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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/drivers/tty/hvc/hvc_dcc.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/drivers/tty/hvc/hvc_dcc.c')
-rw-r--r--kernel/drivers/tty/hvc/hvc_dcc.c89
1 files changed, 89 insertions, 0 deletions
diff --git a/kernel/drivers/tty/hvc/hvc_dcc.c b/kernel/drivers/tty/hvc/hvc_dcc.c
new file mode 100644
index 000000000..809920d80
--- /dev/null
+++ b/kernel/drivers/tty/hvc/hvc_dcc.c
@@ -0,0 +1,89 @@
+/* Copyright (c) 2010, 2014 The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/init.h>
+
+#include <asm/dcc.h>
+#include <asm/processor.h>
+
+#include "hvc_console.h"
+
+/* DCC Status Bits */
+#define DCC_STATUS_RX (1 << 30)
+#define DCC_STATUS_TX (1 << 29)
+
+static int hvc_dcc_put_chars(uint32_t vt, const char *buf, int count)
+{
+ int i;
+
+ for (i = 0; i < count; i++) {
+ while (__dcc_getstatus() & DCC_STATUS_TX)
+ cpu_relax();
+
+ __dcc_putchar(buf[i]);
+ }
+
+ return count;
+}
+
+static int hvc_dcc_get_chars(uint32_t vt, char *buf, int count)
+{
+ int i;
+
+ for (i = 0; i < count; ++i)
+ if (__dcc_getstatus() & DCC_STATUS_RX)
+ buf[i] = __dcc_getchar();
+ else
+ break;
+
+ return i;
+}
+
+static bool hvc_dcc_check(void)
+{
+ unsigned long time = jiffies + (HZ / 10);
+
+ /* Write a test character to check if it is handled */
+ __dcc_putchar('\n');
+
+ while (time_is_after_jiffies(time)) {
+ if (!(__dcc_getstatus() & DCC_STATUS_TX))
+ return true;
+ }
+
+ return false;
+}
+
+static const struct hv_ops hvc_dcc_get_put_ops = {
+ .get_chars = hvc_dcc_get_chars,
+ .put_chars = hvc_dcc_put_chars,
+};
+
+static int __init hvc_dcc_console_init(void)
+{
+ if (!hvc_dcc_check())
+ return -ENODEV;
+
+ hvc_instantiate(0, 0, &hvc_dcc_get_put_ops);
+ return 0;
+}
+console_initcall(hvc_dcc_console_init);
+
+static int __init hvc_dcc_init(void)
+{
+ if (!hvc_dcc_check())
+ return -ENODEV;
+
+ hvc_alloc(0, 0, &hvc_dcc_get_put_ops, 128);
+ return 0;
+}
+device_initcall(hvc_dcc_init);