Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757021Ab2KZSLx (ORCPT ); Mon, 26 Nov 2012 13:11:53 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:47279 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756487Ab2KZRDQ (ORCPT ); Mon, 26 Nov 2012 12:03:16 -0500 From: Herton Ronaldo Krzesinski To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Russell King , Herton Ronaldo Krzesinski Subject: [PATCH 056/270] ARM: vfp: fix saving d16-d31 vfp registers on v6+ kernels Date: Mon, 26 Nov 2012 14:55:46 -0200 Message-Id: <1353949160-26803-57-git-send-email-herton.krzesinski@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1353949160-26803-1-git-send-email-herton.krzesinski@canonical.com> References: <1353949160-26803-1-git-send-email-herton.krzesinski@canonical.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2342 Lines: 68 3.5.7u1 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Russell King commit 846a136881b8f73c1f74250bf6acfaa309cab1f2 upstream. Michael Olbrich reported that his test program fails when built with -O2 -mcpu=cortex-a8 -mfpu=neon, and a kernel which supports v6 and v7 CPUs: volatile int x = 2; volatile int64_t y = 2; int main() { volatile int a = 0; volatile int64_t b = 0; while (1) { a = (a + x) % (1 << 30); b = (b + y) % (1 << 30); assert(a == b); } } and two instances are run. When built for just v7 CPUs, this program works fine. It uses the "vadd.i64 d19, d18, d16" VFP instruction. It appears that we do not save the high-16 double VFP registers across context switches when the kernel is built for v6 CPUs. Fix that. Tested-By: Michael Olbrich Signed-off-by: Russell King Signed-off-by: Herton Ronaldo Krzesinski --- arch/arm/include/asm/vfpmacros.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm/include/asm/vfpmacros.h b/arch/arm/include/asm/vfpmacros.h index 3d5fc41..bf53047 100644 --- a/arch/arm/include/asm/vfpmacros.h +++ b/arch/arm/include/asm/vfpmacros.h @@ -28,7 +28,7 @@ ldr \tmp, =elf_hwcap @ may not have MVFR regs ldr \tmp, [\tmp, #0] tst \tmp, #HWCAP_VFPv3D16 - ldceq p11, cr0, [\base],#32*4 @ FLDMIAD \base!, {d16-d31} + ldceql p11, cr0, [\base],#32*4 @ FLDMIAD \base!, {d16-d31} addne \base, \base, #32*4 @ step over unused register space #else VFPFMRX \tmp, MVFR0 @ Media and VFP Feature Register 0 @@ -52,7 +52,7 @@ ldr \tmp, =elf_hwcap @ may not have MVFR regs ldr \tmp, [\tmp, #0] tst \tmp, #HWCAP_VFPv3D16 - stceq p11, cr0, [\base],#32*4 @ FSTMIAD \base!, {d16-d31} + stceql p11, cr0, [\base],#32*4 @ FSTMIAD \base!, {d16-d31} addne \base, \base, #32*4 @ step over unused register space #else VFPFMRX \tmp, MVFR0 @ Media and VFP Feature Register 0 -- 1.7.9.5 -- 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/