From 9d4b52df4b1242e6ba9a00db5f8d62083a56709f Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Sun, 23 Mar 2014 03:34:44 +0400 Subject: 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: Max Filippov --- arch/xtensa/include/asm/sysmem.h | 5 ++ arch/xtensa/mm/init.c | 103 +++++++++++++++++++++++++++++++++++++-- 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 * Joe Taylor @@ -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; } -- cgit v1.2.3