--- /dev/null
+/*
+ * Copyright (C) 2012 Intel Corporation
+ * Author: Liu Jinsong <jinsong.liu@intel.com>
+ * Author: Jiang Yunhong <yunhong.jiang@intel.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, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for more
+ * details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/acpi.h>
+#include <acpi/acpi_drivers.h>
+#include <xen/acpi.h>
+#include <xen/interface/platform.h>
+#include <asm/xen/hypercall.h>
+
+#define PREFIX "ACPI:xen_memory_hotplug:"
+
+struct acpi_memory_info {
+ struct list_head list;
+ u64 start_addr; /* Memory Range start physical addr */
+ u64 length; /* Memory Range length */
+ unsigned short caching; /* memory cache attribute */
+ unsigned short write_protect; /* memory read/write attribute */
+ /* copied from buffer getting from _CRS */
+ unsigned int enabled:1;
+};
+
+struct acpi_memory_device {
+ struct acpi_device *device;
+ struct list_head res_list;
+};
+
+static bool acpi_hotmem_initialized __read_mostly;
+
+static int xen_hotadd_memory(int pxm, struct acpi_memory_info *info)
+{
+ int rc;
+ struct xen_platform_op op;
+
+ op.cmd = XENPF_mem_hotadd;
+ op.u.mem_add.spfn = info->start_addr >> PAGE_SHIFT;
+ op.u.mem_add.epfn = (info->start_addr + info->length) >> PAGE_SHIFT;
+ op.u.mem_add.pxm = pxm;
+
+ rc = HYPERVISOR_dom0_op(&op);
+ if (rc)
+ pr_err(PREFIX "Xen Hotplug Memory Add failed on "
+ "0x%lx -> 0x%lx, _PXM: %d, error: %d\n",
+ (unsigned long)info->start_addr,
+ (unsigned long)(info->start_addr + info->length),
+ pxm, rc);
+
+ return rc;
+}
+
+static int xen_acpi_get_pxm(acpi_handle h)
+{
+ unsigned long long pxm;
+ acpi_status status;
+ acpi_handle handle;
+ acpi_handle phandle = h;
+
+ do {
+ handle = phandle;
+ status = acpi_evaluate_integer(handle, "_PXM", NULL, &pxm);
+ if (ACPI_SUCCESS(status))
+ return pxm;
+ status = acpi_get_parent(handle, &phandle);
+ } while (ACPI_SUCCESS(status));
+
+ return -ENXIO;
+}
+
+static int xen_acpi_memory_enable_device(struct acpi_memory_device *mem_device)
+{
+ int pxm, result;
+ int num_enabled = 0;
+ struct acpi_memory_info *info;
+
+ if (!mem_device)
+ return -EINVAL;
+
+ pxm = xen_acpi_get_pxm(mem_device->device->handle);
+ if (pxm < 0)
+ return pxm;
+
+ list_for_each_entry(info, &mem_device->res_list, list) {
+ if (info->enabled) { /* just sanity check...*/
+ num_enabled++;
+ continue;
+ }
+
+ if (!info->length)
+ continue;
+
+ result = xen_hotadd_memory(pxm, info);
+ if (result)
+ continue;
+ info->enabled = 1;
+ num_enabled++;
+ }
+
+ if (!num_enabled)
+ return -ENODEV;
+
+ return 0;
+}
+
+static acpi_status
+acpi_memory_get_resource(struct acpi_resource *resource, void *context)
+{
+ struct acpi_memory_device *mem_device = context;
+ struct acpi_resource_address64 address64;
+ struct acpi_memory_info *info, *new;
+ acpi_status status;
+
+ status = acpi_resource_to_address64(resource, &address64);
+ if (ACPI_FAILURE(status) ||
+ (address64.resource_type != ACPI_MEMORY_RANGE))
+ return AE_OK;
+
+ list_for_each_entry(info, &mem_device->res_list, list) {
+ if ((info->caching == address64.info.mem.caching) &&
+ (info->write_protect == address64.info.mem.write_protect) &&
+ (info->start_addr + info->length == address64.minimum)) {
+ info->length += address64.address_length;
+ return AE_OK;
+ }
+ }
+
+ new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
+ if (!new)
+ return AE_ERROR;
+
+ INIT_LIST_HEAD(&new->list);
+ new->caching = address64.info.mem.caching;
+ new->write_protect = address64.info.mem.write_protect;
+ new->start_addr = address64.minimum;
+ new->length = address64.address_length;
+ list_add_tail(&new->list, &mem_device->res_list);
+
+ return AE_OK;
+}
+
+static int
+acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
+{
+ acpi_status status;
+ struct acpi_memory_info *info, *n;
+
+ if (!list_empty(&mem_device->res_list))
+ return 0;
+
+ status = acpi_walk_resources(mem_device->device->handle,
+ METHOD_NAME__CRS, acpi_memory_get_resource, mem_device);
+
+ if (ACPI_FAILURE(status)) {
+ list_for_each_entry_safe(info, n, &mem_device->res_list, list)
+ kfree(info);
+ INIT_LIST_HEAD(&mem_device->res_list);
+ return -EINVAL;
+ }
+
+ 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)) {
+ pr_warn(PREFIX "Cannot find acpi parent\n");
+ return -EINVAL;
+ }
+
+ /* Get the parent device */
+ result = acpi_bus_get_device(phandle, &pdevice);
+ if (result) {
+ pr_warn(PREFIX "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) {
+ pr_warn(PREFIX "Cannot add acpi bus\n");
+ return -EINVAL;
+ }
+
+end:
+ *mem_device = acpi_driver_data(device);
+ if (!(*mem_device)) {
+ pr_err(PREFIX "Driver data not found\n");
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
+{
+ unsigned long long current_status;
+
+ /* Get device present/absent information from the _STA */
+ if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle,
+ "_STA", NULL, ¤t_status)))
+ return -ENODEV;
+ /*
+ * Check for device status. Device should be
+ * present/enabled/functioning.
+ */
+ if (!((current_status & ACPI_STA_DEVICE_PRESENT)
+ && (current_status & ACPI_STA_DEVICE_ENABLED)
+ && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
+ return -ENODEV;
+
+ return 0;
+}
+
+static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
+{
+ pr_debug(PREFIX "Xen does not support memory hotremove\n");
+
+ return -ENOSYS;
+}
+
+static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
+{
+ struct acpi_memory_device *mem_device;
+ struct acpi_device *device;
+ 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)) {
+ pr_err(PREFIX "Cannot find driver data\n");
+ break;
+ }
+
+ ost_code = ACPI_OST_SC_SUCCESS;
+ 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)) {
+ pr_err(PREFIX "Device doesn't exist\n");
+ break;
+ }
+ mem_device = acpi_driver_data(device);
+ if (!mem_device) {
+ pr_err(PREFIX "Driver Data is NULL\n");
+ break;
+ }
+
+ /*
+ * TBD: implement acpi_memory_disable_device and invoke
+ * acpi_bus_remove if Xen support hotremove in the future
+ */
+ acpi_memory_disable_device(mem_device);
+ break;
+
+ default:
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+ "Unsupported event [0x%x]\n", event));
+ /* non-hotplug event; possibly handled by other handler */
+ return;
+ }
+
+ (void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
+ return;
+}
+
+static int xen_acpi_memory_device_add(struct acpi_device *device)
+{
+ int result;
+ struct acpi_memory_device *mem_device = NULL;
+
+
+ if (!device)
+ return -EINVAL;
+
+ mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
+ if (!mem_device)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&mem_device->res_list);
+ mem_device->device = device;
+ sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
+ sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
+ device->driver_data = mem_device;
+
+ /* Get the range from the _CRS */
+ result = acpi_memory_get_device_resources(mem_device);
+ if (result) {
+ kfree(mem_device);
+ return result;
+ }
+
+ /*
+ * For booting existed memory devices, early boot code has recognized
+ * memory area by EFI/E820. If DSDT shows these memory devices on boot,
+ * hotplug is not necessary for them.
+ * For hot-added memory devices during runtime, it need hypercall to
+ * Xen hypervisor to add memory.
+ */
+ if (!acpi_hotmem_initialized)
+ return 0;
+
+ if (!acpi_memory_check_device(mem_device))
+ result = xen_acpi_memory_enable_device(mem_device);
+
+ return result;
+}
+
+static int xen_acpi_memory_device_remove(struct acpi_device *device, int type)
+{
+ struct acpi_memory_device *mem_device = NULL;
+
+ if (!device || !acpi_driver_data(device))
+ return -EINVAL;
+
+ mem_device = acpi_driver_data(device);
+ kfree(mem_device);
+
+ return 0;
+}
+
+/*
+ * Helper function to check for memory device
+ */
+static acpi_status is_memory_device(acpi_handle handle)
+{
+ char *hardware_id;
+ acpi_status status;
+ struct acpi_device_info *info;
+
+ status = acpi_get_object_info(handle, &info);
+ if (ACPI_FAILURE(status))
+ return status;
+
+ if (!(info->valid & ACPI_VALID_HID)) {
+ kfree(info);
+ return AE_ERROR;
+ }
+
+ hardware_id = info->hardware_id.string;
+ if ((hardware_id == NULL) ||
+ (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
+ status = AE_ERROR;
+
+ kfree(info);
+ return status;
+}
+
+static acpi_status
+acpi_memory_register_notify_handler(acpi_handle handle,
+ u32 level, void *ctxt, void **retv)
+{
+ acpi_status status;
+
+ status = is_memory_device(handle);
+ if (ACPI_FAILURE(status))
+ return AE_OK; /* continue */
+
+ status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
+ acpi_memory_device_notify, NULL);
+ /* continue */
+ return AE_OK;
+}
+
+static acpi_status
+acpi_memory_deregister_notify_handler(acpi_handle handle,
+ u32 level, void *ctxt, void **retv)
+{
+ acpi_status status;
+
+ status = is_memory_device(handle);
+ if (ACPI_FAILURE(status))
+ return AE_OK; /* continue */
+
+ status = acpi_remove_notify_handler(handle,
+ ACPI_SYSTEM_NOTIFY,
+ acpi_memory_device_notify);
+
+ return AE_OK; /* continue */
+}
+
+static const struct acpi_device_id memory_device_ids[] = {
+ {ACPI_MEMORY_DEVICE_HID, 0},
+ {"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, memory_device_ids);
+
+static struct acpi_driver xen_acpi_memory_device_driver = {
+ .name = "acpi_memhotplug",
+ .class = ACPI_MEMORY_DEVICE_CLASS,
+ .ids = memory_device_ids,
+ .ops = {
+ .add = xen_acpi_memory_device_add,
+ .remove = xen_acpi_memory_device_remove,
+ },
+};
+
+static int __init xen_acpi_memory_device_init(void)
+{
+ int result;
+ acpi_status status;
+
+ if (!xen_initial_domain())
+ return -ENODEV;
+
+ /* unregister the stub which only used to reserve driver space */
+ xen_stub_memory_device_exit();
+
+ result = acpi_bus_register_driver(&xen_acpi_memory_device_driver);
+ if (result < 0) {
+ xen_stub_memory_device_init();
+ return -ENODEV;
+ }
+
+ status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+ ACPI_UINT32_MAX,
+ acpi_memory_register_notify_handler,
+ NULL, NULL, NULL);
+
+ if (ACPI_FAILURE(status)) {
+ pr_warn(PREFIX "walk_namespace failed\n");
+ acpi_bus_unregister_driver(&xen_acpi_memory_device_driver);
+ xen_stub_memory_device_init();
+ return -ENODEV;
+ }
+
+ acpi_hotmem_initialized = true;
+ return 0;
+}
+
+static void __exit xen_acpi_memory_device_exit(void)
+{
+ acpi_status status;
+
+ if (!xen_initial_domain())
+ return;
+
+ status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+ ACPI_UINT32_MAX,
+ acpi_memory_deregister_notify_handler,
+ NULL, NULL, NULL);
+ if (ACPI_FAILURE(status))
+ pr_warn(PREFIX "walk_namespace failed\n");
+
+ acpi_bus_unregister_driver(&xen_acpi_memory_device_driver);
+
+ /*
+ * stub reserve space again to prevent any chance of native
+ * driver loading.
+ */
+ xen_stub_memory_device_init();
+ return;
+}
+
+module_init(xen_acpi_memory_device_init);
+module_exit(xen_acpi_memory_device_exit);
+ACPI_MODULE_NAME("xen-acpi-memhotplug");
+MODULE_AUTHOR("Liu Jinsong <jinsong.liu@intel.com>");
+MODULE_DESCRIPTION("Xen Hotplug Mem Driver");
+MODULE_LICENSE("GPL");
projects / users / hch / configfs.git / commitdiff