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x86: Make e820_remove_range to handle all covered case 

Rusty found on lguest with trim_bios_range, max_pfn is not right anymore, and
looks e820_remove_range does not work right.

[    0.000000] BIOS-provided physical RAM map:
[    0.000000]  LGUEST: 0000000000000000 - 0000000004000000 (usable)
[    0.000000] Notice: NX (Execute Disable) protection missing in CPU or disabled in BIOS!
[    0.000000] DMI not present or invalid.
[    0.000000] last_pfn = 0x3fa0 max_arch_pfn = 0x100000
[    0.000000] init_memory_mapping: 0000000000000000-0000000003fa0000

root cause is: the e820_remove_range doesn't handle the all covered
case.  e820_remove_range(BIOS_START, BIOS_END - BIOS_START, ...)
produces a bogus range as a result.

Make it match e820_update_range() by handling that case too.

Reported-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Tested-by: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <4BB18E55.6090903@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
This commit is contained in:
Yinghai Lu 2010-03-29 22:38:29 -07:00 committed by H. Peter Anvin
parent 8ae06d223f
commit 9f3a5f52aa
1 changed files with 20 additions and 4 deletions
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24
arch/x86/kernel/e820.c
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@ -519,29 +519,45 @@ u64 __init e820_remove_range(u64 start, u64 size, unsigned old_type,
printk(KERN_DEBUG "e820 remove range: %016Lx - %016Lx ",
(unsigned long long) start,
(unsigned long long) end);
e820_print_type(old_type);
if (checktype)
e820_print_type(old_type);
printk(KERN_CONT "\n");
for (i = 0; i < e820.nr_map; i++) {
struct e820entry *ei = &e820.map[i];
u64 final_start, final_end;
u64 ei_end;
if (checktype && ei->type != old_type)
continue;
ei_end = ei->addr + ei->size;
/* totally covered? */
if (ei->addr >= start &&
(ei->addr + ei->size) <= (start + size)) {
if (ei->addr >= start && ei_end <= end) {
real_removed_size += ei->size;
memset(ei, 0, sizeof(struct e820entry));
continue;
}
/* new range is totally covered? */
if (ei->addr < start && ei_end > end) {
e820_add_region(end, ei_end - end, ei->type);
ei->size = start - ei->addr;
real_removed_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;
real_removed_size += final_end - final_start;
/*
* left range could be head or tail, so need to update
* size at first.
*/
ei->size -= final_end - final_start;
if (ei->addr < final_start)
continue;