From 2ab28bb04ce6432f15cd5086e7c7384f3deab639 Mon Sep 17 00:00:00 2001 From: Brett Creeley Date: Thu, 25 Jul 2019 01:55:32 -0700 Subject: [PATCH] ice: Set WB_ON_ITR when we don't re-enable interrupts Currently when busy polling is enabled we aren't setting/enabling WB_ON_ITR in the driver. This doesn't break the driver, but it does cause issues. If we don't enable WB_ON_ITR mode we will still get write-backs from hardware during polling when a cache line has been filled, but if a cache line is not filled we will not get the write-back because WB_ON_ITR is not set. Fix this by enabling WB_ON_ITR in the driver when interrupts are disabled. Signed-off-by: Brett Creeley Signed-off-by: Tony Nguyen Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher --- .../net/ethernet/intel/ice/ice_hw_autogen.h | 3 ++ drivers/net/ethernet/intel/ice/ice_txrx.c | 54 +++++++++++++++++++ drivers/net/ethernet/intel/ice/ice_txrx.h | 13 +++++ 3 files changed, 70 insertions(+) diff --git a/drivers/net/ethernet/intel/ice/ice_hw_autogen.h b/drivers/net/ethernet/intel/ice/ice_hw_autogen.h index 87652d722a30..6f78ff5534af 100644 --- a/drivers/net/ethernet/intel/ice/ice_hw_autogen.h +++ b/drivers/net/ethernet/intel/ice/ice_hw_autogen.h @@ -127,8 +127,11 @@ #define GLINT_DYN_CTL_CLEARPBA_M BIT(1) #define GLINT_DYN_CTL_SWINT_TRIG_M BIT(2) #define GLINT_DYN_CTL_ITR_INDX_S 3 +#define GLINT_DYN_CTL_ITR_INDX_M ICE_M(0x3, 3) #define GLINT_DYN_CTL_INTERVAL_S 5 +#define GLINT_DYN_CTL_INTERVAL_M ICE_M(0xFFF, 5) #define GLINT_DYN_CTL_SW_ITR_INDX_M ICE_M(0x3, 25) +#define GLINT_DYN_CTL_WB_ON_ITR_M BIT(30) #define GLINT_DYN_CTL_INTENA_MSK_M BIT(31) #define GLINT_ITR(_i, _INT) (0x00154000 + ((_i) * 8192 + (_INT) * 4)) #define GLINT_RATE(_INT) (0x0015A000 + ((_INT) * 4)) diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c index 837d6ae2f33b..c88e0701e1d7 100644 --- a/drivers/net/ethernet/intel/ice/ice_txrx.c +++ b/drivers/net/ethernet/intel/ice/ice_txrx.c @@ -1355,6 +1355,23 @@ ice_update_ena_itr(struct ice_vsi *vsi, struct ice_q_vector *q_vector) struct ice_ring_container *rx = &q_vector->rx; u32 itr_val; + /* when exiting WB_ON_ITR lets set a low ITR value and trigger + * interrupts to expire right away in case we have more work ready to go + * already + */ + if (q_vector->itr_countdown == ICE_IN_WB_ON_ITR_MODE) { + itr_val = ice_buildreg_itr(rx->itr_idx, ICE_WB_ON_ITR_USECS); + wr32(&vsi->back->hw, GLINT_DYN_CTL(q_vector->reg_idx), itr_val); + /* set target back to last user set value */ + rx->target_itr = rx->itr_setting; + /* set current to what we just wrote and dynamic if needed */ + rx->current_itr = ICE_WB_ON_ITR_USECS | + (rx->itr_setting & ICE_ITR_DYNAMIC); + /* allow normal interrupt flow to start */ + q_vector->itr_countdown = 0; + return; + } + /* This will do nothing if dynamic updates are not enabled */ ice_update_itr(q_vector, tx); ice_update_itr(q_vector, rx); @@ -1399,6 +1416,41 @@ ice_update_ena_itr(struct ice_vsi *vsi, struct ice_q_vector *q_vector) itr_val); } +/** + * ice_set_wb_on_itr - set WB_ON_ITR for this q_vector + * @vsi: pointer to the VSI structure + * @q_vector: q_vector to set WB_ON_ITR on + * + * We need to tell hardware to write-back completed descriptors even when + * interrupts are disabled. Descriptors will be written back on cache line + * boundaries without WB_ON_ITR enabled, but if we don't enable WB_ON_ITR + * descriptors may not be written back if they don't fill a cache line until the + * next interrupt. + * + * This sets the write-back frequency to 2 microseconds as that is the minimum + * value that's not 0 due to ITR granularity. Also, set the INTENA_MSK bit to + * make sure hardware knows we aren't meddling with the INTENA_M bit. + */ +static void +ice_set_wb_on_itr(struct ice_vsi *vsi, struct ice_q_vector *q_vector) +{ + /* already in WB_ON_ITR mode no need to change it */ + if (q_vector->itr_countdown == ICE_IN_WB_ON_ITR_MODE) + return; + + if (q_vector->num_ring_rx) + wr32(&vsi->back->hw, GLINT_DYN_CTL(q_vector->reg_idx), + ICE_GLINT_DYN_CTL_WB_ON_ITR(ICE_WB_ON_ITR_USECS, + ICE_RX_ITR)); + + if (q_vector->num_ring_tx) + wr32(&vsi->back->hw, GLINT_DYN_CTL(q_vector->reg_idx), + ICE_GLINT_DYN_CTL_WB_ON_ITR(ICE_WB_ON_ITR_USECS, + ICE_TX_ITR)); + + q_vector->itr_countdown = ICE_IN_WB_ON_ITR_MODE; +} + /** * ice_napi_poll - NAPI polling Rx/Tx cleanup routine * @napi: napi struct with our devices info in it @@ -1459,6 +1511,8 @@ int ice_napi_poll(struct napi_struct *napi, int budget) */ if (likely(napi_complete_done(napi, work_done))) ice_update_ena_itr(vsi, q_vector); + else + ice_set_wb_on_itr(vsi, q_vector); return min_t(int, work_done, budget - 1); } diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.h b/drivers/net/ethernet/intel/ice/ice_txrx.h index ec76aba347b9..94a9280193e2 100644 --- a/drivers/net/ethernet/intel/ice/ice_txrx.h +++ b/drivers/net/ethernet/intel/ice/ice_txrx.h @@ -144,6 +144,19 @@ enum ice_rx_dtype { #define ICE_DFLT_INTRL 0 #define ICE_MAX_INTRL 236 +#define ICE_WB_ON_ITR_USECS 2 +#define ICE_IN_WB_ON_ITR_MODE 255 +/* Sets WB_ON_ITR and assumes INTENA bit is already cleared, which allows + * setting the MSK_M bit to tell hardware to ignore the INTENA_M bit. Also, + * set the write-back latency to the usecs passed in. + */ +#define ICE_GLINT_DYN_CTL_WB_ON_ITR(usecs, itr_idx) \ + ((((usecs) << (GLINT_DYN_CTL_INTERVAL_S - ICE_ITR_GRAN_S)) & \ + GLINT_DYN_CTL_INTERVAL_M) | \ + (((itr_idx) << GLINT_DYN_CTL_ITR_INDX_S) & \ + GLINT_DYN_CTL_ITR_INDX_M) | GLINT_DYN_CTL_INTENA_MSK_M | \ + GLINT_DYN_CTL_WB_ON_ITR_M) + /* Legacy or Advanced Mode Queue */ #define ICE_TX_ADVANCED 0 #define ICE_TX_LEGACY 1