On 01/06/2018 04:06 AM, Stephen Hemminger wrote:
Many drivers are all doing copy/paste of the same code to atomically
update the link status. Reduce duplication, and allow for future
changes by having common function for this.
Signed-off-by: Stephen Hemminger <step...@networkplumber.org>
---
lib/librte_ether/rte_ethdev.c | 35 +++++++++++++++++++++++++++++++++++
lib/librte_ether/rte_ethdev.h | 28 ++++++++++++++++++++++++++++
2 files changed, 63 insertions(+)
diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
index 27b52131ef01..4897e1dcda14 100644
--- a/lib/librte_ether/rte_ethdev.c
+++ b/lib/librte_ether/rte_ethdev.c
@@ -1495,6 +1495,41 @@ rte_eth_link_get_nowait(uint16_t port_id, struct
rte_eth_link *eth_link)
}
}
+int
+_rte_eth_linkstatus_set(struct rte_eth_dev *dev,
+ const struct rte_eth_link *new_link)
+{
+ volatile uint64_t *dev_link
+ = (volatile uint64_t *)&(dev->data->dev_link);
+ union {
+ uint64_t val64;
+ struct rte_eth_link link;
+ } orig;
+
+ RTE_BUILD_BUG_ON(sizeof(*new_link) != sizeof(uint64_t));
+
+ orig.val64 = rte_atomic64_exchange(dev_link,
+ *(const uint64_t *)new_link);
+
+ return (orig.link.link_status == new_link->link_status) ? -1 : 0;
It looks like it contradicts to the function description saying that 0 is
returned if link status is the same.
+}
+
+void
+_rte_eth_linkstatus_get(const struct rte_eth_dev *dev,
+ struct rte_eth_link *link)
+{
+ const uint64_t *src = (const uint64_t *)&(dev->data->dev_link);
+ volatile uint64_t *dst = (uint64_t *)link;
+
+ RTE_BUILD_BUG_ON(sizeof(*link) != sizeof(uint64_t));
+
+ /*
+ * Note: this should never fail since both destination and expected
+ * values are the same and are a pointer from caller.
+ */
+ rte_atomic64_cmpset(dst, *dst, *src);
As I understand nobody says that *link (i.e. *dst) is initialized, so it
could be
reading uninitialized value. Not fatal, but not good as well.
May be it is better to use something like rte_atomic64_read().
+}
+
int
rte_eth_stats_get(uint16_t port_id, struct rte_eth_stats *stats)
{
diff --git a/lib/librte_ether/rte_ethdev.h b/lib/librte_ether/rte_ethdev.h
index b10e2a92da71..b47402b797c3 100644
--- a/lib/librte_ether/rte_ethdev.h
+++ b/lib/librte_ether/rte_ethdev.h
@@ -2218,6 +2218,34 @@ int rte_eth_dev_set_link_down(uint16_t port_id);
*/
void rte_eth_dev_close(uint16_t port_id);
+
+/**
+ * @internal
+ * Atomically set the link status for the specific device.
+ * It is for use by DPDK device driver use only.
+ * User applications should not call it
+ *
+ * @param dev
+ * Pointer to struct rte_eth_dev.
+ * @param link
+ * New link status value.
+ * @return
+ * -1 if link state has changed, 0 if the same.
+ */
+int _rte_eth_linkstatus_set(struct rte_eth_dev *dev,
+ const struct rte_eth_link *link);
+
+/**
+ * @internal
+ * Atomically get the link speed and status.
+ * @param dev
+ * Pointer to struct rte_eth_dev.
+ * @param link
+ * link status value.
+ */
+void _rte_eth_linkstatus_get(const struct rte_eth_dev *dev,
+ struct rte_eth_link *link);
+
/**
* Reset a Ethernet device and keep its port id.
*
