diff options
Diffstat (limited to 'drivers/xen/xen-acpi-memhotplug.c')
| -rw-r--r-- | drivers/xen/xen-acpi-memhotplug.c | 483 |
1 files changed, 483 insertions, 0 deletions
diff --git a/drivers/xen/xen-acpi-memhotplug.c b/drivers/xen/xen-acpi-memhotplug.c new file mode 100644 index 00000000000..853b12dba5b --- /dev/null +++ b/drivers/xen/xen-acpi-memhotplug.c @@ -0,0 +1,483 @@ +/* + * 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_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_scan(handle); + 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) +{ + 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"); |