freebsd-skq/sys/dev/ath/if_ath_pci.c
adrian 2ef1c4bedf I give up - introduce a TX lock to serialise TX operations.
I've tried serialising TX using queues and such but unfortunately
due to how this interacts with the locking going on elsewhere in the
networking stack, the TX task gets delayed, resulting in quite a
noticable throughput loss:

* baseline TCP for 2x2 11n HT40 is ~ 170mbit/sec;
* TCP for TX task in the ath taskq, with the RX also going on - 80mbit/sec;
* TCP for TX task in a separate, second taskq - 100mbit/sec.

So for now I'm going with the Linux wireless stack approach - lock tx
early.  The linux code does in the wireless stack, before the 802.11
state stuff happens and before it's punted to the driver.
But TX locking needs to also occur at the driver layer as the TX
completion code _also_ begins to drain the ifnet TX queue.

Whilst I'm here, add some KTR traces for the TX path.

Note:

* This really should be done at the net80211 layer (as well, at least.)
  But that'll have to wait for a little more thought to happen.
2012-10-31 06:27:58 +00:00

366 lines
9.0 KiB
C

/*-
* Copyright (c) 2002-2008 Sam Leffler, Errno Consulting
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer,
* without modification.
* 2. Redistributions in binary form must reproduce at minimum a disclaimer
* similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
* redistribution must be conditioned upon including a substantially
* similar Disclaimer requirement for further binary redistribution.
*
* NO WARRANTY
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
* OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
* IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGES.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* PCI/Cardbus front-end for the Atheros Wireless LAN controller driver.
*/
#include "opt_ath.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/module.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/errno.h>
#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/bus.h>
#include <sys/rman.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_media.h>
#include <net/if_arp.h>
#include <net80211/ieee80211_var.h>
#include <dev/ath/if_athvar.h>
#include <dev/pci/pcivar.h>
#include <dev/pci/pcireg.h>
/* For EEPROM firmware */
#ifdef ATH_EEPROM_FIRMWARE
#include <sys/linker.h>
#include <sys/firmware.h>
#endif /* ATH_EEPROM_FIRMWARE */
/*
* PCI glue.
*/
struct ath_pci_softc {
struct ath_softc sc_sc;
struct resource *sc_sr; /* memory resource */
struct resource *sc_irq; /* irq resource */
void *sc_ih; /* interrupt handler */
};
#define BS_BAR 0x10
#define PCIR_RETRY_TIMEOUT 0x41
#define PCIR_CFG_PMCSR 0x48
#define DEFAULT_CACHESIZE 32
static void
ath_pci_setup(device_t dev)
{
uint8_t cz;
/* XXX TODO: need to override the _system_ saved copies of this */
/*
* If the cache line size is 0, force it to a reasonable
* value.
*/
cz = pci_read_config(dev, PCIR_CACHELNSZ, 1);
if (cz == 0) {
pci_write_config(dev, PCIR_CACHELNSZ,
DEFAULT_CACHESIZE / 4, 1);
}
/* Override the system latency timer */
pci_write_config(dev, PCIR_LATTIMER, 0xa8, 1);
/* If a PCI NIC, force wakeup */
#ifdef ATH_PCI_WAKEUP_WAR
/* XXX TODO: don't do this for non-PCI (ie, PCIe, Cardbus!) */
if (1) {
uint16_t pmcsr;
pmcsr = pci_read_config(dev, PCIR_CFG_PMCSR, 2);
pmcsr |= 3;
pci_write_config(dev, PCIR_CFG_PMCSR, pmcsr, 2);
pmcsr &= ~3;
pci_write_config(dev, PCIR_CFG_PMCSR, pmcsr, 2);
}
#endif
/*
* Disable retry timeout to keep PCI Tx retries from
* interfering with C3 CPU state.
*/
pci_write_config(dev, PCIR_RETRY_TIMEOUT, 0, 1);
}
static int
ath_pci_probe(device_t dev)
{
const char* devname;
devname = ath_hal_probe(pci_get_vendor(dev), pci_get_device(dev));
if (devname != NULL) {
device_set_desc(dev, devname);
return BUS_PROBE_DEFAULT;
}
return ENXIO;
}
static int
ath_pci_attach(device_t dev)
{
struct ath_pci_softc *psc = device_get_softc(dev);
struct ath_softc *sc = &psc->sc_sc;
int error = ENXIO;
int rid;
#ifdef ATH_EEPROM_FIRMWARE
const struct firmware *fw = NULL;
const char *buf;
#endif
sc->sc_dev = dev;
/*
* Enable bus mastering.
*/
pci_enable_busmaster(dev);
/*
* Setup other PCI bus configuration parameters.
*/
ath_pci_setup(dev);
/*
* Setup memory-mapping of PCI registers.
*/
rid = BS_BAR;
psc->sc_sr = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
RF_ACTIVE);
if (psc->sc_sr == NULL) {
device_printf(dev, "cannot map register space\n");
goto bad;
}
/* XXX uintptr_t is a bandaid for ia64; to be fixed */
sc->sc_st = (HAL_BUS_TAG)(uintptr_t) rman_get_bustag(psc->sc_sr);
sc->sc_sh = (HAL_BUS_HANDLE) rman_get_bushandle(psc->sc_sr);
/*
* Mark device invalid so any interrupts (shared or otherwise)
* that arrive before the HAL is setup are discarded.
*/
sc->sc_invalid = 1;
/*
* Arrange interrupt line.
*/
rid = 0;
psc->sc_irq = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
RF_SHAREABLE|RF_ACTIVE);
if (psc->sc_irq == NULL) {
device_printf(dev, "could not map interrupt\n");
goto bad1;
}
if (bus_setup_intr(dev, psc->sc_irq,
INTR_TYPE_NET | INTR_MPSAFE,
NULL, ath_intr, sc, &psc->sc_ih)) {
device_printf(dev, "could not establish interrupt\n");
goto bad2;
}
/*
* Setup DMA descriptor area.
*/
if (bus_dma_tag_create(bus_get_dma_tag(dev), /* parent */
1, 0, /* alignment, bounds */
BUS_SPACE_MAXADDR_32BIT, /* lowaddr */
BUS_SPACE_MAXADDR, /* highaddr */
NULL, NULL, /* filter, filterarg */
0x3ffff, /* maxsize XXX */
ATH_MAX_SCATTER, /* nsegments */
0x3ffff, /* maxsegsize XXX */
BUS_DMA_ALLOCNOW, /* flags */
NULL, /* lockfunc */
NULL, /* lockarg */
&sc->sc_dmat)) {
device_printf(dev, "cannot allocate DMA tag\n");
goto bad3;
}
#ifdef ATH_EEPROM_FIRMWARE
/*
* If there's an EEPROM firmware image, load that in.
*/
if (resource_string_value(device_get_name(dev), device_get_unit(dev),
"eeprom_firmware", &buf) == 0) {
if (bootverbose)
device_printf(dev, "%s: looking up firmware @ '%s'\n",
__func__, buf);
fw = firmware_get(buf);
if (fw == NULL) {
device_printf(dev, "%s: couldn't find firmware\n",
__func__);
goto bad3;
}
device_printf(dev, "%s: EEPROM firmware @ %p\n",
__func__, fw->data);
sc->sc_eepromdata =
malloc(fw->datasize, M_TEMP, M_WAITOK | M_ZERO);
if (! sc->sc_eepromdata) {
device_printf(dev, "%s: can't malloc eepromdata\n",
__func__);
goto bad3;
}
memcpy(sc->sc_eepromdata, fw->data, fw->datasize);
firmware_put(fw, 0);
}
#endif /* ATH_EEPROM_FIRMWARE */
ATH_LOCK_INIT(sc);
ATH_PCU_LOCK_INIT(sc);
ATH_RX_LOCK_INIT(sc);
ATH_TX_LOCK_INIT(sc);
ATH_TXSTATUS_LOCK_INIT(sc);
error = ath_attach(pci_get_device(dev), sc);
if (error == 0) /* success */
return 0;
ATH_TXSTATUS_LOCK_DESTROY(sc);
ATH_PCU_LOCK_DESTROY(sc);
ATH_RX_LOCK_DESTROY(sc);
ATH_TX_LOCK_DESTROY(sc);
ATH_LOCK_DESTROY(sc);
bus_dma_tag_destroy(sc->sc_dmat);
bad3:
bus_teardown_intr(dev, psc->sc_irq, psc->sc_ih);
bad2:
bus_release_resource(dev, SYS_RES_IRQ, 0, psc->sc_irq);
bad1:
bus_release_resource(dev, SYS_RES_MEMORY, BS_BAR, psc->sc_sr);
bad:
return (error);
}
static int
ath_pci_detach(device_t dev)
{
struct ath_pci_softc *psc = device_get_softc(dev);
struct ath_softc *sc = &psc->sc_sc;
/* check if device was removed */
sc->sc_invalid = !bus_child_present(dev);
/*
* Do a config read to clear pre-existing pci error status.
*/
(void) pci_read_config(dev, PCIR_COMMAND, 4);
ath_detach(sc);
bus_generic_detach(dev);
bus_teardown_intr(dev, psc->sc_irq, psc->sc_ih);
bus_release_resource(dev, SYS_RES_IRQ, 0, psc->sc_irq);
bus_dma_tag_destroy(sc->sc_dmat);
bus_release_resource(dev, SYS_RES_MEMORY, BS_BAR, psc->sc_sr);
if (sc->sc_eepromdata)
free(sc->sc_eepromdata, M_TEMP);
ATH_TXSTATUS_LOCK_DESTROY(sc);
ATH_PCU_LOCK_DESTROY(sc);
ATH_RX_LOCK_DESTROY(sc);
ATH_TX_LOCK_DESTROY(sc);
ATH_LOCK_DESTROY(sc);
return (0);
}
static int
ath_pci_shutdown(device_t dev)
{
struct ath_pci_softc *psc = device_get_softc(dev);
ath_shutdown(&psc->sc_sc);
return (0);
}
static int
ath_pci_suspend(device_t dev)
{
struct ath_pci_softc *psc = device_get_softc(dev);
ath_suspend(&psc->sc_sc);
return (0);
}
static int
ath_pci_resume(device_t dev)
{
struct ath_pci_softc *psc = device_get_softc(dev);
/*
* Suspend/resume resets the PCI configuration space.
*/
ath_pci_setup(dev);
ath_resume(&psc->sc_sc);
return (0);
}
static device_method_t ath_pci_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, ath_pci_probe),
DEVMETHOD(device_attach, ath_pci_attach),
DEVMETHOD(device_detach, ath_pci_detach),
DEVMETHOD(device_shutdown, ath_pci_shutdown),
DEVMETHOD(device_suspend, ath_pci_suspend),
DEVMETHOD(device_resume, ath_pci_resume),
{ 0,0 }
};
static driver_t ath_pci_driver = {
"ath",
ath_pci_methods,
sizeof (struct ath_pci_softc)
};
static devclass_t ath_devclass;
DRIVER_MODULE(ath_pci, pci, ath_pci_driver, ath_devclass, 0, 0);
MODULE_VERSION(ath_pci, 1);
MODULE_DEPEND(ath_pci, wlan, 1, 1, 1); /* 802.11 media layer */
MODULE_DEPEND(ath_pci, if_ath, 1, 1, 1); /* if_ath driver */