Merge tag 'blk-dim-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/saeed/linux

Saeed Mamameed says:

====================
Generic DIM

From: Tal Gilboa and Yamin Fridman

Implement net DIM over a generic DIM library, add RDMA DIM

dim.h lib exposes an implementation of the DIM algorithm for
dynamically-tuned interrupt moderation for networking interfaces.

We want a similar functionality for other protocols, which might need to
optimize interrupts differently. Main motivation here is DIM for NVMf
storage protocol.

Current DIM implementation prioritizes reducing interrupt overhead over
latency. Also, in order to reduce DIM's own overhead, the algorithm might
take some time to identify it needs to change profiles. While this is
acceptable for networking, it might not work well on other scenarios.

Here we propose a new structure to DIM. The idea is to allow a slightly
modified functionality without the risk of breaking Net DIM behavior for
netdev. We verified there are no degradations in current DIM behavior with
the modified solution.

Suggested solution:
- Common logic is implemented in lib/dim/dim.c
- Net DIM (existing) logic is implemented in lib/dim/net_dim.c, which uses
  the common logic in dim.c
- Any new DIM logic will be implemented in "lib/dim/new_dim.c".
  This new implementation will expose modified versions of profiles,
  dim_step() and dim_decision().
- DIM API is declared in include/linux/dim.h for all implementations.

Pros for this solution are:
- Zero impact on existing net_dim implementation and usage
- Relatively more code reuse (compared to two separate solutions)
- Increased extensibility
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 15 insertions, 16 deletions

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index f758b2e0591f..b7b62273c955 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -2130,12 +2130,12 @@ static int bnxt_poll(struct napi_struct *napi, int budget)
 		}
 	}
 	if (bp->flags & BNXT_FLAG_DIM) {
-		struct net_dim_sample dim_sample;
+		struct dim_sample dim_sample;
 
-		net_dim_sample(cpr->event_ctr,
-			       cpr->rx_packets,
-			       cpr->rx_bytes,
-			       &dim_sample);
+		dim_update_sample(cpr->event_ctr,
+				  cpr->rx_packets,
+				  cpr->rx_bytes,
+				  &dim_sample);
 		net_dim(&cpr->dim, dim_sample);
 	}
 	return work_done;
@@ -7813,7 +7813,7 @@ static void bnxt_enable_napi(struct bnxt *bp)
 
 		if (bp->bnapi[i]->rx_ring) {
 			INIT_WORK(&cpr->dim.work, bnxt_dim_work);
-			cpr->dim.mode = NET_DIM_CQ_PERIOD_MODE_START_FROM_EQE;
+			cpr->dim.mode = DIM_CQ_PERIOD_MODE_START_FROM_EQE;
 		}
 		napi_enable(&bp->bnapi[i]->napi);
 	}
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index be438d82f939..4b3ae92a082b 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -24,7 +24,7 @@
 #include <net/devlink.h>
 #include <net/dst_metadata.h>
 #include <net/xdp.h>
-#include <linux/net_dim.h>
+#include <linux/dim.h>
 
 struct tx_bd {
 	__le32 tx_bd_len_flags_type;
@@ -810,7 +810,7 @@ struct bnxt_cp_ring_info {
 	u64			rx_bytes;
 	u64			event_ctr;
 
-	struct net_dim		dim;
+	struct dim		dim;
 
 	union {
 		struct tx_cmp	*cp_desc_ring[MAX_CP_PAGES];
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_debugfs.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_debugfs.c
index 94e208e9789f..61393f351a77 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_debugfs.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_debugfs.c
@@ -11,7 +11,7 @@
 #include <linux/module.h>
 #include <linux/pci.h>
 #include "bnxt_hsi.h"
-#include <linux/net_dim.h>
+#include <linux/dim.h>
 #include "bnxt.h"
 #include "bnxt_debugfs.h"
 
@@ -21,7 +21,7 @@ static ssize_t debugfs_dim_read(struct file *filep,
 				char __user *buffer,
 				size_t count, loff_t *ppos)
 {
-	struct net_dim *dim = filep->private_data;
+	struct dim *dim = filep->private_data;
 	int len;
 	char *buf;
 
@@ -61,7 +61,7 @@ static const struct file_operations debugfs_dim_fops = {
 	.read = debugfs_dim_read,
 };
 
-static struct dentry *debugfs_dim_ring_init(struct net_dim *dim, int ring_idx,
+static struct dentry *debugfs_dim_ring_init(struct dim *dim, int ring_idx,
 					    struct dentry *dd)
 {
 	static char qname[16];
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_dim.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_dim.c
index afa97c8bb081..6f6576dc417a 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_dim.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_dim.c
@@ -7,26 +7,25 @@
  * the Free Software Foundation.
  */
 
-#include <linux/net_dim.h>
+#include <linux/dim.h>
 #include "bnxt_hsi.h"
 #include "bnxt.h"
 
 void bnxt_dim_work(struct work_struct *work)
 {
-	struct net_dim *dim = container_of(work, struct net_dim,
-					   work);
+	struct dim *dim = container_of(work, struct dim, work);
 	struct bnxt_cp_ring_info *cpr = container_of(dim,
 						     struct bnxt_cp_ring_info,
 						     dim);
 	struct bnxt_napi *bnapi = container_of(cpr,
 					       struct bnxt_napi,
 					       cp_ring);
-	struct net_dim_cq_moder cur_moder =
+	struct dim_cq_moder cur_moder =
 		net_dim_get_rx_moderation(dim->mode, dim->profile_ix);
 
 	cpr->rx_ring_coal.coal_ticks = cur_moder.usec;
 	cpr->rx_ring_coal.coal_bufs = cur_moder.pkts;
 
 	bnxt_hwrm_set_ring_coal(bnapi->bp, bnapi);
-	dim->state = NET_DIM_START_MEASURE;
+	dim->state = DIM_START_MEASURE;
 }