From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Subject: Re: [PATCH 1/2] arm64: Expose address bits (physical/virtual) via cpuinfo References: <1548709076-22317-1-git-send-email-bhsharma@redhat.com> <1548709076-22317-2-git-send-email-bhsharma@redhat.com> From: Suzuki K Poulose Message-ID: Date: Tue, 29 Jan 2019 10:09:31 +0000 MIME-Version: 1.0 In-Reply-To: <1548709076-22317-2-git-send-email-bhsharma@redhat.com> Content-Language: en-US List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: bhsharma@redhat.com, linux-arm-kernel@lists.infradead.org Cc: mark.rutland@arm.com, Steve.Capper@arm.com, catalin.marinas@arm.com, ard.biesheuvel@linaro.org, will.deacon@arm.com, bhupesh.linux@gmail.com, kexec@lists.infradead.org Hi Bupesh On 28/01/2019 20:57, Bhupesh Sharma wrote: > With ARMv8.2-LVA and LPA architecture extensions, arm64 hardware which > supports these extensions can support upto 52-bit virtual and 52-bit > physical addresses respectively. > > Since at the moment we enable the support of these extensions via CONFIG > flags, e.g. > - LPA via CONFIG_ARM64_PA_BITS_52, and > - LVA via CONFIG_ARM64_FORCE_52BIT > > The easiest way a user can determine the physical/virtual > addresses supported on the hardware, is via the '/proc/cpuinfo' > interface. Why do we need this information ? Btw, this keeps coming up all the time and the answer to this approach is always no. We cannot break the "unwritten" ABI of /proc/cpuinfo, again. See : https://patchwork.kernel.org/patch/8669301/ Suzuki _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec