Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc

[linux-2.6-omap-h63xx.git] / arch / powerpc / Kconfig

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index adb23ea1c1ef1b2ed2965efb0d0a0da3cff429fe..79f25cef32dfe72b0d230ce6642ce95c747f080d 100644 (file)
--- 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)