[RFC PATCH v2 11/16] ACPIHP: analyse dependences among ACPI system device hotplug slots

[Jiang Liu <jiang.liu@huawei.com>]

From: Jiang Liu <jiang.liu@huawei.com>

Some ACPI hotplug slots may have dependencies on other ACPI hotplug slots.
For example, if a hotpluggable memory board is connected to a hotpluggble
physical processor, the physical processor must be powered on before
powering the memory board on.

We could get dependency relationships by analyze ACPI namespace topology
and evaluate ACPI _EDL method. So this patch implements several functions
to analyze dependencies among ACPI hotplug slots.

Signed-off-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Hanjun Guo <guohanjun@huawei.com>
---
 drivers/acpi/hotplug/Makefile     |    1 +
 drivers/acpi/hotplug/acpihp_drv.h |   14 ++++
 drivers/acpi/hotplug/dependency.c |  167 +++++++++++++++++++++++++++++++++++++
 3 files changed, 182 insertions(+)
 create mode 100644 drivers/acpi/hotplug/dependency.c

diff --git a/drivers/acpi/hotplug/Makefile b/drivers/acpi/hotplug/Makefile
index d69832f..8477c71 100644
--- a/drivers/acpi/hotplug/Makefile
+++ b/drivers/acpi/hotplug/Makefile
@@ -11,3 +11,4 @@ acpihp_enum-y					+= slot_enum_ej0.o
 
 obj-$(CONFIG_ACPI_HOTPLUG_DRIVER)		+= acpihp_drv.o
 acpihp_drv-y					= drv_main.o
+acpihp_drv-y					+= dependency.o
diff --git a/drivers/acpi/hotplug/acpihp_drv.h b/drivers/acpi/hotplug/acpihp_drv.h
index 18330f7..c4ff91c 100644
--- a/drivers/acpi/hotplug/acpihp_drv.h
+++ b/drivers/acpi/hotplug/acpihp_drv.h
@@ -53,10 +53,24 @@ struct acpihp_slot_drv {
 	struct acpihp_cancel_context	cancel_ctx;
 };
 
+struct acpihp_slot_dependency {
+	struct list_head		node;
+	struct acpihp_slot		*slot;
+	u32				opcodes;
+};
+
 void acpihp_drv_get_data(struct acpihp_slot *slot,
 			 struct acpihp_slot_drv **data);
 int acpihp_drv_enumerate_devices(struct acpihp_slot *slot);
 void acpihp_drv_update_slot_state(struct acpihp_slot *slot);
 int acpihp_drv_update_slot_status(struct acpihp_slot *slot);
 
+int acpihp_drv_add_slot_to_dependency_list(struct acpihp_slot *slot,
+					   struct list_head *slot_list);
+void acpihp_drv_destroy_dependency_list(struct list_head *slot_list);
+int acpihp_drv_filter_dependency_list(struct list_head *old_head,
+		struct list_head *new_head, u32 opcode);
+int acpihp_drv_generate_dependency_list(struct acpihp_slot *slot,
+		struct list_head *slot_list, enum acpihp_drv_cmd cmd);
+
 #endif	/* __ACPIHP_DRV_H__ */
diff --git a/drivers/acpi/hotplug/dependency.c b/drivers/acpi/hotplug/dependency.c
new file mode 100644
index 0000000..d2d7dbb
--- /dev/null
+++ b/drivers/acpi/hotplug/dependency.c
@@ -0,0 +1,167 @@
+/*
+ * Copyright (C) 2011 Huawei Tech. Co., Ltd.
+ * Copyright (C) 2011 Jiang Liu <jiang.liu@huawei.com>
+ * Copyright (C) 2011 Hanjun Guo <guohanjun@huawei.com>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/acpi.h>
+#include <acpi/acpi_hotplug.h>
+#include "acpihp_drv.h"
+
+/* Insert a slot into the dependency list at the head */
+int acpihp_drv_add_slot_to_dependency_list(struct acpihp_slot *slot,
+					   struct list_head *slot_list)
+{
+	struct acpihp_slot_dependency *dep;
+
+	list_for_each_entry(dep, slot_list, node)
+		if (dep->slot == slot)
+			return 0;
+
+	dep = kzalloc(sizeof(*dep), GFP_KERNEL);
+	if (!dep) {
+		ACPIHP_DEBUG("fails to allocate memory for %s.\n", slot->name);
+		return -ENOMEM;
+	}
+	dep->slot = slot;
+	list_add(&dep->node, slot_list);
+
+	return 0;
+}
+
+static int acpihp_drv_get_online_dependency(struct acpihp_slot *slot,
+					    struct list_head *slot_list)
+{
+	int ret = 0;
+	struct acpihp_slot *temp;
+
+	for (temp = slot; temp && ret == 0; temp = temp->parent)
+		ret = acpihp_drv_add_slot_to_dependency_list(temp, slot_list);
+
+	return ret;
+}
+
+static int acpihp_drv_for_each_edl(struct acpihp_slot *slot, void *argp,
+	int(*cb)(struct device *dev, void *argp))
+{
+	/* TODO */
+	return 0;
+}
+
+static int acpihp_drv_add_offline_dependency(struct device *dev, void *argp)
+{
+	int ret;
+	struct acpihp_slot *slot;
+	struct list_head *list = argp;
+
+	slot = container_of(dev, struct acpihp_slot, dev);
+	ret = acpihp_drv_add_slot_to_dependency_list(slot, list);
+	if (!ret)
+		ret = device_for_each_child(&slot->dev, argp,
+				&acpihp_drv_add_offline_dependency);
+	if (!ret)
+		ret = acpihp_drv_for_each_edl(slot, argp,
+				&acpihp_drv_add_offline_dependency);
+
+	return ret;
+}
+
+static int acpihp_drv_get_offline_dependency(struct acpihp_slot *slot,
+					     struct list_head *slot_list)
+{
+	return acpihp_drv_add_offline_dependency(&slot->dev, slot_list);
+}
+
+int acpihp_drv_generate_dependency_list(struct acpihp_slot *slot,
+		struct list_head *slot_list, enum acpihp_drv_cmd cmd)
+{
+	int retval;
+
+	switch (cmd) {
+	case ACPIHP_DRV_CMD_POWERON:
+	/* fall through */
+	case ACPIHP_DRV_CMD_CONNECT:
+	/* fall through */
+	case ACPIHP_DRV_CMD_CONFIGURE:
+		retval = acpihp_drv_get_online_dependency(slot, slot_list);
+		break;
+
+	case ACPIHP_DRV_CMD_POWEROFF:
+	/* fall through */
+	case ACPIHP_DRV_CMD_DISCONNECT:
+	/* fall through */
+	case ACPIHP_DRV_CMD_UNCONFIGURE:
+		retval = acpihp_drv_get_offline_dependency(slot, slot_list);
+		break;
+
+	default:
+		retval = -EINVAL;
+		break;
+	}
+
+	return retval;
+}
+
+/*
+ * Generate a new list with slots from the old list which need to
+ * execute a specific operation.
+ */
+int acpihp_drv_filter_dependency_list(struct list_head *old_head,
+		struct list_head *new_head, u32 opcode)
+{
+	struct acpihp_slot_dependency *old_dep, *new_dep;
+
+	/* Initialize new list to empty */
+	INIT_LIST_HEAD(new_head);
+
+	list_for_each_entry(old_dep, old_head, node) {
+		/* Skip if the specified operation is not needed. */
+		if (!(old_dep->opcodes & opcode))
+			continue;
+
+		new_dep = kzalloc(sizeof(*new_dep), GFP_KERNEL);
+		if (!new_dep) {
+			ACPIHP_DEBUG("fails to filter depend list.\n");
+			acpihp_drv_destroy_dependency_list(new_head);
+			return -ENOMEM;
+		}
+
+		new_dep->slot = old_dep->slot;
+		new_dep->opcodes = old_dep->opcodes;
+		list_add_tail(&new_dep->node, new_head);
+	}
+
+	return 0;
+}
+
+void acpihp_drv_destroy_dependency_list(struct list_head *slot_list)
+{
+	struct acpihp_slot_dependency *asd, *temp;
+
+	list_for_each_entry_safe(asd, temp, slot_list, node) {
+		list_del(&asd->node);
+		kfree(asd);
+	}
+}
-- 
1.7.9.5