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Subject[PATCH v2 23/37] PCI, ACPI: Add pci_root_hp hot add hotplug notification
Date
It is from acpiphp_glue.c

How to use it?
Find out root bus number to acpi root name mapping from dmesg or /sys

echo "\_SB.PCIB 0" > /proc/acpi/sci/notify
to add it back
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Len Brown <lenb@kernel.org>
Cc: linux-acpi@vger.kernel.org
---
drivers/acpi/Makefile | 1 +
drivers/acpi/pci_root_hp.c | 237 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 238 insertions(+), 0 deletions(-)
create mode 100644 drivers/acpi/pci_root_hp.c
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 1567028..bc6e53f 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -36,6 +36,7 @@ acpi-y += processor_core.o
acpi-y += ec.o
acpi-$(CONFIG_ACPI_DOCK) += dock.o
acpi-y += pci_root.o pci_link.o pci_irq.o pci_bind.o
+acpi-$(CONFIG_HOTPLUG) += pci_root_hp.o
acpi-y += power.o
acpi-y += event.o
acpi-y += sysfs.o
diff --git a/drivers/acpi/pci_root_hp.c b/drivers/acpi/pci_root_hp.c
new file mode 100644
index 0000000..dc11e81
--- /dev/null
+++ b/drivers/acpi/pci_root_hp.c
@@ -0,0 +1,237 @@
+/*
+ * Separated from drivers/pci/hotplug/acpiphp_glue.c
+ * only support root bridge
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/acpi.h>
+
+static LIST_HEAD(acpi_root_bridge_list);
+struct acpi_root_bridge {
+ struct list_head list;
+ acpi_handle handle;
+ u32 flags;
+};
+
+/* bridge flags */
+#define ROOT_BRIDGE_HAS_EJ0 (0x00000002)
+#define ROOT_BRIDGE_HAS_PS3 (0x00000080)
+
+#define ACPI_STA_FUNCTIONING (0x00000008)
+
+static struct acpi_root_bridge *acpi_root_handle_to_bridge(acpi_handle handle)
+{
+ struct acpi_root_bridge *bridge;
+
+ list_for_each_entry(bridge, &acpi_root_bridge_list, list)
+ if (bridge->handle == handle)
+ return bridge;
+
+ return NULL;
+}
+
+/* allocate and initialize host bridge data structure */
+static void add_acpi_root_bridge(acpi_handle handle)
+{
+ struct acpi_root_bridge *bridge;
+ acpi_handle dummy_handle;
+ acpi_status status;
+
+ /* if the bridge doesn't have _STA, we assume it is always there */
+ status = acpi_get_handle(handle, "_STA", &dummy_handle);
+ if (ACPI_SUCCESS(status)) {
+ unsigned long long tmp;
+
+ status = acpi_evaluate_integer(handle, "_STA", NULL, &tmp);
+ if (ACPI_FAILURE(status)) {
+ printk(KERN_DEBUG "%s: _STA evaluation failure\n",
+ __func__);
+ return;
+ }
+ if ((tmp & ACPI_STA_FUNCTIONING) == 0)
+ /* don't register this object */
+ return;
+ }
+
+ bridge = kzalloc(sizeof(struct acpi_root_bridge), GFP_KERNEL);
+ if (!bridge)
+ return;
+
+ bridge->handle = handle;
+
+ if (ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &dummy_handle)))
+ bridge->flags |= ROOT_BRIDGE_HAS_EJ0;
+ if (ACPI_SUCCESS(acpi_get_handle(handle, "_PS3", &dummy_handle)))
+ bridge->flags |= ROOT_BRIDGE_HAS_PS3;
+
+ list_add(&bridge->list, &acpi_root_bridge_list);
+}
+
+struct acpi_root_hp_work {
+ struct work_struct work;
+ acpi_handle handle;
+ u32 type;
+ void *context;
+};
+
+static void alloc_acpi_root_hp_work(acpi_handle handle, u32 type,
+ void *context,
+ void (*func)(struct work_struct *work))
+{
+ struct acpi_root_hp_work *hp_work;
+ int ret;
+
+ hp_work = kmalloc(sizeof(*hp_work), GFP_KERNEL);
+ if (!hp_work)
+ return;
+
+ hp_work->handle = handle;
+ hp_work->type = type;
+ hp_work->context = context;
+
+ INIT_WORK(&hp_work->work, func);
+ ret = queue_work(kacpi_hotplug_wq, &hp_work->work);
+ if (!ret)
+ kfree(hp_work);
+}
+
+/* Program resources in newly inserted bridge */
+static void acpi_root_configure_bridge(acpi_handle handle)
+{
+ struct acpi_pci_root *root = acpi_pci_find_root(handle);
+
+ pci_assign_unassigned_bus_resources(root->bus);
+}
+
+static void handle_root_bridge_insertion(acpi_handle handle)
+{
+ struct acpi_device *device, *pdevice;
+ acpi_handle phandle;
+ int ret_val;
+
+ acpi_get_parent(handle, &phandle);
+ if (acpi_bus_get_device(phandle, &pdevice)) {
+ printk(KERN_DEBUG "no parent device, assuming NULL\n");
+ pdevice = NULL;
+ }
+ if (!acpi_bus_get_device(handle, &device)) {
+ /* check if pci root_bus is removed */
+ struct acpi_pci_root *root = acpi_driver_data(device);
+ if (pci_find_bus(root->segment, root->secondary.start))
+ return;
+
+ printk(KERN_DEBUG "bus exists... trim\n");
+ /* this shouldn't be in here, so remove
+ * the bus then re-add it...
+ */
+ ret_val = acpi_bus_trim(device, 1);
+ printk(KERN_DEBUG "acpi_bus_trim return %x\n", ret_val);
+ }
+ if (acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE)) {
+ printk(KERN_ERR "cannot add bridge to acpi list\n");
+ return;
+ }
+ acpi_root_configure_bridge(handle);
+ if (acpi_bus_start(device))
+ printk(KERN_ERR "cannot start bridge\n");
+}
+
+static void _handle_hotplug_event_root(struct work_struct *work)
+{
+ struct acpi_root_bridge *bridge;
+ char objname[64];
+ struct acpi_buffer buffer = { .length = sizeof(objname),
+ .pointer = objname };
+ struct acpi_root_hp_work *hp_work;
+ acpi_handle handle;
+ u32 type;
+
+ hp_work = container_of(work, struct acpi_root_hp_work, work);
+ handle = hp_work->handle;
+ type = hp_work->type;
+
+ bridge = acpi_root_handle_to_bridge(handle);
+
+ acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
+
+ switch (type) {
+ case ACPI_NOTIFY_BUS_CHECK:
+ /* bus enumerate */
+ printk(KERN_DEBUG "%s: Bus check notify on %s\n", __func__,
+ objname);
+ if (!bridge) {
+ handle_root_bridge_insertion(handle);
+ add_acpi_root_bridge(handle);
+ }
+
+ break;
+
+ case ACPI_NOTIFY_DEVICE_CHECK:
+ /* device check */
+ printk(KERN_DEBUG "%s: Device check notify on %s\n", __func__,
+ objname);
+ if (!bridge) {
+ handle_root_bridge_insertion(handle);
+ add_acpi_root_bridge(handle);
+ }
+ break;
+
+ default:
+ printk(KERN_WARNING "notify_handler: unknown event type 0x%x for %s\n",
+ type, objname);
+ break;
+ }
+
+ kfree(hp_work); /* allocated in handle_hotplug_event_bridge */
+}
+
+static void handle_hotplug_event_root(acpi_handle handle, u32 type,
+ void *context)
+{
+ alloc_acpi_root_hp_work(handle, type, context,
+ _handle_hotplug_event_root);
+}
+
+static acpi_status __init
+find_root_bridges(acpi_handle handle, u32 lvl, void *context, void **rv)
+{
+ char objname[64];
+ struct acpi_buffer buffer = { .length = sizeof(objname),
+ .pointer = objname };
+ int *count = (int *)context;
+
+ if (!acpi_is_root_bridge(handle))
+ return AE_OK;
+
+ (*count)++;
+
+ acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
+
+ acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
+ handle_hotplug_event_root, NULL);
+ printk(KERN_DEBUG "acpi root: %s notify handler installed\n", objname);
+
+ add_acpi_root_bridge(handle);
+
+ return AE_OK;
+}
+
+static int __init acpi_pci_root_hp_init(void)
+{
+ int num = 0;
+
+ acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+ ACPI_UINT32_MAX, find_root_bridges, NULL, &num, NULL);
+
+ printk(KERN_DEBUG "Found %d acpi root devices\n", num);
+
+ return 0;
+}
+
+subsys_initcall(acpi_pci_root_hp_init);
--
1.7.7


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