Add a helper library for attaching interrupt handlers in userspace.
---
Makefile | 1 +
libirqhelp/Makefile | 28 ++++
libirqhelp/irqhelp.c | 362 +++++++++++++++++++++++++++++++++++++++++++
libirqhelp/irqhelp.h | 49 ++++++
4 files changed, 440 insertions(+)
create mode 100644 libirqhelp/Makefile
create mode 100644 libirqhelp/irqhelp.c
create mode 100644 libirqhelp/irqhelp.h
diff --git a/Makefile b/Makefile
index 874349c06..4d8482219 100644
--- a/Makefile
+++ b/Makefile
@@ -32,6 +32,7 @@ lib-subdirs = libshouldbeinlibc libihash libiohelp libports \
libhurd-slab \
libbpf \
libmachdev \
+ libirqhelp \
# Hurd programs
prog-subdirs = auth proc exec term \
diff --git a/libirqhelp/Makefile b/libirqhelp/Makefile
new file mode 100644
index 000000000..c32632abe
--- /dev/null
+++ b/libirqhelp/Makefile
@@ -0,0 +1,28 @@
+# Copyright (C) 2022 Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 2, or (at
+# your option) any later version.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+dir := libirqhelp
+makemode := library
+
+SRCS = irqhelp.c acpiUser.c
+
+OBJS = $(SRCS:.c=.o)
+HURDLIBS =
+LDLIBS += -lpthread
+libname = libirqhelp
+installhdrs = irqhelp.h
+
+include ../Makeconf
diff --git a/libirqhelp/irqhelp.c b/libirqhelp/irqhelp.c
new file mode 100644
index 000000000..32e59c92c
--- /dev/null
+++ b/libirqhelp/irqhelp.c
@@ -0,0 +1,362 @@
+/* Library providing helper functions for userspace irq handling.
+ Copyright (C) 2022 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License as
+ published by the Free Software Foundation; either version 2, or (at
+ your option) any later version.
+
+ This program is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include "irqhelp.h"
+
+#include <sys/types.h>
+#include <sys/queue.h>
+
+#include <fcntl.h>
+#include <inttypes.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <hurd.h>
+#include <hurd/paths.h>
+#include <device/notify.h>
+#include <device/device.h>
+#include "acpi_U.h"
+#include <mach.h>
+#include <stdbool.h>
+
+#define IRQ_THREAD_PRIORITY 2
+#define log_error(fmt...) fprintf(stderr, ## fmt)
+
+struct irq {
+ void (*handler)(void *);
+ void *context;
+ int gsi;
+ mach_port_t port;
+ bool enabled;
+ bool shutdown;
+ pthread_mutex_t irqlock;
+ pthread_cond_t irqcond;
+};
+
+static mach_port_t irqdev;
+static mach_port_t acpidev;
+
+static error_t
+get_acpi(void)
+{
+ error_t err = 0;
+ mach_port_t tryacpi, device_master;
+
+ acpidev = MACH_PORT_NULL;
+ err = get_privileged_ports (0, &device_master);
+ if (!err)
+ {
+ err = device_open (device_master, D_READ, "acpi", &tryacpi);
+ mach_port_deallocate (mach_task_self (), device_master);
+ if (!err)
+ {
+ acpidev = tryacpi;
+ return 0;
+ }
+ }
+
+ tryacpi = file_name_lookup (_SERVERS_ACPI, O_RDONLY, 0);
+ if (tryacpi == MACH_PORT_NULL)
+ return ENODEV;
+
+ acpidev = tryacpi;
+ return 0;
+}
+
+static error_t
+get_irq(void)
+{
+ error_t err = 0;
+ mach_port_t tryirq, device_master;
+
+ irqdev = MACH_PORT_NULL;
+
+ err = get_privileged_ports (0, &device_master);
+ if (err)
+ return err;
+
+ err = device_open (device_master, D_READ|D_WRITE, "irq", &tryirq);
+ mach_port_deallocate (mach_task_self (), device_master);
+ if (err)
+ return err;
+
+ irqdev = tryirq;
+ return err;
+}
+
+static void
+toggle_irq(struct irq *irq, bool on)
+{
+ pthread_mutex_lock (&irq->irqlock);
+ irq->enabled = on;
+ pthread_mutex_unlock (&irq->irqlock);
+
+ if (on)
+ pthread_cond_signal (&irq->irqcond);
+}
+
+error_t
+irqhelp_init(void)
+{
+ static bool inited = false;
+ error_t err;
+
+ if (inited)
+ {
+ log_error("already inited\n");
+ return 0;
+ }
+
+ err = get_irq();
+ if (err)
+ {
+ log_error("cannot grab irq device\n");
+ return err;
+ }
+
+ err = get_acpi();
+ if (err)
+ {
+ log_error("cannot grab acpi device\n");
+ return err;
+ }
+
+ inited = true;
+ return 0;
+}
+
+void
+irqhelp_disable_irq(struct irq *irq)
+{
+ if (!irq)
+ {
+ log_error("cannot disable this irq\n");
+ return;
+ }
+
+ toggle_irq(irq, false);
+}
+
+void
+irqhelp_enable_irq(struct irq *irq)
+{
+ if (!irq)
+ {
+ log_error("cannot enable this irq\n");
+ return;
+ }
+
+ toggle_irq(irq, true);
+}
+
+void *
+irqhelp_server_loop(void *arg)
+{
+ struct irq *irq = (struct irq *)arg;
+ mach_port_t master_host;
+ mach_port_t pset, psetcntl;
+ error_t err;
+
+ if (!irq)
+ {
+ log_error("cannot start this irq thread\n");
+ return NULL;
+ }
+
+ err = get_privileged_ports (&master_host, 0);
+ if (err)
+ {
+ log_error("cannot get master_host port\n");
+ return NULL;
+ }
+
+ err = thread_get_assignment (mach_thread_self (), &pset);
+ if (err)
+ goto fail;
+
+ err = host_processor_set_priv (master_host, pset, &psetcntl);
+ if (err)
+ goto fail;
+
+ thread_max_priority (mach_thread_self (), psetcntl, 0);
+ err = thread_priority (mach_thread_self (), IRQ_THREAD_PRIORITY, 0);
+ if (err)
+ goto fail;
+
+ mach_port_deallocate (mach_task_self (), master_host);
+
+ int interrupt_demuxer (mach_msg_header_t *inp,
+ mach_msg_header_t *outp)
+ {
+ static bool printed0 = false;
+ static bool printed1 = false;
+ device_intr_notification_t *n = (device_intr_notification_t *) inp;
+
+ ((mig_reply_header_t *) outp)->RetCode = MIG_NO_REPLY;
+ if (n->intr_header.msgh_id != DEVICE_INTR_NOTIFY)
+ {
+ if (!printed0)
+ {
+ log_error("msg received is not an interrupt\n");
+ printed0 = true;
+ }
+ return 0;
+ }
+
+ /* FIXME: id <-> gsi now has an indirection, assuming 1:1 */
+ if (n->id != irq->gsi)
+ {
+ if (!printed1)
+ {
+ log_error("interrupt expected on irq %d arrived on irq %d\n",
irq->gsi, n->id);
+ printed1 = true;
+ }
+ return 0;
+ }
+
+ /* wait if irq disabled */
+ pthread_mutex_lock (&irq->irqlock);
+ while (!irq->enabled)
+ pthread_cond_wait (&irq->irqcond, &irq->irqlock);
+ pthread_mutex_unlock (&irq->irqlock);
+
+ /* call handler */
+ irq->handler(irq->context);
+
+ /* ACK interrupt */
+ device_intr_ack (irqdev, irq->port, MACH_MSG_TYPE_MAKE_SEND);
+
+ if (irq->shutdown)
+ mach_port_deallocate (mach_task_self (), irq->port);
+
+ return 1;
+ }
+
+ /* Server loop */
+ mach_msg_server (interrupt_demuxer, 0, irq->port);
+ goto done;
+
+fail:
+ log_error("failed to register irq %d\n", irq->gsi);
+
+done:
+ pthread_cond_destroy(&irq->irqcond);
+ pthread_mutex_destroy(&irq->irqlock);
+ free(irq);
+ return NULL;
+}
+
+static struct irq *
+interrupt_register(int gsi,
+ void (*handler)(void *),
+ void *context)
+{
+ error_t err;
+ struct irq *irq = NULL;
+ mach_port_t delivery_port;
+
+ irq = malloc(sizeof(struct irq));
+ if (!irq)
+ {
+ log_error("cannot malloc irq\n");
+ return NULL;
+ }
+
+ irq->handler = handler;
+ irq->context = context;
+ irq->gsi = gsi;
+ irq->enabled = true; /* avoid deadlock by not requiring initial explicit
enable */
+ irq->shutdown = false;
+ pthread_mutex_init (&irq->irqlock, NULL);
+ pthread_cond_init (&irq->irqcond, NULL);
+
+ err = mach_port_allocate (mach_task_self (), MACH_PORT_RIGHT_RECEIVE,
+ &delivery_port);
+ if (err)
+ {
+ log_error("cannot allocate mach port\n");
+ return NULL;
+ }
+
+ irq->port = delivery_port;
+
+ err = device_intr_register(irqdev, irq->gsi,
+ 0, irq->port,
+ MACH_MSG_TYPE_MAKE_SEND);
+ if (err)
+ {
+ log_error("device_intr_register failed with %d\n", err);
+ return NULL;
+ }
+
+ return irq;
+}
+
+struct irq *
+irqhelp_install_interrupt_handler(int gsi,
+ int bus,
+ int dev,
+ int fun,
+ void (*handler)(void *),
+ void *context)
+{
+ error_t err;
+
+ if (!handler)
+ {
+ log_error("no handler\n");
+ return NULL;
+ }
+
+ if (gsi < 0)
+ {
+ if ((bus < 0) || (dev < 0) || (fun < 0))
+ {
+ log_error("invalid b/d/f\n");
+ return NULL;
+ }
+
+ /* We need to call acpi translator to get gsi */
+ err = acpi_get_pci_irq (acpidev, bus, dev, fun, &gsi);
+ if (err)
+ {
+ log_error("tried acpi to get pci gsi and failed for %02x:%02x.%d\n",
bus, dev, fun);
+ return NULL;
+ }
+ }
+
+ return interrupt_register(gsi, handler, context);
+}
+
+error_t
+irqhelp_remove_interrupt_handler(struct irq *irq)
+{
+ if (!irq)
+ {
+ log_error("cannot deregister this irq\n");
+ return ENODEV;
+ }
+
+ irq->shutdown = true;
+
+ /* enable irq to fall through to shutdown check */
+ toggle_irq(irq, true);
+
+ return 0;
+}
diff --git a/libirqhelp/irqhelp.h b/libirqhelp/irqhelp.h
new file mode 100644
index 000000000..4ebbed8b8
--- /dev/null
+++ b/libirqhelp/irqhelp.h
@@ -0,0 +1,49 @@
+/* Library providing helper functions for userspace irq handling.
+ Copyright (C) 2022 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License as
+ published by the Free Software Foundation; either version 2, or (at
+ your option) any later version.
+
+ This program is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#ifndef _HURD_IRQHELP_
+#define _HURD_IRQHELP_
+
+#include <mach.h>
+#include <hurd/hurd_types.h>
+#include <pthread.h>
+#include <stdlib.h>
+
+struct irq;
+
+/* Call once before using other functions */
+error_t irqhelp_init(void);
+
+/* Accepts gsi or bus/dev/fun or both, but cant be all -1.
+ If gsi is -1, will lookup the gsi via ACPI.
+ If bus/dev/fun are -1, must pass in gsi.
+ Returns a pointer to be used with other functions. */
+struct irq * irqhelp_install_interrupt_handler(int gsi, int bus, int dev, int
fun,
+ void (*handler)(void *), void
*context);
+/* Install as pthread */
+void * irqhelp_server_loop(void *arg);
+
+/* Enable an irq */
+void irqhelp_enable_irq(struct irq *irq);
+
+/* Disable an irq */
+void irqhelp_disable_irq(struct irq *irq);
+
+/* Call to deregister a handler */
+error_t irqhelp_remove_interrupt_handler(struct irq *irq);
+
+#endif
--
2.43.0
