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| author | Max Filippov <jcmvbkbc@gmail.com> | 2014-02-04 02:17:09 +0400 |
|---|---|---|
| committer | Max Filippov <jcmvbkbc@gmail.com> | 2014-04-06 21:29:21 +0400 |
| commit | 65559100655c6ed6ce2e17ffc8d4f3852bc2858a (patch) | |
| tree | 71cf7391732414bce793d0ad7c5d39a03f60e76f /arch/xtensa/Kconfig | |
| parent | 04c6b3e2b5e5c1dbd99ad7620033eafd05ff4c26 (diff) | |
xtensa: add HIGHMEM support
Introduce fixmap area just below the vmalloc region. Use it for atomic
mapping of high memory pages.
High memory on cores with cache aliasing is not supported and is still
to be implemented. Fail build for such configurations for now.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Diffstat (limited to 'arch/xtensa/Kconfig')
| -rw-r--r-- | arch/xtensa/Kconfig | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig index df6f86ca6c1a..17b31982c566 100644 --- a/arch/xtensa/Kconfig +++ b/arch/xtensa/Kconfig @@ -190,6 +190,24 @@ config INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX If in doubt, say Y. +config HIGHMEM + bool "High Memory Support" + help + Linux can use the full amount of RAM in the system by + default. However, the default MMUv2 setup only maps the + lowermost 128 MB of memory linearly to the areas starting + at 0xd0000000 (cached) and 0xd8000000 (uncached). + When there are more than 128 MB memory in the system not + all of it can be "permanently mapped" by the kernel. + The physical memory that's not permanently mapped is called + "high memory". + + If you are compiling a kernel which will never run on a + machine with more than 128 MB total physical RAM, answer + N here. + + If unsure, say Y. + endmenu config XTENSA_CALIBRATE_CCOUNT |