dpaa_eth: Move bpool refill thresholds to Kconfig

There have been requests to change the thresholds which control the
buffer pool replenishment on the private path of DPAA-Ethernet.
While we normally discourage this (since these values have been
fine-tuned after numerous tests) we nevertheless expose these knobs into
the driver's Kconfig. They now default to the original hardcoded values.

Signed-off-by: Bogdan Hamciuc <bogdan.hamciuc@freescale.com>
Change-Id: Ia6634932e16e4fb771317a04110704a5c3bb5e44
Reviewed-on: http://git.am.freescale.net:8181/1629
Reviewed-by: Sovaiala Cristian-Constantin-B39531 <Cristian.Sovaiala@freescale.com>
Reviewed-by: Radulescu Ruxandra Ioana-B05472 <ruxandra.radulescu@freescale.com>
Reviewed-by: Bucur Madalin-Cristian-B32716 <madalin.bucur@freescale.com>
Reviewed-by: Fleming Andrew-AFLEMING <AFLEMING@freescale.com>
Tested-by: Fleming Andrew-AFLEMING <AFLEMING@freescale.com>

2 files changed, 24 insertions, 7 deletions

diff --git a/drivers/net/ethernet/freescale/dpa/Kconfig b/drivers/net/ethernet/freescale/dpa/Kconfig
index 7c4973d..b54831d 100644
--- a/drivers/net/ethernet/freescale/dpa/Kconfig
+++ b/drivers/net/ethernet/freescale/dpa/Kconfig
@@ -95,6 +95,26 @@ config DPAA_ETH_USE_NDO_SELECT_QUEUE
 	  or simply don't want to use the driver's ndo_select_queue() callback, then unselect this
 	  and use the standard XPS support instead.
 
+config DPAA_ETH_MAX_BUF_COUNT
+	int "Maximum nuber of buffers in private bpool"
+	depends on DPA_ETH
+	range 64 2048
+	default "128"
+	---help---
+	  The maximum number of buffers to be by default allocated in the DPAA-Ethernet private port's
+	  buffer pool. One needn't normally modify this, as it has probably been tuned for performance
+	  already. This cannot be lower than DPAA_ETH_REFILL_THRESHOLD.
+
+config DPAA_ETH_REFILL_THRESHOLD
+	int "Private bpool refill threshold"
+	depends on DPA_ETH
+	range 32 DPAA_ETH_MAX_BUF_COUNT
+	default "80"
+	---help---
+	  The DPAA-Ethernet driver will start replenishing buffer pools whose count
+	  falls below this threshold. This must be related to DPAA_ETH_MAX_BUF_COUNT. One needn't normally
+	  modify this value unless one has very specific performance reasons.
+
 config DPAA_ETH_UNIT_TESTS
 	bool
 	depends on DPA_ETH
diff --git a/drivers/net/ethernet/freescale/dpa/dpaa_eth.c b/drivers/net/ethernet/freescale/dpa/dpaa_eth.c
index 20d0e20..2c24e1e 100644
--- a/drivers/net/ethernet/freescale/dpa/dpaa_eth.c
+++ b/drivers/net/ethernet/freescale/dpa/dpaa_eth.c
@@ -91,9 +91,6 @@
 #undef CONFIG_DPAA_ETH_UNIT_TESTS
 #endif
 
-#define DEFAULT_COUNT		128
-#define REFILL_THRESHOLD	80
-
 #define DPA_NAPI_WEIGHT		64
 
 /* Size in bytes of the Congestion State notification threshold on 10G ports */
@@ -411,15 +408,15 @@ static void dpaa_eth_refill_bpools(struct dpa_priv_s *priv,
 	const struct dpa_bp *dpa_bp = percpu_priv->dpa_bp;
 
 #ifndef CONFIG_DPAA_ETH_SG_SUPPORT
-	if (unlikely(count < REFILL_THRESHOLD)) {
+	if (unlikely(count < CONFIG_DPAA_ETH_REFILL_THRESHOLD)) {
 		int i;
 
-		for (i = count; i < DEFAULT_COUNT; i += 8)
+		for (i = count; i < CONFIG_DPAA_ETH_MAX_BUF_COUNT; i += 8)
 			dpa_bp_add_8(dpa_bp);
 	}
 #else
 	/* Add pages to the buffer pool */
-	while (count < DEFAULT_COUNT)
+	while (count < CONFIG_DPAA_ETH_MAX_BUF_COUNT)
 		count += _dpa_bp_add_8_pages(dpa_bp);
 	*countptr = count;
 
@@ -3176,7 +3173,7 @@ dpa_bp_probe(struct platform_device *_of_dev, size_t *count)
 		dpa_bp = ERR_PTR(-EINVAL);
 		goto _return_of_node_put;
 	} else if (has_kernel_pool) {
-		dpa_bp->target_count = DEFAULT_COUNT;
+		dpa_bp->target_count = CONFIG_DPAA_ETH_MAX_BUF_COUNT;
 		dpa_bp->kernel_pool = 1;
 	}