Commit cd923966 authored by Jonathan Cameron's avatar Jonathan Cameron Committed by Catalin Marinas
Browse files

ACPI: processor: Move checks and availability of acpi_processor earlier 



Make the per_cpu(processors, cpu) entries available earlier so that
they are available in arch_register_cpu() as ARM64 will need access
to the acpi_handle to distinguish between acpi_processor_add()
and earlier registration attempts (which will fail as _STA cannot
be checked).

Reorder the remove flow to clear this per_cpu() after
arch_unregister_cpu() has completed, allowing it to be used in
there as well.

Note that on x86 for the CPU hotplug case, the pr->id prior to
acpi_map_cpu() may be invalid. Thus the per_cpu() structures
must be initialized after that call or after checking the ID
is valid (not hotplug path).

Acked-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: default avatarGavin Shan <gshan@redhat.com>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20240529133446.28446-7-Jonathan.Cameron@huawei.com


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 47ec9b41

drivers/acpi/acpi_processor.c

+52 −36
Original line number Diff line number Diff line
@@ -183,8 +183,38 @@ static void __init acpi_pcc_cpufreq_init(void) {} 
#endif /* CONFIG_X86 */



/* Initialization */

static DEFINE_PER_CPU(void *, processor_device_array);



static int acpi_processor_set_per_cpu(struct acpi_processor *pr,

				      struct acpi_device *device)

{

	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);

		return -EINVAL;

	}

	/*

	 * processor_device_array is not cleared on errors to allow buggy BIOS

	 * checks.

	 */

	per_cpu(processor_device_array, pr->id) = device;

	per_cpu(processors, pr->id) = pr;



	return 0;

}



#ifdef CONFIG_ACPI_HOTPLUG_CPU

static int acpi_processor_hotadd_init(struct acpi_processor *pr)

static int acpi_processor_hotadd_init(struct acpi_processor *pr,

				      struct acpi_device *device)

{

	int ret;
@@ -198,8 +228,16 @@ static int acpi_processor_hotadd_init(struct acpi_processor *pr) 
	if (ret)

		goto out;



	ret = acpi_processor_set_per_cpu(pr, device);

	if (ret) {

		acpi_unmap_cpu(pr->id);

		goto out;

	}



	ret = arch_register_cpu(pr->id);

	if (ret) {

		/* Leave the processor device array in place to detect buggy bios */

		per_cpu(processors, pr->id) = NULL;

		acpi_unmap_cpu(pr->id);

		goto out;

	}
@@ -217,7 +255,8 @@ static int acpi_processor_hotadd_init(struct acpi_processor *pr) 
	return ret;

}

#else

static inline int acpi_processor_hotadd_init(struct acpi_processor *pr)

static inline int acpi_processor_hotadd_init(struct acpi_processor *pr,

					     struct acpi_device *device)

{

	return -ENODEV;

}
@@ -232,6 +271,7 @@ static int acpi_processor_get_info(struct acpi_device *device) 
	acpi_status status = AE_OK;

	static int cpu0_initialized;

	unsigned long long value;

	int ret;



	acpi_processor_errata();
@@ -315,12 +355,12 @@ static int acpi_processor_get_info(struct acpi_device *device) 
	 *  NOTE: Even if the processor has a cpuid, it may not be present

	 *  because cpuid <-> apicid mapping is persistent now.

	 */

	if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id)) {

		int ret = acpi_processor_hotadd_init(pr);



	if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id))

		ret = acpi_processor_hotadd_init(pr, device);

	else

		ret = acpi_processor_set_per_cpu(pr, device);

	if (ret)

		return ret;

	}



	/*

	 * On some boxes several processors use the same processor bus id.
@@ -365,8 +405,6 @@ static int acpi_processor_get_info(struct acpi_device *device) 
 * (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 acpi_processor_add(struct acpi_device *device,

					const struct acpi_device_id *id)

{
@@ -395,28 +433,6 @@ static int acpi_processor_add(struct acpi_device *device, 
	if (result) /* Processor is not physically present or unavailable */

		goto err_clear_driver_data;



	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_clear_driver_data;

	}

	/*

	 * processor_device_array is not cleared on errors to allow buggy BIOS

	 * checks.

	 */

	per_cpu(processor_device_array, pr->id) = device;

	per_cpu(processors, pr->id) = pr;



	dev = get_cpu_device(pr->id);

	if (!dev) {

		result = -ENODEV;
@@ -470,10 +486,6 @@ static void acpi_processor_remove(struct acpi_device *device) 
	device_release_driver(pr->dev);

	acpi_unbind_one(pr->dev);



	/* Clean up. */

	per_cpu(processor_device_array, pr->id) = NULL;

	per_cpu(processors, pr->id) = NULL;



	cpu_maps_update_begin();

	cpus_write_lock();
@@ -481,6 +493,10 @@ static void acpi_processor_remove(struct acpi_device *device) 
	arch_unregister_cpu(pr->id);

	acpi_unmap_cpu(pr->id);



	/* Clean up. */

	per_cpu(processor_device_array, pr->id) = NULL;

	per_cpu(processors, pr->id) = NULL;



	cpus_write_unlock();

	cpu_maps_update_done();