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author | luigi <luigi@FreeBSD.org> | 2001-12-14 17:56:12 +0000 |
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committer | luigi <luigi@FreeBSD.org> | 2001-12-14 17:56:12 +0000 |
commit | f8ad22919e217e5aa0f3f7a246fc37aaee182364 (patch) | |
tree | 4ea0e407bb3cf5815d6067507d1fdc39f76f58e6 /sys/pci/if_sis.c | |
parent | 34c1073cfc26bcfb3b31de63c71ab21bcd44065e (diff) | |
download | FreeBSD-src-f8ad22919e217e5aa0f3f7a246fc37aaee182364.zip FreeBSD-src-f8ad22919e217e5aa0f3f7a246fc37aaee182364.tar.gz |
Device Polling code for -current.
Non-SMP, i386-only, no polling in the idle loop at the moment.
To use this code you must compile a kernel with
options DEVICE_POLLING
and at runtime enable polling with
sysctl kern.polling.enable=1
The percentage of CPU reserved to userland can be set with
sysctl kern.polling.user_frac=NN (default is 50)
while the remainder is used by polling device drivers and netisr's.
These are the only two variables that you should need to touch. There
are a few more parameters in kern.polling but the default values
are adequate for all purposes. See the code in kern_poll.c for
more details on them.
Polling in the idle loop will be implemented shortly by introducing
a kernel thread which does the job. Until then, the amount of CPU
dedicated to polling will never exceed (100-user_frac).
The equivalent (actually, better) code for -stable is at
http://info.iet.unipi.it/~luigi/polling/
and also supports polling in the idle loop.
NOTE to Alpha developers:
There is really nothing in this code that is i386-specific.
If you move the 2 lines supporting the new option from
sys/conf/{files,options}.i386 to sys/conf/{files,options} I am
pretty sure that this should work on the Alpha as well, just that
I do not have a suitable test box to try it. If someone feels like
trying it, I would appreciate it.
NOTE to other developers:
sure some things could be done better, and as always I am open to
constructive criticism, which a few of you have already given and
I greatly appreciated.
However, before proposing radical architectural changes, please
take some time to possibly try out this code, or at the very least
read the comments in kern_poll.c, especially re. the reason why I
am using a soft netisr and cannot (I believe) replace it with a
simple timeout.
Quick description of files touched by this commit:
sys/conf/files.i386
new file kern/kern_poll.c
sys/conf/options.i386
new option
sys/i386/i386/trap.c
poll in trap (disabled by default)
sys/kern/kern_clock.c
initialization and hardclock hooks.
sys/kern/kern_intr.c
minor swi_net changes
sys/kern/kern_poll.c
the bulk of the code.
sys/net/if.h
new flag
sys/net/if_var.h
declaration for functions used in device drivers.
sys/net/netisr.h
NETISR_POLL
sys/dev/fxp/if_fxp.c
sys/dev/fxp/if_fxpvar.h
sys/pci/if_dc.c
sys/pci/if_dcreg.h
sys/pci/if_sis.c
sys/pci/if_sisreg.h
device driver modifications
Diffstat (limited to 'sys/pci/if_sis.c')
-rw-r--r-- | sys/pci/if_sis.c | 78 |
1 files changed, 77 insertions, 1 deletions
diff --git a/sys/pci/if_sis.c b/sys/pci/if_sis.c index e74cfa0..ec7ee82 100644 --- a/sys/pci/if_sis.c +++ b/sys/pci/if_sis.c @@ -1273,6 +1273,13 @@ static void sis_rxeof(sc) while(SIS_OWNDESC(&sc->sis_ldata.sis_rx_list[i])) { +#ifdef DEVICE_POLLING + if (ifp->if_ipending & IFF_POLLING) { + if (sc->rxcycles <= 0) + break; + sc->rxcycles--; + } +#endif /* DEVICE_POLLING */ cur_rx = &sc->sis_ldata.sis_rx_list[i]; rxstat = cur_rx->sis_rxstat; bus_dmamap_sync(sc->sis_tag, @@ -1441,6 +1448,55 @@ static void sis_tick(xsc) return; } +#ifdef DEVICE_POLLING +static poll_handler_t sis_poll; + +static void +sis_poll(struct ifnet *ifp, enum poll_cmd cmd, int count) +{ + struct sis_softc *sc = ifp->if_softc; + SIS_LOCK(sc); + if (cmd == POLL_DEREGISTER) { /* final call, enable interrupts */ + CSR_WRITE_4(sc, SIS_IER, 1); + goto done; + } + + /* + * On the sis, reading the status register also clears it. + * So before returning to intr mode we must make sure that all + * possible pending sources of interrupts have been served. + * In practice this means run to completion the *eof routines, + * and then call the interrupt routine + */ + sc->rxcycles = count; + sis_rxeof(sc); + sis_txeof(sc); + if (ifp->if_snd.ifq_head != NULL) + sis_start(ifp); + + if (sc->rxcycles > 0 || cmd == POLL_AND_CHECK_STATUS) { + u_int32_t status; + + /* Reading the ISR register clears all interrupts. */ + status = CSR_READ_4(sc, SIS_ISR); + + if (status & (SIS_ISR_RX_ERR|SIS_ISR_RX_OFLOW)) + sis_rxeoc(sc); + + if (status & (SIS_ISR_RX_IDLE)) + SIS_SETBIT(sc, SIS_CSR, SIS_CSR_RX_ENABLE); + + if (status & SIS_ISR_SYSERR) { + sis_reset(sc); + sis_init(sc); + } + } +done: + SIS_UNLOCK(sc); + return; +} +#endif /* DEVICE_POLLING */ + static void sis_intr(arg) void *arg; { @@ -1452,6 +1508,15 @@ static void sis_intr(arg) ifp = &sc->arpcom.ac_if; SIS_LOCK(sc); +#ifdef DEVICE_POLLING + if (ifp->if_ipending & IFF_POLLING) + goto done; + if (ether_poll_register(sis_poll, ifp)) { /* ok, disable interrupts */ + CSR_WRITE_4(sc, SIS_IER, 0); + goto done; + } +#endif /* DEVICE_POLLING */ + /* Supress unwanted interrupts */ if (!(ifp->if_flags & IFF_UP)) { sis_stop(sc); @@ -1741,6 +1806,15 @@ static void sis_init(xsc) * Enable interrupts. */ CSR_WRITE_4(sc, SIS_IMR, SIS_INTRS); +#ifdef DEVICE_POLLING + /* + * ... only enable interrupts if we are not polling, make sure + * they are off otherwise. + */ + if (ifp->if_ipending & IFF_POLLING) + CSR_WRITE_4(sc, SIS_IER, 0); + else +#endif /* DEVICE_POLLING */ CSR_WRITE_4(sc, SIS_IER, 1); /* Enable receiver and transmitter. */ @@ -1910,7 +1984,9 @@ static void sis_stop(sc) untimeout(sis_tick, sc, sc->sis_stat_ch); ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE); - +#ifdef DEVICE_POLLING + ether_poll_deregister(ifp); +#endif CSR_WRITE_4(sc, SIS_IER, 0); CSR_WRITE_4(sc, SIS_IMR, 0); SIS_SETBIT(sc, SIS_CSR, SIS_CSR_TX_DISABLE|SIS_CSR_RX_DISABLE); |