diff --git a/sys/arm/arm/machdep_intr.c b/sys/arm/arm/machdep_intr.c index e2fb34ce93c8..cc2e67a6211e 100644 --- a/sys/arm/arm/machdep_intr.c +++ b/sys/arm/arm/machdep_intr.c @@ -1,228 +1,229 @@ /*- * Copyright (c) 2015-2016 Svatopluk Kraus * Copyright (c) 2015-2016 Michal Meloun * 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. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, 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 DAMAGE. */ #include "opt_platform.h" #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "pic_if.h" #ifdef SMP #define INTR_IPI_NAMELEN (MAXCOMLEN + 1) struct intr_ipi { intr_ipi_handler_t * ii_handler; void * ii_handler_arg; intr_ipi_send_t * ii_send; void * ii_send_arg; char ii_name[INTR_IPI_NAMELEN]; u_long * ii_count; }; static struct intr_ipi ipi_sources[INTR_IPI_COUNT]; #endif /* * arm_irq_memory_barrier() * * Ensure all writes to device memory have reached devices before proceeding. * * This is intended to be called from the post-filter and post-thread routines * of an interrupt controller implementation. A peripheral device driver should * use bus_space_barrier() if it needs to ensure a write has reached the * hardware for some reason other than clearing interrupt conditions. * * The need for this function arises from the ARM weak memory ordering model. * Writes to locations mapped with the Device attribute bypass any caches, but * are buffered. Multiple writes to the same device will be observed by that * device in the order issued by the cpu. Writes to different devices may * appear at those devices in a different order than issued by the cpu. That * is, if the cpu writes to device A then device B, the write to device B could * complete before the write to device A. * * Consider a typical device interrupt handler which services the interrupt and * writes to a device status-acknowledge register to clear the interrupt before * returning. That write is posted to the L2 controller which "immediately" * places it in a store buffer and automatically drains that buffer. This can * be less immediate than you'd think... There may be no free slots in the store * buffers, so an existing buffer has to be drained first to make room. The * target bus may be busy with other traffic (such as DMA for various devices), * delaying the drain of the store buffer for some indeterminate time. While * all this delay is happening, execution proceeds on the CPU, unwinding its way * out of the interrupt call stack to the point where the interrupt driver code * is ready to EOI and unmask the interrupt. The interrupt controller may be * accessed via a faster bus than the hardware whose handler just ran; the write * to unmask and EOI the interrupt may complete quickly while the device write * to ack and clear the interrupt source is still lingering in a store buffer * waiting for access to a slower bus. With the interrupt unmasked at the * interrupt controller but still active at the device, as soon as interrupts * are enabled on the core the device re-interrupts immediately: now you've got * a spurious interrupt on your hands. * * The right way to fix this problem is for every device driver to use the * proper bus_space_barrier() calls in its interrupt handler. For ARM a single * barrier call at the end of the handler would work. This would have to be * done to every driver in the system, not just arm-specific drivers. * * Another potential fix is to map all device memory as Strongly-Ordered rather * than Device memory, which takes the store buffers out of the picture. This * has a pretty big impact on overall system performance, because each strongly * ordered memory access causes all L2 store buffers to be drained. * * A compromise solution is to have the interrupt controller implementation call * this function to establish a barrier between writes to the interrupt-source * device and writes to the interrupt controller device. * * This takes the interrupt number as an argument, and currently doesn't use it. * The plan is that maybe some day there is a way to flag certain interrupts as * "memory barrier safe" and we can avoid this overhead with them. */ void arm_irq_memory_barrier(uintptr_t irq) { dsb(); cpu_l2cache_drain_writebuf(); } #ifdef SMP static inline struct intr_ipi * intr_ipi_lookup(u_int ipi) { if (ipi >= INTR_IPI_COUNT) panic("%s: no such IPI %u", __func__, ipi); return (&ipi_sources[ipi]); } void intr_ipi_dispatch(u_int ipi, struct trapframe *tf) { void *arg; struct intr_ipi *ii; ii = intr_ipi_lookup(ipi); if (ii->ii_count == NULL) panic("%s: not setup IPI %u", __func__, ipi); intr_ipi_increment_count(ii->ii_count, PCPU_GET(cpuid)); /* * Supply ipi filter with trapframe argument * if none is registered. */ arg = ii->ii_handler_arg != NULL ? ii->ii_handler_arg : tf; ii->ii_handler(arg); } void intr_ipi_send(cpuset_t cpus, u_int ipi) { struct intr_ipi *ii; ii = intr_ipi_lookup(ipi); if (ii->ii_count == NULL) panic("%s: not setup IPI %u", __func__, ipi); ii->ii_send(ii->ii_send_arg, cpus, ipi); } void intr_ipi_setup(u_int ipi, const char *name, intr_ipi_handler_t *hand, void *h_arg, intr_ipi_send_t *send, void *s_arg) { struct intr_ipi *ii; ii = intr_ipi_lookup(ipi); KASSERT(hand != NULL, ("%s: ipi %u no handler", __func__, ipi)); KASSERT(send != NULL, ("%s: ipi %u no sender", __func__, ipi)); KASSERT(ii->ii_count == NULL, ("%s: ipi %u reused", __func__, ipi)); ii->ii_handler = hand; ii->ii_handler_arg = h_arg; ii->ii_send = send; ii->ii_send_arg = s_arg; strlcpy(ii->ii_name, name, INTR_IPI_NAMELEN); ii->ii_count = intr_ipi_setup_counters(name); } /* * Send IPI thru interrupt controller. */ static void pic_ipi_send(void *arg, cpuset_t cpus, u_int ipi) { KASSERT(intr_irq_root_dev != NULL, ("%s: no root attached", __func__)); PIC_IPI_SEND(intr_irq_root_dev, arg, cpus, ipi); } /* * Setup IPI handler on interrupt controller. * * Not SMP coherent. */ int intr_pic_ipi_setup(u_int ipi, const char *name, intr_ipi_handler_t *hand, void *arg) { int error; struct intr_irqsrc *isrc; KASSERT(intr_irq_root_dev != NULL, ("%s: no root attached", __func__)); error = PIC_IPI_SETUP(intr_irq_root_dev, ipi, &isrc); if (error != 0) return (error); isrc->isrc_handlers++; intr_ipi_setup(ipi, name, hand, arg, pic_ipi_send, isrc); + PIC_ENABLE_INTR(intr_irq_root_dev, isrc); return (0); } #endif