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freebsd_amp_hwpstate
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Mask doorbells while processing them. 

This fixes interrupt storms on hardware using legacy level-triggered
interrupts, since doorbell processing could take time after interrupt
handler completion, that triggered extra interrupts in a loop.

MFC after:	2 weeks
Sponsored by:	iXsystems, Inc.
This commit is contained in:
Alexander Motin 2017-08-28 20:00:21 +00:00
parent e6f000753e
commit 546ec4e544
1 changed files with 7 additions and 2 deletions
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9
sys/dev/ntb/ntb_transport.c
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@ -835,6 +835,7 @@ static void
ntb_transport_rxc_db(void *arg, int pending __unused)
{
struct ntb_transport_qp *qp = arg;
uint64_t qp_mask = 1ull << qp->qp_num;
int rc;
CTR0(KTR_NTB, "RX: transport_rx");
@ -843,11 +844,13 @@ again:
;
CTR1(KTR_NTB, "RX: process_rxc returned %d", rc);
if ((ntb_db_read(qp->dev) & (1ull << qp->qp_num)) != 0) {
if ((ntb_db_read(qp->dev) & qp_mask) != 0) {
/* If db is set, clear it and check queue once more. */
ntb_db_clear(qp->dev, 1ull << qp->qp_num);
ntb_db_clear(qp->dev, qp_mask);
goto again;
}
if (qp->link_is_up)
ntb_db_clear_mask(qp->dev, qp_mask);
}
static int
@ -1009,6 +1012,8 @@ ntb_transport_doorbell_callback(void *data, uint32_t vector)
vec_mask &= nt->qp_bitmap;
if ((vec_mask & (vec_mask - 1)) != 0)
vec_mask &= ntb_db_read(nt->dev);
if (vec_mask != 0)
ntb_db_set_mask(nt->dev, vec_mask);
while (vec_mask != 0) {
qp_num = ffsll(vec_mask) - 1;