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-rw-r--r--arch/um/os-Linux/irq.c202
1 files changed, 107 insertions, 95 deletions
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);
+}