[PATCH v2 0/2] change ARM linux memory layout to support 32 CPUs
Liu Hua
sdu.liu at huawei.com
Fri Apr 11 01:00:50 PDT 2014
Hi Nicolas or Russell,
This patch series change fixmap mapping region to suppport 32 CPUs.
Because the "top_pmd" covers 0xfffe0000 - 0xffffffff(2M). And part
is used by vector table. So I move this region down to 0xffc00000
- 0xffdffff.
I have tested the patches on arma9(2 CPUs) and arma15(16 CPUs) platforms
BTW, As we know we can configure NR_CPUS up to 32. So we need 2048K
at most. But for ARM systems with less cpus, there is a waste
of virtual address. So should we change its size according to
NR_CPUS, as what MIPS linux does ?
Changes from v1:
---------------
- changed documentation for ARM linux memory layout.
- moved fixmap mapping region, not just extended.
Liu Hua (2):
ARM : DMA : remove useless information about DMA
ARM : extend fixmap mapping region to support 32 CPUs
Documentation/arm/memory.txt | 8 ++------
arch/arm/include/asm/fixmap.h | 4 ++--
arch/arm/include/asm/highmem.h | 1 +
arch/arm/include/asm/memory.h | 2 --
arch/arm/mm/highmem.c | 10 +++++-----
arch/arm/mm/mm.h | 7 +++++++
arch/arm/mm/mmu.c | 4 ++++
mm/highmem.c | 1 +
8 files changed, 22 insertions(+), 15 deletions(-)
--
1.9.0
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