[dpdk-dev] [PATCH v2] nfp: avoiding concurrency when hardware reconfig

[dpdk-dev] [PATCH v2] nfp: avoiding concurrency when hardware reconfig

[Alejandro Lucero]

Some apps calling some functions from different threads at the
same time could lead to reconfig problems. Reconfig mechanism is
based on a hardware queue where incrementing a counter signals the
firmware to do the reconfig. If there are two increments before the
 first one has been processed the firmware will stop and a device
reset is necessary.

 - v2: header file to the right place

Signed-off-by: Alejandro Lucero <alejandro.lucero@netronome.com>
---
 drivers/net/nfp/nfp_net.c     | 8 ++++++++
 drivers/net/nfp/nfp_net_pmd.h | 1 +
 2 files changed, 9 insertions(+)

diff --git a/drivers/net/nfp/nfp_net.c b/drivers/net/nfp/nfp_net.c
index bc0a3d8..559ebe6 100644
--- a/drivers/net/nfp/nfp_net.c
+++ b/drivers/net/nfp/nfp_net.c
@@ -54,6 +54,7 @@
 #include <rte_version.h>
 #include <rte_string_fns.h>
 #include <rte_alarm.h>
+#include <rte_spinlock.h>
 
 #include "nfp_net_pmd.h"
 #include "nfp_net_logs.h"
@@ -407,6 +408,8 @@ nfp_net_reconfig(struct nfp_net_hw *hw, uint32_t ctrl, uint32_t update)
 	PMD_DRV_LOG(DEBUG, "nfp_net_reconfig: ctrl=%08x update=%08x\n",
 		    ctrl, update);
 
+	rte_spinlock_lock(&hw->reconfig_lock);
+
 	nn_cfg_writel(hw, NFP_NET_CFG_CTRL, ctrl);
 	nn_cfg_writel(hw, NFP_NET_CFG_UPDATE, update);
 
@@ -414,6 +417,8 @@ nfp_net_reconfig(struct nfp_net_hw *hw, uint32_t ctrl, uint32_t update)
 
 	err = __nfp_net_reconfig(hw, update);
 
+	rte_spinlock_unlock(&hw->reconfig_lock);
+
 	if (!err)
 		return 0;
 
@@ -2399,6 +2404,9 @@ nfp_net_init(struct rte_eth_dev *eth_dev)
 	PMD_INIT_LOG(INFO, "max_rx_queues: %u, max_tx_queues: %u\n",
 		     hw->max_rx_queues, hw->max_tx_queues);
 
+	/* Initializing spinlock for reconfigs */
+	rte_spinlock_init(&hw->reconfig_lock);
+
 	/* Allocating memory for mac addr */
 	eth_dev->data->mac_addrs = rte_zmalloc("mac_addr", ETHER_ADDR_LEN, 0);
 	if (eth_dev->data->mac_addrs == NULL) {
diff --git a/drivers/net/nfp/nfp_net_pmd.h b/drivers/net/nfp/nfp_net_pmd.h
index 232ce5c..c180972 100644
--- a/drivers/net/nfp/nfp_net_pmd.h
+++ b/drivers/net/nfp/nfp_net_pmd.h
@@ -406,6 +406,7 @@ struct nfp_net_hw {
 	int stride_tx;
 
 	uint8_t *qcp_cfg;
+	rte_spinlock_t reconfig_lock;
 
 	uint32_t max_tx_queues;
 	uint32_t max_rx_queues;
-- 
1.9.1

Re: [dpdk-dev] [PATCH v2] nfp: avoiding concurrency when hardware reconfig

[Bruce Richardson]

On Tue, Apr 26, 2016 at 02:03:01PM +0100, Alejandro Lucero wrote:
> Some apps calling some functions from different threads at the
> same time could lead to reconfig problems. Reconfig mechanism is
> based on a hardware queue where incrementing a counter signals the
> firmware to do the reconfig. If there are two increments before the
>  first one has been processed the firmware will stop and a device
> reset is necessary.
> 
>  - v2: header file to the right place
> 
> Signed-off-by: Alejandro Lucero <alejandro.lucero@netronome.com>
Applied to dpdk-next-net/rel_16_07

/Bruce