Commit 9d4b52df authored by Max Filippov's avatar Max Filippov
Browse files

xtensa: keep sysmem banks ordered in add_sysmem_bank 



Rewrite add_sysmem_bank so that it keeps bank order and merges
adjacent/overlapping banks.

Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
parent 9ba067f9

arch/xtensa/include/asm/sysmem.h

+5 −0
Original line number Diff line number Diff line
@@ -18,6 +18,11 @@ struct meminfo { 
	unsigned long end;

};



/*

 * Bank array is sorted by .start.

 * Banks don't overlap and there's at least one page gap

 * between adjacent bank entries.

 */

struct sysmem_info {

	int nr_banks;

	struct meminfo bank[SYSMEM_BANKS_MAX];

arch/xtensa/mm/init.c

+98 −5
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
 * for more details.

 *

 * Copyright (C) 2001 - 2005 Tensilica Inc.

 * Copyright (C) 2014 Cadence Design Systems Inc.

 *

 * Chris Zankel	<chris@zankel.net>

 * Joe Taylor	<joe@tensilica.com, joetylr@yahoo.com>
@@ -31,17 +32,109 @@ 


struct sysmem_info sysmem __initdata;



/*

 * Find bank with maximal .start such that bank.start <= start

 */

static inline struct meminfo * __init find_bank(unsigned long start)

{

	unsigned i;

	struct meminfo *it = NULL;



	for (i = 0; i < sysmem.nr_banks; ++i)

		if (sysmem.bank[i].start <= start)

			it = sysmem.bank + i;

		else

			break;

	return it;

}



/*

 * Move all memory banks starting at 'from' to a new place at 'to',

 * adjust nr_banks accordingly.

 * Both 'from' and 'to' must be inside the sysmem.bank.

 *

 * Returns: 0 (success), -ENOMEM (not enough space in the sysmem.bank).

 */

static int __init move_banks(struct meminfo *to, struct meminfo *from)

{

	unsigned n = sysmem.nr_banks - (from - sysmem.bank);



	if (to > from && to - from + sysmem.nr_banks > SYSMEM_BANKS_MAX)

		return -ENOMEM;

	if (to != from)

		memmove(to, from, n * sizeof(struct meminfo));

	sysmem.nr_banks += to - from;

	return 0;

}



/*

 * Add new bank to sysmem. Resulting sysmem is the union of bytes of the

 * original sysmem and the new bank.

 *

 * Returns: 0 (success), < 0 (error)

 */

int __init add_sysmem_bank(unsigned long start, unsigned long end)

{

	if (sysmem.nr_banks >= SYSMEM_BANKS_MAX) {

		pr_warn("Ignoring memory bank 0x%08lx size %ldKB\n",

	unsigned i;

	struct meminfo *it = NULL;

	unsigned long sz;

	unsigned long bank_sz = 0;



	if (start == end ||

	    (start < end) != (PAGE_ALIGN(start) < (end & PAGE_MASK))) {

		pr_warn("Ignoring small memory bank 0x%08lx size: %ld bytes\n",

			start, end - start);

		return -EINVAL;

	}

	sysmem.bank[sysmem.nr_banks].start = PAGE_ALIGN(start);

	sysmem.bank[sysmem.nr_banks].end   = end & PAGE_MASK;

	sysmem.nr_banks++;



	start = PAGE_ALIGN(start);

	end &= PAGE_MASK;

	sz = end - start;



	it = find_bank(start);



	if (it)

		bank_sz = it->end - it->start;



	if (it && bank_sz >= start - it->start) {

		if (end - it->start > bank_sz)

			it->end = end;

		else

			return 0;

	} else {

		if (!it)

			it = sysmem.bank;

		else

			++it;



		if (it - sysmem.bank < sysmem.nr_banks &&

		    it->start - start <= sz) {

			it->start = start;

			if (it->end - it->start < sz)

				it->end = end;

			else

				return 0;

		} else {

			if (move_banks(it + 1, it) < 0) {

				pr_warn("Ignoring memory bank 0x%08lx size %ld bytes\n",

					start, end - start);

				return -EINVAL;

			}

			it->start = start;

			it->end = end;

			return 0;

		}

	}

	sz = it->end - it->start;

	for (i = it + 1 - sysmem.bank; i < sysmem.nr_banks; ++i)

		if (sysmem.bank[i].start - it->start <= sz) {

			if (sz < sysmem.bank[i].end - it->start)

				it->end = sysmem.bank[i].end;

		} else {

			break;

		}



	move_banks(it + 1, sysmem.bank + i);

	return 0;

}