Date: Tue, 03 Sep 2019 14:07:25 -0000 From: Ian Lepore <ian@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org Subject: svn commit: r346561 - stable/11/sys/arm/arm Message-ID: <201904221523.x3MFN7IX074050@repo.freebsd.org>
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Author: ian Date: Mon Apr 22 15:23:06 2019 New Revision: 346561 URL: https://svnweb.freebsd.org/changeset/base/346561 Log: MFC r346312: Only set up the interrupts that will actually be used in arm generic_timer. The code previously set up interrupt handlers for all the interrupt resources available, including for timers that are not in use. That could lead to interrupt storms. For example, if boot firmware enabled the virtual timer but the kernel is using the physical timer, it could get flooded with interrupts on the virtual timer which it cannot shut off. By only setting up an interrupt handler for the hardware that will actually be used, any interrupts from other timer units will remain masked in the interrupt controller. Differential Revision: https://reviews.freebsd.org/D19871 Modified: stable/11/sys/arm/arm/generic_timer.c Directory Properties: stable/11/ (props changed) Modified: stable/11/sys/arm/arm/generic_timer.c ============================================================================== --- stable/11/sys/arm/arm/generic_timer.c Mon Apr 22 15:20:46 2019 (r346560) +++ stable/11/sys/arm/arm/generic_timer.c Mon Apr 22 15:23:06 2019 (r346561) @@ -359,7 +359,7 @@ arm_tmr_attach(device_t dev) pcell_t clock; #endif int error; - int i; + int i, first_timer, last_timer; sc = device_get_softc(dev); if (arm_tmr_sc) @@ -391,17 +391,25 @@ arm_tmr_attach(device_t dev) return (ENXIO); } -#ifdef __arm__ - sc->physical = true; -#else /* __aarch64__ */ - /* If we do not have a virtual timer use the physical. */ - sc->physical = (sc->res[2] == NULL) ? true : false; +#ifdef __aarch64__ + /* Use the virtual timer if we have one. */ + if (sc->res[2] != NULL) { + sc->physical = false; + first_timer = 2; + last_timer = 2; + } else #endif + /* Otherwise set up the secure and non-secure physical timers. */ + { + sc->physical = true; + first_timer = 0; + last_timer = 1; + } arm_tmr_sc = sc; /* Setup secure, non-secure and virtual IRQs handler */ - for (i = 0; i < 3; i++) { + for (i = first_timer; i <= last_timer; i++) { /* If we do not have the interrupt, skip it. */ if (sc->res[i] == NULL) continue;
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