Re: [PATCH] powerpc: Fix mem= cmdline handling on arch/powerpc for !MULTIPLATFORM

[Michael Ellerman <michael@ellerman.id.au>]

On Sat, 25 Feb 2006 09:43, Kumar Gala wrote:
> On Feb 24, 2006, at 4:27 PM, Michael Ellerman wrote:
> > Hi Kumar,
> >
> > On Sat, 25 Feb 2006 03:54, Kumar Gala wrote:
> >> mem= command line option was being ignored in arch/powerpc if we
> >> were not
> >> a CONFIG_MULTIPLATFORM (which is handled via prom_init stub). The
> >> initial
> >> command line extraction and parsing needed to be moved earlier in
> >> the boot
> >> process and have code to actual parse mem= and do something about it.
> >>
> >> @@ -1004,6 +991,41 @@ static int __init early_init_dt_scan_cho
> >>                 crashk_res.end = crashk_res.start + *lprop - 1;
> >>  #endif
> >>
> >> +	/* Retreive command line */
> >> + 	p = of_get_flat_dt_prop(node, "bootargs", &l);
> >> +	if (p != NULL && l > 0)
> >> +		strlcpy(cmd_line, p, min((int)l, COMMAND_LINE_SIZE));
> >> +
> >> +#ifdef CONFIG_CMDLINE
> >> +	if (l == 0 || (l == 1 && (*p) == 0))
> >> +		strlcpy(cmd_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
> >> +#endif /* CONFIG_CMDLINE */
> >> +
> >> +	DBG("Command line is: %s\n", cmd_line);
> >> +
> >> +	if (strstr(cmd_line, "mem=")) {
> >> +		char *p, *q;
> >> +		unsigned long maxmem = 0;
> >> +
> >> +		for (q = cmd_line; (p = strstr(q, "mem=")) != 0; ) {
> >> +			q = p + 4;
> >> +			if (p > cmd_line && p[-1] != ' ')
> >> +				continue;
> >> +			maxmem = simple_strtoul(q, &q, 0);
> >> +			if (*q == 'k' || *q == 'K') {
> >> +				maxmem <<= 10;
> >> +				++q;
> >> +			} else if (*q == 'm' || *q == 'M') {
> >> +				maxmem <<= 20;
> >> +				++q;
> >> +			} else if (*q == 'g' || *q == 'G') {
> >> +				maxmem <<= 30;
> >> +				++q;
> >> +			}
> >> +		}
> >> +		memory_limit = maxmem;
> >> +	}
> >> +
> >
> > Why not make the mem= parsing an early_param() handler and then call
> > parse_early_param() here?
>
> This would put constraints on the early_param()'s that I dont think
> we should impose.

All they should really be doing is parsing the string and setting some 
variables, so that seems reasonable to me. Is there anything in particular?

> > And I think a switch would be easier to read for the K/M/G handling.
>
> I should probably use memparse() now that I've found it :)

Even better.

cheers

-- 
Michael Ellerman
IBM OzLabs

wwweb: http://michael.ellerman.id.au
phone: +61 2 6212 1183 (tie line 70 21183)

We do not inherit the earth from our ancestors,
we borrow it from our children. - S.M.A.R.T Person

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