[RFC PATCH 07/11] ACPI: Update processor driver for hotplug framework

From: Toshi Kani
Date: Wed Dec 12 2012 - 18:27:16 EST


Added acpi_processor_resource() for the .resource interface,
which sets CPU information to a hotplug request.

Changed acpi_processor_hotplug_notify() to request a hotplug
operation by calling hp_submit_req(). It no longer initiates
hot-add or hot-delete operation by calling acpi_bus_add() or
acpi_bus_hot_remove_device() directly.

acpi_processor_handle_eject() is changed not to call cpu_down()
since .add / .remove may not online / offline a device.

Signed-off-by: Toshi Kani <toshi.kani@xxxxxx>
---
drivers/acpi/processor_driver.c | 150 +++++++++++++++++++---------------------
1 file changed, 70 insertions(+), 80 deletions(-)

diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index e83311b..4b2b7cf 100644
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -45,6 +45,7 @@
#include <linux/cpuidle.h>
#include <linux/slab.h>
#include <linux/acpi.h>
+#include <linux/hotplug.h>

#include <asm/io.h>
#include <asm/cpu.h>
@@ -83,6 +84,8 @@ MODULE_LICENSE("GPL");
static int acpi_processor_add(struct acpi_device *device);
static int acpi_processor_remove(struct acpi_device *device, int type);
static void acpi_processor_notify(struct acpi_device *device, u32 event);
+static int acpi_processor_resource(struct acpi_device *device,
+ struct hp_request *hp_req);
static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr);
static int acpi_processor_handle_eject(struct acpi_processor *pr);
static int acpi_processor_start(struct acpi_processor *pr);
@@ -105,6 +108,7 @@ static struct acpi_driver acpi_processor_driver = {
.add = acpi_processor_add,
.remove = acpi_processor_remove,
.notify = acpi_processor_notify,
+ .resource = acpi_processor_resource,
},
.drv.pm = &acpi_processor_pm,
};
@@ -649,6 +653,33 @@ free:
return 0;
}

+static int
+acpi_processor_resource(struct acpi_device *device, struct hp_request *hp_req)
+{
+ struct acpi_processor *pr;
+ struct hp_device *hp_dev;
+
+ pr = acpi_driver_data(device);
+ if (!pr) {
+ dev_err(&device->dev, "Driver data missing\n");
+ return -EINVAL;
+ }
+
+ hp_dev = kzalloc(sizeof(*hp_dev), GFP_KERNEL);
+ if (!hp_dev) {
+ dev_err(&device->dev, "Failed to allocate hp_dev\n");
+ return -EINVAL;
+ }
+
+ hp_dev->device = &device->dev;
+ hp_dev->class = HP_CLS_CPU;
+ hp_dev->data.cpu.cpu_id = pr->id;
+
+ hp_add_dev_info(hp_req, hp_dev);
+
+ return 0;
+}
+
#ifdef CONFIG_ACPI_HOTPLUG_CPU
/****************************************************************************
* Acpi processor hotplug support *
@@ -677,97 +708,68 @@ static int is_processor_present(acpi_handle handle)
return 0;
}

-static
-int acpi_processor_device_add(acpi_handle handle, struct acpi_device **device)
-{
- acpi_handle phandle;
- struct acpi_device *pdev;
-
-
- if (acpi_get_parent(handle, &phandle)) {
- return -ENODEV;
- }
-
- if (acpi_bus_get_device(phandle, &pdev)) {
- return -ENODEV;
- }
-
- if (acpi_bus_add(device, pdev, handle, ACPI_BUS_TYPE_PROCESSOR)) {
- return -ENODEV;
- }
-
- return 0;
-}
-
static void acpi_processor_hotplug_notify(acpi_handle handle,
u32 event, void *data)
{
struct acpi_device *device = NULL;
- struct acpi_eject_event *ej_event = NULL;
+ struct hp_request *hp_req;
+ enum hp_operation hp_op;
u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
- int result;

switch (event) {
case ACPI_NOTIFY_BUS_CHECK:
case ACPI_NOTIFY_DEVICE_CHECK:
- ACPI_DEBUG_PRINT((ACPI_DB_INFO,
- "Processor driver received %s event\n",
- (event == ACPI_NOTIFY_BUS_CHECK) ?
- "ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK"));
-
- if (!is_processor_present(handle))
- break;
-
- if (!acpi_bus_get_device(handle, &device))
- break;
+ if (!is_processor_present(handle)) {
+ acpi_handle_err(handle, "Device not enabled\n");
+ goto err;
+ }

- result = acpi_processor_device_add(handle, &device);
- if (result) {
- acpi_handle_err(handle, "Unable to add the device\n");
- break;
+ if (!acpi_bus_get_device(handle, &device)) {
+ acpi_handle_err(handle, "Device added already\n");
+ goto err;
}

- ost_code = ACPI_OST_SC_SUCCESS;
+ hp_op = HP_HOTPLUG_ADD;
break;

case ACPI_NOTIFY_EJECT_REQUEST:
- ACPI_DEBUG_PRINT((ACPI_DB_INFO,
- "received ACPI_NOTIFY_EJECT_REQUEST\n"));
-
if (acpi_bus_get_device(handle, &device)) {
- acpi_handle_err(handle,
- "Device don't exist, dropping EJECT\n");
- break;
+ acpi_handle_err(handle, "Device not added yet\n");
+ goto err;
}
if (!acpi_driver_data(device)) {
- acpi_handle_err(handle,
- "Driver data is NULL, dropping EJECT\n");
- break;
+ acpi_handle_err(handle, "Driver data missing\n");
+ goto err;
}

- ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
- if (!ej_event) {
- acpi_handle_err(handle, "No memory, dropping EJECT\n");
- break;
- }
-
- ej_event->handle = handle;
- ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
- acpi_os_hotplug_execute(acpi_bus_hot_remove_device,
- (void *)ej_event);
-
- /* eject is performed asynchronously */
- return;
+ hp_op = HP_HOTPLUG_DEL;
+ break;

default:
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Unsupported event [0x%x]\n", event));
-
- /* non-hotplug event; possibly handled by other handler */
return;
}

- /* Inform firmware that the hotplug operation has completed */
+ hp_req = hp_alloc_request(hp_op);
+ if (!hp_req) {
+ acpi_handle_err(handle, "No memory to request hotplug\n");
+ goto err;
+ }
+
+ hp_req->handle = (void *)handle;
+ hp_req->event = event;
+
+ if (hp_submit_req(hp_req)) {
+ acpi_handle_err(handle, "Failed to request hotplug\n");
+ kfree(hp_req);
+ goto err;
+ }
+
+ return;
+
+err:
+ /* Inform firmware that the hotplug operation completed w/ error */
(void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
return;
}
@@ -865,25 +867,13 @@ static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr)

static int acpi_processor_handle_eject(struct acpi_processor *pr)
{
- if (cpu_online(pr->id))
- cpu_down(pr->id);
-
- get_online_cpus();
- /*
- * The cpu might become online again at this point. So we check whether
- * the cpu has been onlined or not. If the cpu became online, it means
- * that someone wants to use the cpu. So acpi_processor_handle_eject()
- * returns -EAGAIN.
- */
- if (unlikely(cpu_online(pr->id))) {
- put_online_cpus();
- pr_warn("Failed to remove CPU %d, because other task "
- "brought the CPU back online\n", pr->id);
- return -EAGAIN;
+ if (cpu_online(pr->id)) {
+ pr_err("ACPI: cpu %d not off-lined\n", pr->id);
+ return -EINVAL;
}
+
arch_unregister_cpu(pr->id);
acpi_unmap_lsapic(pr->id);
- put_online_cpus();
return (0);
}
#else
--
1.7.11.7

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