From ac212b6980d8d5eda705864fc5a8ecddc6d6eacc Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 3 May 2013 00:26:22 +0200 Subject: ACPI / processor: Use common hotplug infrastructure Split the ACPI processor driver into two parts, one that is non-modular, resides in the ACPI core and handles the enumeration and hotplug of processors and one that implements the rest of the existing processor driver functionality. The non-modular part uses an ACPI scan handler object to enumerate processors on the basis of information provided by the ACPI namespace and to hook up with the common ACPI hotplug infrastructure. It also populates the ACPI handle of each processor device having a corresponding object in the ACPI namespace, which allows the driver proper to bind to those devices, and makes the driver bind to them if it is readily available (i.e. loaded) when the scan handler's .attach() routine is running. There are a few reasons to make this change. First, switching the ACPI processor driver to using the common ACPI hotplug infrastructure reduces code duplication and size considerably, even though a new file is created along with a header comment etc. Second, since the common hotplug code attempts to offline devices before starting the (non-reversible) removal procedure, it will abort (and possibly roll back) hot-remove operations involving processors if cpu_down() returns an error code for one of them instead of continuing them blindly (if /sys/firmware/acpi/hotplug/force_remove is unset). That is a more desirable behavior than what the current code does. Finally, the separation of the scan/hotplug part from the driver proper makes it possible to simplify the driver's .remove() routine, because it doesn't need to worry about the possible cleanup related to processor removal any more (the scan/hotplug part is responsible for that now) and can handle device removal and driver removal symmetricaly (i.e. as appropriate). Some user-visible changes in sysfs are made (for example, the 'sysdev' link from the ACPI device node to the processor device's directory is gone and a 'physical_node' link is present instead and a corresponding 'firmware_node' is present in the processor device's directory, the processor driver is now visible under /sys/bus/cpu/drivers/ and bound to the processor device), but that shouldn't affect the functionality that users care about (frequency scaling, C-states and thermal management). Tested on my venerable Toshiba Portege R500. Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Reviewed-by: Toshi Kani --- drivers/acpi/acpi_processor.c | 484 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 484 insertions(+) create mode 100644 drivers/acpi/acpi_processor.c (limited to 'drivers/acpi/acpi_processor.c') diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c new file mode 100644 index 000000000000..587d2af4b323 --- /dev/null +++ b/drivers/acpi/acpi_processor.c @@ -0,0 +1,484 @@ +/* + * acpi_processor.c - ACPI processor enumeration support + * + * Copyright (C) 2001, 2002 Andy Grover + * Copyright (C) 2001, 2002 Paul Diefenbaugh + * Copyright (C) 2004 Dominik Brodowski + * Copyright (C) 2004 Anil S Keshavamurthy + * Copyright (C) 2013, Intel Corporation + * Rafael J. Wysocki + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + */ + +#include +#include +#include +#include +#include + +#include + +#include + +#include "internal.h" + +#define _COMPONENT ACPI_PROCESSOR_COMPONENT + +ACPI_MODULE_NAME("processor"); + +/* -------------------------------------------------------------------------- + Errata Handling + -------------------------------------------------------------------------- */ + +struct acpi_processor_errata errata __read_mostly; +EXPORT_SYMBOL_GPL(errata); + +static int acpi_processor_errata_piix4(struct pci_dev *dev) +{ + u8 value1 = 0; + u8 value2 = 0; + + + if (!dev) + return -EINVAL; + + /* + * Note that 'dev' references the PIIX4 ACPI Controller. + */ + + switch (dev->revision) { + case 0: + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 A-step\n")); + break; + case 1: + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 B-step\n")); + break; + case 2: + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4E\n")); + break; + case 3: + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4M\n")); + break; + default: + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found unknown PIIX4\n")); + break; + } + + switch (dev->revision) { + + case 0: /* PIIX4 A-step */ + case 1: /* PIIX4 B-step */ + /* + * See specification changes #13 ("Manual Throttle Duty Cycle") + * and #14 ("Enabling and Disabling Manual Throttle"), plus + * erratum #5 ("STPCLK# Deassertion Time") from the January + * 2002 PIIX4 specification update. Applies to only older + * PIIX4 models. + */ + errata.piix4.throttle = 1; + + case 2: /* PIIX4E */ + case 3: /* PIIX4M */ + /* + * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA + * Livelock") from the January 2002 PIIX4 specification update. + * Applies to all PIIX4 models. + */ + + /* + * BM-IDE + * ------ + * Find the PIIX4 IDE Controller and get the Bus Master IDE + * Status register address. We'll use this later to read + * each IDE controller's DMA status to make sure we catch all + * DMA activity. + */ + dev = pci_get_subsys(PCI_VENDOR_ID_INTEL, + PCI_DEVICE_ID_INTEL_82371AB, + PCI_ANY_ID, PCI_ANY_ID, NULL); + if (dev) { + errata.piix4.bmisx = pci_resource_start(dev, 4); + pci_dev_put(dev); + } + + /* + * Type-F DMA + * ---------- + * Find the PIIX4 ISA Controller and read the Motherboard + * DMA controller's status to see if Type-F (Fast) DMA mode + * is enabled (bit 7) on either channel. Note that we'll + * disable C3 support if this is enabled, as some legacy + * devices won't operate well if fast DMA is disabled. + */ + dev = pci_get_subsys(PCI_VENDOR_ID_INTEL, + PCI_DEVICE_ID_INTEL_82371AB_0, + PCI_ANY_ID, PCI_ANY_ID, NULL); + if (dev) { + pci_read_config_byte(dev, 0x76, &value1); + pci_read_config_byte(dev, 0x77, &value2); + if ((value1 & 0x80) || (value2 & 0x80)) + errata.piix4.fdma = 1; + pci_dev_put(dev); + } + + break; + } + + if (errata.piix4.bmisx) + ACPI_DEBUG_PRINT((ACPI_DB_INFO, + "Bus master activity detection (BM-IDE) erratum enabled\n")); + if (errata.piix4.fdma) + ACPI_DEBUG_PRINT((ACPI_DB_INFO, + "Type-F DMA livelock erratum (C3 disabled)\n")); + + return 0; +} + +static int acpi_processor_errata(struct acpi_processor *pr) +{ + int result = 0; + struct pci_dev *dev = NULL; + + + if (!pr) + return -EINVAL; + + /* + * PIIX4 + */ + dev = pci_get_subsys(PCI_VENDOR_ID_INTEL, + PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID, + PCI_ANY_ID, NULL); + if (dev) { + result = acpi_processor_errata_piix4(dev); + pci_dev_put(dev); + } + + return result; +} + +/* -------------------------------------------------------------------------- + Initialization + -------------------------------------------------------------------------- */ + +#ifdef CONFIG_ACPI_HOTPLUG_CPU +static int acpi_processor_hotadd_init(struct acpi_processor *pr) +{ + unsigned long long sta; + acpi_status status; + int ret; + + status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta); + if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT)) + return -ENODEV; + + ret = acpi_map_lsapic(pr->handle, &pr->id); + if (ret) + return ret; + + ret = arch_register_cpu(pr->id); + if (ret) { + acpi_unmap_lsapic(pr->id); + return ret; + } + + /* + * CPU got hot-added, but cpu_data is not initialized yet. Set a flag + * to delay cpu_idle/throttling initialization and do it when the CPU + * gets online for the first time. + */ + pr_info("CPU%d has been hot-added\n", pr->id); + pr->flags.need_hotplug_init = 1; + return 0; +} +#else +static inline int acpi_processor_hotadd_init(struct acpi_processor *pr) +{ + return -ENODEV; +} +#endif /* CONFIG_ACPI_HOTPLUG_CPU */ + +static int acpi_processor_get_info(struct acpi_device *device) +{ + union acpi_object object = { 0 }; + struct acpi_buffer buffer = { sizeof(union acpi_object), &object }; + struct acpi_processor *pr = acpi_driver_data(device); + int cpu_index, device_declaration = 0; + acpi_status status = AE_OK; + static int cpu0_initialized; + + if (num_online_cpus() > 1) + errata.smp = TRUE; + + acpi_processor_errata(pr); + + /* + * Check to see if we have bus mastering arbitration control. This + * is required for proper C3 usage (to maintain cache coherency). + */ + if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) { + pr->flags.bm_control = 1; + ACPI_DEBUG_PRINT((ACPI_DB_INFO, + "Bus mastering arbitration control present\n")); + } else + ACPI_DEBUG_PRINT((ACPI_DB_INFO, + "No bus mastering arbitration control\n")); + + if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) { + /* Declared with "Processor" statement; match ProcessorID */ + status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer); + if (ACPI_FAILURE(status)) { + dev_err(&device->dev, + "Failed to evaluate processor object (0x%x)\n", + status); + return -ENODEV; + } + + /* + * TBD: Synch processor ID (via LAPIC/LSAPIC structures) on SMP. + * >>> 'acpi_get_processor_id(acpi_id, &id)' in + * arch/xxx/acpi.c + */ + pr->acpi_id = object.processor.proc_id; + } else { + /* + * Declared with "Device" statement; match _UID. + * Note that we don't handle string _UIDs yet. + */ + unsigned long long value; + status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID, + NULL, &value); + if (ACPI_FAILURE(status)) { + dev_err(&device->dev, + "Failed to evaluate processor _UID (0x%x)\n", + status); + return -ENODEV; + } + device_declaration = 1; + pr->acpi_id = value; + } + cpu_index = acpi_get_cpuid(pr->handle, device_declaration, pr->acpi_id); + + /* Handle UP system running SMP kernel, with no LAPIC in MADT */ + if (!cpu0_initialized && (cpu_index == -1) && + (num_online_cpus() == 1)) { + cpu_index = 0; + } + + cpu0_initialized = 1; + + pr->id = cpu_index; + + /* + * Extra Processor objects may be enumerated on MP systems with + * less than the max # of CPUs. They should be ignored _iff + * they are physically not present. + */ + if (pr->id == -1) { + int ret = acpi_processor_hotadd_init(pr); + if (ret) + return ret; + } + /* + * On some boxes several processors use the same processor bus id. + * But they are located in different scope. For example: + * \_SB.SCK0.CPU0 + * \_SB.SCK1.CPU0 + * Rename the processor device bus id. And the new bus id will be + * generated as the following format: + * CPU+CPU ID. + */ + sprintf(acpi_device_bid(device), "CPU%X", pr->id); + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id, + pr->acpi_id)); + + if (!object.processor.pblk_address) + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n")); + else if (object.processor.pblk_length != 6) + dev_err(&device->dev, "Invalid PBLK length [%d]\n", + object.processor.pblk_length); + else { + pr->throttling.address = object.processor.pblk_address; + pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset; + pr->throttling.duty_width = acpi_gbl_FADT.duty_width; + + pr->pblk = object.processor.pblk_address; + + /* + * We don't care about error returns - we just try to mark + * these reserved so that nobody else is confused into thinking + * that this region might be unused.. + * + * (In particular, allocating the IO range for Cardbus) + */ + request_region(pr->throttling.address, 6, "ACPI CPU throttle"); + } + + /* + * If ACPI describes a slot number for this CPU, we can use it to + * ensure we get the right value in the "physical id" field + * of /proc/cpuinfo + */ + status = acpi_evaluate_object(pr->handle, "_SUN", NULL, &buffer); + if (ACPI_SUCCESS(status)) + arch_fix_phys_package_id(pr->id, object.integer.value); + + return 0; +} + +/* + * Do not put anything in here which needs the core to be online. + * For example MSR access or setting up things which check for cpuinfo_x86 + * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc. + * Such things have to be put in and set up by the processor driver's .probe(). + */ +static DEFINE_PER_CPU(void *, processor_device_array); + +static int __cpuinit acpi_processor_add(struct acpi_device *device, + const struct acpi_device_id *id) +{ + struct acpi_processor *pr; + struct device *dev; + int result = 0; + + pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL); + if (!pr) + return -ENOMEM; + + if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) { + result = -ENOMEM; + goto err_free_pr; + } + + pr->handle = device->handle; + strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME); + strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS); + device->driver_data = pr; + + result = acpi_processor_get_info(device); + if (result) /* Processor is not physically present or unavailable */ + return 0; + +#ifdef CONFIG_SMP + if (pr->id >= setup_max_cpus && pr->id != 0) + return 0; +#endif + + BUG_ON(pr->id >= nr_cpu_ids); + + /* + * Buggy BIOS check. + * ACPI id of processors can be reported wrongly by the BIOS. + * Don't trust it blindly + */ + if (per_cpu(processor_device_array, pr->id) != NULL && + per_cpu(processor_device_array, pr->id) != device) { + dev_warn(&device->dev, + "BIOS reported wrong ACPI id %d for the processor\n", + pr->id); + /* Give up, but do not abort the namespace scan. */ + goto err; + } + /* + * processor_device_array is not cleared on errors to allow buggy BIOS + * checks. + */ + per_cpu(processor_device_array, pr->id) = device; + + dev = get_cpu_device(pr->id); + ACPI_HANDLE_SET(dev, pr->handle); + result = acpi_bind_one(dev, NULL); + if (result) + goto err; + + pr->dev = dev; + dev->offline = pr->flags.need_hotplug_init; + + /* Trigger the processor driver's .probe() if present. */ + if (device_attach(dev) >= 0) + return 1; + + dev_err(dev, "Processor driver could not be attached\n"); + acpi_unbind_one(dev); + + err: + free_cpumask_var(pr->throttling.shared_cpu_map); + device->driver_data = NULL; + err_free_pr: + kfree(pr); + return result; +} + +#ifdef CONFIG_ACPI_HOTPLUG_CPU +/* -------------------------------------------------------------------------- + Removal + -------------------------------------------------------------------------- */ + +static void acpi_processor_remove(struct acpi_device *device) +{ + struct acpi_processor *pr; + + if (!device || !acpi_driver_data(device)) + return; + + pr = acpi_driver_data(device); + if (pr->id >= nr_cpu_ids) + goto out; + + /* + * The only reason why we ever get here is CPU hot-removal. The CPU is + * already offline and the ACPI device removal locking prevents it from + * being put back online at this point. + * + * Unbind the driver from the processor device and detach it from the + * ACPI companion object. + */ + device_release_driver(pr->dev); + acpi_unbind_one(pr->dev); + + /* Clean up. */ + per_cpu(processor_device_array, pr->id) = NULL; + try_offline_node(cpu_to_node(pr->id)); + + /* Remove the CPU. */ + get_online_cpus(); + arch_unregister_cpu(pr->id); + acpi_unmap_lsapic(pr->id); + put_online_cpus(); + + out: + free_cpumask_var(pr->throttling.shared_cpu_map); + kfree(pr); +} +#endif /* CONFIG_ACPI_HOTPLUG_CPU */ + +/* + * The following ACPI IDs are known to be suitable for representing as + * processor devices. + */ +static const struct acpi_device_id processor_device_ids[] = { + + { ACPI_PROCESSOR_OBJECT_HID, }, + { ACPI_PROCESSOR_DEVICE_HID, }, + + { } +}; + +static struct acpi_scan_handler __refdata processor_handler = { + .ids = processor_device_ids, + .attach = acpi_processor_add, +#ifdef CONFIG_ACPI_HOTPLUG_CPU + .detach = acpi_processor_remove, +#endif + .hotplug = { + .enabled = true, + }, +}; + +void __init acpi_processor_init(void) +{ + acpi_scan_add_handler_with_hotplug(&processor_handler, "processor"); +} -- cgit v1.2.3 From 2e4f1db49d97222110b6add9a2c6cf5251a41e35 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 30 May 2013 21:55:46 +0200 Subject: ACPI / processor: Initialize per_cpu(processors, pr->id) properly Commit ac212b6 (ACPI / processor: Use common hotplug infrastructure) forgot about initializing the per-CPU 'processors' variables which lead to ACPI cpuidle failure to use C-states and caused boot slowdown on multi-CPU machines. Fix the problem by adding per_cpu(processors, pr->id) initialization to acpi_processor_add() and add make acpi_processor_remove() clean it up as appropriate. Also modify acpi_processor_stop() so that it doesn't clear per_cpu(processors, pr->id) on processor driver removal which would then cause problems to happen when the driver is loaded again. This version of the patch contains fixes from Yinghai Lu. Reported-and-tested-by: Yinghai Lu Reported-and-tested-by: Daniel Lezcano Signed-off-by: Rafael J. Wysocki --- drivers/acpi/acpi_processor.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'drivers/acpi/acpi_processor.c') diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 587d2af4b323..cae2641e8d84 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -29,6 +29,9 @@ ACPI_MODULE_NAME("processor"); +DEFINE_PER_CPU(struct acpi_processor *, processors); +EXPORT_PER_CPU_SYMBOL(processors); + /* -------------------------------------------------------------------------- Errata Handling -------------------------------------------------------------------------- */ @@ -387,6 +390,7 @@ static int __cpuinit acpi_processor_add(struct acpi_device *device, * checks. */ per_cpu(processor_device_array, pr->id) = device; + per_cpu(processors, pr->id) = pr; dev = get_cpu_device(pr->id); ACPI_HANDLE_SET(dev, pr->handle); @@ -407,6 +411,7 @@ static int __cpuinit acpi_processor_add(struct acpi_device *device, err: free_cpumask_var(pr->throttling.shared_cpu_map); device->driver_data = NULL; + per_cpu(processors, pr->id) = NULL; err_free_pr: kfree(pr); return result; @@ -441,6 +446,7 @@ static void acpi_processor_remove(struct acpi_device *device) /* Clean up. */ per_cpu(processor_device_array, pr->id) = NULL; + per_cpu(processors, pr->id) = NULL; try_offline_node(cpu_to_node(pr->id)); /* Remove the CPU. */ -- cgit v1.2.3 From be547436c22c3b7d934d9afd841cfd7a6807f7ab Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 23 May 2013 10:40:56 +0200 Subject: ACPI / processor: Pass processor object handle to acpi_bind_one() Make acpi_processor_add() pass the ACPI handle of the processor namespace object to acpi_bind_one() instead of setting it directly to allow acpi_bind_one() to catch possible bugs causing the ACPI handle of the processor device to be set earlier. Signed-off-by: Rafael J. Wysocki Acked-by: Toshi Kani --- drivers/acpi/acpi_processor.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'drivers/acpi/acpi_processor.c') diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index cae2641e8d84..157e7389a5ff 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -393,8 +393,7 @@ static int __cpuinit acpi_processor_add(struct acpi_device *device, per_cpu(processors, pr->id) = pr; dev = get_cpu_device(pr->id); - ACPI_HANDLE_SET(dev, pr->handle); - result = acpi_bind_one(dev, NULL); + result = acpi_bind_one(dev, pr->handle); if (result) goto err; -- cgit v1.2.3 From 173a5a4c909789fcd57d00355d2237618a3824a4 Mon Sep 17 00:00:00 2001 From: Hanjun Guo Date: Fri, 31 May 2013 11:36:08 +0800 Subject: ACPI / processor: Fix potential NULL pointer dereference in acpi_processor_add() In acpi_processor_add(), get_cpu_device() may return NULL in some cases which is then passed to acpi_bind_one() and that will case a NULL pointer dereference to occur. Add a check to prevent that from happening. [rjw: Changelog] Signed-off-by: Hanjun Guo Signed-off-by: Rafael J. Wysocki --- drivers/acpi/acpi_processor.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/acpi/acpi_processor.c') diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 157e7389a5ff..e9b01e35ac37 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -393,6 +393,11 @@ static int __cpuinit acpi_processor_add(struct acpi_device *device, per_cpu(processors, pr->id) = pr; dev = get_cpu_device(pr->id); + if (!dev) { + result = -ENODEV; + goto err; + } + result = acpi_bind_one(dev, pr->handle); if (result) goto err; -- cgit v1.2.3 From fe7bf106ebc22730797ba9b51308b166d68b77f9 Mon Sep 17 00:00:00 2001 From: Paul Gortmaker Date: Wed, 19 Jun 2013 14:30:58 -0400 Subject: acpi: delete __cpuinit usage from all acpi files The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. This removes all the drivers/acpi uses of the __cpuinit macros from all C files. [1] https://lkml.org/lkml/2013/5/20/589 Cc: Len Brown Cc: "Rafael J. Wysocki" Cc: linux-acpi@vger.kernel.org Signed-off-by: Paul Gortmaker --- drivers/acpi/acpi_processor.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/acpi/acpi_processor.c') diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index e9b01e35ac37..fd6c51cc3acb 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -340,7 +340,7 @@ static int acpi_processor_get_info(struct acpi_device *device) */ static DEFINE_PER_CPU(void *, processor_device_array); -static int __cpuinit acpi_processor_add(struct acpi_device *device, +static int acpi_processor_add(struct acpi_device *device, const struct acpi_device_id *id) { struct acpi_processor *pr; -- cgit v1.2.3 From 1e385f6f97b8ab39e16a0956a1951e19a9376bab Mon Sep 17 00:00:00 2001 From: Yasuaki Ishimatsu Date: Tue, 6 Aug 2013 19:11:11 +0900 Subject: ACPI / processor: move try_offline_node() after acpi_unmap_lsapic() try_offline_node() checks that all CPUs associated with the given node have been removed by using cpu_present_bits. If all cpus related to that node have been removed, try_offline_node() clears the node information. However, try_offline_node() called from acpi_processor_remove() never clears the node information. For disabling cpu_present_bits, acpi_unmap_lsapic() needs be called. Yet, acpi_unmap_lsapic() is called after try_offline_node() has run. So when try_offline_node() runs, the CPU's cpu_present_bits is always set. Fix the issue by moving try_offline_node() after acpi_unmap_lsapic(). The problem fixed here was uncovered by commit cecdb19 "ACPI / scan: Change the implementation of acpi_bus_trim()". [rjw: Changelog] Signed-off-by: Yasuaki Ishimatsu Acked-by: Toshi Kani Cc: 3.9+ # 3.9+ Signed-off-by: Rafael J. Wysocki --- drivers/acpi/acpi_processor.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/acpi/acpi_processor.c') diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index fd6c51cc3acb..5a74a9c1e42c 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -451,7 +451,6 @@ static void acpi_processor_remove(struct acpi_device *device) /* Clean up. */ per_cpu(processor_device_array, pr->id) = NULL; per_cpu(processors, pr->id) = NULL; - try_offline_node(cpu_to_node(pr->id)); /* Remove the CPU. */ get_online_cpus(); @@ -459,6 +458,8 @@ static void acpi_processor_remove(struct acpi_device *device) acpi_unmap_lsapic(pr->id); put_online_cpus(); + try_offline_node(cpu_to_node(pr->id)); + out: free_cpumask_var(pr->throttling.shared_cpu_map); kfree(pr); -- cgit v1.2.3