From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 7 Apr 2024 20:49:45 +0200
Subject: Adding upstream version 6.1.76.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 arch/um/drivers/xterm_kern.c | 75 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 75 insertions(+)
 create mode 100644 arch/um/drivers/xterm_kern.c

(limited to 'arch/um/drivers/xterm_kern.c')

diff --git a/arch/um/drivers/xterm_kern.c b/arch/um/drivers/xterm_kern.c
new file mode 100644
index 000000000..50f11b7b4
--- /dev/null
+++ b/arch/um/drivers/xterm_kern.c
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0
+/* 
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#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 < 0) {
+		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;
+}
-- 
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