From 78a8b35bc7abf8b8333d6f625e08c0f7cc1c3742 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Thu, 12 Mar 2009 22:36:01 -0700 Subject: [PATCH] x86: make e820_update_range() handle small range update Impact: enhance e820 code to handle more cases Try to handle new range which could be covered by one entry. Signed-off-by: Yinghai Lu Cc: jbeulich@novell.com LKML-Reference: <49B9F0C1.10402@kernel.org> Signed-off-by: Ingo Molnar --- arch/x86/kernel/e820.c | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index 95b81c18b6b..0c34ff49ff4 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -427,6 +427,7 @@ static u64 __init __e820_update_range(struct e820map *e820x, u64 start, u64 size, unsigned old_type, unsigned new_type) { + u64 end; unsigned int i; u64 real_updated_size = 0; @@ -435,21 +436,35 @@ static u64 __init __e820_update_range(struct e820map *e820x, u64 start, if (size > (ULLONG_MAX - start)) size = ULLONG_MAX - start; + end = start + size; for (i = 0; i < e820x->nr_map; i++) { struct e820entry *ei = &e820x->map[i]; u64 final_start, final_end; + u64 ei_end; + if (ei->type != old_type) continue; - /* totally covered? */ - if (ei->addr >= start && - (ei->addr + ei->size) <= (start + size)) { + + ei_end = ei->addr + ei->size; + /* totally covered by new range? */ + if (ei->addr >= start && ei_end <= end) { ei->type = new_type; real_updated_size += ei->size; continue; } + + /* new range is totally covered? */ + if (ei->addr < start && ei_end > end) { + __e820_add_region(e820x, start, size, new_type); + __e820_add_region(e820x, end, ei_end - end, ei->type); + ei->size = start - ei->addr; + real_updated_size += size; + continue; + } + /* partially covered */ final_start = max(start, ei->addr); - final_end = min(start + size, ei->addr + ei->size); + final_end = min(end, ei_end); if (final_start >= final_end) continue; -- 2.46.0