Subject: Re: [PATCH 5/6] tty: Add SBI debug console support to HVC SBI driver

From: Greg Kroah-Hartman <[email-masked]>
Date: Tue, 10 Oct 2023 19:12:42 +0200

On Tue, Oct 10, 2023 at 10:35:02PM +0530, Anup Patel wrote:
> --- a/drivers/tty/hvc/hvc_riscv_sbi.c
> +++ b/drivers/tty/hvc/hvc_riscv_sbi.c
> @@ -15,6 +15,7 @@
>  
>  #include "hvc_console.h"
>  
> +#ifdef CONFIG_RISCV_SBI_V01

Please no #ifdef in a .c file, that's not a good style for Linux code at
all.

And what if you want to build the driver for both options here?  What
will happen?

> +static int hvc_sbi_dbcn_tty_put(uint32_t vtermno, const char *buf, int count)
>  {
> -	return PTR_ERR_OR_ZERO(hvc_alloc(0, 0, &hvc_sbi_ops, 16));
> +	phys_addr_t pa;
> +	struct sbiret ret;
> +
> +	if (is_vmalloc_addr(buf))
> +		pa = page_to_phys(vmalloc_to_page(buf)) + offset_in_page(buf);
> +	else
> +		pa = __pa(buf);
> +
> +	ret = sbi_ecall(SBI_EXT_DBCN, SBI_EXT_DBCN_CONSOLE_WRITE,
> +#ifdef CONFIG_32BIT
> +		  count, pa, (u64)pa >> 32,
> +#else
> +		  count, pa, 0,
> +#endif

This is not how to do an api, sorry, again, please no #ifdef if you want
to support this code for the next 20+ years.

thanks,

gre gk-h