From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752693AbcKNNed (ORCPT ); Mon, 14 Nov 2016 08:34:33 -0500 Received: from mail-pf0-f195.google.com ([209.85.192.195]:32877 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751750AbcKNNdG (ORCPT ); Mon, 14 Nov 2016 08:33:06 -0500 From: Stafford Horne To: stefan.kristiansson@saunalahti.fi, shorne@gmail.com, jonas@southpole.se Cc: linux@roeck-us.net, blue@cmd.nu, robh@kernel.org, linux-kernel@vger.kernel.org, openrisc@lists.librecores.org Subject: [PATCH v2 3/9] openrisc: Add thread-local storage (TLS) support Date: Mon, 14 Nov 2016 22:30:33 +0900 Message-Id: <36386b99c1c0aa9161b25602f0873116ed3adcf8.1479128947.git.shorne@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1479130239-30707-1-git-send-email-shorne@gmail.com> References: <1479130239-30707-1-git-send-email-shorne@gmail.com> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Christian Svensson Historically OpenRISC GCC has reserved r10 which we now use to hold the thread pointer for thread-local storage (TLS). Signed-off-by: Christian Svensson Signed-off-by: Stefan Kristiansson Signed-off-by: Stafford Horne Tested-by: Guenter Roeck --- arch/openrisc/kernel/process.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/openrisc/kernel/process.c b/arch/openrisc/kernel/process.c index 7095dfe..277123b 100644 --- a/arch/openrisc/kernel/process.c +++ b/arch/openrisc/kernel/process.c @@ -173,6 +173,19 @@ copy_thread(unsigned long clone_flags, unsigned long usp, if (usp) userregs->sp = usp; + + /* + * For CLONE_SETTLS set "tp" (r10) to the TLS pointer passed to sys_clone. + * + * The kernel entry is: + * int clone (long flags, void *child_stack, int *parent_tid, + * int *child_tid, struct void *tls) + * + * This makes the source r7 in the kernel registers. + */ + if (clone_flags & CLONE_SETTLS) + userregs->gpr[10] = userregs->gpr[7]; + userregs->gpr[11] = 0; /* Result from fork() */ kregs->gpr[20] = 0; /* Userspace thread */ -- 2.7.4