2013-10-18 18:14:46

by Christopher Covington

[permalink] [raw]
Subject: [RFC] ARM: tty: Move HVC DCC assembly to arch/arm

Put architecture-specific assembly code where it belongs,
allowing for support of additional architectures such as arm64 in
the future.

Signed-off-by: Christopher Covington <[email protected]>
---
arch/arm/include/asm/dcc.h | 45 +++++++++++++++++++++++++++++++++++++++++++
drivers/tty/hvc/hvc_dcc.c | 48 ++--------------------------------------------
2 files changed, 47 insertions(+), 46 deletions(-)
create mode 100644 arch/arm/include/asm/dcc.h

diff --git a/arch/arm/include/asm/dcc.h b/arch/arm/include/asm/dcc.h
new file mode 100644
index 0000000..306d1fc
--- /dev/null
+++ b/arch/arm/include/asm/dcc.h
@@ -0,0 +1,45 @@
+/* Copyright (c) 2010, 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 <asm/barrier.h>
+
+/* DCC Status Bits */
+#define DCC_STATUS_RX (1 << 30)
+#define DCC_STATUS_TX (1 << 29)
+
+static inline u32 __dcc_getstatus(void)
+{
+ u32 __ret;
+ asm volatile("mrc p14, 0, %0, c0, c1, 0 @ read comms ctrl reg"
+ : "=r" (__ret) : : "cc");
+
+ return __ret;
+}
+
+static inline char __dcc_getchar(void)
+{
+ char __c;
+
+ asm volatile("mrc p14, 0, %0, c0, c5, 0 @ read comms data reg"
+ : "=r" (__c));
+ isb();
+
+ return __c;
+}
+
+static inline void __dcc_putchar(char c)
+{
+ asm volatile("mcr p14, 0, %0, c0, c5, 0 @ write a char"
+ : /* no output register */
+ : "r" (c));
+ isb();
+}
diff --git a/drivers/tty/hvc/hvc_dcc.c b/drivers/tty/hvc/hvc_dcc.c
index 44fbeba..e9f0191 100644
--- a/drivers/tty/hvc/hvc_dcc.c
+++ b/drivers/tty/hvc/hvc_dcc.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
+/* Copyright (c) 2010, 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
@@ -8,57 +8,13 @@
* 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.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
- * 02110-1301, USA.
*/

-#include <linux/console.h>
-#include <linux/delay.h>
-#include <linux/err.h>
-#include <linux/init.h>
-#include <linux/moduleparam.h>
-#include <linux/types.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 inline u32 __dcc_getstatus(void)
-{
- u32 __ret;
- asm volatile("mrc p14, 0, %0, c0, c1, 0 @ read comms ctrl reg"
- : "=r" (__ret) : : "cc");
-
- return __ret;
-}
-
-
-static inline char __dcc_getchar(void)
-{
- char __c;
-
- asm volatile("mrc p14, 0, %0, c0, c5, 0 @ read comms data reg"
- : "=r" (__c));
- isb();
-
- return __c;
-}
-
-static inline void __dcc_putchar(char c)
-{
- asm volatile("mcr p14, 0, %0, c0, c5, 0 @ write a char"
- : /* no output register */
- : "r" (c));
- isb();
-}
-
static int hvc_dcc_put_chars(uint32_t vt, const char *buf, int count)
{
int i;
--
Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by the Linux Foundation.


2013-10-18 18:34:13

by Stephen Boyd

[permalink] [raw]
Subject: Re: [RFC] ARM: tty: Move HVC DCC assembly to arch/arm

On 10/18/13 11:14, Christopher Covington wrote:
> Put architecture-specific assembly code where it belongs,
> allowing for support of additional architectures such as arm64 in
> the future.

Do you have that patch too? There was also a patch a year ago to add
armv5/v4 support to this driver. Maybe we can resurrect that too.

> diff --git a/drivers/tty/hvc/hvc_dcc.c b/drivers/tty/hvc/hvc_dcc.c
> index 44fbeba..e9f0191 100644
> --- a/drivers/tty/hvc/hvc_dcc.c
> +++ b/drivers/tty/hvc/hvc_dcc.c
> @@ -8,57 +8,13 @@
> * 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.
> - *
> - * You should have received a copy of the GNU General Public License
> - * along with this program; if not, write to the Free Software
> - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
> - * 02110-1301, USA.
> */
>
> -#include <linux/console.h>
> -#include <linux/delay.h>
> -#include <linux/err.h>
> -#include <linux/init.h>

We still need init.h

> -#include <linux/moduleparam.h>
> -#include <linux/types.h>
> -
> +#include <asm/dcc.h>
> #include <asm/processor.h>
>
> #include "hvc_console.h"
>
>
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation

2013-10-23 05:59:10

by Kumar Gala

[permalink] [raw]
Subject: Re: [RFC] ARM: tty: Move HVC DCC assembly to arch/arm


On Oct 18, 2013, at 1:14 PM, Christopher Covington wrote:

> Put architecture-specific assembly code where it belongs,
> allowing for support of additional architectures such as arm64 in
> the future.
>
> Signed-off-by: Christopher Covington <[email protected]>
> ---
> arch/arm/include/asm/dcc.h | 45 +++++++++++++++++++++++++++++++++++++++++++
> drivers/tty/hvc/hvc_dcc.c | 48 ++--------------------------------------------
> 2 files changed, 47 insertions(+), 46 deletions(-)
> create mode 100644 arch/arm/include/asm/dcc.h
>
> diff --git a/arch/arm/include/asm/dcc.h b/arch/arm/include/asm/dcc.h
> new file mode 100644
> index 0000000..306d1fc
> --- /dev/null
> +++ b/arch/arm/include/asm/dcc.h
> @@ -0,0 +1,45 @@
> +/* Copyright (c) 2010, 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 <asm/barrier.h>
> +
> +/* DCC Status Bits */
> +#define DCC_STATUS_RX (1 << 30)
> +#define DCC_STATUS_TX (1 << 29)
> +

Why'd you move these define's here? They don't seem to be arch specific and I don't see them used in the asm anywhere.

> +static inline u32 __dcc_getstatus(void)
> +{
> + u32 __ret;
> + asm volatile("mrc p14, 0, %0, c0, c1, 0 @ read comms ctrl reg"
> + : "=r" (__ret) : : "cc");
> +
> + return __ret;
> +}
> +
> +static inline char __dcc_getchar(void)
> +{
> + char __c;
> +
> + asm volatile("mrc p14, 0, %0, c0, c5, 0 @ read comms data reg"
> + : "=r" (__c));
> + isb();
> +
> + return __c;
> +}
> +
> +static inline void __dcc_putchar(char c)
> +{
> + asm volatile("mcr p14, 0, %0, c0, c5, 0 @ write a char"
> + : /* no output register */
> + : "r" (c));
> + isb();
> +}
> diff --git a/drivers/tty/hvc/hvc_dcc.c b/drivers/tty/hvc/hvc_dcc.c
> index 44fbeba..e9f0191 100644
> --- a/drivers/tty/hvc/hvc_dcc.c
> +++ b/drivers/tty/hvc/hvc_dcc.c
> @@ -1,4 +1,4 @@
> -/* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
> +/* Copyright (c) 2010, 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
> @@ -8,57 +8,13 @@
> * 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.
> - *
> - * You should have received a copy of the GNU General Public License
> - * along with this program; if not, write to the Free Software
> - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
> - * 02110-1301, USA.
> */
>
> -#include <linux/console.h>
> -#include <linux/delay.h>
> -#include <linux/err.h>
> -#include <linux/init.h>
> -#include <linux/moduleparam.h>
> -#include <linux/types.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 inline u32 __dcc_getstatus(void)
> -{
> - u32 __ret;
> - asm volatile("mrc p14, 0, %0, c0, c1, 0 @ read comms ctrl reg"
> - : "=r" (__ret) : : "cc");
> -
> - return __ret;
> -}
> -
> -
> -static inline char __dcc_getchar(void)
> -{
> - char __c;
> -
> - asm volatile("mrc p14, 0, %0, c0, c5, 0 @ read comms data reg"
> - : "=r" (__c));
> - isb();
> -
> - return __c;
> -}
> -
> -static inline void __dcc_putchar(char c)
> -{
> - asm volatile("mcr p14, 0, %0, c0, c5, 0 @ write a char"
> - : /* no output register */
> - : "r" (c));
> - isb();
> -}
> -
> static int hvc_dcc_put_chars(uint32_t vt, const char *buf, int count)
> {
> int i;
> --
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> hosted by the Linux Foundation.
>
> --
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--
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation