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cxgbe(4): knobs to enable/disable PAUSE frame based flow control.

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MFC after:	1 week
This commit is contained in:
Navdeep Parhar 2014-09-12 05:25:56 +00:00
parent de3307644e
commit 3eb2c201a6
2 changed files with 91 additions and 1 deletions
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13
share/man/man4/cxgbe.4
View File

@ -240,8 +240,19 @@ The default is -1 which lets the driver pick a pad boundary.
Controls the hardware response to congestion.
-1 disables congestion feedback and is not recommended.
0 instructs the hardware to backpressure its pipeline on congestion.
This usually results in the port emitting pause frames.
This usually results in the port emitting PAUSE frames.
1 instructs the hardware to drop frames destined for congested queues.
.It Va hw.cxgbe.pause_settings
PAUSE frame settings.
Bit 0 is rx_pause, bit 1 is tx_pause.
rx_pause = 1 instructs the hardware to heed incoming PAUSE frames, 0 instructs
it to ignore them.
tx_pause = 1 allows the hardware to emit PAUSE frames when its receive FIFO
reaches a high threshold, 0 prohibits the hardware from emitting PAUSE frames.
The default is 3 (both rx_pause and tx_pause = 1).
This tunable establishes the default PAUSE settings for all ports.
Settings can be displayed and controlled on a per-port basis via the
dev.cxgbe.X.pause_settings (dev.cxl.X.pause_settings for T5 cards) sysctl.
.It Va hw.cxgbe.buffer_packing
Allow the hardware to deliver multiple frames in the same receive buffer
opportunistically.

79
sys/dev/cxgbe/t4_main.c
View File

@ -280,6 +280,15 @@ TUNABLE_INT("hw.cxgbe.interrupt_types", &t4_intr_types);
static char t4_cfg_file[32] = DEFAULT_CF;
TUNABLE_STR("hw.cxgbe.config_file", t4_cfg_file, sizeof(t4_cfg_file));
/*
* PAUSE settings (bit 0, 1 = rx_pause, tx_pause respectively).
* rx_pause = 1 to heed incoming PAUSE frames, 0 to ignore them.
* tx_pause = 1 to emit PAUSE frames when the rx FIFO reaches its high water
* mark or when signalled to do so, 0 to never emit PAUSE.
*/
static int t4_pause_settings = PAUSE_TX | PAUSE_RX;
TUNABLE_INT("hw.cxgbe.pause_settings", &t4_pause_settings);
/*
* Firmware auto-install by driver during attach (0, 1, 2 = prohibited, allowed,
* encouraged respectively).
@ -393,6 +402,7 @@ static int sysctl_holdoff_tmr_idx(SYSCTL_HANDLER_ARGS);
static int sysctl_holdoff_pktc_idx(SYSCTL_HANDLER_ARGS);
static int sysctl_qsize_rxq(SYSCTL_HANDLER_ARGS);
static int sysctl_qsize_txq(SYSCTL_HANDLER_ARGS);
static int sysctl_pause_settings(SYSCTL_HANDLER_ARGS);
static int sysctl_handle_t4_reg64(SYSCTL_HANDLER_ARGS);
static int sysctl_temperature(SYSCTL_HANDLER_ARGS);
#ifdef SBUF_DRAIN
@ -697,6 +707,12 @@ t4_attach(device_t dev)
sc->port[i] = NULL;
goto done;
}
pi->link_cfg.requested_fc &= ~(PAUSE_TX | PAUSE_RX);
pi->link_cfg.requested_fc |= t4_pause_settings;
pi->link_cfg.fc &= ~(PAUSE_TX | PAUSE_RX);
pi->link_cfg.fc |= t4_pause_settings;
rc = -t4_link_start(sc, sc->mbox, pi->tx_chan, &pi->link_cfg);
if (rc != 0) {
device_printf(dev, "port %d l1cfg failed: %d\n", i, rc);
@ -4771,6 +4787,10 @@ cxgbe_sysctls(struct port_info *pi)
CTLTYPE_INT | CTLFLAG_RW, pi, 0, sysctl_qsize_txq, "I",
"tx queue size");
SYSCTL_ADD_PROC(ctx, children, OID_AUTO, "pause_settings",
CTLTYPE_STRING | CTLFLAG_RW, pi, PAUSE_TX, sysctl_pause_settings,
"A", "PAUSE settings (bit 0 = rx_pause, bit 1 = tx_pause)");
/*
* dev.cxgbe.X.stats.
*/
@ -5151,6 +5171,65 @@ sysctl_qsize_txq(SYSCTL_HANDLER_ARGS)
return (rc);
}
static int
sysctl_pause_settings(SYSCTL_HANDLER_ARGS)
{
struct port_info *pi = arg1;
struct adapter *sc = pi->adapter;
struct link_config *lc = &pi->link_cfg;
int rc;
if (req->newptr == NULL) {
struct sbuf *sb;
static char *bits = "\20\1PAUSE_RX\2PAUSE_TX";
rc = sysctl_wire_old_buffer(req, 0);
if (rc != 0)
return(rc);
sb = sbuf_new_for_sysctl(NULL, NULL, 128, req);
if (sb == NULL)
return (ENOMEM);
sbuf_printf(sb, "%b", lc->fc & (PAUSE_TX | PAUSE_RX), bits);
rc = sbuf_finish(sb);
sbuf_delete(sb);
} else {
char s[2];
int n;
s[0] = '0' + (lc->requested_fc & (PAUSE_TX | PAUSE_RX));
s[1] = 0;
rc = sysctl_handle_string(oidp, s, sizeof(s), req);
if (rc != 0)
return(rc);
if (s[1] != 0)
return (EINVAL);
if (s[0] < '0' || s[0] > '9')
return (EINVAL); /* not a number */
n = s[0] - '0';
if (n & ~(PAUSE_TX | PAUSE_RX))
return (EINVAL); /* some other bit is set too */
rc = begin_synchronized_op(sc, pi, SLEEP_OK | INTR_OK, "t4PAUSE");
if (rc)
return (rc);
if ((lc->requested_fc & (PAUSE_TX | PAUSE_RX)) != n) {
int link_ok = lc->link_ok;
lc->requested_fc &= ~(PAUSE_TX | PAUSE_RX);
lc->requested_fc |= n;
rc = -t4_link_start(sc, sc->mbox, pi->tx_chan, lc);
lc->link_ok = link_ok; /* restore */
}
end_synchronized_op(sc, 0);
}
return (rc);
}
static int
sysctl_handle_t4_reg64(SYSCTL_HANDLER_ARGS)
{