Author: gonzo Date: Sat Mar 10 02:49:58 2018 New Revision: 330727 URL: https://svnweb.freebsd.org/changeset/base/330727
Log: [rpi] remove IRQ support for BCM233x RNG Upstream DTBs don't provide IRQ lines for the RNG. Moreover, harvesting bytes as often as the RNG interrupt is triggered (87 times per sec) is an overkill. For these reasons, get rid of the interrupt mode and make callout mode the default, with random bits harvested every 4 seconds. Submitted by: Sylvain Garrigues <syl...@gmail.com> Reviewed by: ian, imp, manu, mmel Approved by: emaste MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D14541 Modified: head/sys/arm/broadcom/bcm2835/bcm2835_rng.c head/sys/dts/arm/rpi.dts head/sys/dts/arm/rpi2.dts Modified: head/sys/arm/broadcom/bcm2835/bcm2835_rng.c ============================================================================== --- head/sys/arm/broadcom/bcm2835/bcm2835_rng.c Sat Mar 10 02:15:45 2018 (r330726) +++ head/sys/arm/broadcom/bcm2835/bcm2835_rng.c Sat Mar 10 02:49:58 2018 (r330727) @@ -51,10 +51,6 @@ __FBSDID("$FreeBSD$"); #include <dev/random/randomdev.h> #include <dev/random/random_harvestq.h> -#if !defined(BCM2835_RNG_USE_CALLOUT) -#define BCM2835_RNG_USE_INTERRUPT -#endif - static device_attach_t bcm2835_rng_attach; static device_detach_t bcm2835_rng_detach; static device_probe_t bcm2835_rng_probe; @@ -92,18 +88,15 @@ static device_probe_t bcm2835_rng_probe; #define RNG_NUM_OSCILLATORS 6 #define RNG_STALL_COUNT_DEFAULT 10 +#define RNG_CALLOUT_TICKS (hz * 4) + struct bcm2835_rng_softc { device_t sc_dev; struct resource * sc_mem_res; struct resource * sc_irq_res; void * sc_intr_hdl; -#if defined(BCM2835_RNG_USE_CALLOUT) || defined(BCM2835_RNG_USE_INTERRUPT) uint32_t sc_buf[RNG_FIFO_WORDS]; -#endif -#if defined(BCM2835_RNG_USE_CALLOUT) struct callout sc_rngto; - int sc_rnghz; -#endif int sc_stall_count; int sc_rbg2x; long sc_underrun; @@ -214,20 +207,7 @@ bcm2835_rng_disable_intr(struct bcm2835_rng_softc *sc) bcm2835_rng_write4(sc, RNG_INT_MASK, mask); } -#if defined(BCM2835_RNG_USE_INTERRUPT) static void -bcm2835_rng_enable_intr(struct bcm2835_rng_softc *sc) -{ - uint32_t mask; - - /* Clear the interrupt off bit in the interrupt mask register */ - mask = bcm2835_rng_read4(sc, RNG_INT_MASK); - mask &= ~RNG_INT_OFF_BIT; - bcm2835_rng_write4(sc, RNG_INT_MASK, mask); -} -#endif - -static void bcm2835_rng_start(struct bcm2835_rng_softc *sc) { uint32_t ctrl; @@ -244,11 +224,6 @@ bcm2835_rng_start(struct bcm2835_rng_softc *sc) if (sc->sc_rbg2x) ctrl |= RNG_RBG2X; bcm2835_rng_write4(sc, RNG_CTRL, ctrl); - -#if defined(BCM2835_RNG_USE_INTERRUPT) - /* Enable the interrupt */ - bcm2835_rng_enable_intr(sc); -#endif } static void @@ -263,12 +238,13 @@ bcm2835_rng_stop(struct bcm2835_rng_softc *sc) } static void -bcm2835_rng_harvest(struct bcm2835_rng_softc *sc) +bcm2835_rng_harvest(void *arg) { uint32_t *dest; uint32_t status; u_int cnt, nread, num_avail, num_words; int seen_underrun, num_stalls; + struct bcm2835_rng_softc *sc = arg; dest = sc->sc_buf; nread = num_words = 0; @@ -316,9 +292,7 @@ bcm2835_rng_harvest(struct bcm2835_rng_softc *sc) random_harvest_queue(sc->sc_buf, cnt, cnt * NBBY / 2, RANDOM_PURE_BROADCOM); -#if defined(BCM2835_RNG_USE_CALLOUT) - callout_reset(&sc->sc_rngto, sc->sc_rnghz, bcm2835_rng_harvest, sc); -#endif + callout_reset(&sc->sc_rngto, RNG_CALLOUT_TICKS, bcm2835_rng_harvest, sc); } static int @@ -390,10 +364,10 @@ bcm2835_rng_attach(device_t dev) sc = device_get_softc(dev); sc->sc_dev = dev; sc->sc_stall_count = RNG_STALL_COUNT_DEFAULT; -#ifdef BCM2835_RNG_USE_CALLOUT + /* Initialize callout */ callout_init(&sc->sc_rngto, CALLOUT_MPSAFE); -#endif + TUNABLE_INT_FETCH("bcmrng.2xspeed", &sc->sc_rbg2x); TUNABLE_INT_FETCH("bcmrng.stall_count", &sc->sc_stall_count); @@ -406,27 +380,6 @@ bcm2835_rng_attach(device_t dev) return (ENXIO); } -#if defined(BCM2835_RNG_USE_INTERRUPT) - /* Allocate interrupt resource */ - rid = 0; - sc->sc_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid, - RF_SHAREABLE | RF_ACTIVE); - if (sc->sc_irq_res == NULL) { - bcm2835_rng_detach(dev); - return (ENXIO); - } - - /* Set up the interrupt handler */ - error = bus_setup_intr(dev, sc->sc_irq_res, INTR_TYPE_BIO | INTR_MPSAFE, - NULL, (driver_intr_t *)bcm2835_rng_harvest, sc, &sc->sc_intr_hdl); - if (error) { - device_printf(dev, "Failed to set up IRQ\n"); - sc->sc_intr_hdl = NULL; - bcm2835_rng_detach(dev); - return (error); - } -#endif - /* Start the RNG */ bcm2835_rng_start(sc); @@ -461,14 +414,11 @@ bcm2835_rng_attach(device_t dev) sysctl_bcm2835_rng_dump, "S", "Dump RNG registers"); #endif -#if defined(BCM2835_RNG_USE_CALLOUT) - /* Reset callout */ - if (hz >= 100) - sc->sc_rnghz = hz / 100; - else - sc->sc_rnghz = 1; - callout_reset(&sc->sc_rngto, sc->sc_rnghz, bcm2835_rng_harvest, sc); -#endif + /* + * Schedule the initial harvesting one second from now, which should give the + * hardware RNG plenty of time to generate the first random bytes. + */ + callout_reset(&sc->sc_rngto, hz, bcm2835_rng_harvest, sc); return (0); } @@ -477,9 +427,6 @@ static int bcm2835_rng_detach(device_t dev) { struct bcm2835_rng_softc *sc; -#if defined(BCM2835_RNG_USE_INTERRUPT) - int error; -#endif sc = device_get_softc(dev); @@ -487,27 +434,7 @@ bcm2835_rng_detach(device_t dev) bcm2835_rng_stop(sc); /* Drain the callout it */ -#if defined(BCM2835_RNG_USE_CALLOUT) callout_drain(&sc->sc_rngto); -#endif - -#if defined(BCM2835_RNG_USE_INTERRUPT) - /* Tear down the interrupt */ - if (sc->sc_irq_res && sc->sc_intr_hdl) { - error = bus_teardown_intr(dev, sc->sc_irq_res, sc->sc_intr_hdl); - if (error != 0) { - device_printf(dev, "could not tear down IRQ\n"); - return (error); - } - sc->sc_intr_hdl = NULL; - } - - /* Release interrupt resource */ - if (sc->sc_irq_res) { - bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res); - sc->sc_irq_res = NULL; - } -#endif /* Release memory resource */ if (sc->sc_mem_res != NULL) Modified: head/sys/dts/arm/rpi.dts ============================================================================== --- head/sys/dts/arm/rpi.dts Sat Mar 10 02:15:45 2018 (r330726) +++ head/sys/dts/arm/rpi.dts Sat Mar 10 02:49:58 2018 (r330727) @@ -51,10 +51,6 @@ status = "okay"; }; - rng@7e104000 { - interrupts = <2 29>; - } - spi@7e204000 { status = "okay"; }; Modified: head/sys/dts/arm/rpi2.dts ============================================================================== --- head/sys/dts/arm/rpi2.dts Sat Mar 10 02:15:45 2018 (r330726) +++ head/sys/dts/arm/rpi2.dts Sat Mar 10 02:49:58 2018 (r330727) @@ -51,10 +51,6 @@ status = "okay"; }; - rng@7e104000 { - interrupts = <2 29>; - } - spi@7e204000 { status = "okay"; }; _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
