Re: [PATCH v4 4/5] tty: Add SBI debug console support to HVC SBI driver

Jiri Slaby
2023-11-20T07:16:21Z

On 18. 11. 23, 4:38, Anup Patel wrote:
> diff --git a/drivers/tty/hvc/hvc_riscv_sbi.c b/drivers/tty/hvc/hvc_riscv_sbi.c
> index 31f53fa77e4a..697c981221b5 100644
> --- a/drivers/tty/hvc/hvc_riscv_sbi.c
> +++ b/drivers/tty/hvc/hvc_riscv_sbi.c
...
> -static int __init hvc_sbi_console_init(void)
> +static int hvc_sbi_dbcn_tty_get(uint32_t vtermno, char *buf, int count)
> {
> - hvc_instantiate(0, 0, &hvc_sbi_ops);
> + phys_addr_t pa;
> +
> + if (is_vmalloc_addr(buf)) {

I wonder, where does this buf come from, so that you have to check for
vmalloc?

> + pa = page_to_phys(vmalloc_to_page(buf)) + offset_in_page(buf);
> + if (PAGE_SIZE < (offset_in_page(buf) + count))

Am I the only one who would prefer:
if (count + offset_in_page(buf) > PAGE_SIZE)
?

> + count = PAGE_SIZE - offset_in_page(buf);
> + } else {
> + pa = __pa(buf);
> + }
> +
> + return sbi_debug_console_read(count, pa);
> +}

thanks,
--
js
suse labs