| Message ID | 1320883635-17194-3-git-send-email-Kyle.D.Moffett@boeing.com (mailing list archive) |
|---|---|
| State | RFC |
| Headers | show |
On Nov 9, 2011, at 6:07 PM, Kyle Moffett wrote: > The "CONFIG_PHYS_64BIT" option violates the Kconfig best-practices in > various colorful ways. It has explicit dependencies, but it is also > "select"ed by various CPUs and platforms. It is not set on 64-bit > systems, but it is used by a number of pieces of powerpc code to enable > or disable 64-bit physical address support. > > To resolve these issues, the option has now been split into 3: > > CONFIG_PHYS_64BIT_SUPPORTED: > This hidden option should be selected by any CPU type which supports > 64-bit physical addresses. This will enable the PHYS_64BIT option > to be selected. It is (obviously) always set on PPC64. > > CONFIG_PHYS_64BIT_DT_REQUIRED: > This hidden option should be selected by any board or platform which > has >32-bit physical devices present in hardware. If this is set > then the CONFIG_PHYS_64BIT option will be forcibly enabled and > hidden from the user. It is (obviously) always set on PPC64. > > CONFIG_PHYS_64BIT: > This option is user-controllable, where allowed by CPU and platform > settings, and should never be pointed at with a "select" statement. > Due to the values of the above two options, this is never visible on > PPC64. > > Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com> > --- > arch/powerpc/Kconfig | 4 ++-- > arch/powerpc/platforms/82xx/Kconfig | 2 +- > arch/powerpc/platforms/83xx/Kconfig | 2 +- > arch/powerpc/platforms/85xx/Kconfig | 12 ++++++------ > arch/powerpc/platforms/86xx/Kconfig | 1 + > arch/powerpc/platforms/Kconfig.cputype | 25 ++++++++++++++++++------- > 6 files changed, 29 insertions(+), 17 deletions(-) I don't really see what this gets us and don't think we should make this change. - k > > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index b177caa..27e31c5 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -18,10 +18,10 @@ config WORD_SIZE > default 32 if !PPC64 > > config ARCH_PHYS_ADDR_T_64BIT > - def_bool PPC64 || PHYS_64BIT > + def_bool PHYS_64BIT > > config ARCH_DMA_ADDR_T_64BIT > - def_bool ARCH_PHYS_ADDR_T_64BIT > + def_bool PHYS_64BIT > > config MMU > bool > diff --git a/arch/powerpc/platforms/82xx/Kconfig b/arch/powerpc/platforms/82xx/Kconfig > index 7c7df40..849d403 100644 > --- a/arch/powerpc/platforms/82xx/Kconfig > +++ b/arch/powerpc/platforms/82xx/Kconfig > @@ -1,6 +1,6 @@ > menuconfig PPC_82xx > bool "82xx-based boards (PQ II)" > - depends on 6xx > + depends on 6xx && !PHYS_64BIT > > if PPC_82xx > > diff --git a/arch/powerpc/platforms/83xx/Kconfig b/arch/powerpc/platforms/83xx/Kconfig > index 670a033..1ed8877 100644 > --- a/arch/powerpc/platforms/83xx/Kconfig > +++ b/arch/powerpc/platforms/83xx/Kconfig > @@ -1,6 +1,6 @@ > menuconfig PPC_83xx > bool "83xx-based boards" > - depends on 6xx > + depends on 6xx && !PHYS_64BIT > select PPC_UDBG_16550 > select PPC_PCI_CHOICE > select FSL_PCI if PCI > diff --git a/arch/powerpc/platforms/85xx/Kconfig b/arch/powerpc/platforms/85xx/Kconfig > index 9088381..37f9de7 100644 > --- a/arch/powerpc/platforms/85xx/Kconfig > +++ b/arch/powerpc/platforms/85xx/Kconfig > @@ -80,7 +80,7 @@ config P1010_RDB > config P1022_DS > bool "Freescale P1022 DS" > select DEFAULT_UIMAGE > - select PHYS_64BIT # The DTS has 36-bit addresses > + select PHYS_64BIT_DT_REQUIRED # The DTS has 36-bit addresses > select SWIOTLB > help > This option enables support for the Freescale P1022DS reference board. > @@ -175,7 +175,7 @@ config P2041_RDB > bool "Freescale P2041 RDB" > select DEFAULT_UIMAGE > select PPC_E500MC > - select PHYS_64BIT > + select PHYS_64BIT_DT_REQUIRED > select SWIOTLB > select ARCH_REQUIRE_GPIOLIB > select GPIO_MPC8XXX > @@ -189,7 +189,7 @@ config P3041_DS > bool "Freescale P3041 DS" > select DEFAULT_UIMAGE > select PPC_E500MC > - select PHYS_64BIT > + select PHYS_64BIT_DT_REQUIRED > select SWIOTLB > select ARCH_REQUIRE_GPIOLIB > select GPIO_MPC8XXX > @@ -203,7 +203,7 @@ config P3060_QDS > bool "Freescale P3060 QDS" > select DEFAULT_UIMAGE > select PPC_E500MC > - select PHYS_64BIT > + select PHYS_64BIT_DT_REQUIRED > select SWIOTLB > select MPC8xxx_GPIO > select HAS_RAPIDIO > @@ -216,7 +216,7 @@ config P4080_DS > bool "Freescale P4080 DS" > select DEFAULT_UIMAGE > select PPC_E500MC > - select PHYS_64BIT > + select PHYS_64BIT_DT_REQUIRED > select SWIOTLB > select ARCH_REQUIRE_GPIOLIB > select GPIO_MPC8XXX > @@ -233,7 +233,7 @@ config P5020_DS > select DEFAULT_UIMAGE > select E500 > select PPC_E500MC > - select PHYS_64BIT > + select PHYS_64BIT_DT_REQUIRED > select SWIOTLB > select ARCH_REQUIRE_GPIOLIB > select GPIO_MPC8XXX > diff --git a/arch/powerpc/platforms/86xx/Kconfig b/arch/powerpc/platforms/86xx/Kconfig > index 8d6599d..576eb43 100644 > --- a/arch/powerpc/platforms/86xx/Kconfig > +++ b/arch/powerpc/platforms/86xx/Kconfig > @@ -5,6 +5,7 @@ menuconfig PPC_86xx > select FSL_SOC > select ALTIVEC > select ARCH_WANT_OPTIONAL_GPIOLIB > + select PHYS_64BIT_SUPPORTED > help > The Freescale E600 SoCs have 74xx cores. > > diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype > index 9210e94..0ab01b0 100644 > --- a/arch/powerpc/platforms/Kconfig.cputype > +++ b/arch/powerpc/platforms/Kconfig.cputype > @@ -26,6 +26,7 @@ config PPC_BOOK3S_32 > > config PPC_85xx > bool "Freescale 85xx" > + select PHYS_64BIT_SUPPORTED > select E500 > > config PPC_8xx > @@ -47,7 +48,8 @@ config 44x > select PPC_UDBG_16550 > select 4xx_SOC > select PPC_PCI_CHOICE > - select PHYS_64BIT > + select PHYS_64BIT_SUPPORTED > + select PHYS_64BIT_DT_REQUIRED > > config E200 > bool "Freescale e200" > @@ -187,14 +189,20 @@ config PPC_FSL_BOOK3E > select PPC_SMP_MUXED_IPI > default y if FSL_BOOKE > > -config PTE_64BIT > - bool > - depends on 44x || E500 || PPC_86xx > - default y if PHYS_64BIT > +## Only some 32-bit CPUs support 64-bit physical addresses > +config PHYS_64BIT_SUPPORTED > + def_bool PPC64 > + > +## Some 32-bit system device trees have >32-bit physical addresses, and so > +## the kernel won't boot unless those are supported. > +config PHYS_64BIT_DT_REQUIRED > + def_bool PPC64 > > +## DO NOT "select" this user-visible symbol, select the two above instead! > config PHYS_64BIT > - bool 'Large physical address support' if E500 || PPC_86xx > - depends on (44x || E500 || PPC_86xx) && !PPC_83xx && !PPC_82xx > + def_bool PHYS_64BIT_DT_REQUIRED > + prompt 'Large physical address support' if !PHYS_64BIT_DT_REQUIRED > + depends on PHYS_64BIT_SUPPORTED > ---help--- > This option enables kernel support for larger than 32-bit physical > addresses. This feature may not be available on all cores. > @@ -205,6 +213,9 @@ config PHYS_64BIT > > If in doubt, say N here. > > +config PTE_64BIT > + def_bool PHYS_64BIT > + > config ALTIVEC > bool "AltiVec Support" > depends on 6xx || POWER4 > -- > 1.7.2.5
Kyle Moffett wrote: > CONFIG_PHYS_64BIT_SUPPORTED: > This hidden option should be selected by any CPU type which supports > 64-bit physical addresses. This will enable the PHYS_64BIT option > to be selected. It is (obviously) always set on PPC64. > > CONFIG_PHYS_64BIT_DT_REQUIRED: > This hidden option should be selected by any board or platform which > has >32-bit physical devices present in hardware. If this is set > then the CONFIG_PHYS_64BIT option will be forcibly enabled and > hidden from the user. It is (obviously) always set on PPC64. > > CONFIG_PHYS_64BIT: > This option is user-controllable, where allowed by CPU and platform > settings, and should never be pointed at with a "select" statement. > Due to the values of the above two options, this is never visible on > PPC64. I'm with Kumar on this. I don't see the point of making it so complicated. No kernel should ever have to care with a DT is 64-bit or 32-bit. If you build a kernel with 64-bit phys support, then it will work with any DT. U-Boot already warns you if the DT and the actual physical addresses of the devices don't match. There are only two reasons to create a 32-bit kernel: 1) A small performance improvement on systems with 2GB or less. 2) Some SOC devices only support 32-bit physical addresses, so the easiest way to ensure a compatible address is to prohibit memory above 4GB. Item #2 is not something that we really worry about. It's only a real problem on true 64-bit kernels, and in those cases, we cannot build a kernel with 32-bit phys support, so the driver needs to handle it internally.
On Nov 10, 2011, at 09:04, Timur Tabi wrote: > Kyle Moffett wrote: >> CONFIG_PHYS_64BIT_SUPPORTED: >> This hidden option should be selected by any CPU type which supports >> 64-bit physical addresses. This will enable the PHYS_64BIT option >> to be selected. It is (obviously) always set on PPC64. >> >> CONFIG_PHYS_64BIT_DT_REQUIRED: >> This hidden option should be selected by any board or platform which >> has >32-bit physical devices present in hardware. If this is set >> then the CONFIG_PHYS_64BIT option will be forcibly enabled and >> hidden from the user. It is (obviously) always set on PPC64. >> >> CONFIG_PHYS_64BIT: >> This option is user-controllable, where allowed by CPU and platform >> settings, and should never be pointed at with a "select" statement. >> Due to the values of the above two options, this is never visible on >> PPC64. > > I'm with Kumar on this. I don't see the point of making it so complicated. Did you look at the existing code? It's already that complicated: config ARCH_PHYS_ADDR_T_64BIT def_bool PPC64 || PHYS_64BIT config ARCH_DMA_ADDR_T_64BIT def_bool ARCH_PHYS_ADDR_T_64BIT config {P1022_DS,P2041_RDB,P3041_DS,P3060_QDS,P4080_DS,P5020_DS} select PHYS_64BIT config 44x select PHYS_64BIT config PTE_64BIT bool depends on 44x || E500 || PPC_86xx default y if PHYS_64BIT config PHYS_64BIT bool 'Large physical address support' if E500 || PPC_86xx depends on (44x || E500 || PPC_86xx) && !PPC_83xx && !PPC_82xx Even worse, PHYS_64BIT is not set on 64-bit processors, but there is a lot of driver code that seems to assume PHYS_64BIT indicates the size of "phys_addr_t". > No kernel should ever have to care with a DT is 64-bit or 32-bit. If > you build a kernel with 64-bit phys support, then it will work with > any DT. > > U-Boot already warns you if the DT and the actual physical addresses > of the devices don't match. The big issue is that the Kconfig docs are very clear that "select" should not be used on user-visible options (AKA: PHYS_64BIT), and yet half the PPC_85xx boards have this tidbit: select PHYS_64BIT # The DTS has 36-bit addresses I'm totally OK with removing that from all those boards, but to preserve the existing behavior (also used by the entire 44x platform) I added the new config symbol PHYS_64BIT_DT_REQUIRED, which is used to control whether or not the "PHYS_64BIT" option is even visible to the user. I originally called it "PHYS_64BIT_REQUIRED", but since all of the board comments talked about 36-bit DTS addresses, I added the _DT_. > There are only two reasons to create a 32-bit kernel: > > 1) A small performance improvement on systems with 2GB or less. > 2) Some SOC devices only support 32-bit physical addresses, so the > easiest way to ensure a compatible address is to prohibit memory above > 4GB. If this is true, then why does PHYS_64BIT have that big ugly list of dependencies right now? I don't know about the other platforms well enough to tell what would break by enabling PHYS_64BIT, but I assume that something in the past caused that dependency list. Cheers, Kyle Moffett -- Curious about my work on the Debian powerpcspe port? I'm keeping a blog here: http://pureperl.blogspot.com/
Moffett, Kyle D wrote: > Did you look at the existing code? It's already that complicated: > > config ARCH_PHYS_ADDR_T_64BIT > def_bool PPC64 || PHYS_64BIT I never understood why we have PHYS_64BIT and ARCH_PHYS_ADDR_T_64BIT, since they mean the same thing. > config ARCH_DMA_ADDR_T_64BIT > def_bool ARCH_PHYS_ADDR_T_64BIT > > config {P1022_DS,P2041_RDB,P3041_DS,P3060_QDS,P4080_DS,P5020_DS} > select PHYS_64BIT I posted a patch to remove the P1022_DS version of this. I'm in favor of removing it from the other boards and letting the defconfig define it, but Kumar nak'd that idea. > config PTE_64BIT > bool > depends on 44x || E500 || PPC_86xx > default y if PHYS_64BIT I think this one is about how our TLB registers look, and it's not related to anything else. > Even worse, PHYS_64BIT is not set on 64-bit processors, but there is > a lot of driver code that seems to assume PHYS_64BIT indicates the > size of "phys_addr_t". There's a Kconfig option somewhere that takes care of this. > The big issue is that the Kconfig docs are very clear that "select" > should not be used on user-visible options (AKA: PHYS_64BIT), and yet > half the PPC_85xx boards have this tidbit: > select PHYS_64BIT # The DTS has 36-bit addresses I'm not sure that Kconfig rule is enforceable. We use 'select' all the time to make sure that our boards enable the options that need to be enabled. I'd rather see this: config X select A config Y select A config Z select A than this: config A default y if X | Y | Z The former is more maintainable and does not allow the option of disabling "A" if someone wants "X". > I'm totally OK with removing that from all those boards, but to preserve > the existing behavior (also used by the entire 44x platform) I added the > new config symbol PHYS_64BIT_DT_REQUIRED, which is used to control > whether or not the "PHYS_64BIT" option is even visible to the user. > > I originally called it "PHYS_64BIT_REQUIRED", but since all of the > board comments talked about 36-bit DTS addresses, I added the _DT_. They're really 64-bit DTS addresses. The 36 bit is just a hardware quirk of our SOCs. From the kernel's perspective, there's no difference between 36-bit and 64-bit physical address. >> There are only two reasons to create a 32-bit kernel: >> >> 1) A small performance improvement on systems with 2GB or less. >> 2) Some SOC devices only support 32-bit physical addresses, so the >> easiest way to ensure a compatible address is to prohibit memory above >> 4GB. > > If this is true, then why does PHYS_64BIT have that big ugly list of > dependencies right now? Because Kumar doesn't want to allow 32-bit kernels on our high-end parts. Like I said, I'm not a fan of that decision. > I don't know about the other platforms well > enough to tell what would break by enabling PHYS_64BIT, but I assume > that something in the past caused that dependency list. It's just an arbitrary decision. We don't ship 32-bit DTs for the P4080-class parts, and we don't have a U-Boot configuration option for building a 32-bit compatible U-Boot.
On Thu, 2011-11-10 at 10:50 -0600, Timur Tabi wrote: > I'm not sure that Kconfig rule is enforceable. We use 'select' all the time to make sure that our boards enable the options that need to be enabled. I'd rather see this: > > config X > select A > > config Y > select A > > config Z > select A > > than this: > > config A > default y if X | Y | Z > > The former is more maintainable and does not allow the option of disabling "A" if someone wants "X". This is fine as long as config A is not a user selectable option. We do the wrong thing in a few places (i2c comes to mind) and we should most certainly consider fixing it. Some of the solution is to move some select's to defconfigs, some is to do things the way Kyle proposed. For PHYS_64BIT, I'm not 100% certain at this point what the best approach it. It should clearly be fixed and hidden for real 64-bit. As for the rest, should it be user selectable ? I tend to think it should be fixed & selected by the board config and keep it that way, avoiding the user question entirely... but you may have good reasons to want to keep it around. Cheers, Ben.
Benjamin Herrenschmidt wrote: > For PHYS_64BIT, I'm not 100% certain at this point what the best > approach it. It should clearly be fixed and hidden for real 64-bit. As > for the rest, should it be user selectable ? I have been unable to convince our BSP teams that the minor performance improvement of a 32-bit kernel vs 36-bit is not worth the hassle. We ship a lot of lower-end e500 systems that will never have more than 2GB of memory. The P1022DS is an example. We ship 32-bit and 36-bit versions of U-Boot, the kernel, and the device tree. I recently added code to U-boot to detect if you have a mismatched U-Boot and device tree, because it is so easy to mess that up. I would like nothing more than to abandon 32-bit for all e500, but I don't see Freescale allowing that any time soon.
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index b177caa..27e31c5 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -18,10 +18,10 @@ config WORD_SIZE default 32 if !PPC64 config ARCH_PHYS_ADDR_T_64BIT - def_bool PPC64 || PHYS_64BIT + def_bool PHYS_64BIT config ARCH_DMA_ADDR_T_64BIT - def_bool ARCH_PHYS_ADDR_T_64BIT + def_bool PHYS_64BIT config MMU bool diff --git a/arch/powerpc/platforms/82xx/Kconfig b/arch/powerpc/platforms/82xx/Kconfig index 7c7df40..849d403 100644 --- a/arch/powerpc/platforms/82xx/Kconfig +++ b/arch/powerpc/platforms/82xx/Kconfig @@ -1,6 +1,6 @@ menuconfig PPC_82xx bool "82xx-based boards (PQ II)" - depends on 6xx + depends on 6xx && !PHYS_64BIT if PPC_82xx diff --git a/arch/powerpc/platforms/83xx/Kconfig b/arch/powerpc/platforms/83xx/Kconfig index 670a033..1ed8877 100644 --- a/arch/powerpc/platforms/83xx/Kconfig +++ b/arch/powerpc/platforms/83xx/Kconfig @@ -1,6 +1,6 @@ menuconfig PPC_83xx bool "83xx-based boards" - depends on 6xx + depends on 6xx && !PHYS_64BIT select PPC_UDBG_16550 select PPC_PCI_CHOICE select FSL_PCI if PCI diff --git a/arch/powerpc/platforms/85xx/Kconfig b/arch/powerpc/platforms/85xx/Kconfig index 9088381..37f9de7 100644 --- a/arch/powerpc/platforms/85xx/Kconfig +++ b/arch/powerpc/platforms/85xx/Kconfig @@ -80,7 +80,7 @@ config P1010_RDB config P1022_DS bool "Freescale P1022 DS" select DEFAULT_UIMAGE - select PHYS_64BIT # The DTS has 36-bit addresses + select PHYS_64BIT_DT_REQUIRED # The DTS has 36-bit addresses select SWIOTLB help This option enables support for the Freescale P1022DS reference board. @@ -175,7 +175,7 @@ config P2041_RDB bool "Freescale P2041 RDB" select DEFAULT_UIMAGE select PPC_E500MC - select PHYS_64BIT + select PHYS_64BIT_DT_REQUIRED select SWIOTLB select ARCH_REQUIRE_GPIOLIB select GPIO_MPC8XXX @@ -189,7 +189,7 @@ config P3041_DS bool "Freescale P3041 DS" select DEFAULT_UIMAGE select PPC_E500MC - select PHYS_64BIT + select PHYS_64BIT_DT_REQUIRED select SWIOTLB select ARCH_REQUIRE_GPIOLIB select GPIO_MPC8XXX @@ -203,7 +203,7 @@ config P3060_QDS bool "Freescale P3060 QDS" select DEFAULT_UIMAGE select PPC_E500MC - select PHYS_64BIT + select PHYS_64BIT_DT_REQUIRED select SWIOTLB select MPC8xxx_GPIO select HAS_RAPIDIO @@ -216,7 +216,7 @@ config P4080_DS bool "Freescale P4080 DS" select DEFAULT_UIMAGE select PPC_E500MC - select PHYS_64BIT + select PHYS_64BIT_DT_REQUIRED select SWIOTLB select ARCH_REQUIRE_GPIOLIB select GPIO_MPC8XXX @@ -233,7 +233,7 @@ config P5020_DS select DEFAULT_UIMAGE select E500 select PPC_E500MC - select PHYS_64BIT + select PHYS_64BIT_DT_REQUIRED select SWIOTLB select ARCH_REQUIRE_GPIOLIB select GPIO_MPC8XXX diff --git a/arch/powerpc/platforms/86xx/Kconfig b/arch/powerpc/platforms/86xx/Kconfig index 8d6599d..576eb43 100644 --- a/arch/powerpc/platforms/86xx/Kconfig +++ b/arch/powerpc/platforms/86xx/Kconfig @@ -5,6 +5,7 @@ menuconfig PPC_86xx select FSL_SOC select ALTIVEC select ARCH_WANT_OPTIONAL_GPIOLIB + select PHYS_64BIT_SUPPORTED help The Freescale E600 SoCs have 74xx cores. diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype index 9210e94..0ab01b0 100644 --- a/arch/powerpc/platforms/Kconfig.cputype +++ b/arch/powerpc/platforms/Kconfig.cputype @@ -26,6 +26,7 @@ config PPC_BOOK3S_32 config PPC_85xx bool "Freescale 85xx" + select PHYS_64BIT_SUPPORTED select E500 config PPC_8xx @@ -47,7 +48,8 @@ config 44x select PPC_UDBG_16550 select 4xx_SOC select PPC_PCI_CHOICE - select PHYS_64BIT + select PHYS_64BIT_SUPPORTED + select PHYS_64BIT_DT_REQUIRED config E200 bool "Freescale e200" @@ -187,14 +189,20 @@ config PPC_FSL_BOOK3E select PPC_SMP_MUXED_IPI default y if FSL_BOOKE -config PTE_64BIT - bool - depends on 44x || E500 || PPC_86xx - default y if PHYS_64BIT +## Only some 32-bit CPUs support 64-bit physical addresses +config PHYS_64BIT_SUPPORTED + def_bool PPC64 + +## Some 32-bit system device trees have >32-bit physical addresses, and so +## the kernel won't boot unless those are supported. +config PHYS_64BIT_DT_REQUIRED + def_bool PPC64 +## DO NOT "select" this user-visible symbol, select the two above instead! config PHYS_64BIT - bool 'Large physical address support' if E500 || PPC_86xx - depends on (44x || E500 || PPC_86xx) && !PPC_83xx && !PPC_82xx + def_bool PHYS_64BIT_DT_REQUIRED + prompt 'Large physical address support' if !PHYS_64BIT_DT_REQUIRED + depends on PHYS_64BIT_SUPPORTED ---help--- This option enables kernel support for larger than 32-bit physical addresses. This feature may not be available on all cores. @@ -205,6 +213,9 @@ config PHYS_64BIT If in doubt, say N here. +config PTE_64BIT + def_bool PHYS_64BIT + config ALTIVEC bool "AltiVec Support" depends on 6xx || POWER4
The "CONFIG_PHYS_64BIT" option violates the Kconfig best-practices in various colorful ways. It has explicit dependencies, but it is also "select"ed by various CPUs and platforms. It is not set on 64-bit systems, but it is used by a number of pieces of powerpc code to enable or disable 64-bit physical address support. To resolve these issues, the option has now been split into 3: CONFIG_PHYS_64BIT_SUPPORTED: This hidden option should be selected by any CPU type which supports 64-bit physical addresses. This will enable the PHYS_64BIT option to be selected. It is (obviously) always set on PPC64. CONFIG_PHYS_64BIT_DT_REQUIRED: This hidden option should be selected by any board or platform which has >32-bit physical devices present in hardware. If this is set then the CONFIG_PHYS_64BIT option will be forcibly enabled and hidden from the user. It is (obviously) always set on PPC64. CONFIG_PHYS_64BIT: This option is user-controllable, where allowed by CPU and platform settings, and should never be pointed at with a "select" statement. Due to the values of the above two options, this is never visible on PPC64. Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com> --- arch/powerpc/Kconfig | 4 ++-- arch/powerpc/platforms/82xx/Kconfig | 2 +- arch/powerpc/platforms/83xx/Kconfig | 2 +- arch/powerpc/platforms/85xx/Kconfig | 12 ++++++------ arch/powerpc/platforms/86xx/Kconfig | 1 + arch/powerpc/platforms/Kconfig.cputype | 25 ++++++++++++++++++------- 6 files changed, 29 insertions(+), 17 deletions(-)