When doing physical processor hotplug, all affected CPUs should be
handled in atomic, shouldn't be disturbed by online/offline requests
from CPU device's online sysfs interface. For example, it's fatal
if a CPU is onlined through CPU device's online sysfs interface
between the hotplug driver offlines all affected CPUs and powers the
physical processor off.
So temporarily reject online/offline requests from CPU device's online
sysfs interface by setting the busy flag when doing physical processor
hotplug.
Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
---
drivers/acpi/processor_driver.c | 23 +++++++++++++++++++++--
1 file changed, 21 insertions(+), 2 deletions(-)
diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index 447bd6d..51e3993 100644
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -702,7 +702,7 @@ static int acpi_processor_pre_configure(struct acpi_device *device,
if (result)
goto out_unlock;
BUG_ON((pr->id >= nr_cpu_ids) || (pr->id < 0));
- result = arch_register_cpu(pr->id, 0);
+ result = arch_register_cpu(pr->id, 1);
if (result)
goto out_unmap;
@@ -755,10 +755,26 @@ static void acpi_processor_post_configure(struct acpi_device *device,
if (!cpu_online(pr->id) && cpu_up(pr->id))
dev_warn(&device->dev,
"fails to online CPU%d.\n", pr->id);
+ cpu_set_busy(pr->id, 0);
} else if (cmd == ACPIHP_DEV_POST_CMD_ROLLBACK)
acpi_processor_reset(device, pr);
}
+static int acpi_processor_pre_release(struct acpi_device *device,
+ struct acpihp_cancel_context *ctx)
+{
+ int result;
+ struct acpi_processor *pr;
+
+ if (!device || !acpi_driver_data(device))
+ return -EINVAL;
+ pr = acpi_driver_data(device);
+
+ result = cpu_set_busy(pr->id, 1);
+
+ return result ? -EBUSY : 0;
+}
+
static int acpi_processor_release(struct acpi_device *device,
struct acpihp_cancel_context *ctx)
{
@@ -783,9 +799,11 @@ static void acpi_processor_post_release(struct acpi_device *device,
BUG_ON(!device || !acpi_driver_data(device));
pr = acpi_driver_data(device);
- if (cmd == ACPIHP_DEV_POST_CMD_ROLLBACK)
+ if (cmd == ACPIHP_DEV_POST_CMD_ROLLBACK) {
if (!cpu_online(pr->id))
cpu_up(pr->id);
+ cpu_set_busy(pr->id, 0);
+ }
}
static void acpi_processor_unconfigure(struct acpi_device *device)
@@ -803,6 +821,7 @@ static struct acpihp_dev_ops acpi_processor_hp_ops = {
.pre_configure = &acpi_processor_pre_configure,
.configure = &acpi_processor_configure,
.post_configure = &acpi_processor_post_configure,
+ .pre_release = &acpi_processor_pre_release,
.release = &acpi_processor_release,
.post_release = &acpi_processor_post_release,
.unconfigure = &acpi_processor_unconfigure,
--
1.7.9.5
--
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