From patchwork Tue Jan 25 00:10:48 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 536686 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CC0CCC433F5 for ; Tue, 25 Jan 2022 03:37:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243990AbiAYDg4 (ORCPT ); Mon, 24 Jan 2022 22:36:56 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37606 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S3421493AbiAYC1C (ORCPT ); Mon, 24 Jan 2022 21:27:02 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 48B50C08B4F0 for ; Mon, 24 Jan 2022 16:16:10 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id DB0186153D for ; Tue, 25 Jan 2022 00:16:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E8B41C340EF; Tue, 25 Jan 2022 00:16:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1643069769; bh=c5P3WzFe/myKJt98GT0tqU73tZQT7e7FvegzOnxWfIU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AHWnueyJUqDc7fMFO/rMEanTGB2pzUEZds5kpV+uTvV4vpGb/ZAa8s/Z29W3o6wyp w2xn9bj1f7E7aEa2VklBnatuBmHwM/Qu5XVN2pD23lFvK0dQRh6JDyxPKBTJib/jF4 VwbCj+vhmOsRsnqIImxahHFA6zCh0XVtCXoJe/KexX1p0iQAAQZH2ifJIeLDi0gBaz sKeTHlnWdEMshMFKlGDhkh5GGQ5IthOTdn5x2AV+HDeuwclRLKYm5HLavqNVoR693W 1u2znq+AJ7HwA98vOaJciO3adlRZMDdMNsRIIfH93Ou79jHROtRObklRYuIp4dA1Ir EeYIwBY7rjU1g== From: Mark Brown To: Catalin Marinas , Will Deacon , Marc Zyngier , Shuah Khan , Shuah Khan Cc: Alan Hayward , Luis Machado , Salil Akerkar , Basant Kumar Dwivedi , Szabolcs Nagy , James Morse , Alexandru Elisei , Suzuki K Poulose , linux-arm-kernel@lists.infradead.org, linux-kselftest@vger.kernel.org, kvmarm@lists.cs.columbia.edu, Mark Brown Subject: [PATCH v8 12/38] arm64/sme: Implement support for TPIDR2 Date: Tue, 25 Jan 2022 00:10:48 +0000 Message-Id: <20220125001114.193425-13-broonie@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220125001114.193425-1-broonie@kernel.org> References: <20220125001114.193425-1-broonie@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=4258; h=from:subject; bh=c5P3WzFe/myKJt98GT0tqU73tZQT7e7FvegzOnxWfIU=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBh70AKq7eZ7r91LceN+pOy5udpzbiaxzgFRcvUb03E Y2wAT9eJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCYe9ACgAKCRAk1otyXVSH0DBwB/ 4l/46jHbDwviP8HhJ8Hd9r3Ga5AvSNQUx2Qwl4tquDJ6Ona0JNymOTQxtcOzUZNNoISjJBpYirS0+A FEX2xvZWo9VyUmUHp8ECMd8QzwzXxXJYAUDGiy0LfSYSnn8BOV5UeEJgbJ+DMosHRa3KaFjfVOke8b zEPZGYylFA+y+OATddIG4yoE/ppNdKxhWvQNSzgZCTNnApFatcvMeQB14nSh8Ax80it3tA6+6hj8bz gXv+qvI2dJe1SR09gW5Ez+bnwUqcKjcjiN+PnLxyRzOb4TiZwqTElM7dBbzzeEp1YNXw2hXjGKlkMD 6H9Zy+89jsRz3V80YYGIrAOofy0PMc X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org The Scalable Matrix Extension introduces support for a new thread specific data register TPIDR2 intended for use by libc. The kernel must save the value of TPIDR2 on context switch and should ensure that all new threads start off with a default value of 0. Add a field to the thread_struct to store TPIDR2 and context switch it with the other thread specific data. In case there are future extensions which also use TPIDR2 we introduce system_supports_tpidr2() and use that rather than system_supports_sme() for TPIDR2 handling. Signed-off-by: Mark Brown --- arch/arm64/include/asm/cpufeature.h | 5 +++++ arch/arm64/include/asm/processor.h | 1 + arch/arm64/kernel/fpsimd.c | 4 ++++ arch/arm64/kernel/process.c | 14 ++++++++++++-- 4 files changed, 22 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 9d36035acce3..12252352d2ee 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -747,6 +747,11 @@ static __always_inline bool system_supports_fa64(void) cpus_have_const_cap(ARM64_SME_FA64); } +static __always_inline bool system_supports_tpidr2(void) +{ + return system_supports_sme(); +} + static __always_inline bool system_supports_cnp(void) { return IS_ENABLED(CONFIG_ARM64_CNP) && diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index f2c2ebd440e2..008a1767ebff 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -168,6 +168,7 @@ struct thread_struct { u64 mte_ctrl; #endif u64 sctlr_user; + u64 tpidr2_el0; }; static inline unsigned int thread_get_vl(struct thread_struct *thread, diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 1edb3996f9cf..40ef89120774 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -1092,6 +1092,10 @@ void sme_kernel_enable(const struct arm64_cpu_capabilities *__always_unused p) /* Allow SME in kernel */ write_sysreg(read_sysreg(CPACR_EL1) | CPACR_EL1_SMEN_EL1EN, CPACR_EL1); isb(); + + /* Allow EL0 to access TPIDR2 */ + write_sysreg(read_sysreg(SCTLR_EL1) | SCTLR_ELx_ENTP2, SCTLR_EL1); + isb(); } /* diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 5369e649fa79..e69a3dcdb0d9 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -250,6 +250,8 @@ void show_regs(struct pt_regs *regs) static void tls_thread_flush(void) { write_sysreg(0, tpidr_el0); + if (system_supports_tpidr2()) + write_sysreg_s(0, SYS_TPIDR2_EL0); if (is_compat_task()) { current->thread.uw.tp_value = 0; @@ -343,6 +345,8 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start, * out-of-sync with the saved value. */ *task_user_tls(p) = read_sysreg(tpidr_el0); + if (system_supports_tpidr2()) + p->thread.tpidr2_el0 = read_sysreg_s(SYS_TPIDR2_EL0); if (stack_start) { if (is_compat_thread(task_thread_info(p))) @@ -353,10 +357,12 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start, /* * If a TLS pointer was passed to clone, use it for the new - * thread. + * thread. We also reset TPIDR2 if it's in use. */ - if (clone_flags & CLONE_SETTLS) + if (clone_flags & CLONE_SETTLS) { p->thread.uw.tp_value = tls; + p->thread.tpidr2_el0 = 0; + } } else { /* * A kthread has no context to ERET to, so ensure any buggy @@ -387,6 +393,8 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start, void tls_preserve_current_state(void) { *task_user_tls(current) = read_sysreg(tpidr_el0); + if (system_supports_tpidr2() && !is_compat_task()) + current->thread.tpidr2_el0 = read_sysreg_s(SYS_TPIDR2_EL0); } static void tls_thread_switch(struct task_struct *next) @@ -399,6 +407,8 @@ static void tls_thread_switch(struct task_struct *next) write_sysreg(0, tpidrro_el0); write_sysreg(*task_user_tls(next), tpidr_el0); + if (system_supports_tpidr2()) + write_sysreg_s(next->thread.tpidr2_el0, SYS_TPIDR2_EL0); } /*