From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Martin Subject: [RFC PATCH 1/4] arm64: fpsimd: Abstract out binding of task's fpsimd context to the cpu. Date: Fri, 17 Nov 2017 16:38:52 +0000 Message-ID: <1510936735-6762-2-git-send-email-Dave.Martin@arm.com> References: <1510936735-6762-1-git-send-email-Dave.Martin@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 6478249D46 for ; Fri, 17 Nov 2017 11:36:42 -0500 (EST) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id cfVhNEgFbeKX for ; Fri, 17 Nov 2017 11:36:41 -0500 (EST) Received: from foss.arm.com (foss.arm.com [217.140.101.70]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 5BA6049D36 for ; Fri, 17 Nov 2017 11:36:41 -0500 (EST) In-Reply-To: <1510936735-6762-1-git-send-email-Dave.Martin@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: linux-arm-kernel@lists.infradead.org Cc: Marc Zyngier , kvmarm@lists.cs.columbia.edu List-Id: kvmarm@lists.cs.columbia.edu There is currently some duplicate logic to associate current's FPSIMD context with the cpu when loading FPSIMD state into the cpu regs. Subsequent patches will update that logic, so in order to ensure it only needs to be done in one place, this patch factors the relevant code out into a new function fpsimd_bind_to_cpu(). Signed-off-by: Dave Martin --- arch/arm64/kernel/fpsimd.c | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-) diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 143b3e7..007140b 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -992,6 +992,18 @@ void fpsimd_signal_preserve_current_state(void) } /* + * Associate current's FPSIMD context with this cpu + * Preemption must be disabled when calling this function. + */ +static void fpsimd_bind_to_cpu(void) +{ + struct fpsimd_state *st = ¤t->thread.fpsimd_state; + + __this_cpu_write(fpsimd_last_state, st); + st->cpu = smp_processor_id(); +} + +/* * Load the userland FPSIMD state of 'current' from memory, but only if the * FPSIMD state already held in the registers is /not/ the most recent FPSIMD * state of 'current' @@ -1004,11 +1016,8 @@ void fpsimd_restore_current_state(void) local_bh_disable(); if (test_and_clear_thread_flag(TIF_FOREIGN_FPSTATE)) { - struct fpsimd_state *st = ¤t->thread.fpsimd_state; - task_fpsimd_load(); - __this_cpu_write(fpsimd_last_state, st); - st->cpu = smp_processor_id(); + fpsimd_bind_to_cpu(); } local_bh_enable(); @@ -1032,12 +1041,8 @@ void fpsimd_update_current_state(struct fpsimd_state *state) } task_fpsimd_load(); - if (test_and_clear_thread_flag(TIF_FOREIGN_FPSTATE)) { - struct fpsimd_state *st = ¤t->thread.fpsimd_state; - - __this_cpu_write(fpsimd_last_state, st); - st->cpu = smp_processor_id(); - } + if (test_and_clear_thread_flag(TIF_FOREIGN_FPSTATE)) + fpsimd_bind_to_cpu(); local_bh_enable(); } -- 2.1.4