[PATCH iwl-next v8 06/11] igc: set the RX packet buffer size for TSN mode

Faizal Rahim
2025-03-05T14:18:51Z

In preparation for supporting frame preemption, when entering TSN mode
set the receive packet buffer to 16KB for the Express MAC, 16KB for
the Preemptible MAC and 2KB for the BMC, according to the datasheet
section 7.1.3.2.

Co-developed-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Faizal Rahim <faizal.abdul.rahim@linux.intel.com>
---
drivers/net/ethernet/intel/igc/igc_defines.h | 3 +++
drivers/net/ethernet/intel/igc/igc_tsn.c | 13 +++++++++++--
2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_defines.h b/drivers/net/ethernet/intel/igc/igc_defines.h
index 516ef70c98e9..b19ac6f30dac 100644
--- a/drivers/net/ethernet/intel/igc/igc_defines.h
+++ b/drivers/net/ethernet/intel/igc/igc_defines.h
@@ -402,6 +402,9 @@

/* 7KB bytes buffer for each tx queue (total 4 queues) + 4KB for BMC*/
#define IGC_TXPBSIZE_TSN 0x041c71c7
+/* 15KB for EXP + 15KB for BE + 2KB for BMC */
+#define IGC_RXPBSIZE_TSN 0x0000f08f
+#define IGC_RXPBSIZE_SIZE_MASK 0x0001FFFF

#define IGC_DTXMXPKTSZ_TSN 0x19 /* 1600 bytes of max TX DMA packet size */
#define IGC_DTXMXPKTSZ_DEFAULT 0x98 /* 9728-byte Jumbo frames */
diff --git a/drivers/net/ethernet/intel/igc/igc_tsn.c b/drivers/net/ethernet/intel/igc/igc_tsn.c
index 1e44374ca1ff..f0213cfce07d 100644
--- a/drivers/net/ethernet/intel/igc/igc_tsn.c
+++ b/drivers/net/ethernet/intel/igc/igc_tsn.c
@@ -132,13 +132,17 @@ static int igc_tsn_disable_offload(struct igc_adapter *adapter)
{
u16 queue_per_tc[4] = { 3, 2, 1, 0 };
struct igc_hw *hw = &adapter->hw;
- u32 tqavctrl;
+ u32 tqavctrl, rxpbs;
int i;

wr32(IGC_GTXOFFSET, 0);
wr32(IGC_TXPBS, I225_TXPBSIZE_DEFAULT);
wr32(IGC_DTXMXPKTSZ, IGC_DTXMXPKTSZ_DEFAULT);

+ rxpbs = rd32(IGC_RXPBS) & ~IGC_RXPBSIZE_SIZE_MASK;
+ rxpbs |= I225_RXPBSIZE_DEFAULT;
+ wr32(IGC_RXPBS, rxpbs);
+
if (igc_is_device_id_i226(hw))
igc_tsn_restore_retx_default(adapter);

@@ -194,7 +198,7 @@ static int igc_tsn_enable_offload(struct igc_adapter *adapter)
{
struct igc_hw *hw = &adapter->hw;
u32 tqavctrl, baset_l, baset_h;
- u32 sec, nsec, cycle;
+ u32 sec, nsec, cycle, rxpbs;
ktime_t base_time, systim;
int i;

@@ -202,6 +206,11 @@ static int igc_tsn_enable_offload(struct igc_adapter *adapter)
wr32(IGC_DTXMXPKTSZ, IGC_DTXMXPKTSZ_TSN);
wr32(IGC_TXPBS, IGC_TXPBSIZE_TSN);

+ rxpbs = rd32(IGC_RXPBS) & ~IGC_RXPBSIZE_SIZE_MASK;
+ rxpbs |= IGC_RXPBSIZE_TSN;
+
+ wr32(IGC_RXPBS, rxpbs);
+
if (igc_is_device_id_i226(hw))
igc_tsn_set_retx_qbvfullthreshold(adapter);

--
2.34.1