RDMA/hfi1: Defer setting VL15 credits to link-up interrupt
Keep VL15 credits at 0 during LNI, before link-up. Store
VL15 credits value during verify cap interrupt and set
in after link-up. This addresses an issue where VL15 MAD
packets could be sent by one side of the link before
the other side is ready to receive them.
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: Dean Luick <dean.luick@intel.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jakub Byczkowski <jakub.byczkowski@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/drivers/infiniband/hw/hfi1/chip.c b/drivers/infiniband/hw/hfi1/chip.c
index 5d6b1ee..2ba00b8 100644
--- a/drivers/infiniband/hw/hfi1/chip.c
+++ b/drivers/infiniband/hw/hfi1/chip.c
@@ -6312,25 +6312,38 @@ static void handle_8051_request(struct hfi1_pportdata *ppd)
}
}
-static void write_global_credit(struct hfi1_devdata *dd,
- u8 vau, u16 total, u16 shared)
+/*
+ * Set up allocation unit vaulue.
+ */
+void set_up_vau(struct hfi1_devdata *dd, u8 vau)
{
- write_csr(dd, SEND_CM_GLOBAL_CREDIT,
- ((u64)total <<
- SEND_CM_GLOBAL_CREDIT_TOTAL_CREDIT_LIMIT_SHIFT) |
- ((u64)shared <<
- SEND_CM_GLOBAL_CREDIT_SHARED_LIMIT_SHIFT) |
- ((u64)vau << SEND_CM_GLOBAL_CREDIT_AU_SHIFT));
+ u64 reg = read_csr(dd, SEND_CM_GLOBAL_CREDIT);
+
+ /* do not modify other values in the register */
+ reg &= ~SEND_CM_GLOBAL_CREDIT_AU_SMASK;
+ reg |= (u64)vau << SEND_CM_GLOBAL_CREDIT_AU_SHIFT;
+ write_csr(dd, SEND_CM_GLOBAL_CREDIT, reg);
}
/*
* Set up initial VL15 credits of the remote. Assumes the rest of
- * the CM credit registers are zero from a previous global or credit reset .
+ * the CM credit registers are zero from a previous global or credit reset.
+ * Shared limit for VL15 will always be 0.
*/
-void set_up_vl15(struct hfi1_devdata *dd, u8 vau, u16 vl15buf)
+void set_up_vl15(struct hfi1_devdata *dd, u16 vl15buf)
{
- /* leave shared count at zero for both global and VL15 */
- write_global_credit(dd, vau, vl15buf, 0);
+ u64 reg = read_csr(dd, SEND_CM_GLOBAL_CREDIT);
+
+ /* set initial values for total and shared credit limit */
+ reg &= ~(SEND_CM_GLOBAL_CREDIT_TOTAL_CREDIT_LIMIT_SMASK |
+ SEND_CM_GLOBAL_CREDIT_SHARED_LIMIT_SMASK);
+
+ /*
+ * Set total limit to be equal to VL15 credits.
+ * Leave shared limit at 0.
+ */
+ reg |= (u64)vl15buf << SEND_CM_GLOBAL_CREDIT_TOTAL_CREDIT_LIMIT_SHIFT;
+ write_csr(dd, SEND_CM_GLOBAL_CREDIT, reg);
write_csr(dd, SEND_CM_CREDIT_VL15, (u64)vl15buf
<< SEND_CM_CREDIT_VL15_DEDICATED_LIMIT_VL_SHIFT);
@@ -6348,9 +6361,11 @@ void reset_link_credits(struct hfi1_devdata *dd)
for (i = 0; i < TXE_NUM_DATA_VL; i++)
write_csr(dd, SEND_CM_CREDIT_VL + (8 * i), 0);
write_csr(dd, SEND_CM_CREDIT_VL15, 0);
- write_global_credit(dd, 0, 0, 0);
+ write_csr(dd, SEND_CM_GLOBAL_CREDIT, 0);
/* reset the CM block */
pio_send_control(dd, PSC_CM_RESET);
+ /* reset cached value */
+ dd->vl15buf_cached = 0;
}
/* convert a vCU to a CU */
@@ -6839,24 +6854,35 @@ void handle_link_up(struct work_struct *work)
{
struct hfi1_pportdata *ppd = container_of(work, struct hfi1_pportdata,
link_up_work);
+ struct hfi1_devdata *dd = ppd->dd;
+
set_link_state(ppd, HLS_UP_INIT);
/* cache the read of DC_LCB_STS_ROUND_TRIP_LTP_CNT */
- read_ltp_rtt(ppd->dd);
+ read_ltp_rtt(dd);
/*
* OPA specifies that certain counters are cleared on a transition
* to link up, so do that.
*/
- clear_linkup_counters(ppd->dd);
+ clear_linkup_counters(dd);
/*
* And (re)set link up default values.
*/
set_linkup_defaults(ppd);
+ /*
+ * Set VL15 credits. Use cached value from verify cap interrupt.
+ * In case of quick linkup or simulator, vl15 value will be set by
+ * handle_linkup_change. VerifyCap interrupt handler will not be
+ * called in those scenarios.
+ */
+ if (!(quick_linkup || dd->icode == ICODE_FUNCTIONAL_SIMULATOR))
+ set_up_vl15(dd, dd->vl15buf_cached);
+
/* enforce link speed enabled */
if ((ppd->link_speed_active & ppd->link_speed_enabled) == 0) {
/* oops - current speed is not enabled, bounce */
- dd_dev_err(ppd->dd,
+ dd_dev_err(dd,
"Link speed active 0x%x is outside enabled 0x%x, downing link\n",
ppd->link_speed_active, ppd->link_speed_enabled);
set_link_down_reason(ppd, OPA_LINKDOWN_REASON_SPEED_POLICY, 0,
@@ -7357,7 +7383,14 @@ void handle_verify_cap(struct work_struct *work)
*/
if (vau == 0)
vau = 1;
- set_up_vl15(dd, vau, vl15buf);
+ set_up_vau(dd, vau);
+
+ /*
+ * Set VL15 credits to 0 in global credit register. Cache remote VL15
+ * credits value and wait for link-up interrupt ot set it.
+ */
+ set_up_vl15(dd, 0);
+ dd->vl15buf_cached = vl15buf;
/* set up the LCB CRC mode */
crc_mask = ppd->port_crc_mode_enabled & partner_supported_crc;