Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752240AbeAEO6O (ORCPT + 1 other); Fri, 5 Jan 2018 09:58:14 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:46086 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752195AbeAEO6J (ORCPT ); Fri, 5 Jan 2018 09:58:09 -0500 From: Mark Rutland To: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Cc: dan.j.williams@intel.com, elena.reshetova@intel.com, corbet@lwn.net, alan@linux.intel.com, peterz@infradead.org, will.deacon@arm.com, gregkh@linuxfoundation.org, tglx@linutronix.de, Mark Rutland Subject: [RFCv2 3/4] arm64: implement nospec_ptr() Date: Fri, 5 Jan 2018 14:57:49 +0000 Message-Id: <20180105145750.53294-4-mark.rutland@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20180105145750.53294-1-mark.rutland@arm.com> References: <20180105145750.53294-1-mark.rutland@arm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: This patch implements nospec_ptr() for arm64, following the recommended architectural sequence. Signed-off-by: Mark Rutland Signed-off-by: Will Deacon Cc: Dan Williams Cc: Peter Zijlstra --- arch/arm64/include/asm/barrier.h | 55 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h index 77651c49ef44..b4819f6a0e5c 100644 --- a/arch/arm64/include/asm/barrier.h +++ b/arch/arm64/include/asm/barrier.h @@ -40,6 +40,61 @@ #define dma_rmb() dmb(oshld) #define dma_wmb() dmb(oshst) +#define __load_no_speculate_n(ptr, lo, hi, failval, cmpptr, w, sz) \ +({ \ + typeof(*ptr) __nln_val; \ + typeof(*ptr) __failval = \ + (typeof(*ptr))(unsigned long)(failval); \ + \ + asm volatile ( \ + " cmp %[c], %[l]\n" \ + " ccmp %[c], %[h], 2, cs\n" \ + " b.cs 1f\n" \ + " ldr" #sz " %" #w "[v], %[p]\n" \ + "1: csel %" #w "[v], %" #w "[v], %" #w "[f], cc\n" \ + " hint #0x14 // CSDB\n" \ + : [v] "=&r" (__nln_val) \ + : [p] "m" (*(ptr)), [l] "r" (lo), [h] "r" (hi), \ + [f] "rZ" (__failval), [c] "r" (cmpptr) \ + : "cc"); \ + \ + __nln_val; \ +}) + +#define __load_no_speculate(ptr, lo, hi, failval, cmpptr) \ +({ \ + typeof(*(ptr)) __nl_val; \ + \ + switch (sizeof(__nl_val)) { \ + case 1: \ + __nl_val = __load_no_speculate_n(ptr, lo, hi, failval, \ + cmpptr, w, b); \ + break; \ + case 2: \ + __nl_val = __load_no_speculate_n(ptr, lo, hi, failval, \ + cmpptr, w, h); \ + break; \ + case 4: \ + __nl_val = __load_no_speculate_n(ptr, lo, hi, failval, \ + cmpptr, w, ); \ + break; \ + case 8: \ + __nl_val = __load_no_speculate_n(ptr, lo, hi, failval, \ + cmpptr, x, ); \ + break; \ + default: \ + BUILD_BUG(); \ + } \ + \ + __nl_val; \ +}) + +#define nospec_ptr(ptr, lo, hi) \ +({ \ + typeof(ptr) __np_ptr = (ptr); \ + __load_no_speculate(&__np_ptr, lo, hi, 0, __np_ptr); \ +}) + #define __smp_mb() dmb(ish) #define __smp_rmb() dmb(ishld) #define __smp_wmb() dmb(ishst) -- 2.11.0