Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
index 05588f9..6299705 100644
--- a/arch/um/drivers/chan_kern.c
+++ b/arch/um/drivers/chan_kern.c
@@ -1,6 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
- * Licensed under the GPL
*/
#include <linux/slab.h>
@@ -171,19 +171,55 @@
return err;
}
+/* Items are added in IRQ context, when free_irq can't be called, and
+ * removed in process context, when it can.
+ * This handles interrupt sources which disappear, and which need to
+ * be permanently disabled. This is discovered in IRQ context, but
+ * the freeing of the IRQ must be done later.
+ */
+static DEFINE_SPINLOCK(irqs_to_free_lock);
+static LIST_HEAD(irqs_to_free);
+
+void free_irqs(void)
+{
+ struct chan *chan;
+ LIST_HEAD(list);
+ struct list_head *ele;
+ unsigned long flags;
+
+ spin_lock_irqsave(&irqs_to_free_lock, flags);
+ list_splice_init(&irqs_to_free, &list);
+ spin_unlock_irqrestore(&irqs_to_free_lock, flags);
+
+ list_for_each(ele, &list) {
+ chan = list_entry(ele, struct chan, free_list);
+
+ if (chan->input && chan->enabled)
+ um_free_irq(chan->line->driver->read_irq, chan);
+ if (chan->output && chan->enabled)
+ um_free_irq(chan->line->driver->write_irq, chan);
+ chan->enabled = 0;
+ }
+}
+
static void close_one_chan(struct chan *chan, int delay_free_irq)
{
+ unsigned long flags;
+
if (!chan->opened)
return;
- /* we can safely call free now - it will be marked
- * as free and freed once the IRQ stopped processing
- */
- if (chan->input && chan->enabled)
- um_free_irq(chan->line->driver->read_irq, chan);
- if (chan->output && chan->enabled)
- um_free_irq(chan->line->driver->write_irq, chan);
- chan->enabled = 0;
+ if (delay_free_irq) {
+ spin_lock_irqsave(&irqs_to_free_lock, flags);
+ list_add(&chan->free_list, &irqs_to_free);
+ spin_unlock_irqrestore(&irqs_to_free_lock, flags);
+ } else {
+ if (chan->input && chan->enabled)
+ um_free_irq(chan->line->driver->read_irq, chan);
+ if (chan->output && chan->enabled)
+ um_free_irq(chan->line->driver->write_irq, chan);
+ chan->enabled = 0;
+ }
if (chan->ops->close != NULL)
(*chan->ops->close)(chan->fd, chan->data);
@@ -211,12 +247,6 @@
deactivate_fd(chan->fd, irq);
}
-void reactivate_chan(struct chan *chan, int irq)
-{
- if (chan && chan->enabled)
- reactivate_fd(chan->fd, irq);
-}
-
int write_chan(struct chan *chan, const char *buf, int len,
int write_irq)
{
@@ -228,8 +258,6 @@
n = chan->ops->write(chan->fd, buf, len, chan->data);
if (chan->primary) {
ret = n;
- if ((ret == -EAGAIN) || ((ret >= 0) && (ret < len)))
- reactivate_fd(chan->fd, write_irq);
}
return ret;
}
@@ -527,8 +555,6 @@
tty_insert_flip_char(port, c, TTY_NORMAL);
} while (err > 0);
- if (err == 0)
- reactivate_fd(chan->fd, irq);
if (err == -EIO) {
if (chan->primary) {
tty_port_tty_hangup(&line->port, false);