[dpdk-dev] [PATCH v2] i40e: workaround for XL710 performance

[Helin Zhang <helin.zhang@intel.com>]

On XL710, performance number is far from the expectation on recent
firmware versions, if promiscuous mode is disabled, or promiscuous
mode is enabled and port MAC address is equal to the packet
destination MAC address. The fix for this issue may not be
integrated in the following firmware version. So the workaround in
software driver is needed. For XL710, it needs to modify the initial
values of 3 internal only registers, which are the same as X710.
Note that the values for X710 and XL710 registers could be different,
and the workaround can be removed when it is fixed in firmware in
the future.

Signed-off-by: Helin Zhang <helin.zhang@intel.com>
---
 lib/librte_pmd_i40e/i40e_ethdev.c | 44 ++++++++++++++++++++++++++-------------
 1 file changed, 30 insertions(+), 14 deletions(-)

v2 changes:
* Supported modifying the address of 0x269FBC of XL710 during
  initialization, to fix the minor performance gap to expectation.
  That means XL710 can meet the performance expectation with this
  workaround.

diff --git a/lib/librte_pmd_i40e/i40e_ethdev.c b/lib/librte_pmd_i40e/i40e_ethdev.c
index b47a3d2..8982920 100644
--- a/lib/librte_pmd_i40e/i40e_ethdev.c
+++ b/lib/librte_pmd_i40e/i40e_ethdev.c
@@ -5327,38 +5327,54 @@ i40e_debug_read_register(struct i40e_hw *hw, uint32_t addr, uint64_t *val)
 
 /*
  * On X710, performance number is far from the expectation on recent firmware
- * versions. The fix for this issue may not be integrated in the following
+ * versions; on XL710, performance number is also far from the expectation on
+ * recent firmware versions, if promiscuous mode is disabled, or promiscuous
+ * mode is enabled and port MAC address is equal to the packet destination MAC
+ * address. The fix for this issue may not be integrated in the following
  * firmware version. So the workaround in software driver is needed. It needs
- * to modify the initial values of 3 internal only registers. Note that the
+ * to modify the initial values of 3 internal only registers for both X710 and
+ * XL710. Note that the values for X710 or XL710 could be different, and the
  * workaround can be removed when it is fixed in firmware in the future.
  */
-static void
-i40e_configure_registers(struct i40e_hw *hw)
-{
+
+/* For both X710 and XL710 */
+#define I40E_GL_SWR_PRI_JOIN_MAP_0_VALUE 0x10000200
 #define I40E_GL_SWR_PRI_JOIN_MAP_0       0x26CE00
+
+#define I40E_GL_SWR_PRI_JOIN_MAP_2_VALUE 0x011f0200
 #define I40E_GL_SWR_PRI_JOIN_MAP_2       0x26CE08
+
+/* For X710 */
+#define I40E_GL_SWR_PM_UP_THR_EF_VALUE   0x03030303
+/* For XL710 */
+#define I40E_GL_SWR_PM_UP_THR_SF_VALUE   0x06060606
 #define I40E_GL_SWR_PM_UP_THR            0x269FBC
-#define I40E_GL_SWR_PRI_JOIN_MAP_0_VALUE 0x10000200
-#define I40E_GL_SWR_PRI_JOIN_MAP_2_VALUE 0x011f0200
-#define I40E_GL_SWR_PM_UP_THR_VALUE      0x03030303
 
-	static const struct {
+static void
+i40e_configure_registers(struct i40e_hw *hw)
+{
+	static struct {
 		uint32_t addr;
 		uint64_t val;
 	} reg_table[] = {
 		{I40E_GL_SWR_PRI_JOIN_MAP_0, I40E_GL_SWR_PRI_JOIN_MAP_0_VALUE},
 		{I40E_GL_SWR_PRI_JOIN_MAP_2, I40E_GL_SWR_PRI_JOIN_MAP_2_VALUE},
-		{I40E_GL_SWR_PM_UP_THR, I40E_GL_SWR_PM_UP_THR_VALUE},
+		{I40E_GL_SWR_PM_UP_THR, 0}, /* Compute value dynamically */
 	};
 	uint64_t reg;
 	uint32_t i;
 	int ret;
 
-	/* Below fix is for X710 only */
-	if (i40e_is_40G_device(hw->device_id))
-		return;
-
 	for (i = 0; i < RTE_DIM(reg_table); i++) {
+		if (reg_table[i].addr == I40E_GL_SWR_PM_UP_THR) {
+			if (i40e_is_40G_device(hw->device_id)) /* For XL710 */
+				reg_table[i].val =
+					I40E_GL_SWR_PM_UP_THR_SF_VALUE;
+			else /* For X710 */
+				reg_table[i].val =
+					I40E_GL_SWR_PM_UP_THR_EF_VALUE;
+		}
+
 		ret = i40e_debug_read_register(hw, reg_table[i].addr, &reg);
 		if (ret < 0) {
 			PMD_DRV_LOG(ERR, "Failed to read from 0x%"PRIx32,
-- 
1.9.3