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| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2016-12-07 08:47:28 +0100 |
|---|---|---|
| committer | Scott Wood <oss@buserror.net> | 2016-12-10 05:49:07 +0100 |
| commit | 4b91428699477532ab1255c2dd5819713e9e8985 (patch) | |
| tree | fdfb7370974a1ec518d40cc4b145c02886de831e /arch/powerpc/platforms | |
| parent | powerpc: get hugetlbpage handling more generic (diff) | |
| download | linux-4b91428699477532ab1255c2dd5819713e9e8985.tar.xz linux-4b91428699477532ab1255c2dd5819713e9e8985.zip | |
powerpc/8xx: Implement support of hugepages
8xx uses a two level page table with two different linux page size
support (4k and 16k). 8xx also support two different hugepage sizes
512k and 8M. In order to support them on linux we define two different
page table layout.
The size of pages is in the PGD entry, using PS field (bits 28-29):
00 : Small pages (4k or 16k)
01 : 512k pages
10 : reserved
11 : 8M pages
For 512K hugepage size a pgd entry have the below format
[<hugepte address >0101] . The hugepte table allocated will contain 8
entries pointing to 512K huge pte in 4k pages mode and 64 entries in
16k pages mode.
For 8M in 16k mode, a pgd entry have the below format
[<hugepte address >1101] . The hugepte table allocated will contain 8
entries pointing to 8M huge pte.
For 8M in 4k mode, multiple pgd entries point to the same hugepte
address and pgd entry will have the below format
[<hugepte address>1101]. The hugepte table allocated will only have one
entry.
For the time being, we do not support CPU15 ERRATA when HUGETLB is
selected
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> (v3, for the generic bits)
Signed-off-by: Scott Wood <oss@buserror.net>
Diffstat (limited to 'arch/powerpc/platforms')
| -rw-r--r-- | arch/powerpc/platforms/8xx/Kconfig | 1 | ||||
| -rw-r--r-- | arch/powerpc/platforms/Kconfig.cputype | 1 |
2 files changed, 2 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/8xx/Kconfig b/arch/powerpc/platforms/8xx/Kconfig index 564d99bb2a26..80cbcb0ad9b1 100644 --- a/arch/powerpc/platforms/8xx/Kconfig +++ b/arch/powerpc/platforms/8xx/Kconfig @@ -130,6 +130,7 @@ config 8xx_CPU6 config 8xx_CPU15 bool "CPU15 Silicon Errata" + depends on !HUGETLB_PAGE default y help This enables a workaround for erratum CPU15 on MPC8xx chips. diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype index ca2da30ad2ab..6e89e5a8d4fb 100644 --- a/arch/powerpc/platforms/Kconfig.cputype +++ b/arch/powerpc/platforms/Kconfig.cputype @@ -34,6 +34,7 @@ config PPC_8xx select FSL_SOC select 8xx select PPC_LIB_RHEAP + select SYS_SUPPORTS_HUGETLBFS config 40x bool "AMCC 40x" |