From: Mark Rutland <mark.rutland@arm.com>
Date: Tue, 30 Aug 2011 16:45:10 +0000 (+0100)
Subject: ARM: 7067/1: mm: keep significant bits in pfn_valid
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=fb492c9160f3d40d09456a79cc669fba74d7d9cc;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git

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>
---

diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 91bca355cd31..cc7e2d8be9aa 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -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