Date: Thu, 3 Aug 2023 16:12:05 GMT From: Vladimir Kondratyev <wulf@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 5adcec04b5ab - main - intelspi: Add support for ddb/kdb -compatible polled mode Message-ID: <202308031612.373GC5pK006147@gitrepo.freebsd.org>
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The branch main has been updated by wulf: URL: https://cgit.FreeBSD.org/src/commit/?id=5adcec04b5abd4971f1678d6ee1369cc9ecaa90d commit 5adcec04b5abd4971f1678d6ee1369cc9ecaa90d Author: Vladimir Kondratyev <wulf@FreeBSD.org> AuthorDate: 2023-08-03 16:10:50 +0000 Commit: Vladimir Kondratyev <wulf@FreeBSD.org> CommitDate: 2023-08-03 16:10:50 +0000 intelspi: Add support for ddb/kdb -compatible polled mode Required for Apple and Microsoft -compatible HID-over-SPI drivers. Most logic was already implemented in commit 3c0867343819 "spibus: extend API: add cs_delay ivar, KEEP_CS and NO_SLEEP flags". It dissallowed driver sleeps in the interrupt context. This commit extends this feature to handle ddb/kdb context with following: - Skip driver locking if SPI functions were called from kdb/ddb. - Reinitialize controller if kdb/ddb initiated SPI transfer has interrupted another already running one. Does not work very reliable yet. Reviewed by: manu Differential Revision: https://reviews.freebsd.org/D41247 --- sys/dev/intel/spi.c | 57 ++++++++++++++++++++++++++++++++++++++--------------- sys/dev/intel/spi.h | 2 +- 2 files changed, 42 insertions(+), 17 deletions(-) diff --git a/sys/dev/intel/spi.c b/sys/dev/intel/spi.c index 6dd063511e26..3bcbd8fbd4f4 100644 --- a/sys/dev/intel/spi.c +++ b/sys/dev/intel/spi.c @@ -30,6 +30,7 @@ #include <sys/param.h> #include <sys/bus.h> +#include <sys/kdb.h> #include <sys/kernel.h> #include <sys/module.h> #include <sys/proc.h> @@ -46,14 +47,27 @@ /** * Macros for driver mutex locking */ -#define INTELSPI_LOCK(_sc) mtx_lock(&(_sc)->sc_mtx) -#define INTELSPI_UNLOCK(_sc) mtx_unlock(&(_sc)->sc_mtx) +#define INTELSPI_IN_POLLING_MODE() (SCHEDULER_STOPPED() || kdb_active) +#define INTELSPI_LOCK(_sc) do { \ + if(!INTELSPI_IN_POLLING_MODE()) \ + mtx_lock(&(_sc)->sc_mtx); \ +} while (0) +#define INTELSPI_UNLOCK(_sc) do { \ + if(!INTELSPI_IN_POLLING_MODE()) \ + mtx_unlock(&(_sc)->sc_mtx); \ +} while (0) #define INTELSPI_LOCK_INIT(_sc) \ mtx_init(&_sc->sc_mtx, device_get_nameunit((_sc)->sc_dev), \ "intelspi", MTX_DEF) #define INTELSPI_LOCK_DESTROY(_sc) mtx_destroy(&(_sc)->sc_mtx) -#define INTELSPI_ASSERT_LOCKED(_sc) mtx_assert(&(_sc)->sc_mtx, MA_OWNED) -#define INTELSPI_ASSERT_UNLOCKED(_sc) mtx_assert(&(_sc)->sc_mtx, MA_NOTOWNED) +#define INTELSPI_ASSERT_LOCKED(_sc) do { \ + if(!INTELSPI_IN_POLLING_MODE()) \ + mtx_assert(&(_sc)->sc_mtx, MA_OWNED); \ +} while (0) +#define INTELSPI_ASSERT_UNLOCKED(_sc) do { \ + if(!INTELSPI_IN_POLLING_MODE()) \ + mtx_assert(&(_sc)->sc_mtx, MA_NOTOWNED);\ +} while (0) #define INTELSPI_WRITE(_sc, _off, _val) \ bus_write_4((_sc)->sc_mem_res, (_off), (_val)) @@ -342,17 +356,26 @@ intelspi_transfer(device_t dev, device_t child, struct spi_command *cmd) INTELSPI_LOCK(sc); - /* If the controller is in use wait until it is available. */ - while (sc->sc_flags & INTELSPI_BUSY) { - if ((cmd->flags & SPI_FLAG_NO_SLEEP) == SPI_FLAG_NO_SLEEP) { - INTELSPI_UNLOCK(sc); - return (EBUSY); - } - err = mtx_sleep(dev, &sc->sc_mtx, 0, "intelspi", 0); - if (err == EINTR) { - INTELSPI_UNLOCK(sc); - return (err); + if (!INTELSPI_IN_POLLING_MODE()) { + /* If the controller is in use wait until it is available. */ + while (sc->sc_flags & INTELSPI_BUSY) { + if ((cmd->flags & SPI_FLAG_NO_SLEEP) != 0) { + INTELSPI_UNLOCK(sc); + return (EBUSY); + } + err = mtx_sleep(dev, &sc->sc_mtx, 0, "intelspi", 0); + if (err == EINTR) { + INTELSPI_UNLOCK(sc); + return (err); + } } + } else { + /* + * Now we are in the middle of other transfer. Try to reset + * controller state to get predictable context. + */ + if ((sc->sc_flags & INTELSPI_BUSY) != 0) + intelspi_init(sc); } /* Now we have control over SPI controller. */ @@ -411,7 +434,8 @@ intelspi_transfer(device_t dev, device_t child, struct spi_command *cmd) DELAY(cs_delay); /* Transfer as much as possible to FIFOs */ - if ((cmd->flags & SPI_FLAG_NO_SLEEP) == SPI_FLAG_NO_SLEEP) { + if ((cmd->flags & SPI_FLAG_NO_SLEEP) != 0 || + INTELSPI_IN_POLLING_MODE() || cold) { /* We cannot wait with mtx_sleep if we're called from e.g. an ithread */ poll_limit = 2000; while (!intelspi_transact(sc) && poll_limit-- > 0) @@ -449,7 +473,8 @@ intelspi_transfer(device_t dev, device_t child, struct spi_command *cmd) /* Release the controller and wakeup the next thread waiting for it. */ sc->sc_flags = 0; - wakeup_one(dev); + if (!INTELSPI_IN_POLLING_MODE()) + wakeup_one(dev); INTELSPI_UNLOCK(sc); /* diff --git a/sys/dev/intel/spi.h b/sys/dev/intel/spi.h index bd79ec1e812a..fa145f8f73d7 100644 --- a/sys/dev/intel/spi.h +++ b/sys/dev/intel/spi.h @@ -54,7 +54,7 @@ struct intelspi_softc { struct spi_command *sc_cmd; uint32_t sc_len; uint32_t sc_read; - uint32_t sc_flags; + volatile uint32_t sc_flags; uint32_t sc_written; uint32_t sc_clock; uint32_t sc_mode;
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