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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH V1 1/2] Xen acpi memory hotplug driver
On Wed, Nov 21, 2012 at 11:45:04AM +0000, Liu, Jinsong wrote:
> >From 630c65690c878255ce71e7c1172338ed08709273 Mon Sep 17 00:00:00 2001
> From: Liu Jinsong <jinsong.liu@xxxxxxxxx>
> Date: Tue, 20 Nov 2012 21:14:37 +0800
> Subject: [PATCH 1/2] Xen acpi memory hotplug driver
>
> Xen acpi memory hotplug consists of 2 logic components:
> Xen acpi memory hotplug driver and Xen hypercall.
>
> This patch implement Xen acpi memory hotplug driver. When running
> under xen platform, Xen driver will early occupy (so native driver
How will it 'early occupy'? Can you spell it out here please?
> will be blocked). When acpi memory notify OSPM, xen driver will take
> effect, adding related memory device and parsing memory information.
>
> Signed-off-by: Liu Jinsong <jinsong.liu@xxxxxxxxx>
> ---
> drivers/xen/Kconfig | 11 +
> drivers/xen/Makefile | 1 +
> drivers/xen/xen-acpi-memhotplug.c | 383
> +++++++++++++++++++++++++++++++++++++
> 3 files changed, 395 insertions(+), 0 deletions(-)
> create mode 100644 drivers/xen/xen-acpi-memhotplug.c
>
> diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
> index 126d8ce..abd0396 100644
> --- a/drivers/xen/Kconfig
> +++ b/drivers/xen/Kconfig
> @@ -206,4 +206,15 @@ config XEN_MCE_LOG
> Allow kernel fetching MCE error from Xen platform and
> converting it into Linux mcelog format for mcelog tools
>
> +config XEN_ACPI_MEMORY_HOTPLUG
> + bool "Xen ACPI memory hotplug"
There should be a way to make this a module.
> + depends on XEN_DOM0 && X86_64 && ACPI
> + default n
> + help
> + This is Xen acpi memory hotplug.
^^^^ -> ACPI
> +
> + Currently Xen only support acpi memory hot-add. If you want
^^^^-> ACPI
> + to hot-add memory at runtime (the hot-added memory cannot be
> + removed until machine stop), select Y here, otherwise select N.
> +
> endmenu
> diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
> index 7435470..c339eb4 100644
> --- a/drivers/xen/Makefile
> +++ b/drivers/xen/Makefile
> @@ -30,6 +30,7 @@ obj-$(CONFIG_XEN_MCE_LOG) += mcelog.o
> obj-$(CONFIG_XEN_PCIDEV_BACKEND) += xen-pciback/
> obj-$(CONFIG_XEN_PRIVCMD) += xen-privcmd.o
> obj-$(CONFIG_XEN_ACPI_PROCESSOR) += xen-acpi-processor.o
> +obj-$(CONFIG_XEN_ACPI_MEMORY_HOTPLUG) += xen-acpi-memhotplug.o
> xen-evtchn-y := evtchn.o
> xen-gntdev-y := gntdev.o
> xen-gntalloc-y := gntalloc.o
> diff --git a/drivers/xen/xen-acpi-memhotplug.c
> b/drivers/xen/xen-acpi-memhotplug.c
> new file mode 100644
> index 0000000..f0c7990
> --- /dev/null
> +++ b/drivers/xen/xen-acpi-memhotplug.c
> @@ -0,0 +1,383 @@
> +/*
> + * Copyright (C) 2012 Intel Corporation
> + * Author: Liu Jinsong <jinsong.liu@xxxxxxxxx>
> + * Author: Jiang Yunhong <yunhong.jiang@xxxxxxxxx>
> + *
> + * 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/init.h>
> +#include <linux/types.h>
> +#include <acpi/acpi_drivers.h>
> +
> +#define ACPI_MEMORY_DEVICE_CLASS "memory"
> +#define ACPI_MEMORY_DEVICE_HID "PNP0C80"
> +#define ACPI_MEMORY_DEVICE_NAME "Hotplug Mem Device"
Weird tabs?
> +
> +#undef PREFIX
Why the #undef ?
> +#define PREFIX "ACPI:memory_hp:"
Not "ACPI:memory_xen:" ?
> +
> +static int acpi_memory_device_add(struct acpi_device *device);
> +static int acpi_memory_device_remove(struct acpi_device *device, int type);
> +
> +static const struct acpi_device_id memory_device_ids[] = {
> + {ACPI_MEMORY_DEVICE_HID, 0},
> + {"", 0},
> +};
> +
> +static struct acpi_driver acpi_memory_device_driver = {
> + .name = "acpi_memhotplug",
Not 'xen_acpi_memhotplug' ?
> + .class = ACPI_MEMORY_DEVICE_CLASS,
> + .ids = memory_device_ids,
> + .ops = {
> + .add = acpi_memory_device_add,
> + .remove = acpi_memory_device_remove,
Just for sake of clarity I would prefix those with 'xen_'.
> + },
> +};
> +
> +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 */
Can't the write_protect by a bit field like the 'enabled'? So
unsigned int write_protect:1;
?
> + unsigned int enabled:1;
> +};
> +
> +struct acpi_memory_device {
> + struct acpi_device *device;
> + struct list_head res_list;
> +};
> +
> +static int acpi_hotmem_initialized;
Just make it a bool and also use __read_mostly please.
> +
> +
> +int xen_acpi_memory_enable_device(struct acpi_memory_device *mem_device)
> +{
> + return 0;
> +}
Why even have this function if it does not do anything?
> +
> +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) {
> + /* Can we combine the resource range information? */
I don't know? Is this is a future TODO?
> + 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_warn(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;
> + }
> +
> + /* Inform firmware that the hotplug operation has completed */
> + (void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
Hm, even if we failed? Say for the ACPI_NOTIFY_EJECT_REQUEST ?
> + return;
> +}
> +
> +static int 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;
> + }
> +
> + /*
> + * Early boot code has recognized memory area by EFI/E820.
> + * If DSDT shows these memory devices on boot, hotplug is not necessary
> + * for them. So, it just returns until completion of this driver's
> + * start up.
> + */
> + if (!acpi_hotmem_initialized)
> + return 0;
> +
> + if (!acpi_memory_check_device(mem_device))
> + result = xen_acpi_memory_enable_device(mem_device);
This is a nop. Could you just do:
result = 0;
?
> +
> + return result;
> +}
> +
> +static int 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 int __init xen_acpi_memory_device_init(void)
> +{
> + int result;
> + acpi_status status;
> +
> + /* only dom0 is responsible for xen acpi memory hotplug */
> + if (!xen_initial_domain())
> + return -ENODEV;
> +
> + result = acpi_bus_register_driver(&acpi_memory_device_driver);
> + if (result < 0)
> + 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(&acpi_memory_device_driver);
> + return -ENODEV;
> + }
> +
> + acpi_hotmem_initialized = 1;
> + return 0;
> +}
> +subsys_initcall(xen_acpi_memory_device_init);
> --
> 1.7.1
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