[PATCH] ARM: use default ioremap alignment for SMP or LPAE

From: Sergey Dyasly
Date: Thu Jan 22 2015 - 02:18:15 EST


16MB alignment for ioremap mappings was added by commit a069c896d0d6 ("[ARM]
3705/1: add supersection support to ioremap()") in order to support supersection
mappings. But __arm_ioremap_pfn_caller uses section and supersection mappings
only in !SMP && !LPAE case. There is no need for such big alignment if either
SMP or LPAE is enabled.

After this change, ioremap will use default maximum alignment of 128 pages.

Cc: Russell King <linux@xxxxxxxxxxxxxxxx>
Cc: Guan Xuetao <gxt@xxxxxxxxxxxxxxx>
Cc: Nicolas Pitre <nicolas.pitre@xxxxxxxxxx>
Cc: James Bottomley <JBottomley@xxxxxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Arnd Bergmann <arnd.bergmann@xxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Dmitry Safonov <d.safonov@xxxxxxxxxxxxxxxxxxx>
Link: https://lkml.kernel.org/g/1419328813-2211-1-git-send-email-d.safonov@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Sergey Dyasly <s.dyasly@xxxxxxxxxxx>
---
arch/arm/include/asm/memory.h | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h
index 184def0..c3ef139 100644
--- a/arch/arm/include/asm/memory.h
+++ b/arch/arm/include/asm/memory.h
@@ -78,10 +78,12 @@
*/
#define XIP_VIRT_ADDR(physaddr) (MODULES_VADDR + ((physaddr) & 0x000fffff))

+#if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
/*
* Allow 16MB-aligned ioremap pages
*/
#define IOREMAP_MAX_ORDER 24
+#endif

#else /* CONFIG_MMU */

--
1.7.9.5

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