Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / arch / um / drivers / xterm_kern.c

diff --git a/kernel/arch/um/drivers/xterm_kern.c b/kernel/arch/um/drivers/xterm_kern.c
new file mode 100644 (file)
index 0000000..e8f9957
--- /dev/null
+++ b/kernel/arch/um/drivers/xterm_kern.c
@@ -0,0 +1,75 @@
+/* 
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Licensed under the GPL
+ */
+
+#include <linux/slab.h>
+#include <linux/completion.h>
+#include <linux/irqreturn.h>
+#include <asm/irq.h>
+#include <irq_kern.h>
+#include <os.h>
+
+struct xterm_wait {
+       struct completion ready;
+       int fd;
+       int pid;
+       int new_fd;
+};
+
+static irqreturn_t xterm_interrupt(int irq, void *data)
+{
+       struct xterm_wait *xterm = data;
+       int fd;
+
+       fd = os_rcv_fd(xterm->fd, &xterm->pid);
+       if (fd == -EAGAIN)
+               return IRQ_NONE;
+
+       xterm->new_fd = fd;
+       complete(&xterm->ready);
+
+       return IRQ_HANDLED;
+}
+
+int xterm_fd(int socket, int *pid_out)
+{
+       struct xterm_wait *data;
+       int err, ret;
+
+       data = kmalloc(sizeof(*data), GFP_KERNEL);
+       if (data == NULL) {
+               printk(KERN_ERR "xterm_fd : failed to allocate xterm_wait\n");
+               return -ENOMEM;
+       }
+
+       /* This is a locked semaphore... */
+       *data = ((struct xterm_wait) { .fd              = socket,
+                                      .pid             = -1,
+                                      .new_fd          = -1 });
+       init_completion(&data->ready);
+
+       err = um_request_irq(XTERM_IRQ, socket, IRQ_READ, xterm_interrupt,
+                            IRQF_SHARED, "xterm", data);
+       if (err) {
+               printk(KERN_ERR "xterm_fd : failed to get IRQ for xterm, "
+                      "err = %d\n",  err);
+               ret = err;
+               goto out;
+       }
+
+       /* ... so here we wait for an xterm interrupt.
+        *
+        * XXX Note, if the xterm doesn't work for some reason (eg. DISPLAY
+        * isn't set) this will hang... */
+       wait_for_completion(&data->ready);
+
+       um_free_irq(XTERM_IRQ, data);
+
+       ret = data->new_fd;
+       *pid_out = data->pid;
+ out:
+       kfree(data);
+
+       return ret;
+}