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-rw-r--r--arch/um/drivers/chan_kern.c53
-rw-r--r--arch/um/drivers/line.c2
-rw-r--r--arch/um/drivers/random.c11
-rw-r--r--arch/um/drivers/ubd_kern.c4
-rw-r--r--arch/um/include/shared/irq_user.h12
-rw-r--r--arch/um/include/shared/os.h17
-rw-r--r--arch/um/kernel/irq.c460
-rw-r--r--arch/um/os-Linux/irq.c202
8 files changed, 444 insertions, 317 deletions
diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
index acbe6c67afba..05588f9466c7 100644
--- a/arch/um/drivers/chan_kern.c
+++ b/arch/um/drivers/chan_kern.c
@@ -171,56 +171,19 @@ int enable_chan(struct line *line)
return err;
}
-/* Items are added in IRQ context, when free_irq can't be called, and
- * removed in process context, when it can.
- * This handles interrupt sources which disappear, and which need to
- * be permanently disabled. This is discovered in IRQ context, but
- * the freeing of the IRQ must be done later.
- */
-static DEFINE_SPINLOCK(irqs_to_free_lock);
-static LIST_HEAD(irqs_to_free);
-
-void free_irqs(void)
-{
- struct chan *chan;
- LIST_HEAD(list);
- struct list_head *ele;
- unsigned long flags;
-
- spin_lock_irqsave(&irqs_to_free_lock, flags);
- list_splice_init(&irqs_to_free, &list);
- spin_unlock_irqrestore(&irqs_to_free_lock, flags);
-
- list_for_each(ele, &list) {
- chan = list_entry(ele, struct chan, free_list);
-
- if (chan->input && chan->enabled)
- um_free_irq(chan->line->driver->read_irq, chan);
- if (chan->output && chan->enabled)
- um_free_irq(chan->line->driver->write_irq, chan);
- chan->enabled = 0;
- }
-}
-
static void close_one_chan(struct chan *chan, int delay_free_irq)
{
- unsigned long flags;
-
if (!chan->opened)
return;
- if (delay_free_irq) {
- spin_lock_irqsave(&irqs_to_free_lock, flags);
- list_add(&chan->free_list, &irqs_to_free);
- spin_unlock_irqrestore(&irqs_to_free_lock, flags);
- }
- else {
- if (chan->input && chan->enabled)
- um_free_irq(chan->line->driver->read_irq, chan);
- if (chan->output && chan->enabled)
- um_free_irq(chan->line->driver->write_irq, chan);
- chan->enabled = 0;
- }
+ /* we can safely call free now - it will be marked
+ * as free and freed once the IRQ stopped processing
+ */
+ if (chan->input && chan->enabled)
+ um_free_irq(chan->line->driver->read_irq, chan);
+ if (chan->output && chan->enabled)
+ um_free_irq(chan->line->driver->write_irq, chan);
+ chan->enabled = 0;
if (chan->ops->close != NULL)
(*chan->ops->close)(chan->fd, chan->data);
diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index 366e57f5e8d6..8d80b27502e6 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -284,7 +284,7 @@ int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
if (err)
return err;
if (output)
- err = um_request_irq(driver->write_irq, fd, IRQ_WRITE,
+ err = um_request_irq(driver->write_irq, fd, IRQ_NONE,
line_write_interrupt, IRQF_SHARED,
driver->write_irq_name, data);
return err;
diff --git a/arch/um/drivers/random.c b/arch/um/drivers/random.c
index 37c51a6be690..778a0e52d5a5 100644
--- a/arch/um/drivers/random.c
+++ b/arch/um/drivers/random.c
@@ -13,6 +13,7 @@
#include <linux/miscdevice.h>
#include <linux/delay.h>
#include <linux/uaccess.h>
+#include <init.h>
#include <irq_kern.h>
#include <os.h>
@@ -154,7 +155,14 @@ err_out_cleanup_hw:
/*
* rng_cleanup - shutdown RNG module
*/
-static void __exit rng_cleanup (void)
+
+static void cleanup(void)
+{
+ free_irq_by_fd(random_fd);
+ os_close_file(random_fd);
+}
+
+static void __exit rng_cleanup(void)
{
os_close_file(random_fd);
misc_deregister (&rng_miscdev);
@@ -162,6 +170,7 @@ static void __exit rng_cleanup (void)
module_init (rng_init);
module_exit (rng_cleanup);
+__uml_exitcall(cleanup);
MODULE_DESCRIPTION("UML Host Random Number Generator (RNG) driver");
MODULE_LICENSE("GPL");
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index b55fe9bf5d3e..d4e8c497ae86 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -1587,11 +1587,11 @@ int io_thread(void *arg)
do {
res = os_write_file(kernel_fd, ((char *) io_req_buffer) + written, n);
- if (res > 0) {
+ if (res >= 0) {
written += res;
} else {
if (res != -EAGAIN) {
- printk("io_thread - read failed, fd = %d, "
+ printk("io_thread - write failed, fd = %d, "
"err = %d\n", kernel_fd, -n);
}
}
diff --git a/arch/um/include/shared/irq_user.h b/arch/um/include/shared/irq_user.h
index df5633053957..a7a6120f19d5 100644
--- a/arch/um/include/shared/irq_user.h
+++ b/arch/um/include/shared/irq_user.h
@@ -7,6 +7,7 @@
#define __IRQ_USER_H__
#include <sysdep/ptrace.h>
+#include <stdbool.h>
struct irq_fd {
struct irq_fd *next;
@@ -15,10 +16,17 @@ struct irq_fd {
int type;
int irq;
int events;
- int current_events;
+ bool active;
+ bool pending;
+ bool purge;
};
-enum { IRQ_READ, IRQ_WRITE };
+#define IRQ_READ 0
+#define IRQ_WRITE 1
+#define IRQ_NONE 2
+#define MAX_IRQ_TYPE (IRQ_NONE + 1)
+
+
struct siginfo;
extern void sigio_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs);
diff --git a/arch/um/include/shared/os.h b/arch/um/include/shared/os.h
index d8ddaf9790d2..048ae37eb5aa 100644
--- a/arch/um/include/shared/os.h
+++ b/arch/um/include/shared/os.h
@@ -290,15 +290,16 @@ extern void halt_skas(void);
extern void reboot_skas(void);
/* irq.c */
-extern int os_waiting_for_events(struct irq_fd *active_fds);
-extern int os_create_pollfd(int fd, int events, void *tmp_pfd, int size_tmpfds);
-extern void os_free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg,
- struct irq_fd *active_fds, struct irq_fd ***last_irq_ptr2);
-extern void os_free_irq_later(struct irq_fd *active_fds,
- int irq, void *dev_id);
-extern int os_get_pollfd(int i);
-extern void os_set_pollfd(int i, int fd);
+extern int os_waiting_for_events_epoll(void);
+extern void *os_epoll_get_data_pointer(int index);
+extern int os_epoll_triggered(int index, int events);
+extern int os_event_mask(int irq_type);
+extern int os_setup_epoll(void);
+extern int os_add_epoll_fd(int events, int fd, void *data);
+extern int os_mod_epoll_fd(int events, int fd, void *data);
+extern int os_del_epoll_fd(int fd);
extern void os_set_ioignore(void);
+extern void os_close_epoll_fd(void);
/* sigio.c */
extern int add_sigio_fd(int fd);
diff --git a/arch/um/kernel/irq.c b/arch/um/kernel/irq.c
index 23cb9350d47e..980148d56537 100644
--- a/arch/um/kernel/irq.c
+++ b/arch/um/kernel/irq.c
@@ -1,4 +1,6 @@
/*
+ * Copyright (C) 2017 - Cambridge Greys Ltd
+ * Copyright (C) 2011 - 2014 Cisco Systems Inc
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
* Derived (i.e. mostly copied) from arch/i386/kernel/irq.c:
@@ -16,243 +18,361 @@
#include <as-layout.h>
#include <kern_util.h>
#include <os.h>
+#include <irq_user.h>
-/*
- * This list is accessed under irq_lock, except in sigio_handler,
- * where it is safe from being modified. IRQ handlers won't change it -
- * if an IRQ source has vanished, it will be freed by free_irqs just
- * before returning from sigio_handler. That will process a separate
- * list of irqs to free, with its own locking, coming back here to
- * remove list elements, taking the irq_lock to do so.
+
+/* When epoll triggers we do not know why it did so
+ * we can also have different IRQs for read and write.
+ * This is why we keep a small irq_fd array for each fd -
+ * one entry per IRQ type
*/
-static struct irq_fd *active_fds = NULL;
-static struct irq_fd **last_irq_ptr = &active_fds;
-extern void free_irqs(void);
+struct irq_entry {
+ struct irq_entry *next;
+ int fd;
+ struct irq_fd *irq_array[MAX_IRQ_TYPE + 1];
+};
+
+static struct irq_entry *active_fds;
+
+static DEFINE_SPINLOCK(irq_lock);
+
+static void irq_io_loop(struct irq_fd *irq, struct uml_pt_regs *regs)
+{
+/*
+ * irq->active guards against reentry
+ * irq->pending accumulates pending requests
+ * if pending is raised the irq_handler is re-run
+ * until pending is cleared
+ */
+ if (irq->active) {
+ irq->active = false;
+ do {
+ irq->pending = false;
+ do_IRQ(irq->irq, regs);
+ } while (irq->pending && (!irq->purge));
+ if (!irq->purge)
+ irq->active = true;
+ } else {
+ irq->pending = true;
+ }
+}
void sigio_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
{
- struct irq_fd *irq_fd;
- int n;
+ struct irq_entry *irq_entry;
+ struct irq_fd *irq;
+
+ int n, i, j;
while (1) {
- n = os_waiting_for_events(active_fds);
+ /* This is now lockless - epoll keeps back-referencesto the irqs
+ * which have trigger it so there is no need to walk the irq
+ * list and lock it every time. We avoid locking by turning off
+ * IO for a specific fd by executing os_del_epoll_fd(fd) before
+ * we do any changes to the actual data structures
+ */
+ n = os_waiting_for_events_epoll();
+
if (n <= 0) {
if (n == -EINTR)
continue;
- else break;
+ else
+ break;
}
- for (irq_fd = active_fds; irq_fd != NULL;
- irq_fd = irq_fd->next) {
- if (irq_fd->current_events != 0) {
- irq_fd->current_events = 0;
- do_IRQ(irq_fd->irq, regs);
+ for (i = 0; i < n ; i++) {
+ /* Epoll back reference is the entry with 3 irq_fd
+ * leaves - one for each irq type.
+ */
+ irq_entry = (struct irq_entry *)
+ os_epoll_get_data_pointer(i);
+ for (j = 0; j < MAX_IRQ_TYPE ; j++) {
+ irq = irq_entry->irq_array[j];
+ if (irq == NULL)
+ continue;
+ if (os_epoll_triggered(i, irq->events) > 0)
+ irq_io_loop(irq, regs);
+ if (irq->purge) {
+ irq_entry->irq_array[j] = NULL;
+ kfree(irq);
+ }
}
}
}
+}
+
+static int assign_epoll_events_to_irq(struct irq_entry *irq_entry)
+{
+ int i;
+ int events = 0;
+ struct irq_fd *irq;
- free_irqs();
+ for (i = 0; i < MAX_IRQ_TYPE ; i++) {
+ irq = irq_entry->irq_array[i];
+ if (irq != NULL)
+ events = irq->events | events;
+ }
+ if (events > 0) {
+ /* os_add_epoll will call os_mod_epoll if this already exists */
+ return os_add_epoll_fd(events, irq_entry->fd, irq_entry);
+ }
+ /* No events - delete */
+ return os_del_epoll_fd(irq_entry->fd);
}
-static DEFINE_SPINLOCK(irq_lock);
+
static int activate_fd(int irq, int fd, int type, void *dev_id)
{
- struct pollfd *tmp_pfd;
- struct irq_fd *new_fd, *irq_fd;
+ struct irq_fd *new_fd;
+ struct irq_entry *irq_entry;
+ int i, err, events;
unsigned long flags;
- int events, err, n;
err = os_set_fd_async(fd);
if (err < 0)
goto out;
- err = -ENOMEM;
- new_fd = kmalloc(sizeof(struct irq_fd), GFP_KERNEL);
- if (new_fd == NULL)
- goto out;
+ spin_lock_irqsave(&irq_lock, flags);
- if (type == IRQ_READ)
- events = UM_POLLIN | UM_POLLPRI;
- else events = UM_POLLOUT;
- *new_fd = ((struct irq_fd) { .next = NULL,
- .id = dev_id,
- .fd = fd,
- .type = type,
- .irq = irq,
- .events = events,
- .current_events = 0 } );
+ /* Check if we have an entry for this fd */
err = -EBUSY;
- spin_lock_irqsave(&irq_lock, flags);
- for (irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next) {
- if ((irq_fd->fd == fd) && (irq_fd->type == type)) {
- printk(KERN_ERR "Registering fd %d twice\n", fd);
- printk(KERN_ERR "Irqs : %d, %d\n", irq_fd->irq, irq);
- printk(KERN_ERR "Ids : 0x%p, 0x%p\n", irq_fd->id,
- dev_id);
+ for (irq_entry = active_fds;
+ irq_entry != NULL; irq_entry = irq_entry->next) {
+ if (irq_entry->fd == fd)
+ break;
+ }
+
+ if (irq_entry == NULL) {
+ /* This needs to be atomic as it may be called from an
+ * IRQ context.
+ */
+ irq_entry = kmalloc(sizeof(struct irq_entry), GFP_ATOMIC);
+ if (irq_entry == NULL) {
+ printk(KERN_ERR
+ "Failed to allocate new IRQ entry\n");
goto out_unlock;
}
+ irq_entry->fd = fd;
+ for (i = 0; i < MAX_IRQ_TYPE; i++)
+ irq_entry->irq_array[i] = NULL;
+ irq_entry->next = active_fds;
+ active_fds = irq_entry;
}
- if (type == IRQ_WRITE)
- fd = -1;
-
- tmp_pfd = NULL;
- n = 0;
+ /* Check if we are trying to re-register an interrupt for a
+ * particular fd
+ */
- while (1) {
- n = os_create_pollfd(fd, events, tmp_pfd, n);
- if (n == 0)
- break;
+ if (irq_entry->irq_array[type] != NULL) {
+ printk(KERN_ERR
+ "Trying to reregister IRQ %d FD %d TYPE %d ID %p\n",
+ irq, fd, type, dev_id
+ );
+ goto out_unlock;
+ } else {
+ /* New entry for this fd */
+
+ err = -ENOMEM;
+ new_fd = kmalloc(sizeof(struct irq_fd), GFP_ATOMIC);
+ if (new_fd == NULL)
+ goto out_unlock;
- /*
- * n > 0
- * It means we couldn't put new pollfd to current pollfds
- * and tmp_fds is NULL or too small for new pollfds array.
- * Needed size is equal to n as minimum.
- *
- * Here we have to drop the lock in order to call
- * kmalloc, which might sleep.
- * If something else came in and changed the pollfds array
- * so we will not be able to put new pollfd struct to pollfds
- * then we free the buffer tmp_fds and try again.
+ events = os_event_mask(type);
+
+ *new_fd = ((struct irq_fd) {
+ .id = dev_id,
+ .irq = irq,
+ .type = type,
+ .events = events,
+ .active = true,
+ .pending = false,
+ .purge = false
+ });
+ /* Turn off any IO on this fd - allows us to
+ * avoid locking the IRQ loop
*/
- spin_unlock_irqrestore(&irq_lock, flags);
- kfree(tmp_pfd);
-
- tmp_pfd = kmalloc(n, GFP_KERNEL);
- if (tmp_pfd == NULL)
- goto out_kfree;
-
- spin_lock_irqsave(&irq_lock, flags);
+ os_del_epoll_fd(irq_entry->fd);
+ irq_entry->irq_array[type] = new_fd;
}
- *last_irq_ptr = new_fd;
- last_irq_ptr = &new_fd->next;
-
+ /* Turn back IO on with the correct (new) IO event mask */
+ assign_epoll_events_to_irq(irq_entry);
spin_unlock_irqrestore(&irq_lock, flags);
-
- /*
- * This calls activate_fd, so it has to be outside the critical
- * section.
- */
- maybe_sigio_broken(fd, (type == IRQ_READ));
+ maybe_sigio_broken(fd, (type != IRQ_NONE));
return 0;
-
- out_unlock:
+out_unlock:
spin_unlock_irqrestore(&irq_lock, flags);
- out_kfree:
- kfree(new_fd);
- out:
+out:
return err;
}
-static void free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg)
+/*
+ * Walk the IRQ list and dispose of any unused entries.
+ * Should be done under irq_lock.
+ */
+
+static void garbage_collect_irq_entries(void)
{
- unsigned long flags;
+ int i;
+ bool reap;
+ struct irq_entry *walk;
+ struct irq_entry *previous = NULL;
+ struct irq_entry *to_free;
- spin_lock_irqsave(&irq_lock, flags);
- os_free_irq_by_cb(test, arg, active_fds, &last_irq_ptr);
- spin_unlock_irqrestore(&irq_lock, flags);
+ if (active_fds == NULL)
+ return;
+ walk = active_fds;
+ while (walk != NULL) {
+ reap = true;
+ for (i = 0; i < MAX_IRQ_TYPE ; i++) {
+ if (walk->irq_array[i] != NULL) {
+ reap = false;
+ break;
+ }
+ }
+ if (reap) {
+ if (previous == NULL)
+ active_fds = walk->next;
+ else
+ previous->next = walk->next;
+ to_free = walk;
+ } else {
+ to_free = NULL;
+ }
+ walk = walk->next;
+ if (to_free != NULL)
+ kfree(to_free);
+ }
}
-struct irq_and_dev {
- int irq;
- void *dev;
-};
+/*
+ * Walk the IRQ list and get the descriptor for our FD
+ */
-static int same_irq_and_dev(struct irq_fd *irq, void *d)
+static struct irq_entry *get_irq_entry_by_fd(int fd)
{
- struct irq_and_dev *data = d;
+ struct irq_entry *walk = active_fds;
- return ((irq->irq == data->irq) && (irq->id == data->dev));
+ while (walk != NULL) {
+ if (walk->fd == fd)
+ return walk;
+ walk = walk->next;
+ }
+ return NULL;
}
-static void free_irq_by_irq_and_dev(unsigned int irq, void *dev)
-{
- struct irq_and_dev data = ((struct irq_and_dev) { .irq = irq,
- .dev = dev });
- free_irq_by_cb(same_irq_and_dev, &data);
-}
+/*
+ * Walk the IRQ list and dispose of an entry for a specific
+ * device, fd and number. Note - if sharing an IRQ for read
+ * and writefor the same FD it will be disposed in either case.
+ * If this behaviour is undesirable use different IRQ ids.
+ */
-static int same_fd(struct irq_fd *irq, void *fd)
-{
- return (irq->fd == *((int *)fd));
-}
+#define IGNORE_IRQ 1
+#define IGNORE_DEV (1<<1)
-void free_irq_by_fd(int fd)
+static void do_free_by_irq_and_dev(
+ struct irq_entry *irq_entry,
+ unsigned int irq,
+ void *dev,
+ int flags
+)
{
- free_irq_by_cb(same_fd, &fd);
+ int i;
+ struct irq_fd *to_free;
+
+ for (i = 0; i < MAX_IRQ_TYPE ; i++) {
+ if (irq_entry->irq_array[i] != NULL) {
+ if (
+ ((flags & IGNORE_IRQ) ||
+ (irq_entry->irq_array[i]->irq == irq)) &&
+ ((flags & IGNORE_DEV) ||
+ (irq_entry->irq_array[i]->id == dev))
+ ) {
+ /* Turn off any IO on this fd - allows us to
+ * avoid locking the IRQ loop
+ */
+ os_del_epoll_fd(irq_entry->fd);
+ to_free = irq_entry->irq_array[i];
+ irq_entry->irq_array[i] = NULL;
+ assign_epoll_events_to_irq(irq_entry);
+ if (to_free->active)
+ to_free->purge = true;
+ else
+ kfree(to_free);
+ }
+ }
+ }
}
-/* Must be called with irq_lock held */
-static struct irq_fd *find_irq_by_fd(int fd, int irqnum, int *index_out)
+void free_irq_by_fd(int fd)
{
- struct irq_fd *irq;
- int i = 0;
- int fdi;
+ struct irq_entry *to_free;
+ unsigned long flags;
- for (irq = active_fds; irq != NULL; irq = irq->next) {
- if ((irq->fd == fd) && (irq->irq == irqnum))
- break;
- i++;
- }
- if (irq == NULL) {
- printk(KERN_ERR "find_irq_by_fd doesn't have descriptor %d\n",
- fd);
- goto out;
- }
- fdi = os_get_pollfd(i);
- if ((fdi != -1) && (fdi != fd)) {
- printk(KERN_ERR "find_irq_by_fd - mismatch between active_fds "
- "and pollfds, fd %d vs %d, need %d\n", irq->fd,
- fdi, fd);
- irq = NULL;
- goto out;
+ spin_lock_irqsave(&irq_lock, flags);
+ to_free = get_irq_entry_by_fd(fd);
+ if (to_free != NULL) {
+ do_free_by_irq_and_dev(
+ to_free,
+ -1,
+ NULL,
+ IGNORE_IRQ | IGNORE_DEV
+ );
}
- *index_out = i;
- out:
- return irq;
+ garbage_collect_irq_entries();
+ spin_unlock_irqrestore(&irq_lock, flags);
}
-void reactivate_fd(int fd, int irqnum)
+static void free_irq_by_irq_and_dev(unsigned int irq, void *dev)
{
- struct irq_fd *irq;
+ struct irq_entry *to_free;
unsigned long flags;
- int i;
spin_lock_irqsave(&irq_lock, flags);
- irq = find_irq_by_fd(fd, irqnum, &i);
- if (irq == NULL) {
- spin_unlock_irqrestore(&irq_lock, flags);
- return;
+ to_free = active_fds;
+ while (to_free != NULL) {
+ do_free_by_irq_and_dev(
+ to_free,
+ irq,
+ dev,
+ 0
+ );
+ to_free = to_free->next;
}
- os_set_pollfd(i, irq->fd);
+ garbage_collect_irq_entries();
spin_unlock_irqrestore(&irq_lock, flags);
+}
- add_sigio_fd(fd);
+
+void reactivate_fd(int fd, int irqnum)
+{
+ /** NOP - we do auto-EOI now **/
}
void deactivate_fd(int fd, int irqnum)
{
- struct irq_fd *irq;
+ struct irq_entry *to_free;
unsigned long flags;
- int i;
+ os_del_epoll_fd(fd);
spin_lock_irqsave(&irq_lock, flags);
- irq = find_irq_by_fd(fd, irqnum, &i);
- if (irq == NULL) {
- spin_unlock_irqrestore(&irq_lock, flags);
- return;
+ to_free = get_irq_entry_by_fd(fd);
+ if (to_free != NULL) {
+ do_free_by_irq_and_dev(
+ to_free,
+ irqnum,
+ NULL,
+ IGNORE_DEV
+ );
}
-
- os_set_pollfd(i, -1);
+ garbage_collect_irq_entries();
spin_unlock_irqrestore(&irq_lock, flags);
-
ignore_sigio_fd(fd);
}
EXPORT_SYMBOL(deactivate_fd);
@@ -265,17 +385,28 @@ EXPORT_SYMBOL(deactivate_fd);
*/
int deactivate_all_fds(void)
{
- struct irq_fd *irq;
- int err;
+ unsigned long flags;
+ struct irq_entry *to_free;
- for (irq = active_fds; irq != NULL; irq = irq->next) {
- err = os_clear_fd_async(irq->fd);
- if (err)
- return err;
- }
- /* If there is a signal already queued, after unblocking ignore it */
+ spin_lock_irqsave(&irq_lock, flags);
+ /* Stop IO. The IRQ loop has no lock so this is our
+ * only way of making sure we are safe to dispose
+ * of all IRQ handlers
+ */
os_set_ioignore();
-
+ to_free = active_fds;
+ while (to_free != NULL) {
+ do_free_by_irq_and_dev(
+ to_free,
+ -1,
+ NULL,
+ IGNORE_IRQ | IGNORE_DEV
+ );
+ to_free = to_free->next;
+ }
+ garbage_collect_irq_entries();
+ spin_unlock_irqrestore(&irq_lock, flags);
+ os_close_epoll_fd();
return 0;
}
@@ -353,8 +484,11 @@ void __init init_IRQ(void)
irq_set_chip_and_handler(TIMER_IRQ, &SIGVTALRM_irq_type, handle_edge_irq);
+
for (i = 1; i < NR_IRQS; i++)
irq_set_chip_and_handler(i, &normal_irq_type, handle_edge_irq);
+ /* Initialize EPOLL Loop */
+ os_setup_epoll();
}
/*
diff --git a/arch/um/os-Linux/irq.c b/arch/um/os-Linux/irq.c
index b9afb74b79ad..365823010346 100644
--- a/arch/um/os-Linux/irq.c
+++ b/arch/um/os-Linux/irq.c
@@ -1,135 +1,147 @@
/*
+ * Copyright (C) 2017 - Cambridge Greys Ltd
+ * Copyright (C) 2011 - 2014 Cisco Systems Inc
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
#include <stdlib.h>
#include <errno.h>
-#include <poll.h>
+#include <sys/epoll.h>
#include <signal.h>
#include <string.h>
#include <irq_user.h>
#include <os.h>
#include <um_malloc.h>
+/* Epoll support */
+
+static int epollfd = -1;
+
+#define MAX_EPOLL_EVENTS 64
+
+static struct epoll_event epoll_events[MAX_EPOLL_EVENTS];
+
+/* Helper to return an Epoll data pointer from an epoll event structure.
+ * We need to keep this one on the userspace side to keep includes separate
+ */
+
+void *os_epoll_get_data_pointer(int index)
+{
+ return epoll_events[index].data.ptr;
+}
+
+/* Helper to compare events versus the events in the epoll structure.
+ * Same as above - needs to be on the userspace side
+ */
+
+
+int os_epoll_triggered(int index, int events)
+{
+ return epoll_events[index].events & events;
+}
+/* Helper to set the event mask.
+ * The event mask is opaque to the kernel side, because it does not have
+ * access to the right includes/defines for EPOLL constants.
+ */
+
+int os_event_mask(int irq_type)
+{
+ if (irq_type == IRQ_READ)
+ return EPOLLIN | EPOLLPRI;
+ if (irq_type == IRQ_WRITE)
+ return EPOLLOUT;
+ return 0;
+}
+
/*
- * Locked by irq_lock in arch/um/kernel/irq.c. Changed by os_create_pollfd
- * and os_free_irq_by_cb, which are called under irq_lock.
+ * Initial Epoll Setup
*/
-static struct pollfd *pollfds = NULL;
-static int pollfds_num = 0;
-static int pollfds_size = 0;
+int os_setup_epoll(void)
+{
+ epollfd = epoll_create(MAX_EPOLL_EVENTS);
+ return epollfd;
+}
-int os_waiting_for_events(struct irq_fd *active_fds)
+/*
+ * Helper to run the actual epoll_wait
+ */
+int os_waiting_for_events_epoll(void)
{
- struct irq_fd *irq_fd;
- int i, n, err;
+ int n, err;
- n = poll(pollfds, pollfds_num, 0);
+ n = epoll_wait(epollfd,
+ (struct epoll_event *) &epoll_events, MAX_EPOLL_EVENTS, 0);
if (n < 0) {
err = -errno;
if (errno != EINTR)
- printk(UM_KERN_ERR "os_waiting_for_events:"
- " poll returned %d, errno = %d\n", n, errno);
+ printk(
+ UM_KERN_ERR "os_waiting_for_events:"
+ " epoll returned %d, error = %s\n", n,
+ strerror(errno)
+ );
return err;
}
-
- if (n == 0)
- return 0;
-
- irq_fd = active_fds;
-
- for (i = 0; i < pollfds_num; i++) {
- if (pollfds[i].revents != 0) {
- irq_fd->current_events = pollfds[i].revents;
- pollfds[i].fd = -1;
- }
- irq_fd = irq_fd->next;
- }
return n;
}
-int os_create_pollfd(int fd, int events, void *tmp_pfd, int size_tmpfds)
-{
- if (pollfds_num == pollfds_size) {
- if (size_tmpfds <= pollfds_size * sizeof(pollfds[0])) {
- /* return min size needed for new pollfds area */
- return (pollfds_size + 1) * sizeof(pollfds[0]);
- }
-
- if (pollfds != NULL) {
- memcpy(tmp_pfd, pollfds,
- sizeof(pollfds[0]) * pollfds_size);
- /* remove old pollfds */
- kfree(pollfds);
- }
- pollfds = tmp_pfd;
- pollfds_size++;
- } else
- kfree(tmp_pfd); /* remove not used tmp_pfd */
-
- pollfds[pollfds_num] = ((struct pollfd) { .fd = fd,
- .events = events,
- .revents = 0 });
- pollfds_num++;
-
- return 0;
-}
-void os_free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg,
- struct irq_fd *active_fds, struct irq_fd ***last_irq_ptr2)
+/*
+ * Helper to add a fd to epoll
+ */
+int os_add_epoll_fd(int events, int fd, void *data)
{
- struct irq_fd **prev;
- int i = 0;
-
- prev = &active_fds;
- while (*prev != NULL) {
- if ((*test)(*prev, arg)) {
- struct irq_fd *old_fd = *prev;
- if ((pollfds[i].fd != -1) &&
- (pollfds[i].fd != (*prev)->fd)) {
- printk(UM_KERN_ERR "os_free_irq_by_cb - "
- "mismatch between active_fds and "
- "pollfds, fd %d vs %d\n",
- (*prev)->fd, pollfds[i].fd);
- goto out;
- }
-
- pollfds_num--;
-
- /*
- * This moves the *whole* array after pollfds[i]
- * (though it doesn't spot as such)!
- */
- memmove(&pollfds[i], &pollfds[i + 1],
- (pollfds_num - i) * sizeof(pollfds[0]));
- if (*last_irq_ptr2 == &old_fd->next)
- *last_irq_ptr2 = prev;
-
- *prev = (*prev)->next;
- if (old_fd->type == IRQ_WRITE)
- ignore_sigio_fd(old_fd->fd);
- kfree(old_fd);
- continue;
- }
- prev = &(*prev)->next;
- i++;
- }
- out:
- return;
+ struct epoll_event event;
+ int result;
+
+ event.data.ptr = data;
+ event.events = events | EPOLLET;
+ result = epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &event);
+ if ((result) && (errno == EEXIST))
+ result = os_mod_epoll_fd(events, fd, data);
+ if (result)
+ printk("epollctl add err fd %d, %s\n", fd, strerror(errno));
+ return result;
}
-int os_get_pollfd(int i)
+/*
+ * Helper to mod the fd event mask and/or data backreference
+ */
+int os_mod_epoll_fd(int events, int fd, void *data)
{
- return pollfds[i].fd;
+ struct epoll_event event;
+ int result;
+
+ event.data.ptr = data;
+ event.events = events;
+ result = epoll_ctl(epollfd, EPOLL_CTL_MOD, fd, &event);
+ if (result)
+ printk(UM_KERN_ERR
+ "epollctl mod err fd %d, %s\n", fd, strerror(errno));
+ return result;
}
-void os_set_pollfd(int i, int fd)
+/*
+ * Helper to delete the epoll fd
+ */
+int os_del_epoll_fd(int fd)
{
- pollfds[i].fd = fd;
+ struct epoll_event event;
+ int result;
+ /* This is quiet as we use this as IO ON/OFF - so it is often
+ * invoked on a non-existent fd
+ */
+ result = epoll_ctl(epollfd, EPOLL_CTL_DEL, fd, &event);
+ return result;
}
void os_set_ioignore(void)
{
signal(SIGIO, SIG_IGN);
}
+
+void os_close_epoll_fd(void)
+{
+ /* Needed so we do not leak an fd when rebooting */
+ os_close_file(epollfd);
+}