2023-11-15 13:32:16

by Heinrich Schuchardt

[permalink] [raw]
Subject: [PATCH 1/1] tty/serial: RISC-V SBI earlycon via DBCN extension

Up to now an SBI based early console was limited to SBI version 0.1.
With the DBCN SBI extension we can provide an early console on systems that
have a recent SBI implementation.

Signed-off-by: Heinrich Schuchardt <[email protected]>
---
arch/riscv/kernel/sbi.c | 14 ++++++++++++++
drivers/tty/serial/Kconfig | 1 -
2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c
index 5a62ed1da453..6e1644a95bb7 100644
--- a/arch/riscv/kernel/sbi.c
+++ b/arch/riscv/kernel/sbi.c
@@ -195,6 +195,20 @@ static void sbi_set_power_off(void)
pm_power_off = sbi_shutdown;
}
#else
+
+/**
+ * sbi_console_putchar() - Writes given character to the console device.
+ * @ch: The data to be written to the console.
+ *
+ * Return: None
+ */
+void sbi_console_putchar(int ch)
+{
+ sbi_ecall(SBI_EXT_DBCN, SBI_EXT_DBCN_CONSOLE_WRITE_BYTE,
+ ch, 0, 0, 0, 0, 0);
+}
+EXPORT_SYMBOL(sbi_console_putchar);
+
static void __sbi_set_timer_v01(uint64_t stime_value)
{
pr_warn("Timer extension is not available in SBI v%lu.%lu\n",
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 732c893c8d16..454c2a612389 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -87,7 +87,6 @@ config SERIAL_EARLYCON_SEMIHOST

config SERIAL_EARLYCON_RISCV_SBI
bool "Early console using RISC-V SBI"
- depends on RISCV_SBI_V01
select SERIAL_CORE
select SERIAL_CORE_CONSOLE
select SERIAL_EARLYCON
--
2.40.1


2023-11-15 16:23:02

by Anup Patel

[permalink] [raw]
Subject: Re: [PATCH 1/1] tty/serial: RISC-V SBI earlycon via DBCN extension

On Wed, Nov 15, 2023 at 7:01 PM Heinrich Schuchardt
<[email protected]> wrote:
>
> Up to now an SBI based early console was limited to SBI version 0.1.
> With the DBCN SBI extension we can provide an early console on systems that
> have a recent SBI implementation.
>
> Signed-off-by: Heinrich Schuchardt <[email protected]>

There is already a series in-flight adding SBI DBCN support.
Refer, https://lore.kernel.org/lkml/[email protected]/

Regards,
Anup

> ---
> arch/riscv/kernel/sbi.c | 14 ++++++++++++++
> drivers/tty/serial/Kconfig | 1 -
> 2 files changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c
> index 5a62ed1da453..6e1644a95bb7 100644
> --- a/arch/riscv/kernel/sbi.c
> +++ b/arch/riscv/kernel/sbi.c
> @@ -195,6 +195,20 @@ static void sbi_set_power_off(void)
> pm_power_off = sbi_shutdown;
> }
> #else
> +
> +/**
> + * sbi_console_putchar() - Writes given character to the console device.
> + * @ch: The data to be written to the console.
> + *
> + * Return: None
> + */
> +void sbi_console_putchar(int ch)
> +{
> + sbi_ecall(SBI_EXT_DBCN, SBI_EXT_DBCN_CONSOLE_WRITE_BYTE,
> + ch, 0, 0, 0, 0, 0);
> +}
> +EXPORT_SYMBOL(sbi_console_putchar);
> +
> static void __sbi_set_timer_v01(uint64_t stime_value)
> {
> pr_warn("Timer extension is not available in SBI v%lu.%lu\n",
> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
> index 732c893c8d16..454c2a612389 100644
> --- a/drivers/tty/serial/Kconfig
> +++ b/drivers/tty/serial/Kconfig
> @@ -87,7 +87,6 @@ config SERIAL_EARLYCON_SEMIHOST
>
> config SERIAL_EARLYCON_RISCV_SBI
> bool "Early console using RISC-V SBI"
> - depends on RISCV_SBI_V01
> select SERIAL_CORE
> select SERIAL_CORE_CONSOLE
> select SERIAL_EARLYCON
> --
> 2.40.1
>

2023-11-20 21:29:10

by kernel test robot

[permalink] [raw]
Subject: Re: [PATCH 1/1] tty/serial: RISC-V SBI earlycon via DBCN extension

Hi Heinrich,

kernel test robot noticed the following build errors:

[auto build test ERROR on tty/tty-testing]
[also build test ERROR on tty/tty-next tty/tty-linus linus/master v6.7-rc2 next-20231120]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url: https://github.com/intel-lab-lkp/linux/commits/Heinrich-Schuchardt/tty-serial-RISC-V-SBI-earlycon-via-DBCN-extension/20231115-213355
base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git tty-testing
patch link: https://lore.kernel.org/r/20231115133127.107575-1-heinrich.schuchardt%40canonical.com
patch subject: [PATCH 1/1] tty/serial: RISC-V SBI earlycon via DBCN extension
config: arm64-allmodconfig (https://download.01.org/0day-ci/archive/20231121/[email protected]/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231121/[email protected]/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <[email protected]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/

All errors (new ones prefixed by >>):

>> drivers/tty/serial/earlycon-riscv-sbi.c:11:10: fatal error: 'asm/sbi.h' file not found
11 | #include <asm/sbi.h>
| ^~~~~~~~~~~
1 error generated.


vim +11 drivers/tty/serial/earlycon-riscv-sbi.c

27de1f541f1f91 Anup Patel 2018-12-04 @11 #include <asm/sbi.h>
27de1f541f1f91 Anup Patel 2018-12-04 12

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki