From patchwork Mon Feb 7 15:20:43 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 540649 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 836CCC4167B for ; Mon, 7 Feb 2022 15:36:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239355AbiBGPfN (ORCPT ); Mon, 7 Feb 2022 10:35:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44578 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348243AbiBGPYF (ORCPT ); Mon, 7 Feb 2022 10:24:05 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CF770C0401C1 for ; Mon, 7 Feb 2022 07:24:04 -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 ams.source.kernel.org (Postfix) with ESMTPS id 8E8A9B815B0 for ; Mon, 7 Feb 2022 15:24:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CFEA0C340F4; Mon, 7 Feb 2022 15:23:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1644247442; bh=c5P3WzFe/myKJt98GT0tqU73tZQT7e7FvegzOnxWfIU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WkBumWqkdpz43bQWlzm4d80dvU/vfojs9V8ysixVQTKr1N3E+IjEa2PC3xKPd7pAv glPSlEUHRoL6pjj/hwu3T/pT1HixHh5YafpldJddcFOc/fZg8dQ9q5gN8BJ1NrCOAJ +SPIlTns8Op0xFHHfTAmxdACH3L+jxfXSwyDBaG902vyUhevUL0QWCJl5HqtgnRn+T FPbMAPRcftfOOROKoEDaUGsyQQeHipKpdUlouzr0sBijfEvUn9N9LmSM1s/L9ip1g9 gOedHi4i44KukA1QAS5aPk2QJqUcjL5U2HtRS4Gtlo4uklJnCDXjgQH80uLBZ2Nm98 yyOunXUcz454g== 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 v11 14/40] arm64/sme: Implement support for TPIDR2 Date: Mon, 7 Feb 2022 15:20:43 +0000 Message-Id: <20220207152109.197566-15-broonie@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220207152109.197566-1-broonie@kernel.org> References: <20220207152109.197566-1-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/pANAwAKASTWi3JdVIfQAcsmYgBiATjPq7eZ7r91LceN+pOy5udpzbiaxzgFRcvUb03E Y2wAT9eJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCYgE4zwAKCRAk1otyXVSH0ESRB/ oDKlmw2p8i8C+nF4VMW0Wie1UQnj0ogKIF1pld0lWR61S8MCXndTwp1fMFj4aXcB4YwFn1Opx0On0l mmS4nfO6lC+Pnp1/mn/ccOAxvcMjEZwAkYWHRER/NvlIAwnIn/IQdx9y+3fBMzZt5tSt0MpBlVIqnn 7FeYhQaQeinCq0g2xNugt7Ra+u9/o36NWJzSjbeVBstgcyGN6dzB5tbRfUuxYfQpZh/mAyAFKO98v2 WHCWDx0IyxVsc0rfoDIbQ5QQJ5MeXLhmCeKj4qShiBU9xnw8at0cCbkE/G9AIGKGIgbpzxmBspJSKM L2xp7qklR14OpbDF8sDKlLdPL4nZao 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 Reviewed-by: Catalin Marinas --- 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); } /*