Commit 0f4a9041 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman

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: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 63b2bc61
......@@ -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"
......
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