2023-11-18 03:39:46

by Anup Patel

Subject: [PATCH v4 1/5] RISC-V: Add stubs for sbi_console_putchar/getchar()

The functions sbi_console_putchar() and sbi_console_getchar() are
not defined when CONFIG_RISCV_SBI_V01 is disabled so let us add
stub of these functions to avoid "#ifdef" on user side.

Signed-off-by: Anup Patel <[email protected]>
Reviewed-by: Andrew Jones <[email protected]>
---
arch/riscv/include/asm/sbi.h | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
index 0892f4421bc4..66f3933c14f6 100644
--- a/arch/riscv/include/asm/sbi.h
+++ b/arch/riscv/include/asm/sbi.h
@@ -271,8 +271,13 @@ struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
unsigned long arg3, unsigned long arg4,
unsigned long arg5);

+#ifdef CONFIG_RISCV_SBI_V01
void sbi_console_putchar(int ch);
int sbi_console_getchar(void);
+#else
+static inline void sbi_console_putchar(int ch) { }
+static inline int sbi_console_getchar(void) { return -ENOENT; }
+#endif
long sbi_get_mvendorid(void);
long sbi_get_marchid(void);
long sbi_get_mimpid(void);
--
2.34.1

2023-11-21 22:36:44

by Samuel Holland

Subject: Re: [PATCH v4 1/5] RISC-V: Add stubs for sbi_console_putchar/getchar()

Hi Anup,

On 2023-11-17 9:38 PM, Anup Patel wrote:
> The functions sbi_console_putchar() and sbi_console_getchar() are
> not defined when CONFIG_RISCV_SBI_V01 is disabled so let us add
> stub of these functions to avoid "#ifdef" on user side.
>
> Signed-off-by: Anup Patel <[email protected]>
> Reviewed-by: Andrew Jones <[email protected]>
> ---
> arch/riscv/include/asm/sbi.h | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
> index 0892f4421bc4..66f3933c14f6 100644
> --- a/arch/riscv/include/asm/sbi.h
> +++ b/arch/riscv/include/asm/sbi.h
> @@ -271,8 +271,13 @@ struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
> unsigned long arg3, unsigned long arg4,
> unsigned long arg5);
>
> +#ifdef CONFIG_RISCV_SBI_V01
> void sbi_console_putchar(int ch);
> int sbi_console_getchar(void);
> +#else
> +static inline void sbi_console_putchar(int ch) { }
> +static inline int sbi_console_getchar(void) { return -ENOENT; }

"The SBI call returns the byte on success, or -1 for failure."

So -ENOENT is not really an appropriate value to return here.

Regards,
Samuel

> +#endif
> long sbi_get_mvendorid(void);
> long sbi_get_marchid(void);
> long sbi_get_mimpid(void);

2023-11-23 10:39:15

by Anup Patel

Subject: Re: [PATCH v4 1/5] RISC-V: Add stubs for sbi_console_putchar/getchar()

On Wed, Nov 22, 2023 at 4:06 AM Samuel Holland
<[email protected]> wrote:
>
> Hi Anup,
>
> On 2023-11-17 9:38 PM, Anup Patel wrote:
> > The functions sbi_console_putchar() and sbi_console_getchar() are
> > not defined when CONFIG_RISCV_SBI_V01 is disabled so let us add
> > stub of these functions to avoid "#ifdef" on user side.
> >
> > Signed-off-by: Anup Patel <[email protected]>
> > Reviewed-by: Andrew Jones <[email protected]>
> > ---
> > arch/riscv/include/asm/sbi.h | 5 +++++
> > 1 file changed, 5 insertions(+)
> >
> > diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
> > index 0892f4421bc4..66f3933c14f6 100644
> > --- a/arch/riscv/include/asm/sbi.h
> > +++ b/arch/riscv/include/asm/sbi.h
> > @@ -271,8 +271,13 @@ struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
> > unsigned long arg3, unsigned long arg4,
> > unsigned long arg5);
> >
> > +#ifdef CONFIG_RISCV_SBI_V01
> > void sbi_console_putchar(int ch);
> > int sbi_console_getchar(void);
> > +#else
> > +static inline void sbi_console_putchar(int ch) { }
> > +static inline int sbi_console_getchar(void) { return -ENOENT; }
>
> "The SBI call returns the byte on success, or -1 for failure."
>
> So -ENOENT is not really an appropriate value to return here.

Actually, I had -1 over here previously but based on GregKH's
suggestion, we are now returning proper Linux error code here.

Also, all users of sbi_console_getchar() onlyl expect a negative
value upon error so better to return proper Linux error code.

>
> Regards,
> Samuel
>
> > +#endif
> > long sbi_get_mvendorid(void);
> > long sbi_get_marchid(void);
> > long sbi_get_mimpid(void);
>

Regards,
Anup

2023-11-23 14:47:31

by Samuel Holland

Subject: Re: [PATCH v4 1/5] RISC-V: Add stubs for sbi_console_putchar/getchar()

Hi Anup,

On 2023-11-23 4:38 AM, Anup Patel wrote:
> On Wed, Nov 22, 2023 at 4:06 AM Samuel Holland
> <[email protected]> wrote:
>> On 2023-11-17 9:38 PM, Anup Patel wrote:
>>> The functions sbi_console_putchar() and sbi_console_getchar() are
>>> not defined when CONFIG_RISCV_SBI_V01 is disabled so let us add
>>> stub of these functions to avoid "#ifdef" on user side.
>>>
>>> Signed-off-by: Anup Patel <[email protected]>
>>> Reviewed-by: Andrew Jones <[email protected]>
>>> ---
>>> arch/riscv/include/asm/sbi.h | 5 +++++
>>> 1 file changed, 5 insertions(+)
>>>
>>> diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
>>> index 0892f4421bc4..66f3933c14f6 100644
>>> --- a/arch/riscv/include/asm/sbi.h
>>> +++ b/arch/riscv/include/asm/sbi.h
>>> @@ -271,8 +271,13 @@ struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
>>> unsigned long arg3, unsigned long arg4,
>>> unsigned long arg5);
>>>
>>> +#ifdef CONFIG_RISCV_SBI_V01
>>> void sbi_console_putchar(int ch);
>>> int sbi_console_getchar(void);
>>> +#else
>>> +static inline void sbi_console_putchar(int ch) { }
>>> +static inline int sbi_console_getchar(void) { return -ENOENT; }
>>
>> "The SBI call returns the byte on success, or -1 for failure."
>>
>> So -ENOENT is not really an appropriate value to return here.
>
> Actually, I had -1 over here previously but based on GregKH's
> suggestion, we are now returning proper Linux error code here.
>
> Also, all users of sbi_console_getchar() onlyl expect a negative
> value upon error so better to return proper Linux error code.

Alright, makes sense to me.

Regards,
Samuel