aboutsummaryrefslogtreecommitdiff
path: root/arch/um/drivers/port_kern.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/um/drivers/port_kern.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/um/drivers/port_kern.c')
-rw-r--r--arch/um/drivers/port_kern.c309
1 files changed, 309 insertions, 0 deletions
diff --git a/arch/um/drivers/port_kern.c b/arch/um/drivers/port_kern.c
new file mode 100644
index 00000000000..b5ee07472f7
--- /dev/null
+++ b/arch/um/drivers/port_kern.c
@@ -0,0 +1,309 @@
+/*
+ * Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include "linux/list.h"
+#include "linux/sched.h"
+#include "linux/slab.h"
+#include "linux/interrupt.h"
+#include "linux/irq.h"
+#include "linux/spinlock.h"
+#include "linux/errno.h"
+#include "asm/atomic.h"
+#include "asm/semaphore.h"
+#include "asm/errno.h"
+#include "kern_util.h"
+#include "kern.h"
+#include "irq_user.h"
+#include "irq_kern.h"
+#include "port.h"
+#include "init.h"
+#include "os.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 pt_regs *regs)
+{
+ 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, ret = 0;
+
+ 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,
+ SA_INTERRUPT | SA_SHIRQ | SA_SAMPLE_RANDOM,
+ "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("No one waiting for port\n");
+ }
+ list_add(&conn->list, &port->pending);
+ return(1);
+
+ out_free:
+ kfree(conn);
+ out_close:
+ os_close_file(fd);
+ if(pid != -1)
+ os_kill_process(pid, 1);
+ out:
+ return(ret);
+}
+
+DECLARE_MUTEX(ports_sem);
+struct list_head ports = LIST_HEAD_INIT(ports);
+
+void port_work_proc(void *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, NULL);
+
+static irqreturn_t port_interrupt(int irq, void *data, struct pt_regs *regs)
+{
+ 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;
+
+ down(&ports_sem);
+ 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,
+ SA_INTERRUPT | SA_SHIRQ | SA_SAMPLE_RANDOM, "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_free:
+ kfree(port);
+ out_close:
+ os_close_file(fd);
+ out:
+ up(&ports_sem);
+ 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.
+ */
+ free_irq_by_irq_and_dev(TELNETD_IRQ, conn);
+ 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);