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Commit 06bd2824 authored by Max Filippov's avatar Max Filippov
Browse files

xtensa: handle memmap kernel option 



This option is useful for reserving memory regions for secondary cores
in AMP configurations.

Implement the following memmap variants:
- memmap=nn[KMG]@ss[KMG]: force usage of a specific region of memory;
- memmap=nn[KMG]$ss[KMG]: mark specified memory as reserved;
- memmap=nn[KMG]: set end of memory.

Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
parent 62327918

arch/xtensa/kernel/setup.c

+1 −0
Original line number Diff line number Diff line
@@ -507,6 +507,7 @@ void __init setup_arch(char **cmdline_p) 
		    __pa(&_Level6InterruptVector_text_end), 0);

#endif



	parse_early_param();

	bootmem_init();



	unflatten_and_copy_device_tree();

arch/xtensa/mm/init.c

+50 −0
Original line number Diff line number Diff line
@@ -332,3 +332,53 @@ void free_initmem(void) 
{

	free_initmem_default(-1);

}



static void __init parse_memmap_one(char *p)

{

	char *oldp;

	unsigned long start_at, mem_size;



	if (!p)

		return;



	oldp = p;

	mem_size = memparse(p, &p);

	if (p == oldp)

		return;



	switch (*p) {

	case '@':

		start_at = memparse(p + 1, &p);

		add_sysmem_bank(start_at, start_at + mem_size);

		break;



	case '$':

		start_at = memparse(p + 1, &p);

		mem_reserve(start_at, start_at + mem_size, 0);

		break;



	case 0:

		mem_reserve(mem_size, 0, 0);

		break;



	default:

		pr_warn("Unrecognized memmap syntax: %s\n", p);

		break;

	}

}



static int __init parse_memmap_opt(char *str)

{

	while (str) {

		char *k = strchr(str, ',');



		if (k)

			*k++ = 0;



		parse_memmap_one(str);

		str = k;

	}



	return 0;

}

early_param("memmap", parse_memmap_opt);