[RFC PATCH 08/11] ACPI: Update memory driver for hotplug framework

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


Changed acpi_memory_device_notify() to request a hotplug operation
by calling hp_submit_req(). It no longer initiates hot-add or
hot-delete operation by calling add_memory() or remove_memory()
directly.

Changed acpi_memory_device_add() to not call add_memory() to online
a memory device. Similarly, changed acpi_memory_device_remove()
to not call remove_memory() to offline a memory device.

Added acpi_memory_resource() to set memory information to a hotplug
request.

Signed-off-by: Toshi Kani <toshi.kani@xxxxxx>
---
drivers/acpi/acpi_memhotplug.c | 290 +++++++++++++----------------------------
1 file changed, 90 insertions(+), 200 deletions(-)

diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index eb30e5a..3409264 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -32,6 +32,7 @@
#include <linux/memory_hotplug.h>
#include <linux/slab.h>
#include <linux/acpi.h>
+#include <linux/hotplug.h>
#include <acpi/acpi_drivers.h>

#define ACPI_MEMORY_DEVICE_CLASS "memory"
@@ -55,6 +56,8 @@ MODULE_LICENSE("GPL");

static int acpi_memory_device_add(struct acpi_device *device);
static int acpi_memory_device_remove(struct acpi_device *device, int type);
+static int acpi_memory_device_resource(struct acpi_device *device,
+ struct hp_request *hp_req);

static const struct acpi_device_id memory_device_ids[] = {
{ACPI_MEMORY_DEVICE_HID, 0},
@@ -69,6 +72,7 @@ static struct acpi_driver acpi_memory_device_driver = {
.ops = {
.add = acpi_memory_device_add,
.remove = acpi_memory_device_remove,
+ .resource = acpi_memory_device_resource,
},
};

@@ -153,59 +157,12 @@ acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
return 0;
}

-static int
-acpi_memory_get_device(acpi_handle handle,
- struct acpi_memory_device **mem_device)
-{
- acpi_status status;
- acpi_handle phandle;
- struct acpi_device *device = NULL;
- struct acpi_device *pdevice = NULL;
- int result;
-
-
- if (!acpi_bus_get_device(handle, &device) && device)
- goto end;
-
- status = acpi_get_parent(handle, &phandle);
- if (ACPI_FAILURE(status)) {
- ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
- return -EINVAL;
- }
-
- /* Get the parent device */
- result = acpi_bus_get_device(phandle, &pdevice);
- if (result) {
- acpi_handle_warn(phandle, "Cannot get acpi bus device\n");
- return -EINVAL;
- }
-
- /*
- * Now add the notified device. This creates the acpi_device
- * and invokes .add function
- */
- result = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
- if (result) {
- acpi_handle_warn(handle, "Cannot add acpi bus\n");
- return -EINVAL;
- }
-
- end:
- *mem_device = acpi_driver_data(device);
- if (!(*mem_device)) {
- dev_err(&device->dev, "driver data not found\n");
- return -ENODEV;
- }
-
- return 0;
-}
-
-static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
+static int acpi_memory_check_device(acpi_handle handle)
{
unsigned long long current_status;

/* Get device present/absent information from the _STA */
- if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
+ if (ACPI_FAILURE(acpi_evaluate_integer(handle, "_STA",
NULL, &current_status)))
return -ENODEV;
/*
@@ -220,166 +177,46 @@ static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
return 0;
}

-static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
-{
- int result, num_enabled = 0;
- struct acpi_memory_info *info;
- int node;
-
-
- /* Get the range from the _CRS */
- result = acpi_memory_get_device_resources(mem_device);
- if (result) {
- dev_err(&mem_device->device->dev,
- "get_device_resources failed\n");
- mem_device->state = MEMORY_INVALID_STATE;
- return result;
- }
-
- node = acpi_get_node(mem_device->device->handle);
- /*
- * Tell the VM there is more memory here...
- * Note: Assume that this function returns zero on success
- * We don't have memory-hot-add rollback function,now.
- * (i.e. memory-hot-remove function)
- */
- list_for_each_entry(info, &mem_device->res_list, list) {
- if (info->enabled) { /* just sanity check...*/
- num_enabled++;
- continue;
- }
- /*
- * If the memory block size is zero, please ignore it.
- * Don't try to do the following memory hotplug flowchart.
- */
- if (!info->length)
- continue;
- if (node < 0)
- node = memory_add_physaddr_to_nid(info->start_addr);
-
- result = add_memory(node, info->start_addr, info->length);
-
- /*
- * If the memory block has been used by the kernel, add_memory()
- * returns -EEXIST. If add_memory() returns the other error, it
- * means that this memory block is not used by the kernel.
- */
- if (result && result != -EEXIST) {
- info->failed = 1;
- continue;
- }
-
- if (!result)
- info->enabled = 1;
- /*
- * Add num_enable even if add_memory() returns -EEXIST, so the
- * device is bound to this driver.
- */
- num_enabled++;
- }
- if (!num_enabled) {
- dev_err(&mem_device->device->dev, "add_memory failed\n");
- mem_device->state = MEMORY_INVALID_STATE;
- return -EINVAL;
- }
- /*
- * Sometimes the memory device will contain several memory blocks.
- * When one memory block is hot-added to the system memory, it will
- * be regarded as a success.
- * Otherwise if the last memory block can't be hot-added to the system
- * memory, it will be failure and the memory device can't be bound with
- * driver.
- */
- return 0;
-}
-
-static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
-{
- int result = 0;
- struct acpi_memory_info *info, *n;
-
- list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
- if (info->failed)
- /* The kernel does not use this memory block */
- continue;
-
- if (!info->enabled)
- /*
- * The kernel uses this memory block, but it may be not
- * managed by us.
- */
- return -EBUSY;
-
- result = remove_memory(info->start_addr, info->length);
- if (result)
- return result;
-
- list_del(&info->list);
- kfree(info);
- }
-
- return result;
-}
-
static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
{
struct acpi_memory_device *mem_device;
struct acpi_device *device;
- 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 */

switch (event) {
case ACPI_NOTIFY_BUS_CHECK:
- ACPI_DEBUG_PRINT((ACPI_DB_INFO,
- "\nReceived BUS CHECK notification for device\n"));
/* Fall Through */
case ACPI_NOTIFY_DEVICE_CHECK:
- if (event == ACPI_NOTIFY_DEVICE_CHECK)
- ACPI_DEBUG_PRINT((ACPI_DB_INFO,
- "\nReceived DEVICE CHECK notification for device\n"));
- if (acpi_memory_get_device(handle, &mem_device)) {
- acpi_handle_err(handle, "Cannot find driver data\n");
- break;
+ if (acpi_memory_check_device(handle)) {
+ acpi_handle_err(handle, "Device not enabled\n");
+ goto err;
}

- if (acpi_memory_check_device(mem_device))
- break;
-
- if (acpi_memory_enable_device(mem_device)) {
- acpi_handle_err(handle,"Cannot enable memory 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,
- "\nReceived EJECT REQUEST notification for device\n"));
-
if (acpi_bus_get_device(handle, &device)) {
- acpi_handle_err(handle, "Device doesn't exist\n");
- break;
+ acpi_handle_err(handle, "Device not added yet\n");
+ goto err;
}
+
mem_device = acpi_driver_data(device);
if (!mem_device) {
- acpi_handle_err(handle, "Driver Data is NULL\n");
- break;
- }
-
- ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
- if (!ej_event) {
- pr_err(PREFIX "No memory, dropping EJECT\n");
- break;
+ acpi_handle_err(handle, "Driver data missing\n");
+ goto err;
}

- ej_event->handle = handle;
- ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
- acpi_os_hotplug_execute(acpi_bus_hot_remove_device,
- (void *)ej_event);
+ hp_op = HP_HOTPLUG_DEL;
+ break;

- /* eject is performed asynchronously */
- return;
default:
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Unsupported event [0x%x]\n", event));
@@ -388,7 +225,25 @@ static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
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;
}
@@ -432,38 +287,73 @@ static int acpi_memory_device_add(struct acpi_device *device)
mem_device->state = MEMORY_POWER_ON_STATE;

pr_debug("%s\n", acpi_device_name(device));
-
- if (!acpi_memory_check_device(mem_device)) {
- /* call add_memory func */
- result = acpi_memory_enable_device(mem_device);
- if (result) {
- dev_err(&device->dev,
- "Error in acpi_memory_enable_device\n");
- acpi_memory_device_free(mem_device);
- }
- }
return result;
}

static int acpi_memory_device_remove(struct acpi_device *device, int type)
{
struct acpi_memory_device *mem_device = NULL;
- int result;
+ struct acpi_memory_info *info, *n;

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

mem_device = acpi_driver_data(device);

- result = acpi_memory_remove_memory(mem_device);
- if (result)
- return result;
+ /* remove the memory_info list of this mem_device */
+ list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
+ list_del(&info->list);
+ kfree(info);
+ }

acpi_memory_device_free(mem_device);

return 0;
}

+static int acpi_memory_device_resource(struct acpi_device *device,
+ struct hp_request *hp_req)
+{
+ struct acpi_memory_device *mem_device = NULL;
+ struct acpi_memory_info *info, *n;
+ struct hp_device *hp_dev;
+ int node;
+
+ mem_device = acpi_driver_data(device);
+ if (!mem_device) {
+ dev_err(&device->dev, "Invalid device\n");
+ return -EINVAL;
+ }
+
+ node = acpi_get_node(mem_device->device->handle);
+
+ /*
+ * REVISIT: Check if the original info->enabled & info->failed handling
+ * is still necessary here.
+ */
+ list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
+
+ if (!info->length)
+ continue;
+
+ 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_MEMORY;
+ hp_dev->data.mem.node = node;
+ hp_dev->data.mem.start_addr = info->start_addr;
+ hp_dev->data.mem.length = info->length;
+
+ hp_add_dev_info(hp_req, hp_dev);
+ }
+
+ return 0;
+}
+
/*
* Helper function to check for memory device
*/
--
1.7.11.7

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