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author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/drivers/tty/hvc/hvc_dcc.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (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.c | 89 |
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); |