Commit 083bc6b3 authored Aug 29, 2005 by Deepak Saxena Committed by Russell King Aug 29, 2005

[ARM] 2853/1: Make alloc_init_supersection() work with 36-bit mappings



Patch from Deepak Saxena

Working on adding support for 36-bit static mappings for ARMv6 and
Intel's XSC3 core and noticed that alloc_init_supersection currently
increments the phys addr by 1MB on each of the 16 iterations and then
forces alignment to supersection size (16MB).  This is really uneeded
b/c we have already forced the phys address to be 16MB aligned in
create_mapping(). Furthermore, this breaks 36-bit addressing b/c bits
[23:20] of the PMD contain bits [35:32] of the physical address and
the masking causes us to loose those bits thus ending up with an
incorrect virt -> phys translation.  The other option is to have an
alloc_init_supersection36.
Tested on Intel IXP2350 CPU with 36-bit static I/O mappings.

Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

parent 3e88a579

arch/arm/mm/mm-armv.c

+1 −3

Original line number	Diff line number	Diff line
		@@ -275,11 +275,9 @@ alloc_init_supersection(unsigned long virt, unsigned long phys, int prot)
		int i;

		for (i = 0; i < 16; i += 1) {
		alloc_init_section(virt, phys & SUPERSECTION_MASK,
		prot \| PMD_SECT_SUPER);
		alloc_init_section(virt, phys, prot \| PMD_SECT_SUPER);

		virt += (PGDIR_SIZE / 2);
		phys += (PGDIR_SIZE / 2);
		}
		}

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