summaryrefslogtreecommitdiff
path: root/arch/powerpc/Kconfig
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc/Kconfig')
-rw-r--r--arch/powerpc/Kconfig64
1 files changed, 49 insertions, 15 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index adb23ea1c1ef..79f25cef32df 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -285,6 +285,10 @@ config IOMMU_VMERGE
config IOMMU_HELPER
def_bool PPC64
+config PPC_NEED_DMA_SYNC_OPS
+ def_bool y
+ depends on NOT_COHERENT_CACHE
+
config HOTPLUG_CPU
bool "Support for enabling/disabling CPUs"
depends on SMP && HOTPLUG && EXPERIMENTAL && (PPC_PSERIES || PPC_PMAC)
@@ -322,7 +326,7 @@ config KEXEC
config CRASH_DUMP
bool "Build a kdump crash kernel"
- depends on PPC_MULTIPLATFORM && PPC64 && RELOCATABLE
+ depends on (PPC64 && RELOCATABLE) || 6xx
help
Build a kernel suitable for use as a kdump capture kernel.
The same kernel binary can be used as production kernel and dump
@@ -401,23 +405,53 @@ config PPC_HAS_HASH_64K
depends on PPC64
default n
-config PPC_64K_PAGES
- bool "64k page size"
- depends on PPC64
- select PPC_HAS_HASH_64K
+choice
+ prompt "Page size"
+ default PPC_4K_PAGES
help
- This option changes the kernel logical page size to 64k. On machines
- without processor support for 64k pages, the kernel will simulate
- them by loading each individual 4k page on demand transparently,
- while on hardware with such support, it will be used to map
- normal application pages.
+ Select the kernel logical page size. Increasing the page size
+ will reduce software overhead at each page boundary, allow
+ hardware prefetch mechanisms to be more effective, and allow
+ larger dma transfers increasing IO efficiency and reducing
+ overhead. However the utilization of memory will increase.
+ For example, each cached file will using a multiple of the
+ page size to hold its contents and the difference between the
+ end of file and the end of page is wasted.
+
+ Some dedicated systems, such as software raid serving with
+ accelerated calculations, have shown significant increases.
+
+ If you configure a 64 bit kernel for 64k pages but the
+ processor does not support them, then the kernel will simulate
+ them with 4k pages, loading them on demand, but with the
+ reduced software overhead and larger internal fragmentation.
+ For the 32 bit kernel, a large page option will not be offered
+ unless it is supported by the configured processor.
+
+ If unsure, choose 4K_PAGES.
+
+config PPC_4K_PAGES
+ bool "4k page size"
+
+config PPC_16K_PAGES
+ bool "16k page size" if 44x
+
+config PPC_64K_PAGES
+ bool "64k page size" if 44x || PPC_STD_MMU_64
+ select PPC_HAS_HASH_64K if PPC_STD_MMU_64
+
+endchoice
config FORCE_MAX_ZONEORDER
int "Maximum zone order"
- range 9 64 if PPC_64K_PAGES
- default "9" if PPC_64K_PAGES
- range 13 64 if PPC64 && !PPC_64K_PAGES
- default "13" if PPC64 && !PPC_64K_PAGES
+ range 9 64 if PPC_STD_MMU_64 && PPC_64K_PAGES
+ default "9" if PPC_STD_MMU_64 && PPC_64K_PAGES
+ range 13 64 if PPC_STD_MMU_64 && !PPC_64K_PAGES
+ default "13" if PPC_STD_MMU_64 && !PPC_64K_PAGES
+ range 9 64 if PPC_STD_MMU_32 && PPC_16K_PAGES
+ default "9" if PPC_STD_MMU_32 && PPC_16K_PAGES
+ range 7 64 if PPC_STD_MMU_32 && PPC_64K_PAGES
+ default "7" if PPC_STD_MMU_32 && PPC_64K_PAGES
range 11 64
default "11"
help
@@ -437,7 +471,7 @@ config FORCE_MAX_ZONEORDER
config PPC_SUBPAGE_PROT
bool "Support setting protections for 4k subpages"
- depends on PPC_64K_PAGES
+ depends on PPC_STD_MMU_64 && PPC_64K_PAGES
help
This option adds support for a system call to allow user programs
to set access permissions (read/write, readonly, or no access)