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-rw-r--r--arch/xtensa/include/asm/sysmem.h5
-rw-r--r--arch/xtensa/mm/init.c103
2 files changed, 103 insertions, 5 deletions
diff --git a/arch/xtensa/include/asm/sysmem.h b/arch/xtensa/include/asm/sysmem.h
index fe7ad750a158..c015c5c8e3f7 100644
--- a/arch/xtensa/include/asm/sysmem.h
+++ b/arch/xtensa/include/asm/sysmem.h
@@ -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];
diff --git a/arch/xtensa/mm/init.c b/arch/xtensa/mm/init.c
index 4f78264e8bd8..79c0c3d52ae3 100644
--- a/arch/xtensa/mm/init.c
+++ b/arch/xtensa/mm/init.c
@@ -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;
}