From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755639AbdC1MpD (ORCPT ); Tue, 28 Mar 2017 08:45:03 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:34096 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755606AbdC1MpA (ORCPT ); Tue, 28 Mar 2017 08:45:00 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stanislaw Gruszka , Konrad Rzeszutek Wilk , Ankur Arora , Boris Ostrovsky Subject: [PATCH 4.9 67/88] xen/acpi: upload PM state from init-domain to Xen Date: Tue, 28 Mar 2017 14:31:22 +0200 Message-Id: <20170328122751.396780435@linuxfoundation.org> X-Mailer: git-send-email 2.12.1 In-Reply-To: <20170328122748.656530096@linuxfoundation.org> References: <20170328122748.656530096@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ankur Arora commit 1914f0cd203c941bba72f9452c8290324f1ef3dc upstream. This was broken in commit cd979883b9ed ("xen/acpi-processor: fix enabling interrupts on syscore_resume"). do_suspend (from xen/manage.c) and thus xen_resume_notifier never get called on the initial-domain at resume (it is if running as guest.) The rationale for the breaking change was that upload_pm_data() potentially does blocking work in syscore_resume(). This patch addresses the original issue by scheduling upload_pm_data() to execute in workqueue context. Cc: Stanislaw Gruszka Based-on-patch-by: Konrad Wilk Reviewed-by: Konrad Rzeszutek Wilk Reviewed-by: Stanislaw Gruszka Signed-off-by: Ankur Arora Signed-off-by: Boris Ostrovsky Signed-off-by: Greg Kroah-Hartman --- drivers/xen/xen-acpi-processor.c | 34 ++++++++++++++++++++++++++-------- 1 file changed, 26 insertions(+), 8 deletions(-) --- a/drivers/xen/xen-acpi-processor.c +++ b/drivers/xen/xen-acpi-processor.c @@ -27,10 +27,10 @@ #include #include #include +#include #include #include #include -#include #include #include @@ -466,15 +466,33 @@ static int xen_upload_processor_pm_data( return rc; } -static int xen_acpi_processor_resume(struct notifier_block *nb, - unsigned long action, void *data) +static void xen_acpi_processor_resume_worker(struct work_struct *dummy) { + int rc; + bitmap_zero(acpi_ids_done, nr_acpi_bits); - return xen_upload_processor_pm_data(); + + rc = xen_upload_processor_pm_data(); + if (rc != 0) + pr_info("ACPI data upload failed, error = %d\n", rc); +} + +static void xen_acpi_processor_resume(void) +{ + static DECLARE_WORK(wq, xen_acpi_processor_resume_worker); + + /* + * xen_upload_processor_pm_data() calls non-atomic code. + * However, the context for xen_acpi_processor_resume is syscore + * with only the boot CPU online and in an atomic context. + * + * So defer the upload for some point safer. + */ + schedule_work(&wq); } -struct notifier_block xen_acpi_processor_resume_nb = { - .notifier_call = xen_acpi_processor_resume, +static struct syscore_ops xap_syscore_ops = { + .resume = xen_acpi_processor_resume, }; static int __init xen_acpi_processor_init(void) @@ -527,7 +545,7 @@ static int __init xen_acpi_processor_ini if (rc) goto err_unregister; - xen_resume_notifier_register(&xen_acpi_processor_resume_nb); + register_syscore_ops(&xap_syscore_ops); return 0; err_unregister: @@ -544,7 +562,7 @@ static void __exit xen_acpi_processor_ex { int i; - xen_resume_notifier_unregister(&xen_acpi_processor_resume_nb); + unregister_syscore_ops(&xap_syscore_ops); kfree(acpi_ids_done); kfree(acpi_id_present); kfree(acpi_id_cst_present);