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| author |   Christophe Leroy <christophe.leroy@c-s.fr> | 2019-02-21 19:08:50 +0000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2019-02-23 21:04:32 +1100 |
| commit | 0f4a9041c7a77240fa1ff927775620b574151f34 (patch) | |
| tree | a3a9cc95df286eaabeeb9fd4247f261bcdd44ede /arch/powerpc/Kconfig | |
| parent | powerpc/mm/32s: Use BATs for STRICT_KERNEL_RWX (diff) | |
| download | linux-dev-0f4a9041c7a77240fa1ff927775620b574151f34.tar.xz linux-dev-0f4a9041c7a77240fa1ff927775620b574151f34.zip | |
powerpc/kconfig: make _etext and data areas alignment configurable on Book3s 32
Depending on the number of available BATs for mapping the different
kernel areas, it might be needed to increase the alignment of _etext
and/or of data areas.
This patchs allows the user to do it via Kconfig.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/Kconfig')
| -rw-r--r-- | arch/powerpc/Kconfig | 32 |
1 files changed, 30 insertions, 2 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 2544dae471e1..81df0dbc8a9a 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -721,16 +721,44 @@ config THREAD_SHIFT Used to define the stack size. The default is almost always what you want. Only change this if you know what you are doing. +config ETEXT_SHIFT_BOOL + bool "Set custom etext alignment" if STRICT_KERNEL_RWX && PPC_BOOK3S_32 + depends on ADVANCED_OPTIONS + help + This option allows you to set the kernel end of text alignment. When + RAM is mapped by blocks, the alignment needs to fit the size and + number of possible blocks. The default should be OK for most configs. + + Say N here unless you know what you are doing. + config ETEXT_SHIFT - int + int "_etext shift" if ETEXT_SHIFT_BOOL + range 17 28 if STRICT_KERNEL_RWX && PPC_BOOK3S_32 default 17 if STRICT_KERNEL_RWX && PPC_BOOK3S_32 default PPC_PAGE_SHIFT + help + On Book3S 32 (603+), IBATs are used to map kernel text. + Smaller is the alignment, greater is the number of necessary IBATs. + +config DATA_SHIFT_BOOL + bool "Set custom data alignment" if STRICT_KERNEL_RWX && PPC_BOOK3S_32 + depends on ADVANCED_OPTIONS + help + This option allows you to set the kernel data alignment. When + RAM is mapped by blocks, the alignment needs to fit the size and + number of possible blocks. The default should be OK for most configs. + + Say N here unless you know what you are doing. config DATA_SHIFT - int + int "Data shift" if DATA_SHIFT_BOOL default 24 if STRICT_KERNEL_RWX && PPC64 + range 17 28 if STRICT_KERNEL_RWX && PPC_BOOK3S_32 default 22 if STRICT_KERNEL_RWX && PPC_BOOK3S_32 default PPC_PAGE_SHIFT + help + On Book3S 32 (603+), DBATs are used to map kernel text and rodata RO. + Smaller is the alignment, greater is the number of necessary DBATs. config FORCE_MAX_ZONEORDER int "Maximum zone order" |