On Thu, 2012-02-16 at 20:10 +0800, Li Yang wrote: > Fix the problem that large physical address support cannot be > disabled when some platforms which only provides 36-bit support > are selected. According to the philosophy of kernel config > enabling a platform support doesn't mean the kernel is only > running on that platform. Remove the auto selection of PHYS_64BIT > option for these platforms. They will need to use a 36bit default > config that selects PHYS_64BIT explicitly.
No, but unless I'm wrong, with your patch, enabling those platforms will build the code ... but they won't work unless you -also- enable PHYS_64BIT one way or another. I thus disagree. If I enable CONFIG_P1022_DS, I expect those boards to work. If that's going to negatively impact perfs on other boards that I also enabled, then so be it (and we should document it in the help text). Cheers, Ben. > The reason why we need to keep PHYS_64BIT option configurable is > that enabling it cause negative performance impact on various > aspects like TLB miss and physical address manipulating. We should > not enable it unless really needed, e.g. use large memory of 4GB > or bigger. > > Signed-off-by: Li Yang <le...@freescale.com> > --- > arch/powerpc/platforms/85xx/Kconfig | 6 ------ > 1 files changed, 0 insertions(+), 6 deletions(-) > > diff --git a/arch/powerpc/platforms/85xx/Kconfig > b/arch/powerpc/platforms/85xx/Kconfig > index d7946be..d9bc0bd 100644 > --- a/arch/powerpc/platforms/85xx/Kconfig > +++ b/arch/powerpc/platforms/85xx/Kconfig > @@ -80,7 +80,6 @@ config P1010_RDB > config P1022_DS > bool "Freescale P1022 DS" > select DEFAULT_UIMAGE > - select PHYS_64BIT # The DTS has 36-bit addresses > select SWIOTLB > help > This option enables support for the Freescale P1022DS reference board. > @@ -175,7 +174,6 @@ config P2041_RDB > bool "Freescale P2041 RDB" > select DEFAULT_UIMAGE > select PPC_E500MC > - select PHYS_64BIT > select SWIOTLB > select ARCH_REQUIRE_GPIOLIB > select GPIO_MPC8XXX > @@ -188,7 +186,6 @@ config P3041_DS > bool "Freescale P3041 DS" > select DEFAULT_UIMAGE > select PPC_E500MC > - select PHYS_64BIT > select SWIOTLB > select ARCH_REQUIRE_GPIOLIB > select GPIO_MPC8XXX > @@ -201,7 +198,6 @@ config P3060_QDS > bool "Freescale P3060 QDS" > select DEFAULT_UIMAGE > select PPC_E500MC > - select PHYS_64BIT > select SWIOTLB > select GPIO_MPC8XXX > select HAS_RAPIDIO > @@ -213,7 +209,6 @@ config P4080_DS > bool "Freescale P4080 DS" > select DEFAULT_UIMAGE > select PPC_E500MC > - select PHYS_64BIT > select SWIOTLB > select ARCH_REQUIRE_GPIOLIB > select GPIO_MPC8XXX > @@ -229,7 +224,6 @@ config P5020_DS > select DEFAULT_UIMAGE > select E500 > select PPC_E500MC > - select PHYS_64BIT > select SWIOTLB > select ARCH_REQUIRE_GPIOLIB > select GPIO_MPC8XXX _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
