Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752894AbbHMM2a (ORCPT ); Thu, 13 Aug 2015 08:28:30 -0400 Received: from mail-io0-f175.google.com ([209.85.223.175]:36527 "EHLO mail-io0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752504AbbHMM23 (ORCPT ); Thu, 13 Aug 2015 08:28:29 -0400 MIME-Version: 1.0 In-Reply-To: <1439465645-22584-13-git-send-email-suzuki.poulose@arm.com> References: <1439465645-22584-1-git-send-email-suzuki.poulose@arm.com> <1439465645-22584-13-git-send-email-suzuki.poulose@arm.com> Date: Thu, 13 Aug 2015 13:28:28 +0100 Message-ID: Subject: Re: [PATCH 12/14] arm64: Check for selected granule support From: Steve Capper To: "Suzuki K. Poulose" Cc: "linux-arm-kernel@lists.infradead.org" , kvm@vger.kernel.org, Marc Zyngier , Catalin Marinas , Will Deacon , "linux-kernel@vger.kernel.org" , kvmarm@lists.cs.columbia.edu Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3209 Lines: 98 On 13 August 2015 at 12:34, Suzuki K. Poulose wrote: > From: "Suzuki K. Poulose" > > Ensure that the selected page size is supported by the > CPU(s). > > Cc: Mark Rutland > Cc: Catalin Marinas > Cc: Will Deacon > Signed-off-by: Suzuki K. Poulose > --- > 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 > #include > #include > -#include > #include > #include > #include > +#include > +#include > #include > > #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 linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/