From patchwork Tue Jul 20 04:25:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Kuppuswamy Sathyanarayanan X-Patchwork-Id: 481654 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E5ADEC07E95 for ; Tue, 20 Jul 2021 04:25:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C660961107 for ; Tue, 20 Jul 2021 04:25:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234900AbhGTDpD (ORCPT ); Mon, 19 Jul 2021 23:45:03 -0400 Received: from mga06.intel.com ([134.134.136.31]:35128 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232252AbhGTDox (ORCPT ); Mon, 19 Jul 2021 23:44:53 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10050"; a="272288708" X-IronPort-AV: E=Sophos;i="5.84,254,1620716400"; d="scan'208";a="272288708" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jul 2021 21:25:28 -0700 X-IronPort-AV: E=Sophos;i="5.84,254,1620716400"; d="scan'208";a="494528464" Received: from ywei11-mobl1.amr.corp.intel.com (HELO skuppusw-desk1.amr.corp.intel.com) ([10.251.138.31]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jul 2021 21:25:27 -0700 From: Kuppuswamy Sathyanarayanan To: Thomas Gleixner , Ingo Molnar , Rafael J Wysocki , H Peter Anvin , Peter Zijlstra Cc: Len Brown , Kuppuswamy Sathyanarayanan , Sean Christopherson , Andi Kleen , x86@kernel.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, Sean Christopherson , "Rafael J . Wysocki" Subject: [PATCH v7 1/1] x86/acpi, x86/boot: Add multiprocessor wake-up support Date: Mon, 19 Jul 2021 21:25:06 -0700 Message-Id: <20210720042506.2123009-1-sathyanarayanan.kuppuswamy@linux.intel.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org As per ACPI specification r6.4, sec 5.2.12.19, a new sub structure – multiprocessor wake-up structure - is added to the ACPI Multiple APIC Description Table (MADT) to describe the information of the mailbox. If a platform firmware produces the multiprocessor wake-up structure, then OS may use this new mailbox-based mechanism to wake up the APs. Add ACPI MADT wake table parsing support for x86 platform and if MADT wake table is present, update apic->wakeup_secondary_cpu with new API which uses MADT wake mailbox to wake-up CPU. Co-developed-by: Sean Christopherson Signed-off-by: Sean Christopherson Reviewed-by: Andi Kleen Reviewed-by: Rafael J. Wysocki Signed-off-by: Kuppuswamy Sathyanarayanan --- Changes since v6: * Rebased on top of v5.14-rc1. Changes since v5: * None ( CCed ACPI list) Changes since v4: * Used smp_store_release() in place of WRITE_ONCE(). * Addressed some checkpatch warnings. Changes since v3: * Removed acpi_mp_wake_mailbox_init() and moved init code to acpi_wakeup_cpu(). * Removed redundant NULL pointer check for acpi_mp_wake_mailbox. * Added comments/debug prints as per Rafael's suggestion. * Removed MADT/SVKL ACPI patches from this patchset. It will be merged via ACPICA submission. arch/x86/include/asm/apic.h | 3 ++ arch/x86/kernel/acpi/boot.c | 96 +++++++++++++++++++++++++++++++++++++ arch/x86/kernel/apic/apic.c | 8 ++++ 3 files changed, 107 insertions(+) diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h index 48067af94678..463905172cd0 100644 --- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -488,6 +488,9 @@ static inline unsigned int read_apic_id(void) return apic->get_apic_id(reg); } +typedef int (*wakeup_cpu_handler)(int apicid, unsigned long start_eip); +extern void acpi_wake_cpu_handler_update(wakeup_cpu_handler handler); + extern int default_apic_id_valid(u32 apicid); extern int default_acpi_madt_oem_check(char *, char *); extern void default_setup_apic_routing(void); diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index e55e0c1fad8c..c2df8843950d 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -64,6 +64,10 @@ int acpi_fix_pin2_polarity __initdata; static u64 acpi_lapic_addr __initdata = APIC_DEFAULT_PHYS_BASE; #endif +static struct acpi_madt_multiproc_wakeup_mailbox *acpi_mp_wake_mailbox; +static u64 acpi_mp_wake_mailbox_paddr; +static physid_mask_t apic_id_wakemap = PHYSID_MASK_NONE; + #ifdef CONFIG_X86_IO_APIC /* * Locks related to IOAPIC hotplug @@ -327,6 +331,68 @@ acpi_parse_lapic_nmi(union acpi_subtable_headers * header, const unsigned long e return 0; } +static int acpi_wakeup_cpu(int apicid, unsigned long start_ip) +{ + u8 timeout = 0xFF; + + /* Remap mailbox memory only for the first call to acpi_wakeup_cpu() */ + if (physids_empty(apic_id_wakemap)) { + acpi_mp_wake_mailbox = memremap(acpi_mp_wake_mailbox_paddr, + sizeof(*acpi_mp_wake_mailbox), + MEMREMAP_WB); + } + + /* + * According to the ACPI specification r6.4, sec 5.2.12.19, the + * mailbox-based wakeup mechanism cannot be used more than once + * for the same CPU, so skip sending wake commands to already + * awake CPU. + */ + if (physid_isset(apicid, apic_id_wakemap)) { + pr_err("CPU already awake (APIC ID %x), skipping wakeup\n", + apicid); + return -EINVAL; + } + + /* + * Mailbox memory is shared between firmware and OS. Firmware will + * listen on mailbox command address, and once it receives the wakeup + * command, CPU associated with the given apicid will be booted. So, + * the value of apic_id and wakeup_vector has to be set before updating + * the wakeup command. So use smp_store_release to let the compiler know + * about it and preserve the order of writes. + */ + smp_store_release(&acpi_mp_wake_mailbox->apic_id, apicid); + smp_store_release(&acpi_mp_wake_mailbox->wakeup_vector, start_ip); + smp_store_release(&acpi_mp_wake_mailbox->command, + ACPI_MP_WAKE_COMMAND_WAKEUP); + + /* + * After writing wakeup command, wait for maximum timeout of 0xFF + * for firmware to reset the command address back zero to indicate + * the successful reception of command. + * NOTE: 255 as timeout value is decided based on our experiments. + * + * XXX: Change the timeout once ACPI specification comes up with + * standard maximum timeout value. + */ + while (READ_ONCE(acpi_mp_wake_mailbox->command) && timeout--) + cpu_relax(); + + if (timeout) { + /* + * If the CPU wakeup process is successful, store the + * status in apic_id_wakemap to prevent re-wakeup + * requests. + */ + physid_set(apicid, apic_id_wakemap); + return 0; + } + + /* If timed out (timeout == 0), return error */ + return -EIO; +} + #endif /*CONFIG_X86_LOCAL_APIC */ #ifdef CONFIG_X86_IO_APIC @@ -1074,6 +1140,30 @@ static int __init acpi_parse_madt_lapic_entries(void) } return 0; } + +static int __init acpi_parse_mp_wake(union acpi_subtable_headers *header, + const unsigned long end) +{ + struct acpi_madt_multiproc_wakeup *mp_wake; + + if (acpi_mp_wake_mailbox) + return -EINVAL; + + if (!IS_ENABLED(CONFIG_SMP)) + return -ENODEV; + + mp_wake = (struct acpi_madt_multiproc_wakeup *)header; + if (BAD_MADT_ENTRY(mp_wake, end)) + return -EINVAL; + + acpi_table_print_madt_entry(&header->common); + + acpi_mp_wake_mailbox_paddr = mp_wake->base_address; + + acpi_wake_cpu_handler_update(acpi_wakeup_cpu); + + return 0; +} #endif /* CONFIG_X86_LOCAL_APIC */ #ifdef CONFIG_X86_IO_APIC @@ -1269,6 +1359,12 @@ static void __init acpi_process_madt(void) smp_found_config = 1; } + + /* + * Parse MADT MP Wake entry. + */ + acpi_table_parse_madt(ACPI_MADT_TYPE_MULTIPROC_WAKEUP, + acpi_parse_mp_wake, 1); } if (error == -EINVAL) { /* diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index d262811ce14b..2a5b0bd16846 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -2554,6 +2554,14 @@ u32 x86_msi_msg_get_destid(struct msi_msg *msg, bool extid) } EXPORT_SYMBOL_GPL(x86_msi_msg_get_destid); +void __init acpi_wake_cpu_handler_update(wakeup_cpu_handler handler) +{ + struct apic **drv; + + for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) + (*drv)->wakeup_secondary_cpu = handler; +} + /* * Override the generic EOI implementation with an optimized version. * Only called during early boot when only one CPU is active and with