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xtensa: keep sysmem banks ordered in add_sysmem_bank

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

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
This commit is contained in:
Max Filippov 2014-03-23 03:34:44 +04:00
parent 9ba067f93f
commit 9d4b52df4b
2 changed files with 103 additions and 5 deletions
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5
arch/xtensa/include/asm/sysmem.h
View File

@ -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];

103
arch/xtensa/mm/init.c
View File

@ -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;
}