From patchwork Wed Jan 26 15:10:54 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 537022 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 9E53AC63684 for ; Wed, 26 Jan 2022 15:12:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242598AbiAZPMc (ORCPT ); Wed, 26 Jan 2022 10:12:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40858 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235639AbiAZPMb (ORCPT ); Wed, 26 Jan 2022 10:12:31 -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 C3C6FC06161C for ; Wed, 26 Jan 2022 07:12:31 -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 5632C61842 for ; Wed, 26 Jan 2022 15:12:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 56875C36AE5; Wed, 26 Jan 2022 15:12:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1643209950; bh=3ak/TkOEva2A1EWWMZ6rEAo+xuM7bHsmgGI8j+vb0mA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ilmv31MYAj37zUV8Cap4i3AmyUQP9Xohmcf9+06VFwI9RkKBTdbHMKs4wNk1NSd4k sM6X/x5T//3ePbKx5IzVEX4m+am7fR5jqKGt1f8raUW60ZmiycgzP7HYiHrY8Oqmx9 VlyW9UbRN5OsyP5AYptFCd6su8SJ5QBxppRohqaC2YRTNPloJ40fwHV8pyFzpv8bfy zwM7l7Kdjs5lnM0pMHrqbACo9+my2nmMVRwo+pCuIMSyqWR8D/REO6IBmygG1YLrwG L3jzliIDgzw1OwjYIZ8l7GNIkv6vHiq250U5mS33pol1d7QltFkpmF/pTAMhsiUVSf UYf+9X0weTLdg== 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 v9 14/40] arm64/sme: Implement SVCR context switching Date: Wed, 26 Jan 2022 15:10:54 +0000 Message-Id: <20220126151120.3811248-15-broonie@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220126151120.3811248-1-broonie@kernel.org> References: <20220126151120.3811248-1-broonie@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=6142; h=from:subject; bh=3ak/TkOEva2A1EWWMZ6rEAo+xuM7bHsmgGI8j+vb0mA=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBh8WSBxHICk/aRefIWC+RRWEwIqJy9Ttg8s+gBA7Ye 7XUSftuJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCYfFkgQAKCRAk1otyXVSH0J04B/ 45bSUx+fDZN41Pz+nVxj/3A8ENkn+ght7A+wYN6dQ+zmRXtuktYM5ZEg2MFUT2mHcB1qzx70yxJ0LA aLRmO18S5PWhERXcqapr8Y4DWoI1QSIV+0tFs9cOFxmgmxpqzAM8ES2RDISUdLDB+q+LCck6YXVG89 cR08Q1VhQKYQ3Mm2iHlCkoAGnQwFsYN6CcopUuTFjKD3mDZvDhTDYo/OcnfX80Ol6kWeniAYmmlZzd QHYcVyHY7l26N1y0IqbJtGoFFvyTeJ3M5rI9IkJxnlbbKoT1xsl6QjaKAMDM5AhmzjPW+Es328U/0t 9mQzPmBK12iuWK/KYiuDtF6fYlJ2K+ X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org In SME the use of both streaming SVE mode and ZA are tracked through PSTATE.SM and PSTATE.ZA, visible through the system register SVCR. In order to context switch the floating point state for SME we need to context switch the contents of this register as part of context switching the floating point state. Since changing the vector length exits streaming SVE mode and disables ZA we also make sure we update SVCR appropriately when setting vector length, and similarly ensure that new threads have streaming SVE mode and ZA disabled. Signed-off-by: Mark Brown --- arch/arm64/include/asm/fpsimd.h | 3 ++- arch/arm64/include/asm/processor.h | 1 + arch/arm64/include/asm/thread_info.h | 1 + arch/arm64/kernel/fpsimd.c | 18 +++++++++++++++++- arch/arm64/kernel/process.c | 2 ++ arch/arm64/kvm/fpsimd.c | 4 ++++ 6 files changed, 27 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h index babf944e7c0c..d1bae65d3dba 100644 --- a/arch/arm64/include/asm/fpsimd.h +++ b/arch/arm64/include/asm/fpsimd.h @@ -46,7 +46,8 @@ extern void fpsimd_restore_current_state(void); extern void fpsimd_update_current_state(struct user_fpsimd_state const *state); extern void fpsimd_bind_state_to_cpu(struct user_fpsimd_state *state, - void *sve_state, unsigned int sve_vl); + void *sve_state, unsigned int sve_vl, + u64 *svcr); extern void fpsimd_flush_task_state(struct task_struct *target); extern void fpsimd_save_and_flush_cpu_state(void); diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index 008a1767ebff..7e08a4d48c24 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 svcr; u64 tpidr2_el0; }; diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h index 4e6b58dcd6f9..848739c15de8 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -82,6 +82,7 @@ int arch_dup_task_struct(struct task_struct *dst, #define TIF_SVE_VL_INHERIT 24 /* Inherit SVE vl_onexec across exec */ #define TIF_SSBD 25 /* Wants SSB mitigation */ #define TIF_TAGGED_ADDR 26 /* Allow tagged user addresses */ +#define TIF_SME 27 /* SME in use */ #define TIF_SME_VL_INHERIT 28 /* Inherit SME vl_onexec across exec */ #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 40ef89120774..a1918b71d335 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -121,6 +121,7 @@ struct fpsimd_last_state_struct { struct user_fpsimd_state *st; void *sve_state; + u64 *svcr; unsigned int sve_vl; }; @@ -359,6 +360,9 @@ static void task_fpsimd_load(void) WARN_ON(!system_supports_fpsimd()); WARN_ON(!have_cpu_fpsimd_context()); + if (IS_ENABLED(CONFIG_ARM64_SME) && test_thread_flag(TIF_SME)) + write_sysreg_s(current->thread.svcr, SYS_SVCR_EL0); + if (IS_ENABLED(CONFIG_ARM64_SVE) && test_thread_flag(TIF_SVE)) { sve_set_vq(sve_vq_from_vl(task_get_sve_vl(current)) - 1); sve_load_state(sve_pffr(¤t->thread), @@ -384,6 +388,12 @@ static void fpsimd_save(void) if (test_thread_flag(TIF_FOREIGN_FPSTATE)) return; + if (IS_ENABLED(CONFIG_ARM64_SME) && + test_thread_flag(TIF_SME)) { + u64 *svcr = last->svcr; + *svcr = read_sysreg_s(SYS_SVCR_EL0); + } + if (IS_ENABLED(CONFIG_ARM64_SVE) && test_thread_flag(TIF_SVE)) { if (WARN_ON(sve_get_vl() != last->sve_vl)) { @@ -735,6 +745,10 @@ int vec_set_vector_length(struct task_struct *task, enum vec_type type, if (test_and_clear_tsk_thread_flag(task, TIF_SVE)) sve_to_fpsimd(task); + if (system_supports_sme() && type == ARM64_VEC_SME) + task->thread.svcr &= ~(SYS_SVCR_EL0_SM_MASK | + SYS_SVCR_EL0_ZA_MASK); + if (task == current) put_cpu_fpsimd_context(); @@ -1398,6 +1412,7 @@ static void fpsimd_bind_task_to_cpu(void) last->st = ¤t->thread.uw.fpsimd_state; last->sve_state = current->thread.sve_state; last->sve_vl = task_get_sve_vl(current); + last->svcr = ¤t->thread.svcr; current->thread.fpsimd_cpu = smp_processor_id(); if (system_supports_sve()) { @@ -1412,7 +1427,7 @@ static void fpsimd_bind_task_to_cpu(void) } void fpsimd_bind_state_to_cpu(struct user_fpsimd_state *st, void *sve_state, - unsigned int sve_vl) + unsigned int sve_vl, u64 *svcr) { struct fpsimd_last_state_struct *last = this_cpu_ptr(&fpsimd_last_state); @@ -1421,6 +1436,7 @@ void fpsimd_bind_state_to_cpu(struct user_fpsimd_state *st, void *sve_state, WARN_ON(!in_softirq() && !irqs_disabled()); last->st = st; + last->svcr = svcr; last->sve_state = sve_state; last->sve_vl = sve_vl; } diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index e69a3dcdb0d9..f2d32a29641c 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -310,6 +310,8 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) dst->thread.sve_state = NULL; clear_tsk_thread_flag(dst, TIF_SVE); + dst->thread.svcr = 0; + /* clear any pending asynchronous tag fault raised by the parent */ clear_tsk_thread_flag(dst, TIF_MTE_ASYNC_FAULT); diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index 2f48fd362a8c..04698c4bcd30 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -103,6 +103,10 @@ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu) WARN_ON_ONCE(!irqs_disabled()); if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) { + /* + * Currently we do not support SME guests so SVCR is + * always 0 and we just need a variable to point to. + */ fpsimd_bind_state_to_cpu(&vcpu->arch.ctxt.fp_regs, vcpu->arch.sve_state, vcpu->arch.sve_max_vl);