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

[Kumar Gala <galak@kernel.crashing.org>]

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.

> 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 :)

- k