[RFC PATCH v3 21/28] ACPIHP/processor: reorganize ACPI processor driver for new hotplug framework

From: Jiang Liu
Date: Sat Oct 06 2012 - 11:35:00 EST


This patch reorganizes code in processor_driver.c to parepare for
integration with the new hotplug framework. Common code could be
shared among acpi_processor_add(), acpi_processor_remove() and hotplug
has been reorganized as:
acpi_processor_start()
acpi_processor_stop()
acpi_processor_link()
acpi_processor_unlink()

Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
---
drivers/acpi/processor_driver.c | 179 +++++++++++++++++++++++----------------
include/acpi/processor.h | 2 +
2 files changed, 108 insertions(+), 73 deletions(-)

diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index abbce9e..4f2fec0 100644
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -105,6 +105,8 @@ static struct acpi_driver acpi_processor_driver = {
#define INSTALL_NOTIFY_HANDLER 1
#define UNINSTALL_NOTIFY_HANDLER 2

+static DEFINE_PER_CPU(void *, processor_device_array);
+
DEFINE_PER_CPU(struct acpi_processor *, processors);
EXPORT_PER_CPU_SYMBOL(processors);

@@ -327,11 +329,11 @@ static int acpi_processor_get_info(struct acpi_device *device)
* \_SB.SCK1.CPU0
* Rename the processor device bus id. And the new bus id will be
* generated as the following format:
- * CPU+CPU ID.
+ * CPU+ACPI 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));
+ sprintf(acpi_device_bid(device), "CPU%X", pr->acpi_id);
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->acpi_id,
+ pr->id));

if (!object.processor.pblk_address)
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
@@ -355,19 +357,67 @@ static int acpi_processor_get_info(struct acpi_device *device)
request_region(pr->throttling.address, 6, "ACPI CPU throttle");
}

+ return 0;
+}
+
+static int acpi_processor_link(struct acpi_device *device,
+ struct acpi_processor *pr)
+{
+ struct device *dev;
+ acpi_status status;
+ unsigned long long value;
+
+ if (pr->flags.device_linked)
+ return 0;
+
/*
* If ACPI describes a slot number for this CPU, we can use it
* ensure we get the right value in the "physical id" field
* of /proc/cpuinfo
*/
- status = acpi_evaluate_object(pr->handle, "_SUN", NULL, &buffer);
+ status = acpi_evaluate_integer(pr->handle, "_SUN", NULL, &value);
if (ACPI_SUCCESS(status))
- arch_fix_phys_package_id(pr->id, object.integer.value);
+ arch_fix_phys_package_id(pr->id, value);
+
+ /*
+ * 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 for the processor\n");
+ return -ENODEV;
+ }
+ per_cpu(processor_device_array, pr->id) = device;
+ per_cpu(processors, pr->id) = pr;
+
+ dev = get_cpu_device(pr->id);
+ if (sysfs_create_link(&device->dev.kobj, &dev->kobj, "sysdev")) {
+ /*
+ * processor_device_array is not cleared to allow checks
+ * for buggy BIOS
+ */
+ per_cpu(processors, pr->id) = NULL;
+ return -EFAULT;
+ }
+
+ pr->flags.device_linked = 1;

return 0;
}

-static DEFINE_PER_CPU(void *, processor_device_array);
+static void acpi_processor_unlink(struct acpi_device *device,
+ struct acpi_processor *pr)
+{
+ if (pr->flags.device_linked) {
+ sysfs_remove_link(&device->dev.kobj, "sysdev");
+ per_cpu(processor_device_array, pr->id) = NULL;
+ per_cpu(processors, pr->id) = NULL;
+ pr->flags.device_linked = 0;
+ }
+}

static void acpi_processor_notify(struct acpi_device *device, u32 event)
{
@@ -422,11 +472,11 @@ static int acpi_cpu_soft_notify(struct notifier_block *nfb,
if (pr->flags.need_hotplug_init) {
printk(KERN_INFO "Will online and init hotplugged "
"CPU: %d\n", pr->id);
- WARN(acpi_processor_start(pr), "Failed to start CPU:"
- " %d\n", pr->id);
+ WARN(acpi_processor_start(pr),
+ "Failed to start CPU: %d\n", pr->id);
pr->flags.need_hotplug_init = 0;
/* Normal CPU soft online event */
- } else {
+ } else if (pr->flags.device_started) {
acpi_processor_ppc_has_changed(pr, 0);
acpi_processor_hotplug(pr);
acpi_processor_reevaluate_tstate(pr, action);
@@ -458,6 +508,9 @@ static __ref int acpi_processor_start(struct acpi_processor *pr)
struct acpi_device *device = per_cpu(processor_device_array, pr->id);
int result = 0;

+ if (pr->flags.device_started)
+ return 0;
+
#ifdef CONFIG_CPU_FREQ
acpi_processor_ppc_has_changed(pr, 0);
acpi_processor_load_module(pr);
@@ -493,6 +546,8 @@ static __ref int acpi_processor_start(struct acpi_processor *pr)
goto err_remove_sysfs_thermal;
}

+ pr->flags.device_started = 1;
+
return 0;

err_remove_sysfs_thermal:
@@ -505,6 +560,21 @@ err_power_exit:
return result;
}

+static void acpi_processor_stop(struct acpi_device *device,
+ struct acpi_processor *pr)
+{
+ if (pr->flags.device_started) {
+ acpi_processor_power_exit(pr, device);
+ if (pr->cdev) {
+ sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
+ sysfs_remove_link(&pr->cdev->device.kobj, "device");
+ thermal_cooling_device_unregister(pr->cdev);
+ pr->cdev = NULL;
+ }
+ pr->flags.device_started = 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
@@ -513,9 +583,8 @@ err_power_exit:
*/
static int __cpuinit acpi_processor_add(struct acpi_device *device)
{
- struct acpi_processor *pr = NULL;
- int result = 0;
- struct device *dev;
+ struct acpi_processor *pr;
+ int result;

pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
if (!pr)
@@ -532,60 +601,36 @@ static int __cpuinit acpi_processor_add(struct acpi_device *device)
device->driver_data = pr;

result = acpi_processor_get_info(device);
- if (result) {
- /* Processor is physically not present */
- return 0;
- }
-
-#ifdef CONFIG_SMP
- if (pr->id >= setup_max_cpus && pr->id != 0)
- return 0;
-#endif
-
- BUG_ON((pr->id >= nr_cpu_ids) || (pr->id < 0));
-
- /*
- * 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) {
- printk(KERN_WARNING "BIOS reported wrong ACPI id "
- "for the processor\n");
- result = -ENODEV;
+ if (result)
goto err_free_cpumask;
- }
- per_cpu(processor_device_array, pr->id) = device;
-
- per_cpu(processors, pr->id) = pr;
-
- dev = get_cpu_device(pr->id);
- if (sysfs_create_link(&device->dev.kobj, &dev->kobj, "sysdev")) {
- result = -EFAULT;
- goto err_clear_processor;
- }

/*
- * Do not start hotplugged CPUs now, but when they
- * are onlined the first time
+ * Delay linking with logical CPU device if:
+ * 1) no CPUID assigned yet
+ * 2) processor won't be boot if CPUID is bigger than setup_max_cpus
+ * They will be handled by CPU hotplug logical later.
*/
- if (pr->flags.need_hotplug_init)
+ if (pr->id == -1)
return 0;
+ if (IS_BUILTIN(CONFIG_SMP) && pr->id >= setup_max_cpus && pr->id != 0)
+ return 0;
+ BUG_ON((pr->id >= nr_cpu_ids) || (pr->id < 0));

- result = acpi_processor_start(pr);
+ result = acpi_processor_link(device, pr);
if (result)
- goto err_remove_sysfs;
+ goto err_unlock;
+ if (cpu_online(pr->id)) {
+ result = acpi_processor_start(pr);
+ if (result)
+ goto err_unlink;
+ }

return 0;

-err_remove_sysfs:
- sysfs_remove_link(&device->dev.kobj, "sysdev");
-err_clear_processor:
- /*
- * processor_device_array is not cleared to allow checks for buggy BIOS
- */
- per_cpu(processors, pr->id) = NULL;
+err_unlink:
+ acpi_processor_unlink(device, pr);
+err_unlock:
+ put_online_cpus();
err_free_cpumask:
free_cpumask_var(pr->throttling.shared_cpu_map);
err_free_pr:
@@ -595,14 +640,12 @@ err_free_pr:

static int acpi_processor_remove(struct acpi_device *device, int type)
{
- struct acpi_processor *pr = NULL;
-
+ struct acpi_processor *pr;

if (!device || !acpi_driver_data(device))
return -EINVAL;

pr = acpi_driver_data(device);
-
if (pr->id >= nr_cpu_ids)
goto free;

@@ -611,21 +654,11 @@ static int acpi_processor_remove(struct acpi_device *device, int type)
return -EINVAL;
}

- acpi_processor_power_exit(pr, device);
-
- sysfs_remove_link(&device->dev.kobj, "sysdev");
-
- if (pr->cdev) {
- sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
- sysfs_remove_link(&pr->cdev->device.kobj, "device");
- thermal_cooling_device_unregister(pr->cdev);
- pr->cdev = NULL;
- }
-
- per_cpu(processors, pr->id) = NULL;
- per_cpu(processor_device_array, pr->id) = NULL;
+ acpi_processor_stop(device, pr);
+ acpi_processor_unlink(device, pr);

free:
+ device->driver_data = NULL;
free_cpumask_var(pr->throttling.shared_cpu_map);
kfree(pr);

diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index 64ec644..ae7d94e 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -193,6 +193,8 @@ struct acpi_processor_flags {
u8 power_setup_done:1;
u8 bm_rld_set:1;
u8 need_hotplug_init:1;
+ u8 device_linked:1;
+ u8 device_started:1;
};

struct acpi_processor {
--
1.7.9.5

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