On 13 August 2015 at 12:34, Suzuki K. Poulose <suzuki.poulose@xxxxxxx> wrote: > From: "Suzuki K. Poulose" <suzuki.poulose@xxxxxxx> > > Ensure that the selected page size is supported by the > CPU(s). > > Cc: Mark Rutland <mark.rutland@xxxxxxx> > Cc: Catalin Marinas <catalin.marinas@xxxxxxx> > Cc: Will Deacon <will.deacon@xxxxxxx> > Signed-off-by: Suzuki K. Poulose <suzuki.poulose@xxxxxxx> > --- > arch/arm64/include/asm/sysreg.h | 6 ++++++ > arch/arm64/kernel/head.S | 24 +++++++++++++++++++++++- > 2 files changed, 29 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h > index a7f3d4b..e01d323 100644 > --- a/arch/arm64/include/asm/sysreg.h > +++ b/arch/arm64/include/asm/sysreg.h > @@ -87,4 +87,10 @@ static inline void config_sctlr_el1(u32 clear, u32 set) > } > #endif > > +#define ID_AA64MMFR0_TGran4_SHIFT 28 > +#define ID_AA64MMFR0_TGran64_SHIFT 24 > + > +#define ID_AA64MMFR0_TGran4_ENABLED 0x0 > +#define ID_AA64MMFR0_TGran64_ENABLED 0x0 > + > #endif /* __ASM_SYSREG_H */ > diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S > index 01b8e58..0cb04db 100644 > --- a/arch/arm64/kernel/head.S > +++ b/arch/arm64/kernel/head.S > @@ -31,10 +31,11 @@ > #include <asm/cputype.h> > #include <asm/kernel-pgtable.h> > #include <asm/memory.h> > -#include <asm/thread_info.h> > #include <asm/pgtable-hwdef.h> > #include <asm/pgtable.h> > #include <asm/page.h> > +#include <asm/sysreg.h> > +#include <asm/thread_info.h> > #include <asm/virt.h> > > #define __PHYS_OFFSET (KERNEL_START - TEXT_OFFSET) > @@ -606,9 +607,25 @@ ENDPROC(__secondary_switched) > * x27 = *virtual* address to jump to upon completion > * > * other registers depend on the function called upon completion > + * Checks if the selected granule size is supported by the CPU. > */ > +#if defined(CONFIG_ARM64_64K_PAGES) > + > +#define ID_AA64MMFR0_TGran_SHIFT ID_AA64MMFR0_TGran64_SHIFT > +#define ID_AA64MMFR0_TGran_ENABLED ID_AA64MMFR0_TGran64_ENABLED > + > +#else > + > +#define ID_AA64MMFR0_TGran_SHIFT ID_AA64MMFR0_TGran4_SHIFT > +#define ID_AA64MMFR0_TGran_ENABLED ID_AA64MMFR0_TGran4_ENABLED > + > +#endif > .section ".idmap.text", "ax" > __enable_mmu: > + mrs x1, ID_AA64MMFR0_EL1 > + ubfx x2, x1, #ID_AA64MMFR0_TGran_SHIFT, 4 > + cmp x2, #ID_AA64MMFR0_TGran_ENABLED > + b.ne __no_granule_support > ldr x5, =vectors > msr vbar_el1, x5 > msr ttbr0_el1, x25 // load TTBR0 > @@ -626,3 +643,8 @@ __enable_mmu: > isb > br x27 > ENDPROC(__enable_mmu) > + > +__no_granule_support: > + wfe > + b __no_granule_support > +ENDPROC(__no_granule_support) > -- > 1.7.9.5 > Hi Suzuki, Is is possible to tell the user that the kernel has failed to boot due to the kernel granule being unsupported? Cheers, -- Steve -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
