIALIZER;
 
+struct dev_next_ctx {
+       struct rte_dev_iterator *it;
+       const char *bus_str;
+       const char *cls_str;
+};
+
+#define CTX(it, bus_str, cls_str) \
+       (&(const struct dev_next_ctx){ \
+               .it = it, \
+               .bus_str = bus_str, \
+               .cls_str = cls_str, \
+       })
+
+#define ITCTX(ptr) \
+       (((struct dev_next_ctx *)(intptr_t)ptr)->it)
+
+#define BUSCTX(ptr) \
+       (((struct dev_next_ctx *)(intptr_t)ptr)->bus_str)
+
+#define CLSCTX(ptr) \
+       (((struct dev_next_ctx *)(intptr_t)ptr)->cls_str)
+
 static int cmp_detached_dev_name(const struct rte_device *dev,
        const void *_name)
 {
@@ -398,3 +420,149 @@ rte_dev_iterator_init(struct rte_dev_iterator *it,
 get_out:
        return -rte_errno;
 }
+
+static char *
+dev_str_sane_copy(const char *str)
+{
+       size_t end;
+       char *copy;
+
+       end = strcspn(str, ",/");
+       if (str[end] == ',') {
+               copy = strdup(&str[end + 1]);
+       } else {
+               /* '/' or '\0' */
+               copy = strdup("");
+       }
+       if (copy == NULL) {
+               rte_errno = ENOMEM;
+       } else {
+               char *slash;
+
+               slash = strchr(copy, '/');
+               if (slash != NULL)
+                       slash[0] = '\0';
+       }
+       return copy;
+}
+
+static int
+class_next_dev_cmp(const struct rte_class *cls,
+                  const void *ctx)
+{
+       struct rte_dev_iterator *it;
+       const char *cls_str = NULL;
+       void *dev;
+
+       if (cls->dev_iterate == NULL)
+               return 1;
+       it = ITCTX(ctx);
+       cls_str = CLSCTX(ctx);
+       dev = it->class_device;
+       /* it->cls_str != NULL means a class
+        * was specified in the devstr.
+        */
+       if (it->cls_str != NULL && cls != it->cls)
+               return 1;
+       /* If an error occurred previously,
+        * no need to test further.
+        */
+       if (rte_errno != 0)
+               return -1;
+       dev = cls->dev_iterate(dev, cls_str, it);
+       it->class_device = dev;
+       return dev == NULL;
+}
+
+static int
+bus_next_dev_cmp(const struct rte_bus *bus,
+                const void *ctx)
+{
+       struct rte_device *dev = NULL;
+       struct rte_class *cls = NULL;
+       struct rte_dev_iterator *it;
+       const char *bus_str = NULL;
+
+       if (bus->dev_iterate == NULL)
+               return 1;
+       it = ITCTX(ctx);
+       bus_str = BUSCTX(ctx);
+       dev = it->device;
+       /* it->bus_str != NULL means a bus
+        * was specified in the devstr.
+        */
+       if (it->bus_str != NULL && bus != it->bus)
+               return 1;
+       /* If an error occurred previously,
+        * no need to test further.
+        */
+       if (rte_errno != 0)
+               return -1;
+       if (it->cls_str == NULL) {
+               dev = bus->dev_iterate(dev, bus_str, it);
+               goto end;
+       }
+       /* cls_str != NULL */
+       if (dev == NULL) {
+next_dev_on_bus:
+               dev = bus->dev_iterate(dev, bus_str, it);
+               it->device = dev;
+       }
+       if (dev == NULL)
+               return 1;
+       if (it->cls != NULL)
+               cls = TAILQ_PREV(it->cls, rte_class_list, next);
+       cls = rte_class_find(cls, class_next_dev_cmp, ctx);
+       if (cls != NULL) {
+               it->cls = cls;
+               goto end;
+       }
+       goto next_dev_on_bus;
+end:
+       it->device = dev;
+       return dev == NULL;
+}
+__rte_experimental
+struct rte_device *
+rte_dev_iterator_next(struct rte_dev_iterator *it)
+{
+       struct rte_bus *bus = NULL;
+       int old_errno = rte_errno;
+       char *bus_str = NULL;
+       char *cls_str = NULL;
+
+       rte_errno = 0;
+       if (it->bus_str == NULL && it->cls_str == NULL) {
+               /* Invalid iterator. */
+               rte_errno = EINVAL;
+               return NULL;
+       }
+       if (it->bus != NULL)
+               bus = TAILQ_PREV(it->bus, rte_bus_list, next);
+       if (it->bus_str != NULL) {
+               bus_str = dev_str_sane_copy(it->bus_str);
+               if (bus_str == NULL)
+                       goto out;
+       }
+       if (it->cls_str != NULL) {
+               cls_str = dev_str_sane_copy(it->cls_str);
+               if (cls_str == NULL)
+                       goto out;
+       }
+       while ((bus = rte_bus_find(bus, bus_next_dev_cmp,
+                                  CTX(it, bus_str, cls_str)))) {
+               if (it->device != NULL) {
+                       it->bus = bus;
+                       goto out;
+               }
+               if (it->bus_str != NULL ||
+                   rte_errno != 0)
+                       break;
+       }
+       if (rte_errno == 0)
+               rte_errno = old_errno;
+out:
+       free(bus_str);
+       free(cls_str);
+       return it->device;
+}

diff --git a/lib/librte_eal/common/include/rte_dev.h b/lib/librte_eal/common/include/rte_dev.h
index 2ce3c8c..a603f48 100644 (file)
--- a/lib/librte_eal/common/include/rte_dev.h
+++ b/lib/librte_eal/common/include/rte_dev.h
@@ -354,6 +354,32 @@ __rte_experimental
 int
 rte_dev_iterator_init(struct rte_dev_iterator *it, const char *str);
 
+/**
+ * Iterates on a device iterator.
+ *
+ * Generates a new rte_device handle corresponding to the next element
+ * in the list described in comprehension by the iterator.
+ *
+ * The next object is returned, and the iterator is updated.
+ *
+ * @param it
+ *   Device iterator handle.
+ *
+ * @return
+ *   An rte_device handle if found.
+ *   NULL if an error occurred (rte_errno is set).
+ *   NULL if no device could be found (rte_errno is not set).
+ */
+__rte_experimental
+struct rte_device *
+rte_dev_iterator_next(struct rte_dev_iterator *it);
+
+#define RTE_DEV_FOREACH(dev, devstr, it) \
+       for (rte_dev_iterator_init(it, devstr), \
+            dev = rte_dev_iterator_next(it); \
+            dev != NULL; \
+            dev = rte_dev_iterator_next(it))
+
 #ifdef __cplusplus
 }
 #endif

diff --git a/lib/librte_eal/rte_eal_version.map b/lib/librte_eal/rte_eal_version.map
index f0d1289..b2cb3c1 100644 (file)
--- a/lib/librte_eal/rte_eal_version.map
+++ b/lib/librte_eal/rte_eal_version.map
@@ -264,6 +264,7 @@ EXPERIMENTAL {
        rte_dev_event_monitor_start;
        rte_dev_event_monitor_stop;
        rte_dev_iterator_init;
+       rte_dev_iterator_next;
        rte_devargs_add;
        rte_devargs_dump;
        rte_devargs_insert;