From 63f545ed1285a5f904c260ff22c958609c3c11c5 Mon Sep 17 00:00:00 2001 From: Brett Creeley Date: Wed, 19 Dec 2018 10:03:29 -0800 Subject: [PATCH] ice: Add support for adaptive interrupt moderation Currently the driver does not support adaptive/dynamic interrupt moderation. This patch adds support for this. Also, adaptive/dynamic interrupt moderation is turned on by default upon driver load. In order to support adaptive interrupt moderation, two functions were added, ice_update_itr() and ice_itr_divisor(). These are used to determine the current packet load and to determine a divisor based on link speed respectively. This patch also adds the ICE_ITR_GRAN_S define that is used in the hot-path when setting a new ITR value. The shift is used to pet two birds with one hand, set the ITR value while re-enabling the interrupt. Also, the ICE_ITR_GRAN_S is defined as 1 because the device has a ITR granularity of 2usecs. Signed-off-by: Brett Creeley Signed-off-by: Anirudh Venkataramanan Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher --- .../net/ethernet/intel/ice/ice_hw_autogen.h | 1 + drivers/net/ethernet/intel/ice/ice_lib.c | 24 +++++-- drivers/net/ethernet/intel/ice/ice_main.c | 23 +++++-- drivers/net/ethernet/intel/ice/ice_txrx.c | 65 ++++++++++++++++++- drivers/net/ethernet/intel/ice/ice_txrx.h | 30 +++++---- 5 files changed, 120 insertions(+), 23 deletions(-) diff --git a/drivers/net/ethernet/intel/ice/ice_hw_autogen.h b/drivers/net/ethernet/intel/ice/ice_hw_autogen.h index 5507928c8fbe..f9a38f2cd470 100644 --- a/drivers/net/ethernet/intel/ice/ice_hw_autogen.h +++ b/drivers/net/ethernet/intel/ice/ice_hw_autogen.h @@ -110,6 +110,7 @@ #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_INTERVAL_S 5 #define GLINT_DYN_CTL_SW_ITR_INDX_M ICE_M(0x3, 25) #define GLINT_DYN_CTL_INTENA_MSK_M BIT(31) #define GLINT_ITR(_i, _INT) (0x00154000 + ((_i) * 8192 + (_INT) * 4)) diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c b/drivers/net/ethernet/intel/ice/ice_lib.c index a1f523a9d39d..27c3760ae5cb 100644 --- a/drivers/net/ethernet/intel/ice/ice_lib.c +++ b/drivers/net/ethernet/intel/ice/ice_lib.c @@ -1717,22 +1717,34 @@ static u32 ice_intrl_usec_to_reg(u8 intrl, u8 gran) static void ice_cfg_itr(struct ice_hw *hw, struct ice_q_vector *q_vector, u16 vector) { - u8 itr_gran = hw->itr_gran; - if (q_vector->num_ring_rx) { struct ice_ring_container *rc = &q_vector->rx; - rc->itr = ITR_TO_REG(ICE_DFLT_RX_ITR, itr_gran); + /* if this value is set then don't overwrite with default */ + if (!rc->itr_setting) + rc->itr_setting = ICE_DFLT_RX_ITR; + + rc->target_itr = ITR_TO_REG(rc->itr_setting); + rc->next_update = jiffies + 1; + rc->current_itr = rc->target_itr; rc->latency_range = ICE_LOW_LATENCY; - wr32(hw, GLINT_ITR(rc->itr_idx, vector), rc->itr); + wr32(hw, GLINT_ITR(rc->itr_idx, vector), + ITR_REG_ALIGN(rc->current_itr) >> ICE_ITR_GRAN_S); } if (q_vector->num_ring_tx) { struct ice_ring_container *rc = &q_vector->tx; - rc->itr = ITR_TO_REG(ICE_DFLT_TX_ITR, itr_gran); + /* if this value is set then don't overwrite with default */ + if (!rc->itr_setting) + rc->itr_setting = ICE_DFLT_TX_ITR; + + rc->target_itr = ITR_TO_REG(rc->itr_setting); + rc->next_update = jiffies + 1; + rc->current_itr = rc->target_itr; rc->latency_range = ICE_LOW_LATENCY; - wr32(hw, GLINT_ITR(rc->itr_idx, vector), rc->itr); + wr32(hw, GLINT_ITR(rc->itr_idx, vector), + ITR_REG_ALIGN(rc->current_itr) >> ICE_ITR_GRAN_S); } } diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c index 093708b5c0ef..e59f8b29af49 100644 --- a/drivers/net/ethernet/intel/ice/ice_main.c +++ b/drivers/net/ethernet/intel/ice/ice_main.c @@ -1389,7 +1389,6 @@ static int ice_req_irq_msix_misc(struct ice_pf *pf) { struct ice_hw *hw = &pf->hw; int oicr_idx, err = 0; - u8 itr_gran; u32 val; if (!pf->int_name[0]) @@ -1453,10 +1452,8 @@ skip_req_irq: PFINT_MBX_CTL_CAUSE_ENA_M); wr32(hw, PFINT_MBX_CTL, val); - itr_gran = hw->itr_gran; - wr32(hw, GLINT_ITR(ICE_RX_ITR, pf->hw_oicr_idx), - ITR_TO_REG(ICE_ITR_8K, itr_gran)); + ITR_REG_ALIGN(ICE_ITR_8K) >> ICE_ITR_GRAN_S); ice_flush(hw); ice_irq_dynamic_ena(hw, NULL, NULL); @@ -1997,6 +1994,23 @@ static int ice_init_interrupt_scheme(struct ice_pf *pf) return 0; } +/** + * ice_verify_itr_gran - verify driver's assumption of ITR granularity + * @pf: pointer to the PF structure + * + * There is no error returned here because the driver will be able to handle a + * different ITR granularity, but interrupt moderation will not be accurate if + * the driver's assumptions are not verified. This assumption is made so we can + * use constants in the hot path instead of accessing structure members. + */ +static void ice_verify_itr_gran(struct ice_pf *pf) +{ + if (pf->hw.itr_gran != (ICE_ITR_GRAN_S << 1)) + dev_warn(&pf->pdev->dev, + "%d ITR granularity assumption is invalid, actual ITR granularity is %d. Interrupt moderation will be inaccurate!\n", + (ICE_ITR_GRAN_S << 1), pf->hw.itr_gran); +} + /** * ice_verify_cacheline_size - verify driver's assumption of 64 Byte cache lines * @pf: pointer to the PF structure @@ -2163,6 +2177,7 @@ static int ice_probe(struct pci_dev *pdev, mod_timer(&pf->serv_tmr, round_jiffies(jiffies + pf->serv_tmr_period)); ice_verify_cacheline_size(pf); + ice_verify_itr_gran(pf); return 0; diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c index 49fc38094185..384ac5c82e00 100644 --- a/drivers/net/ethernet/intel/ice/ice_txrx.c +++ b/drivers/net/ethernet/intel/ice/ice_txrx.c @@ -1052,6 +1052,69 @@ static int ice_clean_rx_irq(struct ice_ring *rx_ring, int budget) return failure ? budget : (int)total_rx_pkts; } +/** + * ice_buildreg_itr - build value for writing to the GLINT_DYN_CTL register + * @itr_idx: interrupt throttling index + * @reg_itr: interrupt throttling value adjusted based on ITR granularity + */ +static u32 ice_buildreg_itr(int itr_idx, u16 reg_itr) +{ + return GLINT_DYN_CTL_INTENA_M | GLINT_DYN_CTL_CLEARPBA_M | + (itr_idx << GLINT_DYN_CTL_ITR_INDX_S) | + (reg_itr << GLINT_DYN_CTL_INTERVAL_S); +} + +/** + * ice_update_ena_itr - Update ITR and re-enable MSIX interrupt + * @vsi: the VSI associated with the q_vector + * @q_vector: q_vector for which ITR is being updated and interrupt enabled + */ +static void +ice_update_ena_itr(struct ice_vsi *vsi, struct ice_q_vector *q_vector) +{ + struct ice_hw *hw = &vsi->back->hw; + struct ice_ring_container *rc; + u32 itr_val; + + /* This block of logic allows us to get away with only updating + * one ITR value with each interrupt. The idea is to perform a + * pseudo-lazy update with the following criteria. + * + * 1. Rx is given higher priority than Tx if both are in same state + * 2. If we must reduce an ITR that is given highest priority. + * 3. We then give priority to increasing ITR based on amount. + */ + if (q_vector->rx.target_itr < q_vector->rx.current_itr) { + rc = &q_vector->rx; + /* Rx ITR needs to be reduced, this is highest priority */ + itr_val = ice_buildreg_itr(rc->itr_idx, rc->target_itr); + rc->current_itr = rc->target_itr; + } else if ((q_vector->tx.target_itr < q_vector->tx.current_itr) || + ((q_vector->rx.target_itr - q_vector->rx.current_itr) < + (q_vector->tx.target_itr - q_vector->tx.current_itr))) { + rc = &q_vector->tx; + /* Tx ITR needs to be reduced, this is second priority + * Tx ITR needs to be increased more than Rx, fourth priority + */ + itr_val = ice_buildreg_itr(rc->itr_idx, rc->target_itr); + rc->current_itr = rc->target_itr; + } else if (q_vector->rx.current_itr != q_vector->rx.target_itr) { + rc = &q_vector->rx; + /* Rx ITR needs to be increased, third priority */ + itr_val = ice_buildreg_itr(rc->itr_idx, rc->target_itr); + rc->current_itr = rc->target_itr; + } else { + /* Still have to re-enable the interrupts */ + itr_val = ice_buildreg_itr(ICE_ITR_NONE, 0); + } + + if (!test_bit(__ICE_DOWN, vsi->state)) { + int vector = vsi->hw_base_vector + q_vector->v_idx; + + wr32(hw, GLINT_DYN_CTL(vector), itr_val); + } +} + /** * ice_napi_poll - NAPI polling Rx/Tx cleanup routine * @napi: napi struct with our devices info in it @@ -1108,7 +1171,7 @@ int ice_napi_poll(struct napi_struct *napi, int budget) */ if (likely(napi_complete_done(napi, work_done))) if (test_bit(ICE_FLAG_MSIX_ENA, pf->flags)) - ice_irq_dynamic_ena(&vsi->back->hw, vsi, q_vector); + ice_update_ena_itr(vsi, q_vector); return min(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 75d0eaf6c9dd..aa646002d653 100644 --- a/drivers/net/ethernet/intel/ice/ice_txrx.h +++ b/drivers/net/ethernet/intel/ice/ice_txrx.h @@ -116,16 +116,15 @@ enum ice_rx_dtype { /* indices into GLINT_ITR registers */ #define ICE_RX_ITR ICE_IDX_ITR0 #define ICE_TX_ITR ICE_IDX_ITR1 -#define ICE_ITR_DYNAMIC 0x8000 /* use top bit as a flag */ -#define ICE_ITR_8K 125 +#define ICE_ITR_8K 124 #define ICE_ITR_20K 50 -#define ICE_DFLT_TX_ITR ICE_ITR_20K -#define ICE_DFLT_RX_ITR ICE_ITR_20K -/* apply ITR granularity translation to program the register. itr_gran is either - * 2 or 4 usecs so we need to divide by 2 first then shift by that value - */ -#define ITR_TO_REG(val, itr_gran) (((val) & ~ICE_ITR_DYNAMIC) >> \ - ((itr_gran) / 2)) +#define ICE_DFLT_TX_ITR (ICE_ITR_20K | ICE_ITR_DYNAMIC) +#define ICE_DFLT_RX_ITR (ICE_ITR_20K | ICE_ITR_DYNAMIC) +#define ICE_ITR_DYNAMIC 0x8000 /* used as flag for itr_setting */ +#define ITR_TO_REG(setting) ((setting) & ~ICE_ITR_DYNAMIC) +#define ICE_ITR_GRAN_S 1 /* Assume ITR granularity is 2us */ +#define ICE_ITR_MASK 0x1FFE /* ITR register value alignment mask */ +#define ITR_REG_ALIGN(setting) __ALIGN_MASK(setting, ~ICE_ITR_MASK) #define ICE_DFLT_INTRL 0 @@ -180,13 +179,20 @@ enum ice_latency_range { }; struct ice_ring_container { - /* array of pointers to rings */ + /* head of linked-list of rings */ struct ice_ring *ring; + unsigned long next_update; /* jiffies value of next queue update */ unsigned int total_bytes; /* total bytes processed this int */ unsigned int total_pkts; /* total packets processed this int */ enum ice_latency_range latency_range; - int itr_idx; /* index in the interrupt vector */ - u16 itr; + int itr_idx; /* index in the interrupt vector */ + u16 target_itr; /* value in usecs divided by the hw->itr_gran */ + u16 current_itr; /* value in usecs divided by the hw->itr_gran */ + /* high bit set means dynamic ITR, rest is used to store user + * readable ITR value in usecs and must be converted before programming + * to a register. + */ + u16 itr_setting; }; /* iterator for handling rings in ring container */ -- 2.30.2