summaryrefslogtreecommitdiffstats
path: root/kernel/arch/um/drivers/port_kern.c
diff options
context:
space:
mode:
authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/um/drivers/port_kern.c
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/um/drivers/port_kern.c')
-rw-r--r--kernel/arch/um/drivers/port_kern.c304
1 files changed, 304 insertions, 0 deletions
diff --git a/kernel/arch/um/drivers/port_kern.c b/kernel/arch/um/drivers/port_kern.c
new file mode 100644
index 000000000..40ca5cc27
--- /dev/null
+++ b/kernel/arch/um/drivers/port_kern.c
@@ -0,0 +1,304 @@
+/*
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
+ * Licensed under the GPL
+ */
+
+#include <linux/completion.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+#include <asm/atomic.h>
+#include <init.h>
+#include <irq_kern.h>
+#include <os.h>
+#include "port.h"
+
+struct port_list {
+ struct list_head list;
+ atomic_t wait_count;
+ int has_connection;
+ struct completion done;
+ int port;
+ int fd;
+ spinlock_t lock;
+ struct list_head pending;
+ struct list_head connections;
+};
+
+struct port_dev {
+ struct port_list *port;
+ int helper_pid;
+ int telnetd_pid;
+};
+
+struct connection {
+ struct list_head list;
+ int fd;
+ int helper_pid;
+ int socket[2];
+ int telnetd_pid;
+ struct port_list *port;
+};
+
+static irqreturn_t pipe_interrupt(int irq, void *data)
+{
+ struct connection *conn = data;
+ int fd;
+
+ fd = os_rcv_fd(conn->socket[0], &conn->helper_pid);
+ if (fd < 0) {
+ if (fd == -EAGAIN)
+ return IRQ_NONE;
+
+ printk(KERN_ERR "pipe_interrupt : os_rcv_fd returned %d\n",
+ -fd);
+ os_close_file(conn->fd);
+ }
+
+ list_del(&conn->list);
+
+ conn->fd = fd;
+ list_add(&conn->list, &conn->port->connections);
+
+ complete(&conn->port->done);
+ return IRQ_HANDLED;
+}
+
+#define NO_WAITER_MSG \
+ "****\n" \
+ "There are currently no UML consoles waiting for port connections.\n" \
+ "Either disconnect from one to make it available or activate some more\n" \
+ "by enabling more consoles in the UML /etc/inittab.\n" \
+ "****\n"
+
+static int port_accept(struct port_list *port)
+{
+ struct connection *conn;
+ int fd, socket[2], pid;
+
+ fd = port_connection(port->fd, socket, &pid);
+ if (fd < 0) {
+ if (fd != -EAGAIN)
+ printk(KERN_ERR "port_accept : port_connection "
+ "returned %d\n", -fd);
+ goto out;
+ }
+
+ conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
+ if (conn == NULL) {
+ printk(KERN_ERR "port_accept : failed to allocate "
+ "connection\n");
+ goto out_close;
+ }
+ *conn = ((struct connection)
+ { .list = LIST_HEAD_INIT(conn->list),
+ .fd = fd,
+ .socket = { socket[0], socket[1] },
+ .telnetd_pid = pid,
+ .port = port });
+
+ if (um_request_irq(TELNETD_IRQ, socket[0], IRQ_READ, pipe_interrupt,
+ IRQF_SHARED, "telnetd", conn)) {
+ printk(KERN_ERR "port_accept : failed to get IRQ for "
+ "telnetd\n");
+ goto out_free;
+ }
+
+ if (atomic_read(&port->wait_count) == 0) {
+ os_write_file(fd, NO_WAITER_MSG, sizeof(NO_WAITER_MSG));
+ printk(KERN_ERR "No one waiting for port\n");
+ }
+ list_add(&conn->list, &port->pending);
+ return 1;
+
+ out_free:
+ kfree(conn);
+ out_close:
+ os_close_file(fd);
+ os_kill_process(pid, 1);
+ out:
+ return 0;
+}
+
+static DEFINE_MUTEX(ports_mutex);
+static LIST_HEAD(ports);
+
+static void port_work_proc(struct work_struct *unused)
+{
+ struct port_list *port;
+ struct list_head *ele;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ list_for_each(ele, &ports) {
+ port = list_entry(ele, struct port_list, list);
+ if (!port->has_connection)
+ continue;
+
+ reactivate_fd(port->fd, ACCEPT_IRQ);
+ while (port_accept(port))
+ ;
+ port->has_connection = 0;
+ }
+ local_irq_restore(flags);
+}
+
+DECLARE_WORK(port_work, port_work_proc);
+
+static irqreturn_t port_interrupt(int irq, void *data)
+{
+ struct port_list *port = data;
+
+ port->has_connection = 1;
+ schedule_work(&port_work);
+ return IRQ_HANDLED;
+}
+
+void *port_data(int port_num)
+{
+ struct list_head *ele;
+ struct port_list *port;
+ struct port_dev *dev = NULL;
+ int fd;
+
+ mutex_lock(&ports_mutex);
+ list_for_each(ele, &ports) {
+ port = list_entry(ele, struct port_list, list);
+ if (port->port == port_num)
+ goto found;
+ }
+ port = kmalloc(sizeof(struct port_list), GFP_KERNEL);
+ if (port == NULL) {
+ printk(KERN_ERR "Allocation of port list failed\n");
+ goto out;
+ }
+
+ fd = port_listen_fd(port_num);
+ if (fd < 0) {
+ printk(KERN_ERR "binding to port %d failed, errno = %d\n",
+ port_num, -fd);
+ goto out_free;
+ }
+
+ if (um_request_irq(ACCEPT_IRQ, fd, IRQ_READ, port_interrupt,
+ IRQF_SHARED, "port", port)) {
+ printk(KERN_ERR "Failed to get IRQ for port %d\n", port_num);
+ goto out_close;
+ }
+
+ *port = ((struct port_list)
+ { .list = LIST_HEAD_INIT(port->list),
+ .wait_count = ATOMIC_INIT(0),
+ .has_connection = 0,
+ .port = port_num,
+ .fd = fd,
+ .pending = LIST_HEAD_INIT(port->pending),
+ .connections = LIST_HEAD_INIT(port->connections) });
+ spin_lock_init(&port->lock);
+ init_completion(&port->done);
+ list_add(&port->list, &ports);
+
+ found:
+ dev = kmalloc(sizeof(struct port_dev), GFP_KERNEL);
+ if (dev == NULL) {
+ printk(KERN_ERR "Allocation of port device entry failed\n");
+ goto out;
+ }
+
+ *dev = ((struct port_dev) { .port = port,
+ .helper_pid = -1,
+ .telnetd_pid = -1 });
+ goto out;
+
+ out_close:
+ os_close_file(fd);
+ out_free:
+ kfree(port);
+ out:
+ mutex_unlock(&ports_mutex);
+ return dev;
+}
+
+int port_wait(void *data)
+{
+ struct port_dev *dev = data;
+ struct connection *conn;
+ struct port_list *port = dev->port;
+ int fd;
+
+ atomic_inc(&port->wait_count);
+ while (1) {
+ fd = -ERESTARTSYS;
+ if (wait_for_completion_interruptible(&port->done))
+ goto out;
+
+ spin_lock(&port->lock);
+
+ conn = list_entry(port->connections.next, struct connection,
+ list);
+ list_del(&conn->list);
+ spin_unlock(&port->lock);
+
+ os_shutdown_socket(conn->socket[0], 1, 1);
+ os_close_file(conn->socket[0]);
+ os_shutdown_socket(conn->socket[1], 1, 1);
+ os_close_file(conn->socket[1]);
+
+ /* This is done here because freeing an IRQ can't be done
+ * within the IRQ handler. So, pipe_interrupt always ups
+ * the semaphore regardless of whether it got a successful
+ * connection. Then we loop here throwing out failed
+ * connections until a good one is found.
+ */
+ um_free_irq(TELNETD_IRQ, conn);
+
+ if (conn->fd >= 0)
+ break;
+ os_close_file(conn->fd);
+ kfree(conn);
+ }
+
+ fd = conn->fd;
+ dev->helper_pid = conn->helper_pid;
+ dev->telnetd_pid = conn->telnetd_pid;
+ kfree(conn);
+ out:
+ atomic_dec(&port->wait_count);
+ return fd;
+}
+
+void port_remove_dev(void *d)
+{
+ struct port_dev *dev = d;
+
+ if (dev->helper_pid != -1)
+ os_kill_process(dev->helper_pid, 0);
+ if (dev->telnetd_pid != -1)
+ os_kill_process(dev->telnetd_pid, 1);
+ dev->helper_pid = -1;
+ dev->telnetd_pid = -1;
+}
+
+void port_kern_free(void *d)
+{
+ struct port_dev *dev = d;
+
+ port_remove_dev(dev);
+ kfree(dev);
+}
+
+static void free_port(void)
+{
+ struct list_head *ele;
+ struct port_list *port;
+
+ list_for_each(ele, &ports) {
+ port = list_entry(ele, struct port_list, list);
+ free_irq_by_fd(port->fd);
+ os_close_file(port->fd);
+ }
+}
+
+__uml_exitcall(free_port);