Date: Sun, 2 Oct 2011 08:48:48 +0000 (UTC) From: Adrian Chadd <adrian@FreeBSD.org> To: src-committers@freebsd.org, svn-src-user@freebsd.org Subject: svn commit: r225915 - user/adrian/if_ath_tx/sys/dev/ath Message-ID: <201110020848.p928mm7P055169@svn.freebsd.org>
index | next in thread | raw e-mail
Author: adrian Date: Sun Oct 2 08:48:47 2011 New Revision: 225915 URL: http://svn.freebsd.org/changeset/base/225915 Log: Add the PCU mutex. This mutex may eventually be used to protect access to the PCU. The reference driver (and thus ath9k) serialises access to the PCU (TX, RX, reset/channel change, interrupts) through a lock. Modified: user/adrian/if_ath_tx/sys/dev/ath/if_ath_ahb.c user/adrian/if_ath_tx/sys/dev/ath/if_ath_pci.c user/adrian/if_ath_tx/sys/dev/ath/if_athvar.h Modified: user/adrian/if_ath_tx/sys/dev/ath/if_ath_ahb.c ============================================================================== --- user/adrian/if_ath_tx/sys/dev/ath/if_ath_ahb.c Sun Oct 2 05:11:02 2011 (r225914) +++ user/adrian/if_ath_tx/sys/dev/ath/if_ath_ahb.c Sun Oct 2 08:48:47 2011 (r225915) @@ -190,11 +190,13 @@ ath_ahb_attach(device_t dev) } ATH_LOCK_INIT(sc); + ATH_PCU_LOCK_INIT(sc); error = ath_attach(AR9130_DEVID, sc); if (error == 0) /* success */ return 0; + ATH_PCU_LOCK_DESTROY(sc); ATH_LOCK_DESTROY(sc); bus_dma_tag_destroy(sc->sc_dmat); bad3: Modified: user/adrian/if_ath_tx/sys/dev/ath/if_ath_pci.c ============================================================================== --- user/adrian/if_ath_tx/sys/dev/ath/if_ath_pci.c Sun Oct 2 05:11:02 2011 (r225914) +++ user/adrian/if_ath_tx/sys/dev/ath/if_ath_pci.c Sun Oct 2 08:48:47 2011 (r225915) @@ -164,11 +164,13 @@ ath_pci_attach(device_t dev) } ATH_LOCK_INIT(sc); + ATH_PCU_LOCK_INIT(sc); error = ath_attach(pci_get_device(dev), sc); if (error == 0) /* success */ return 0; + ATH_PCU_LOCK_DESTROY(sc); ATH_LOCK_DESTROY(sc); bus_dma_tag_destroy(sc->sc_dmat); bad3: Modified: user/adrian/if_ath_tx/sys/dev/ath/if_athvar.h ============================================================================== --- user/adrian/if_ath_tx/sys/dev/ath/if_athvar.h Sun Oct 2 05:11:02 2011 (r225914) +++ user/adrian/if_ath_tx/sys/dev/ath/if_athvar.h Sun Oct 2 08:48:47 2011 (r225915) @@ -351,6 +351,8 @@ struct ath_softc { HAL_BUS_HANDLE sc_sh; /* bus space handle */ bus_dma_tag_t sc_dmat; /* bus DMA tag */ struct mtx sc_mtx; /* master lock (recursive) */ + struct mtx sc_pcu_mtx; /* PCU access mutex */ + char sc_pcu_mtx_name[32]; struct taskqueue *sc_tq; /* private task queue */ struct ath_hal *sc_ah; /* Atheros HAL */ struct ath_ratectrl *sc_rc; /* tx rate control support */ @@ -543,6 +545,37 @@ struct ath_softc { #define ATH_UNLOCK(_sc) mtx_unlock(&(_sc)->sc_mtx) #define ATH_LOCK_ASSERT(_sc) mtx_assert(&(_sc)->sc_mtx, MA_OWNED) +/* + * The PCU lock is non-recursive and should be treated as a spinlock. + * Although currently the interrupt code is run in netisr context and + * doesn't require this, this may change in the future. + * Please keep this in mind when protecting certain code paths + * with the PCU lock. + * + * The PCU lock is used to serialise access to the PCU so things such + * as TX, RX, state change (eg channel change), channel reset and updates + * from interrupt context (eg kickpcu, txqactive bits) do not clash. + * + * Although the current single-thread taskqueue mechanism protects the + * majority of these situations by simply serialising them, there are + * a few others which occur at the same time. These include the TX path + * (which only acquires ATH_LOCK when recycling buffers to the free list), + * ath_set_channel, the channel scanning API and perhaps quite a bit more. + */ +#define ATH_PCU_LOCK_INIT(_sc) do {\ + snprintf((_sc)->sc_pcu_mtx_name, \ + sizeof((_sc)->sc_pcu_mtx_name), \ + "%s PCU lock", \ + device_get_nameunit((_sc)->sc_dev)); \ + mtx_init(&(_sc)->sc_pcu_mtx, (_sc)->sc_pcu_mtx_name, \ + NULL, MTX_DEF); \ + } while (0) +#define ATH_PCU_LOCK_DESTROY(_sc) mtx_destroy(&(_sc)->sc_pcu_mtx) +#define ATH_PCU_LOCK(_sc) mtx_lock(&(_sc)->sc_pcu_mtx) +#define ATH_PCU_UNLOCK(_sc) mtx_unlock(&(_sc)->sc_pcu_mtx) +#define ATH_PCU_LOCK_ASSERT(_sc) mtx_assert(&(_sc)->sc_pcu_mtx, \ + MA_OWNED) + #define ATH_TXQ_SETUP(sc, i) ((sc)->sc_txqsetup & (1<<i)) #define ATH_TXBUF_LOCK_INIT(_sc) do { \help
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201110020848.p928mm7P055169>