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memblock, bootmem: Round pfn properly for memory and reserved regions

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We need to round memory regions correctly -- specifically, we need to
round reserved region in the more expansive direction (lower limit
down, upper limit up) whereas usable memory regions need to be rounded
in the more restrictive direction (lower limit up, upper limit down).

This introduces two set of inlines:

	memblock_region_memory_base_pfn()
	memblock_region_memory_end_pfn()
	memblock_region_reserved_base_pfn()
	memblock_region_reserved_end_pfn()

Although they are antisymmetric (and therefore are technically
duplicates) the use of the different inlines explicitly documents the
programmer's intention.

The lack of proper rounding caused a bug on ARM, which was then found
to also affect other architectures.

Reported-by: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4CB4CDFD.4020105@kernel.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This commit is contained in:
Yinghai Lu
2010-10-12 14:07:09 -07:00
committed by H. Peter Anvin
parent 8e4029ee35
commit c7fc2de0c8
6 changed files with 29 additions and 30 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
arch/arm/mm/init.c
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@@ -182,8 +182,8 @@ static void __init arm_bootmem_init(struct meminfo *mi,
* Reserve the memblock reserved regions in bootmem.
*/
for_each_memblock(reserved, reg) {
phys_addr_t start = memblock_region_base_pfn(reg);
phys_addr_t end = memblock_region_end_pfn(reg);
phys_addr_t start = memblock_region_reserved_base_pfn(reg);
phys_addr_t end = memblock_region_reserved_end_pfn(reg);
if (start >= start_pfn && end <= end_pfn)
reserve_bootmem_node(pgdat, __pfn_to_phys(start),
(end - start) << PAGE_SHIFT,
@@ -251,8 +251,8 @@ static void arm_memory_present(void)
struct memblock_region *reg;
for_each_memblock(memory, reg)
memory_present(0, memblock_region_base_pfn(reg),
memblock_region_end_pfn(reg));
memory_present(0, memblock_region_memory_base_pfn(reg),
memblock_region_memory_end_pfn(reg));
}
#endif