[PATCH] cacheflush.2: Document Architecture-specific variants

[Michael Kerrisk (man-pages)]

Hi Alex

On 12/14/20 3:38 PM, Alejandro Colomar wrote:
> Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
> ---
> 
> Hi Michael,
> 
> Please apply this patch after
> '[PATCH v5] cacheflush.2: Document __builtin___clear_cache() as a more
>  portable alternative'.

Thanks. Applied.

>  man2/cacheflush.2 | 42 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 42 insertions(+)
> 
> diff --git a/man2/cacheflush.2 b/man2/cacheflush.2
> index fc35f1a0b..0761b429a 100644
> --- a/man2/cacheflush.2
> +++ b/man2/cacheflush.2
> @@ -31,6 +31,10 @@ cacheflush \- flush contents of instruction and/or data cache
>  .PP
>  .BI "int cacheflush(char *" addr ", int "nbytes ", int "cache );
>  .fi
> +.PP
> +.IR Note :
> +On some architectures,
> +there is no glibc wrapper for this system call; see NOTES.
>  .SH DESCRIPTION
>  .BR cacheflush ()
>  flushes the contents of the indicated cache(s) for the
> @@ -87,6 +91,44 @@ but nowadays, Linux provides a
>  .BR cacheflush ()
>  system call on some other architectures, but with different arguments.
>  .SH NOTES
> +.SS Architecture-specific variants
> +Glibc provides a wrapper for this system call,
> +with the prototype shown in SYNOPSIS,
> +for the following architectures:
> +ARC, CSKY, MIPS, and NIOS2.
> +.PP
> +On some other architectures,
> +Linux provides this system call, with different arguments:
> +.TP
> +M68K:
> +.PP
> +.in +4n
> +.EX
> +.BI "int cacheflush(unsigned long " addr ", int " scope ", int " cache ,
> +.BI "               unsigned long " len );
> +.EE
> +.in

I made the formatting rather:

[[
.TP
M68K:
.nf
.BI "int cacheflush(unsigned long " addr ", int " scope ", int " cache ,
.BI "               unsigned long " len );
.fi
]]

That's for consistency wqith the SYNOPSIS sections, where .EX/.EE 
isn't used.

> +.TP
> +SH:
> +.PP
> +.in +4n
> +.EX
> +.BI "int cacheflush(unsigned long " addr ", unsigned long " len ", int " op );
> +.EE
> +.in
> +.TP
> +NDS32:
> +.PP
> +.in +4n
> +.EX
> +.BI "int cacheflush(unsigned int " start ", unsigned int " end ", int " cache );
> +.EE
> +.in
> +.PP
> +On the above architectures,
> +glibc does not provide a wrapper for this system call; call it using
> +.BR syscall (2).
> +.SS GCC alternative
>  Unless you need the finer grained control that this system call provides,
>  you probably want to use the GCC built-in function
>  .BR __builtin___clear_cache (),


Cheers,

Michael



-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/