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Message-Id: <20190820215048.14377-6-jeffrey.t.kirsher@intel.com>
Date: Tue, 20 Aug 2019 14:50:39 -0700
From: Jeff Kirsher <jeffrey.t.kirsher@...el.com>
To: davem@...emloft.net
Cc: Brett Creeley <brett.creeley@...el.com>, netdev@...r.kernel.org,
nhorman@...hat.com, sassmann@...hat.com,
Tony Nguyen <anthony.l.nguyen@...el.com>,
Andrew Bowers <andrewx.bowers@...el.com>,
Jeff Kirsher <jeffrey.t.kirsher@...el.com>
Subject: [net-next v3 05/14] ice: Set WB_ON_ITR when we don't re-enable interrupts
From: Brett Creeley <brett.creeley@...el.com>
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 <brett.creeley@...el.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@...el.com>
Tested-by: Andrew Bowers <andrewx.bowers@...el.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@...el.com>
---
.../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
--
2.21.0
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