Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751142Ab2KPBsg (ORCPT ); Thu, 15 Nov 2012 20:48:36 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:29805 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1750784Ab2KPBse (ORCPT ); Thu, 15 Nov 2012 20:48:34 -0500 X-IronPort-AV: E=Sophos;i="4.83,261,1352044800"; d="scan'208";a="6209380" Message-ID: <50A59CE3.9020907@cn.fujitsu.com> Date: Fri, 16 Nov 2012 09:54:43 +0800 From: Wen Congyang User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100413 Fedora/3.0.4-2.fc13 Thunderbird/3.0.4 MIME-Version: 1.0 To: David Rientjes CC: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-acpi@vger.kernel.org, Len Brown , "Rafael J. Wysocki" , Andrew Morton , Yasuaki Ishimatsu , Lai Jiangshan , Jiang Liu , KOSAKI Motohiro , Minchan Kim , Mel Gorman , Konrad Rzeszutek Wilk , Toshi Kani , Jiang Liu , Benjamin Herrenschmidt , Paul Mackerras , Christoph Lameter Subject: Re: [Patch v5 2/7] acpi,memory-hotplug: deal with eject request in hotplug queue References: <1352962777-24407-1-git-send-email-wency@cn.fujitsu.com> <1352962777-24407-3-git-send-email-wency@cn.fujitsu.com> In-Reply-To: X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/11/16 09:48:20, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/11/16 09:48:26, Serialize complete at 2012/11/16 09:48:26 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5897 Lines: 174 At 11/16/2012 07:32 AM, David Rientjes Wrote: > On Thu, 15 Nov 2012, Wen Congyang wrote: > >> The memory device can be removed by 2 ways: >> 1. send eject request by SCI >> 2. echo 1 >/sys/bus/pci/devices/PNP0C80:XX/eject >> >> We handle the 1st case in the module acpi_memhotplug, and handle >> the 2nd case in ACPI eject notification. This 2 events may happen >> at the same time, so we may touch acpi_memory_device.res_list at >> the same time. This patch reimplements memory-hotremove support >> through an ACPI eject notification. Now the memory device is >> offlined and hotremoved only in the function acpi_memory_device_remove() >> which is protected by device_lock(). >> > > You mean it's protected by device_lock() before calling the remove() > function for eject? Yes. We call device_release_driver() to unbind the device from the driver (the memory will be offlined/removed when it is unbound from the driver). we call device_lock() in device_release_driver(), so we only unbind it from the driver once. Thanks Wen Congyang > >> CC: David Rientjes >> CC: Jiang Liu >> CC: Len Brown >> CC: Benjamin Herrenschmidt >> CC: Paul Mackerras >> CC: Christoph Lameter >> Cc: Minchan Kim >> CC: Andrew Morton >> CC: KOSAKI Motohiro >> CC: Yasuaki Ishimatsu >> CC: Rafael J. Wysocki >> CC: Konrad Rzeszutek Wilk >> Signed-off-by: Wen Congyang >> --- >> drivers/acpi/acpi_memhotplug.c | 87 +++++------------------------------------- >> 1 file changed, 9 insertions(+), 78 deletions(-) >> >> diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c >> index 2918be1..6e12042 100644 >> --- a/drivers/acpi/acpi_memhotplug.c >> +++ b/drivers/acpi/acpi_memhotplug.c >> @@ -272,40 +272,6 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device) >> return 0; >> } >> >> -static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device) >> -{ >> - acpi_status status; >> - struct acpi_object_list arg_list; >> - union acpi_object arg; >> - unsigned long long current_status; >> - >> - >> - /* Issue the _EJ0 command */ >> - arg_list.count = 1; >> - arg_list.pointer = &arg; >> - arg.type = ACPI_TYPE_INTEGER; >> - arg.integer.value = 1; >> - status = acpi_evaluate_object(mem_device->device->handle, >> - "_EJ0", &arg_list, NULL); >> - /* Return on _EJ0 failure */ >> - if (ACPI_FAILURE(status)) { >> - ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed")); >> - return -ENODEV; >> - } >> - >> - /* Evalute _STA to check if the device is disabled */ >> - status = acpi_evaluate_integer(mem_device->device->handle, "_STA", >> - NULL, ¤t_status); >> - if (ACPI_FAILURE(status)) >> - return -ENODEV; >> - >> - /* Check for device status. Device should be disabled */ >> - if (current_status & ACPI_STA_DEVICE_ENABLED) >> - return -EINVAL; >> - >> - return 0; >> -} >> - >> static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device) >> { >> int result; >> @@ -325,34 +291,11 @@ static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device) >> return 0; >> } >> >> -static int acpi_memory_disable_device(struct acpi_memory_device *mem_device) >> -{ >> - int result; >> - >> - /* >> - * Ask the VM to offline this memory range. >> - * Note: Assume that this function returns zero on success >> - */ >> - result = acpi_memory_remove_memory(mem_device); >> - if (result) >> - return result; >> - >> - /* Power-off and eject the device */ >> - result = acpi_memory_powerdown_device(mem_device); >> - if (result) { >> - /* Set the status of the device to invalid */ >> - mem_device->state = MEMORY_INVALID_STATE; >> - return result; >> - } >> - >> - mem_device->state = MEMORY_POWER_OFF_STATE; >> - return result; >> -} >> - >> static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data) >> { >> struct acpi_memory_device *mem_device; >> struct acpi_device *device; >> + struct acpi_eject_event *ej_event = NULL; >> u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */ >> >> switch (event) { >> @@ -394,31 +337,19 @@ static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data) >> break; >> } >> >> - /* >> - * Currently disabling memory device from kernel mode >> - * TBD: Can also be disabled from user mode scripts >> - * TBD: Can also be disabled by Callback registration >> - * with generic sysfs driver >> - */ >> - if (acpi_memory_disable_device(mem_device)) { >> - printk(KERN_ERR PREFIX "Disable memory device\n"); >> - /* >> - * If _EJ0 was called but failed, _OST is not >> - * necessary. >> - */ >> - if (mem_device->state == MEMORY_INVALID_STATE) >> - return; >> - >> + ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL); >> + if (!ej_event) { >> + pr_err(PREFIX "No memory, dropping EJECT\n"); >> break; >> } >> >> - /* >> - * TBD: Invoke acpi_bus_remove to cleanup data structures >> - */ >> + ej_event->handle = handle; >> + ej_event->event = ACPI_NOTIFY_EJECT_REQUEST; >> + acpi_os_hotplug_execute(acpi_bus_hot_remove_device, >> + (void *)ej_event); >> >> - /* _EJ0 succeeded; _OST is not necessary */ >> + /* eject is performed asynchronously */ >> return; >> - >> default: >> ACPI_DEBUG_PRINT((ACPI_DB_INFO, >> "Unsupported event [0x%x]\n", event)); > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/