Commit fb492c91 authored Aug 30, 2011 by Mark Rutland Committed by Russell King Sep 04, 2011

ARM: 7067/1: mm: keep significant bits in pfn_valid



When ARCH_HAS_HOLES_MEMORYMODEL is selected, pfn_valid calls
memblock_is_memory to test validity of a pfn:

> memblock_is_memory(pfn << PAGE_SHIFT);

On LPAE systems this cuts off the top bits, as the shift occurs before
the value is promoted to a phys_addr_t.

This patch replaces the shift with a call to __pfn_to_phys (which casts
pfn to phys_addr_t before shifting), preventing the loss of significant
bits.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

parent 9e79e3e9

arch/arm/mm/init.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -298,7 +298,7 @@ static void __init arm_bootmem_free(unsigned long min, unsigned long max_low,
		#ifdef CONFIG_HAVE_ARCH_PFN_VALID
		int pfn_valid(unsigned long pfn)
		{
		return memblock_is_memory(pfn << PAGE_SHIFT);
		return memblock_is_memory(__pfn_to_phys(pfn));
		}
		EXPORT_SYMBOL(pfn_valid);
		#endif