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authorJacob Keller <jacob.e.keller@intel.com>2013-09-21 06:24:20 +0000
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>2013-10-29 04:08:12 -0700
commitc777cdfa4e69548f45078165d17828dd6711120f (patch)
tree3827913cc728796e3c6198cf6c5c8f4869836837 /drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
parent08e50a20ed05fba11c7dbc9e325369bef6a1c194 (diff)
downloadlinux-linaro-stable-c777cdfa4e69548f45078165d17828dd6711120f.tar.gz
ixgbevf: implement CONFIG_NET_RX_BUSY_POLL
This patch enables CONFIG_NET_RX_BUSY_POLL support in the VF code. This enables sockets which have enabled the SO_BUSY_POLL socket option to use the ndo_busy_poll_recv operation which could result in lower latency, at the cost of higher CPU utilization, and increased power usage. This support is similar to how the ixgbe driver works. Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Diffstat (limited to 'drivers/net/ethernet/intel/ixgbevf/ixgbevf.h')
-rw-r--r--drivers/net/ethernet/intel/ixgbevf/ixgbevf.h109
1 files changed, 109 insertions, 0 deletions
diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h b/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
index d7837dcc9897..85c7560e237b 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
@@ -38,6 +38,10 @@
#include "vf.h"
+#ifdef CONFIG_NET_RX_BUSY_POLL
+#include <net/busy_poll.h>
+#endif
+
/* wrapper around a pointer to a socket buffer,
* so a DMA handle can be stored along with the buffer */
struct ixgbevf_tx_buffer {
@@ -145,7 +149,112 @@ struct ixgbevf_q_vector {
struct napi_struct napi;
struct ixgbevf_ring_container rx, tx;
char name[IFNAMSIZ + 9];
+#ifdef CONFIG_NET_RX_BUSY_POLL
+ unsigned int state;
+#define IXGBEVF_QV_STATE_IDLE 0
+#define IXGBEVF_QV_STATE_NAPI 1 /* NAPI owns this QV */
+#define IXGBEVF_QV_STATE_POLL 2 /* poll owns this QV */
+#define IXGBEVF_QV_STATE_DISABLED 4 /* QV is disabled */
+#define IXGBEVF_QV_OWNED (IXGBEVF_QV_STATE_NAPI | IXGBEVF_QV_STATE_POLL)
+#define IXGBEVF_QV_LOCKED (IXGBEVF_QV_OWNED | IXGBEVF_QV_STATE_DISABLED)
+#define IXGBEVF_QV_STATE_NAPI_YIELD 8 /* NAPI yielded this QV */
+#define IXGBEVF_QV_STATE_POLL_YIELD 16 /* poll yielded this QV */
+#define IXGBEVF_QV_YIELD (IXGBEVF_QV_STATE_NAPI_YIELD | IXGBEVF_QV_STATE_POLL_YIELD)
+#define IXGBEVF_QV_USER_PEND (IXGBEVF_QV_STATE_POLL | IXGBEVF_QV_STATE_POLL_YIELD)
+ spinlock_t lock;
+#endif /* CONFIG_NET_RX_BUSY_POLL */
};
+#ifdef CONFIG_NET_RX_BUSY_POLL
+static inline void ixgbevf_qv_init_lock(struct ixgbevf_q_vector *q_vector)
+{
+
+ spin_lock_init(&q_vector->lock);
+ q_vector->state = IXGBEVF_QV_STATE_IDLE;
+}
+
+/* called from the device poll routine to get ownership of a q_vector */
+static inline bool ixgbevf_qv_lock_napi(struct ixgbevf_q_vector *q_vector)
+{
+ int rc = true;
+ spin_lock_bh(&q_vector->lock);
+ if (q_vector->state & IXGBEVF_QV_LOCKED) {
+ WARN_ON(q_vector->state & IXGBEVF_QV_STATE_NAPI);
+ q_vector->state |= IXGBEVF_QV_STATE_NAPI_YIELD;
+ rc = false;
+ } else {
+ /* we don't care if someone yielded */
+ q_vector->state = IXGBEVF_QV_STATE_NAPI;
+ }
+ spin_unlock_bh(&q_vector->lock);
+ return rc;
+}
+
+/* returns true is someone tried to get the qv while napi had it */
+static inline bool ixgbevf_qv_unlock_napi(struct ixgbevf_q_vector *q_vector)
+{
+ int rc = false;
+ spin_lock_bh(&q_vector->lock);
+ WARN_ON(q_vector->state & (IXGBEVF_QV_STATE_POLL |
+ IXGBEVF_QV_STATE_NAPI_YIELD));
+
+ if (q_vector->state & IXGBEVF_QV_STATE_POLL_YIELD)
+ rc = true;
+ /* reset state to idle, unless QV is disabled */
+ q_vector->state &= IXGBEVF_QV_STATE_DISABLED;
+ spin_unlock_bh(&q_vector->lock);
+ return rc;
+}
+
+/* called from ixgbevf_low_latency_poll() */
+static inline bool ixgbevf_qv_lock_poll(struct ixgbevf_q_vector *q_vector)
+{
+ int rc = true;
+ spin_lock_bh(&q_vector->lock);
+ if ((q_vector->state & IXGBEVF_QV_LOCKED)) {
+ q_vector->state |= IXGBEVF_QV_STATE_POLL_YIELD;
+ rc = false;
+ } else {
+ /* preserve yield marks */
+ q_vector->state |= IXGBEVF_QV_STATE_POLL;
+ }
+ spin_unlock_bh(&q_vector->lock);
+ return rc;
+}
+
+/* returns true if someone tried to get the qv while it was locked */
+static inline bool ixgbevf_qv_unlock_poll(struct ixgbevf_q_vector *q_vector)
+{
+ int rc = false;
+ spin_lock_bh(&q_vector->lock);
+ WARN_ON(q_vector->state & (IXGBEVF_QV_STATE_NAPI));
+
+ if (q_vector->state & IXGBEVF_QV_STATE_POLL_YIELD)
+ rc = true;
+ /* reset state to idle, unless QV is disabled */
+ q_vector->state &= IXGBEVF_QV_STATE_DISABLED;
+ spin_unlock_bh(&q_vector->lock);
+ return rc;
+}
+
+/* true if a socket is polling, even if it did not get the lock */
+static inline bool ixgbevf_qv_busy_polling(struct ixgbevf_q_vector *q_vector)
+{
+ WARN_ON(!(q_vector->state & IXGBEVF_QV_OWNED));
+ return q_vector->state & IXGBEVF_QV_USER_PEND;
+}
+
+/* false if QV is currently owned */
+static inline bool ixgbevf_qv_disable(struct ixgbevf_q_vector *q_vector)
+{
+ int rc = true;
+ spin_lock_bh(&q_vector->lock);
+ if (q_vector->state & IXGBEVF_QV_OWNED)
+ rc = false;
+ spin_unlock_bh(&q_vector->lock);
+ return rc;
+}
+
+#endif /* CONFIG_NET_RX_BUSY_POLL */
/*
* microsecond values for various ITR rates shifted by 2 to fit itr register