[RFC, PATCH] selection of CPU optimization
Arnd Bergmann
arnd at arndb.de
Thu Apr 12 23:01:33 EST 2007
On Tuesday 10 April 2007, Benjamin Herrenschmidt wrote:
> On Tue, 2007-04-10 at 20:15 +0900, Akinobu Mita wrote:
> > An Alignment interrupt occurs when the instruction is lmw, stmw, lswi, lswx,
> > stswi, or stswx, and the operand is in local store.
> >
> > GCC generated such instructions to handle memcpy() instead of kernel
> > defined memcpy() without -mno-string option.
> >
> > Signed-off-by: Akinobu Mita <mita at fixstars.com>
>
> I would personally prefer building the entire kernel with -mno-string
> when cell support is enabled...
The -mno-string flag should be set when _optimizing_ for cell, which it
probably is, but not when enabling a platform that runs on cell.
I recently experimented with cleaning up the CPU type selection in powerpc
in general, by splitting the selection into four groups:
1. CPU architecture (64 bit powerpc, 32 bit common, FSL book E, 4xx, ...)
this is roughly what we have already and limits the other options
2. Minimum CPU level (power3, power4, 970, cell, ....)
this selects the instruction set with -mcpu=xxx, but assumes that some
CPUs use are a superset of others.
3. Optimization for a CPU (same list as above)
compatible in both ways, but can optimize only for CPUs that were not
excluded in step 2.
4. platform selection (mac, pseries, prep, 83xx, 86xx, ...)
unchanged from now, but depends on 1. and 2. Depending on 1, you may
choose multiple platforms simultaneously, or just one.
Signed-off-by: Arnd Bergmann <arnd at arndb.de>
Index: linux-cg/arch/powerpc/Kconfig.cputype
===================================================================
--- /dev/null
+++ linux-cg/arch/powerpc/Kconfig.cputype
@@ -0,0 +1,610 @@
+menu "Processor support"
+choice
+ prompt "Processor Type"
+ default 6xx
+ help
+ There are four families of PowerPC chips supported. The more common
+ types (601, 603, 604, 740, 750, 7400), the Motorola embedded
+ versions (821, 823, 850, 855, 860, 52xx, 82xx, 83xx), the AMCC
+ embedded versions (403 and 405) and the high end 64 bit Power
+ processors (POWER 3, POWER4, and IBM PPC970 also known as G5).
+
+config PPC64
+ bool "Any 64 bit processor"
+ help
+ This option is the catch-all for all 64 bit processors, including
+ the IBM Power3/4/5/6, PowerPC 970 (G5), Cell Broadband Engine,
+ and the PA Semi PA6T.
+
+config PPC_6xx
+ bool "52xx/6xx/7xx/74xx/82xx/83xx/86xx"
+ select PPC_FPU
+ select 6xx
+ help
+ This option is the catch-all for 6xx types, including some of the
+ embedded versions. Unless there is see an option for the specific
+ chip family you are using, you want this option.
+
+ If unsure, select this option.
+
+config PPC_85xx
+ bool "Freescale 85xx"
+ select E500
+ select FSL_SOC
+ select 85xx
+
+config PPC_8xx
+ bool "Freescale 8xx"
+ select FSL_SOC
+ select 8xx
+
+config 40x
+ bool "AMCC 40x"
+ select PPC_DCR_NATIVE
+
+config 44x
+ bool "AMCC 44x"
+ select PPC_DCR_NATIVE
+
+config E200
+ bool "Freescale e200"
+
+endchoice
+
+#choice
+# prompt "Type of 6xx package"
+# default CLASSIC32
+# depends on PPC_6xx
+#
+config CLASSIC32
+ bool "Classic 52xx/6xx/7xx/74xx"
+ select 6xx
+ select PPC_FPU
+
+config PPC_82xx
+ bool "Embedded Freescale 82xx"
+ select 6xx
+ select PPC_FPU
+
+config PPC_83xx
+ bool "Embedded Freescale 83xx"
+ select 6xx
+ select FSL_SOC
+ select 83xx
+ select PPC_FPU
+
+config PPC_86xx
+ bool "Embedded Freescale 86xx"
+ select 6xx
+ select FSL_SOC
+ select PPC_FPU
+ select ALTIVEC
+ help
+ The Freescale E600 SoCs have 74xx cores.
+# endchoice
+
+choice
+ prompt "Processor level"
+ default PPC_CPU_POWER3 if PPC64
+
+config PPC_CPU_UNSPECIFIED
+ bool "Use compiler default"
+
+config PPC_CPU_ANY64
+ bool "Generic 64 bit PowerPC"
+ depends on PPC64
+ select PPC_ENABLE_ANY64
+
+config PPC_CPU_RS64
+ bool "RS64 (Northstar/Pulsar/Icestar/Sstar)"
+ depends on PPC64
+ select PPC_ENABLE_RS64
+
+config PPC_CPU_POWER3
+ bool "Power3"
+ depends on PPC64
+ select PPC_ENABLE_POWER3
+
+config PPC_CPU_POWER4
+ bool "Power4"
+ depends on PPC64
+ select PPC_ENABLE_POWER4
+
+config PPC_CPU_POWER5
+ bool "Power5"
+ depends on PPC64
+ select PPC_ENABLE_POWER5
+ select ALTIVEC
+
+config PPC_CPU_POWER5PLUS
+ bool "Power5+"
+ depends on PPC64
+ select PPC_ENABLE_POWER5PLUS
+ select ALTIVEC
+
+config PPC_CPU_POWER6
+ bool "Power6"
+ depends on PPC64
+ select PPC_ENABLE_PA6T
+ select PPC_ENABLE_POWER6
+ select ALTIVEC
+
+config PPC_CPU_970
+ bool "PowerPC 970 (G5)"
+ depends on PPC64
+ select PPC_ENABLE_970
+ select ALTIVEC
+
+config PPC_CPU_CELLBE
+ bool "Cell Broadband Engine"
+ depends on PPC64
+ select PPC_ENABLE_CELLBE
+ select PPC_ENABLE_PA6T
+ select PPC_ENABLE_POWER6
+ select ALTIVEC
+
+config PPC_CPU_PA6T
+ bool "PA Semi PA6T"
+ depends on PPC64
+ select PPC_ENABLE_PA6T
+ select PPC_ENABLE_POWER6
+ select ALTIVEC
+
+config PPC_CPU_ANY32
+ bool "Generic 32 bit PowerPC"
+ depends on PPC_6xx || PPC_8xx || 4xx || E200 || E500
+ select PPC_ENABLE_ALTIVEC
+
+config PPC_CPU_601
+ bool "601 (G1)"
+ depends on CLASSIC32
+
+config PPC_CPU_603
+ bool "603/603e/82xx/83xx/e300 (G2)"
+ depends on CLASSIC32 || PPC_82xx || PPC_83xx
+
+config PPC_CPU_604
+ bool "604/604e/604r/604ev"
+ depends on CLASSIC32
+
+config PPC_CPU_750
+ bool "750/750CX/750CXe/750FX/750GX (G3)"
+ depends on CLASSIC32
+
+config PPC_CPU_7400
+ bool "7400/7410"
+ depends on CLASSIC32
+ select ALTIVEC
+
+config PPC_CPU_7450
+ bool "7450/7447/7457/7448/7450/86xx (G4)"
+ depends on CLASSIC32 || PPC_86xx
+ select ALTIVEC
+
+config PPC_CPU_801
+ bool "801"
+ depends on PPC_8xx
+
+config PPC_CPU_821
+ bool "821"
+ depends on PPC_8xx
+
+config PPC_CPU_823
+ bool "823"
+ depends on PPC_8xx
+
+config PPC_CPU_860
+ bool "860"
+ depends on PPC_8xx
+
+config PPC_CPU_403
+ bool "403"
+ depends on 40x
+
+config PPC_CPU_405
+ bool "405"
+ depends on 40x
+
+config PPC_CPU_440
+ bool "440"
+ depends on 44x
+
+config PPC_CPU_E200
+ bool "e200/5554"
+ depends on E200
+
+config PPC_CPU_E500
+ bool "e500/8540/8548"
+ depends on E500
+endchoice
+
+config PPC_ENABLE_ANY64
+ bool
+ select PPC_ENABLE_RS64
+
+config PPC_ENABLE_POWER3
+ bool
+ select PPC_ENABLE_POWER4
+
+config PPC_ENABLE_POWER4
+ bool
+ select PPC_ENABLE_POWER5
+ select PPC_ENABLE_970
+
+config PPC_ENABLE_POWER5
+ bool
+ select PPC_ENABLE_POWER5PLUS
+ select PPC_ENABLE_CELLBE
+
+config PPC_ENABLE_POWER5PLUS
+ bool
+ select PPC_ENABLE_POWER6
+
+config PPC_ENABLE_POWER6
+ bool
+ select PPC_ENABLE_ALTIVEC
+
+config PPC_ENABLE_RS64
+ bool
+ select PPC_ENABLE_POWER3
+
+config PPC_ENABLE_970
+ bool
+ select PPC_ENABLE_POWER5
+
+config PPC_ENABLE_CELLBE
+ bool
+
+config PPC_ENABLE_PA6T
+ bool
+
+choice
+ prompt "Tune for processor"
+
+config PPC_TUNE_UNSPECIFIED
+ bool "Use compiler default"
+
+config PPC_TUNE_ANY64
+ bool "Generic 64 bit PowerPC"
+ depends on PPC64
+
+config PPC_TUNE_RS64
+ bool "RS64 (Northstar/Pulsar/Icestar/Sstar)"
+ depends on PPC_ENABLE_RS64
+
+config PPC_TUNE_POWER3
+ bool "Power3"
+ depends on PPC_ENABLE_POWER3
+
+config PPC_TUNE_POWER4
+ bool "Power4"
+ depends on PPC_ENABLE_POWER4
+
+config PPC_TUNE_POWER5
+ bool "Power5"
+ depends on PPC_ENABLE_POWER5
+
+config PPC_TUNE_POWER5PLUS
+ bool "Power5+"
+ depends on PPC_ENABLE_POWER5PLUS
+
+config PPC_TUNE_POWER6
+ bool "Power6"
+ depends on PPC_ENABLE_POWER6
+
+config PPC_TUNE_970
+ bool "PowerPC 970 (G5)"
+ depends on PPC_ENABLE_970
+
+config PPC_TUNE_CELLBE
+ bool "Cell Broadband Engine"
+ depends on PPC_ENABLE_CELLBE
+
+config PPC_TUNE_PA6T
+ bool "PA Semi PA6T"
+ depends on PPC_ENABLE_PA6T
+
+config PPC_TUNE_ANY32
+ bool "Generic 32 bit PowerPC"
+ depends on PPC32
+ select PPC_ENABLE_ALTIVEC
+
+config PPC_TUNE_601
+ bool "601 (G1)"
+ depends on CLASSIC32
+
+config PPC_TUNE_603
+ bool "603/603e/82xx/83xx/e300 (G2)"
+ depends on CLASSIC32 || PPC_82xx || PPC_83xx
+
+config PPC_TUNE_604
+ bool "604/604e/604r/604ev"
+ depends on CLASSIC32
+
+config PPC_TUNE_750
+ bool "750/750CX/750CXe/750FX/750GX (G3)"
+ depends on CLASSIC32
+
+config PPC_TUNE_7400
+ bool "7400/7410"
+ depends on CLASSIC32
+
+config PPC_TUNE_7450
+ bool "7450/7447/7457/7448/7450/86xx (G4)"
+ depends on CLASSIC32 || PPC_86xx
+
+config PPC_TUNE_801
+ bool "801"
+ depends on PPC_8xx
+
+config PPC_TUNE_821
+ bool "821"
+ depends on PPC_8xx
+
+config PPC_TUNE_823
+ bool "823"
+ depends on PPC_8xx
+
+config PPC_TUNE_860
+ bool "860"
+ depends on PPC_8xx
+
+config PPC_TUNE_403
+ bool "403"
+ depends on 40x
+
+config PPC_TUNE_405
+ bool "405"
+ depends on 40x
+
+config PPC_TUNE_440
+ bool "440"
+ depends on 44x
+
+config PPC_TUNE_E200
+ bool "e200/5554"
+ depends on E200
+
+config PPC_TUNE_E500
+ bool "e500/8540/8548"
+ depends on E500
+
+endchoice
+
+config PPC_ENABLE_ALTIVEC
+ bool
+
+config PPC_CPU_FLAG
+ string
+ default "" if PPC_CPU_UNSPECIFIED
+ default "-mcpu=powerpc64" if PPC_CPU_ANY64
+ default "-mcpu=rs64" if PPC_CPU_RS64
+ default "-mcpu=power3" if PPC_CPU_POWER3
+ default "-mcpu=power4" if PPC_CPU_POWER4
+ default "-mcpu=power5" if PPC_CPU_POWER5
+ default "-mcpu=power5+" if PPC_CPU_POWER5PLUS
+ default "-mcpu=power6" if PPC_CPU_POWER6
+ default "-mcpu=970" if PPC_CPU_970
+ default "" if PPC_CPU_CELLBE
+ default "" if PPC_CPU_PA6T
+ default "-mcpu=powerpc" if PPC_CPU_ANY32
+ default "-mcpu=601" if PPC_CPU_601
+ default "-mcpu=603" if PPC_CPU_603
+ default "-mcpu=604" if PPC_CPU_604
+ default "-mcpu=750" if PPC_CPU_750
+ default "-mcpu=7400" if PPC_CPU_7400
+ default "-mcpu=7450" if PPC_CPU_7450
+ default "-mcpu=801" if PPC_CPU_801
+ default "-mcpu=821" if PPC_CPU_821
+ default "-mcpu=823" if PPC_CPU_823
+ default "-mcpu=860" if PPC_CPU_860
+ default "-mcpu=403" if PPC_CPU_403
+ default "-mcpu=405" if PPC_CPU_405
+ default "-mcpu=440" if PPC_CPU_440
+ default "" if PPC_CPU_E200
+ default "" if PPC_CPU_E500
+
+config PPC_TUNE_FLAG
+ string
+ default "" if PPC_TUNE_UNSPECIFIED
+ default "-mtune=powerpc64" if PPC_TUNE_ANY64
+ default "-mtune=rs64" if PPC_TUNE_RS64
+ default "-mtune=power3" if PPC_TUNE_POWER3
+ default "-mtune=power4" if PPC_TUNE_POWER4
+ default "-mtune=power5" if PPC_TUNE_POWER5
+ default "-mtune=power5+" if PPC_TUNE_POWER5PLUS
+ default "-mtune=power6" if PPC_TUNE_POWER6
+ default "-mtune=970" if PPC_TUNE_970
+ default "" if PPC_TUNE_CELLBE
+ default "" if PPC_TUNE_PA6T
+ default "-mtune=powerpc" if PPC_TUNE_ANY32
+ default "-mtune=601" if PPC_TUNE_601
+ default "-mtune=603" if PPC_TUNE_603
+ default "-mtune=604" if PPC_TUNE_604
+ default "-mtune=750" if PPC_TUNE_750
+ default "-mtune=7400" if PPC_TUNE_7400
+ default "-mtune=7450" if PPC_TUNE_7450
+ default "-mtune=801" if PPC_TUNE_801
+ default "-mtune=821" if PPC_TUNE_821
+ default "-mtune=823" if PPC_TUNE_823
+ default "-mtune=860" if PPC_TUNE_860
+ default "-mtune=403" if PPC_TUNE_403
+ default "-mtune=405" if PPC_TUNE_405
+ default "-mtune=440" if PPC_TUNE_440
+ default "" if PPC_TUNE_E200
+ default "" if PPC_TUNE_E500
+
+# these are temp to transition to new cpu selection
+config POWER3
+ bool
+ depends on PPC_ENABLE_POWER3 || PPC_ENABLE_RS64
+ default y
+
+config POWER4
+ depends on PPC64
+ def_bool y
+
+config POWER4_ONLY
+ bool
+ default y if !PPC_POWER3
+
+config 6xx
+ bool
+
+# this is temp to handle compat with arch=ppc
+config 8xx
+ bool
+
+# this is temp to handle compat with arch=ppc
+config 83xx
+ bool
+
+# this is temp to handle compat with arch=ppc
+config 85xx
+ bool
+
+config E500
+ bool
+
+config PPC_FPU
+ bool
+ default y if PPC64
+
+config PPC_DCR_NATIVE
+ bool
+ default n
+
+config PPC_DCR_MMIO
+ bool
+ default n
+
+config PPC_DCR
+ bool
+ depends on PPC_DCR_NATIVE || PPC_DCR_MMIO
+ default y
+
+config PPC_OF_PLATFORM_PCI
+ bool
+ depends on PPC64 # not supported on 32 bits yet
+ default n
+
+config BOOKE
+ bool
+ depends on E200 || E500
+ default y
+
+config FSL_BOOKE
+ bool
+ depends on E200 || E500
+ default y
+
+config PTE_64BIT
+ bool
+ depends on 44x || E500
+ default y if 44x
+ default y if E500 && PHYS_64BIT
+
+config PHYS_64BIT
+ bool 'Large physical address support' if E500
+ depends on 44x || E500
+ select RESOURCES_64BIT
+ default y if 44x
+ ---help---
+ This option enables kernel support for larger than 32-bit physical
+ addresses. This features is not be available on all e500 cores.
+
+ If in doubt, say N here.
+
+config ALTIVEC
+ bool "AltiVec Support"
+ depends on PPC64 || PPC_CPU_ANY32 || CLASSIC32
+ ---help---
+ This option enables kernel support for the Altivec extensions to the
+ PowerPC processor. The kernel currently supports saving and restoring
+ altivec registers, and turning on the 'altivec enable' bit so user
+ processes can execute altivec instructions.
+
+ This option is only usefully if you have a processor that supports
+ altivec (G4, otherwise known as 74xx series), but does not have
+ any affect on a non-altivec cpu (it does, however add code to the
+ kernel).
+
+ If in doubt, say Y here.
+
+config SPE
+ bool "SPE Support"
+ depends on E200 || E500
+ default y
+ ---help---
+ This option enables kernel support for the Signal Processing
+ Extensions (SPE) to the PowerPC processor. The kernel currently
+ supports saving and restoring SPE registers, and turning on the
+ 'spe enable' bit so user processes can execute SPE instructions.
+
+ This option is only useful if you have a processor that supports
+ SPE (e500, otherwise known as 85xx series), but does not have any
+ effect on a non-spe cpu (it does, however add code to the kernel).
+
+ If in doubt, say Y here.
+
+config PPC_STD_MMU
+ bool
+ depends on 6xx || POWER3 || POWER4 || PPC64
+ default y
+
+config PPC_STD_MMU_32
+ def_bool y
+ depends on PPC_STD_MMU && PPC32
+
+config PPC_MM_SLICES
+ bool
+ default y if HUGETLB_PAGE
+ default n
+
+config VIRT_CPU_ACCOUNTING
+ bool "Deterministic task and CPU time accounting"
+ depends on PPC64
+ default y
+ help
+ Select this option to enable more accurate task and CPU time
+ accounting. This is done by reading a CPU counter on each
+ kernel entry and exit and on transitions within the kernel
+ between system, softirq and hardirq state, so there is a
+ small performance impact. This also enables accounting of
+ stolen time on logically-partitioned systems running on
+ IBM POWER5-based machines.
+
+ If in doubt, say Y here.
+
+config SMP
+ depends on PPC_STD_MMU
+ bool "Symmetric multi-processing support"
+ ---help---
+ This enables support for systems with more than one CPU. If you have
+ a system with only one CPU, say N. If you have a system with more
+ than one CPU, say Y. Note that the kernel does not currently
+ support SMP machines with 603/603e/603ev or PPC750 ("G3") processors
+ since they have inadequate hardware support for multiprocessor
+ operation.
+
+ If you say N here, the kernel will run on single and multiprocessor
+ machines, but will use only one CPU of a multiprocessor machine. If
+ you say Y here, the kernel will run on single-processor machines.
+ On a single-processor machine, the kernel will run faster if you say
+ N here.
+
+ If you don't know what to do here, say N.
+
+config NR_CPUS
+ int "Maximum number of CPUs (2-128)"
+ range 2 128
+ depends on SMP
+ default "32" if PPC64
+ default "4"
+
+config NOT_COHERENT_CACHE
+ bool
+ depends on 4xx || 8xx || E200
+ default y
+
+endmenu
Index: linux-cg/arch/powerpc/Kconfig
===================================================================
--- linux-cg.orig/arch/powerpc/Kconfig
+++ linux-cg/arch/powerpc/Kconfig
@@ -4,12 +4,7 @@
mainmenu "Linux/PowerPC Kernel Configuration"
-config PPC64
- bool "64-bit kernel"
- default n
- help
- This option selects whether a 32-bit or a 64-bit kernel
- will be built.
+source "arch/powerpc/Kconfig.cputype"
config PPC32
bool
@@ -118,258 +113,6 @@ config DEFAULT_UIMAGE
Used to allow a board to specify it wants a uImage built by default
default n
-menu "Processor support"
-choice
- prompt "Processor Type"
- depends on PPC32
- default 6xx
-
-config CLASSIC32
- bool "52xx/6xx/7xx/74xx"
- select PPC_FPU
- select 6xx
- help
- There are four families of PowerPC chips supported. The more common
- types (601, 603, 604, 740, 750, 7400), the Motorola embedded
- versions (821, 823, 850, 855, 860, 52xx, 82xx, 83xx), the AMCC
- embedded versions (403 and 405) and the high end 64 bit Power
- processors (POWER 3, POWER4, and IBM PPC970 also known as G5).
-
- This option is the catch-all for 6xx types, including some of the
- embedded versions. Unless there is see an option for the specific
- chip family you are using, you want this option.
-
- You do not want this if you are building a kernel for a 64 bit
- IBM RS/6000 or an Apple G5, choose 6xx.
-
- If unsure, select this option
-
- Note that the kernel runs in 32-bit mode even on 64-bit chips.
-
-config PPC_82xx
- bool "Freescale 82xx"
- select 6xx
- select PPC_FPU
-
-config PPC_83xx
- bool "Freescale 83xx"
- select 6xx
- select FSL_SOC
- select 83xx
- select PPC_FPU
-
-config PPC_85xx
- bool "Freescale 85xx"
- select E500
- select FSL_SOC
- select 85xx
-
-config PPC_86xx
- bool "Freescale 86xx"
- select 6xx
- select FSL_SOC
- select PPC_FPU
- select ALTIVEC
- help
- The Freescale E600 SoCs have 74xx cores.
-
-config PPC_8xx
- bool "Freescale 8xx"
- select FSL_SOC
- select 8xx
-
-config 40x
- bool "AMCC 40x"
- select PPC_DCR_NATIVE
-
-config 44x
- bool "AMCC 44x"
- select PPC_DCR_NATIVE
-
-
-config E200
- bool "Freescale e200"
-
-endchoice
-
-config POWER4_ONLY
- bool "Optimize for POWER4"
- depends on PPC64
- default n
- ---help---
- Cause the compiler to optimize for POWER4/POWER5/PPC970 processors.
- The resulting binary will not work on POWER3 or RS64 processors
- when compiled with binutils 2.15 or later.
-
-config POWER3
- bool
- depends on PPC64
- default y if !POWER4_ONLY
-
-config POWER4
- depends on PPC64
- def_bool y
-
-config 6xx
- bool
-
-# this is temp to handle compat with arch=ppc
-config 8xx
- bool
-
-# this is temp to handle compat with arch=ppc
-config 83xx
- bool
-
-# this is temp to handle compat with arch=ppc
-config 85xx
- bool
-
-config E500
- bool
-
-config PPC_FPU
- bool
- default y if PPC64
-
-config PPC_DCR_NATIVE
- bool
- default n
-
-config PPC_DCR_MMIO
- bool
- default n
-
-config PPC_DCR
- bool
- depends on PPC_DCR_NATIVE || PPC_DCR_MMIO
- default y
-
-config PPC_OF_PLATFORM_PCI
- bool
- depends on PPC64 # not supported on 32 bits yet
- default n
-
-config BOOKE
- bool
- depends on E200 || E500
- default y
-
-config FSL_BOOKE
- bool
- depends on E200 || E500
- default y
-
-config PTE_64BIT
- bool
- depends on 44x || E500
- default y if 44x
- default y if E500 && PHYS_64BIT
-
-config PHYS_64BIT
- bool 'Large physical address support' if E500
- depends on 44x || E500
- select RESOURCES_64BIT
- default y if 44x
- ---help---
- This option enables kernel support for larger than 32-bit physical
- addresses. This features is not be available on all e500 cores.
-
- If in doubt, say N here.
-
-config ALTIVEC
- bool "AltiVec Support"
- depends on CLASSIC32 || POWER4
- ---help---
- This option enables kernel support for the Altivec extensions to the
- PowerPC processor. The kernel currently supports saving and restoring
- altivec registers, and turning on the 'altivec enable' bit so user
- processes can execute altivec instructions.
-
- This option is only usefully if you have a processor that supports
- altivec (G4, otherwise known as 74xx series), but does not have
- any affect on a non-altivec cpu (it does, however add code to the
- kernel).
-
- If in doubt, say Y here.
-
-config SPE
- bool "SPE Support"
- depends on E200 || E500
- default y
- ---help---
- This option enables kernel support for the Signal Processing
- Extensions (SPE) to the PowerPC processor. The kernel currently
- supports saving and restoring SPE registers, and turning on the
- 'spe enable' bit so user processes can execute SPE instructions.
-
- This option is only useful if you have a processor that supports
- SPE (e500, otherwise known as 85xx series), but does not have any
- effect on a non-spe cpu (it does, however add code to the kernel).
-
- If in doubt, say Y here.
-
-config PPC_STD_MMU
- bool
- depends on 6xx || POWER3 || POWER4 || PPC64
- default y
-
-config PPC_STD_MMU_32
- def_bool y
- depends on PPC_STD_MMU && PPC32
-
-config PPC_MM_SLICES
- bool
- default y if HUGETLB_PAGE
- default n
-
-config VIRT_CPU_ACCOUNTING
- bool "Deterministic task and CPU time accounting"
- depends on PPC64
- default y
- help
- Select this option to enable more accurate task and CPU time
- accounting. This is done by reading a CPU counter on each
- kernel entry and exit and on transitions within the kernel
- between system, softirq and hardirq state, so there is a
- small performance impact. This also enables accounting of
- stolen time on logically-partitioned systems running on
- IBM POWER5-based machines.
-
- If in doubt, say Y here.
-
-config SMP
- depends on PPC_STD_MMU
- bool "Symmetric multi-processing support"
- ---help---
- This enables support for systems with more than one CPU. If you have
- a system with only one CPU, say N. If you have a system with more
- than one CPU, say Y. Note that the kernel does not currently
- support SMP machines with 603/603e/603ev or PPC750 ("G3") processors
- since they have inadequate hardware support for multiprocessor
- operation.
-
- If you say N here, the kernel will run on single and multiprocessor
- machines, but will use only one CPU of a multiprocessor machine. If
- you say Y here, the kernel will run on single-processor machines.
- On a single-processor machine, the kernel will run faster if you say
- N here.
-
- If you don't know what to do here, say N.
-
-config NR_CPUS
- int "Maximum number of CPUs (2-128)"
- range 2 128
- depends on SMP
- default "32" if PPC64
- default "4"
-
-config NOT_COHERENT_CACHE
- bool
- depends on 4xx || 8xx || E200
- default y
-endmenu
-
source "init/Kconfig"
menu "Platform support"
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