[dpdk-dev] [PATCH v2 37/66] net/ice/base: calculate rate limit burst size correctly

Leyi Rong leyi.rong at intel.com
Tue Jun 11 17:51:52 CEST 2019


When the MSB is not set, the lower 11 bits do not represent bytes, but
chunks of 64 bytes. Adjust the rate limit burst size calculation
accordingly, and update the comments to indicate the way the hardware
actually works.

Signed-off-by: Ben Shelton <benjamin.h.shelton at intel.com>
Signed-off-by: Paul M Stillwell Jr <paul.m.stillwell.jr at intel.com>
Signed-off-by: Leyi Rong <leyi.rong at intel.com>
---
 drivers/net/ice/base/ice_sched.c | 17 ++++++++---------
 drivers/net/ice/base/ice_sched.h | 14 ++++++++------
 2 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/drivers/net/ice/base/ice_sched.c b/drivers/net/ice/base/ice_sched.c
index 0c1c18ba1..a72e72982 100644
--- a/drivers/net/ice/base/ice_sched.c
+++ b/drivers/net/ice/base/ice_sched.c
@@ -5060,16 +5060,15 @@ enum ice_status ice_cfg_rl_burst_size(struct ice_hw *hw, u32 bytes)
 	if (bytes < ICE_MIN_BURST_SIZE_ALLOWED ||
 	    bytes > ICE_MAX_BURST_SIZE_ALLOWED)
 		return ICE_ERR_PARAM;
-	if (bytes <= ICE_MAX_BURST_SIZE_BYTE_GRANULARITY) {
-		/* byte granularity case */
+	if (ice_round_to_num(bytes, 64) <=
+	    ICE_MAX_BURST_SIZE_64_BYTE_GRANULARITY) {
+		/* 64 byte granularity case */
 		/* Disable MSB granularity bit */
-		burst_size_to_prog = ICE_BYTE_GRANULARITY;
-		/* round number to nearest 256 granularity */
-		bytes = ice_round_to_num(bytes, 256);
-		/* check rounding doesn't go beyond allowed */
-		if (bytes > ICE_MAX_BURST_SIZE_BYTE_GRANULARITY)
-			bytes = ICE_MAX_BURST_SIZE_BYTE_GRANULARITY;
-		burst_size_to_prog |= (u16)bytes;
+		burst_size_to_prog = ICE_64_BYTE_GRANULARITY;
+		/* round number to nearest 64 byte granularity */
+		bytes = ice_round_to_num(bytes, 64);
+		/* The value is in 64 byte chunks */
+		burst_size_to_prog |= (u16)(bytes / 64);
 	} else {
 		/* k bytes granularity case */
 		/* Enable MSB granularity bit */
diff --git a/drivers/net/ice/base/ice_sched.h b/drivers/net/ice/base/ice_sched.h
index 56f9977ab..e444dc880 100644
--- a/drivers/net/ice/base/ice_sched.h
+++ b/drivers/net/ice/base/ice_sched.h
@@ -13,14 +13,16 @@
 #define ICE_SCHED_INVAL_LAYER_NUM	0xFF
 /* Burst size is a 12 bits register that is configured while creating the RL
  * profile(s). MSB is a granularity bit and tells the granularity type
- * 0 - LSB bits are in bytes granularity
+ * 0 - LSB bits are in 64 bytes granularity
  * 1 - LSB bits are in 1K bytes granularity
  */
-#define ICE_BYTE_GRANULARITY			0
-#define ICE_KBYTE_GRANULARITY			0x800
-#define ICE_MIN_BURST_SIZE_ALLOWED		1 /* In Bytes */
-#define ICE_MAX_BURST_SIZE_ALLOWED		(2047 * 1024) /* In Bytes */
-#define ICE_MAX_BURST_SIZE_BYTE_GRANULARITY	2047 /* In Bytes */
+#define ICE_64_BYTE_GRANULARITY			0
+#define ICE_KBYTE_GRANULARITY			BIT(11)
+#define ICE_MIN_BURST_SIZE_ALLOWED		64 /* In Bytes */
+#define ICE_MAX_BURST_SIZE_ALLOWED \
+	((BIT(11) - 1) * 1024) /* In Bytes */
+#define ICE_MAX_BURST_SIZE_64_BYTE_GRANULARITY \
+	((BIT(11) - 1) * 64) /* In Bytes */
 #define ICE_MAX_BURST_SIZE_KBYTE_GRANULARITY	ICE_MAX_BURST_SIZE_ALLOWED
 
 #define ICE_RL_PROF_FREQUENCY 446000000
-- 
2.17.1



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